Aeroic Alpenbrise 157 (Konrad’s Gag 4 meter F3F Racer)

[Konrad]

This time I’ll be doing things a bit different. I’ll start off with a product review followed by my build. This will not be my normal follow along build as I’ve actually finished and flown the Aeroic Alpenbrise.

On a scale of 1 star to 5 stars with 5 stars being exquisite I’d give the Alpenbrise a 3 star rating being on par with what I see in the market place. If looking for a molded 4 meter this Alpenbrise might be a good model to get before the supply change gets disrupted with the new USA trade wars on the horizon.

 

Now at the sale price of $1800 USD it is a great value in a 4 meter sport ship! My ship is from a late 2022 production run with replacement 6 surface wings from mid 2023. This and all the Aeroic models I’ve seen are definitely not "European Quality” (whatever that is)! Paint is delicate and will break down with alcohol cleaners, fuse part line has a lot of voids as a result of the heavy overlap, surface wipers too large (limited upwards surface movement to 13°), course fiber weave shows in the finish, canopy opening does not have strengthening lip. If looking for the quality we got with Multiplex/Tangent this is not it. Energy retention is not as good as some of the more modern airfoils (it is an all rounder alpine soarer). On the plus side love the roll rate with the 6 surface wing. This roll rate is faster than the previous large Aeroic model, the F3F Redshift. The aft loaded airfoil responds very well to reflex. My AUW with SS wings is 4.6 Kg. The manual is down right atrocious and full of traps. The model has great value and potential at under $2K if you have the skills, inclination and time to correct the many minor quality and design issues. The Alpenbrise does need some advanced glider programing.

 

Now the title of this thread is as a result of me waiting far too long for Aeroic to release their 3 meter go fast ship. So at a cost well under what we are paying for a full blown F3F racer I thought I’d have some fun and try to get a 4 meter to run the F3F course.

 

You can get these in the USA at mrMPX and I think they are now available in Europe under various brand names.

https://mrmpxhobbies.com/product/aeroic-alpenbrise-157-4m-alpine-soarer/

 

Build to start with the next post.

 

Edited December 13, 2024 by Konrad

[Konrad]

I just saw in some of the ads a writeup stating that the Aeroic Alpenbrise is; "As part of the original design envelope, the Alpenbrise is also eminently suitable for the Triangle GPS light class”. Looking at the stats for both SS & S lay-ups of the model, neither are suitable for the Light class of GPS triangle racing.  The SS version is too heavy at 3.4 kg (max allowable is 3.0 kg .   And the lighter S lay-up is over the wing loading max of 30g/dm2.  So that leaves the Sport GPS class where max weight is 7.0 kg and it would also come inside the wing loading max of 75g/dm2.  However it will be compromised by being a meter short on span (max allowable 5m) and hence more difficult to see at long distance compared to a 5m model.  So when compared with the current 5 meter ships, I suspect it would be at a severe disadvantage for us mere mortals, unless you have super distance eyesight.  In my area people who were using 4m models have already long retired them and gone up in size to 4.7 to 4.9m in the sport class.

 

As I’m thinking of using the Aeroic Alpenbrise as an F3F  class ship here are the requirements, per the FAI Sporting Code  5.8.2.

 

CLASS F3F - RADIO CONTROL SLOPE SOARING
Definition: This contest is a speed event for radio controlled slope gliders. Characteristics of Radio Controlled Slope Gliders
Paragraph B.3.1 a) of Section 4B (Builder of the Model) is not applicable to class F3F.
Maximum surface area ..................................... 150 dm2
Maximum flying mass . ....................................... 5 kg
Loading .............................................................. less than 75 g/dm2
Minimum radius of fuselage nose 7.5 mm in all orientations.

 

Other than the FAI nose radius the Aeroic Alpenbrise 157 should be able to meet these requirement straight out of the box!

 

Edited December 14, 2024 by Konrad

[Wookman]

You may not get it on an F3f course. 
Span: 157” (4.0M) 
Length: 67.3” (1.710M)
Wing Area 1,182 Sq.” (76.3 Dm/2)
These are some of the specs from the Hyperflight website here in the U.K. It would appear to have to much wing area to be legal. 

[Konrad]

7 hours ago, Wookman said:

You may not get it on an F3f course. 
Span: 157” (4.0M) 
Length: 67.3” (1.710M)
Wing Area 1,182 Sq.” (76.3 Dm/2)
These are some of the specs from the Hyperflight website here in the U.K. It would appear to have to much wing area to be legal. 

Hum?

 

Per the spec the max FAI wing area is to be 150dm^2

Per the sales page the Alpenbrise is 76.3 dm^2

 

By my math 76 is smaller than 150 so I think I'm legal.

 

Now I think you landed on the term "Gag".

 

Because of the large wing I can't reach the FAI legal max wing loading of 75g per dm^2 at the max legal weight of 5kg.

Historically Aeroic has had difficulty interpreting the FAI spec's (See the nose radius on the Redshift). But I'm going to take the designer's published spec's at face value and assume that the wing area is measured by the FAI method at 76.3 dm^2 *.  So at 5kg divided by 76.3dm^2 I get a very light 65g per dm^2 well under the 75g per dm^2 max surface loading

 

On the other end of speed spectrum my all up weight of 4.6 kg with the SS wings will not allow the Alpenbrise to fly at the lowest wind speeds allowed in F3F racing.

So at both ends of the flight envelope the Alpenbrise is crippled.

 

Add to these issues, the airfoil is a high cambered type suitable for the designed application, Alpine slope soaring, but wholly unsuited for F3F racing.

 

But with the long high aspect ratio planform and 6 surface wing much of these design limitations can be overcome. I have flown the Alpenbrise and can say that she will out fly the last Aeroic F3F ship (Redshift) in all but the highest wind speeds. This is because the Alpenbrise does not suffer from the control and stability issues we experienced with the Redshift. I attribute most of this to the nice long tail boom and large vertical fin of the Tangent Alpina that the Alpenbrise is modeled on. Also the airfoil on the Alpenbrise really responds positively to reflex even if it is a bit thick and has too much camber for F3F racing!

 

*FAI wing area is calculated by adding the projected surface area of both the wing and stab.

Edited December 16, 2024 by Konrad

[Konrad]

For FAI competitions the nose needs to meet the FAI F3B nose requirements of a 7.5mm radius over a 90° arc in all attitudes. These requirements still results in a rather pointed nose for a 4m glider. This will be the only "design" change that I'll need to make to bring the Alpenbrise compliant with the FAI F3F rules.

 

I was shocked when I got home and actually measured the nose radius to find that the Aeroic Alpenbrise was sporting a grossly undersized nose radius. I was a bit shocked that the designer would chose such a pointed unsafe arrow like nose in today’s litigious environment. I also can’t see why he would want to exclude sales to those of us that would want to use this airframe in any of the FAI competitions. 

To use the Alpenbrise as an F3F ship the first upgrade was to re-profile the nose to meet the FAI F3B nose requirement. Easy enough to do, as there is alot of material in the nose to alow the re-profiling of the nose. Now that I had an airframe that might make a legal FAI F3F racer, it was time to look at the quality of the model to see if it could stand up to the riggers of competition.  More to follow.

Edited December 16, 2024 by Konrad

[Konrad]

Staying with the fuselage but looking at the other end, I like seeing that the designer has chosen to place the servos in the tail fin. This addresses the issues often found with long push rods running down narrow tail booms.

Now I’m often puzzled why designers don’t fully commit to ideas or the concepts they are implementing. For example with the Alpenbrise the designer is still trying to actuate the large rudder from the extreme lower end of the rudder. Driving a surface from the extreme end is a bad practice if looking to get the most out of the surface. First holding the surface at one extreme allows the flexibility of the surface to absorb much of the motion, such that little of the command makes it the other extreme end of the control surface.   To counter this the surface has to be built a lot heavier than otherwise would be needed to add the required stiffness in the structure. The second hit against driving the control surface from the extreme end is that it does nothing to control the vibratory response of the surface. This is a major concern when it comes to delaying the point at which the surface will go into flutter. One does not want to attach the control horn at a vibratory node. For the first order response, this means at the ends or the middle of the control surface. It looks to me that the designer is trying to leave the option open, for marketing reason, for the use of push rods going down the tail boom. I don’t understand why, but please don’t fall into that trap . 

 I’m showing how I actuate the rudder. While I can’t control the weight of the rudder structure. We can get a lot more rudder power (control response) by moving the actuation point up along the hinge. Here I’m also concerned with the loads placed on the tail boom. For this reason I’ve chosen to switch the servos from what is shown in the Aeroic manual. I wanted to place the larger more powerful and durable elevator servo down low in the fin to align the mass of the servo with the tail boom. As the rudder servo will now be up high on the fin its mass now needs to be dealt with. This is why I’m using a 9 to 11 gram class of servo. Most high voltage, high quality servos in this class are powerful enough electrically for the actuation of the rudder. You might notice that I’ve tried to place the rudder servo as low as practical in the fin in the upper servo window. A concern with lowering the servo was to keep it away from the elevator actuation spherical joint (This elevator rod needs a spherical joint on each end)!  My concern is that the small gear train in these small class of servo can easily be damaged. I’ve found that the use of an external bearing servo tray adds a great deal of durability to the servo gear train. They also add a lot of rigidity to the actuation system, aiding in the postponing of flutter. Since I’m using an external bearing support I’ve chosen to use the Servorahmen IDS. These are a great value and work great with the live hinge we see on most composite models. They also have the added benefit of lowering the control system’s aerodynamic drag. 

My particular model has the rudder hinge and upper servo window on opposite sides of the fin. This is the first time I have set up an IDS with the servo tray mounted on the same side as the hinge. I had some concerns with coming up against the 3 point actuation line, but the geometry appears to actually be superior to mounting the tray on the side opposite the hinge.

I had some concerns with my model about cutting the vertical fin’s rear drag spar to allow the IDS push rod to pass. This is because the stiffening carbon patch on my model did NOT span both the forward fin half spar and the rear drag spar. This forced me to add my own carbon patch to tie the two spars together. (Sorry my photos of this did not come out well.) I’d have also liked to have seen the factory carbon stiffeners span past the drag spar and stop near the live rudder hinge. As I was going to cut a hole in the drag spar I added some more carbon aft of the drag spar on the skins as an alternate load path around the pass through hole. Please note that my model was purchased as a Sport (S) lay up. The Super Sport (SS) might have the needed extra carbon to span both support structures.

 

Since I'm swapping the rudder and elevator servo location I'll go into the fitting of the elevator servo next time.

[Konrad]

Reading the allowed wind condition that we are allowed to race F3F it is looking like weight (wing loading) might be an issue at the lower allowed wind speeds. This is driving me to reevaluate my choice in servos. Earlier you might have noticed that the rudder servo was a KST HS08. But to save 1.5 grams I'm changing over to the X08+. My understanding is that these have close to the same gearbox. You will also have noticed that I've changed from the MKS 6130 to the KST X10mini again to save 2 grams of weight in the tail.  3.5 grams might not seem worth it (and its not) but multiply this by the moment arm of 3:1  that's 10.5 grams I don't need in the nose, for a total weight savings of 14 grams! 

Things to note the external bearing tray for the rudder servo is down as low as is practical limited by the need to clear the upper spherical joint of the elevator push rod. Unfortunately this means half the epoxy rake is not under any part of the fin's skin. I've left the rake as supplied by Servorahmen in the hopes that I'll have enough weight head room to be able to tie both sides of the fin together.

I'm also showing where I placed the elevator servo. Again I've swapped the elevator and rudder servos from that shown in the Aeroic manuals to lessen the landing loads on the tail boom. I also think that the elevator servo wouldn't properly fit in the upper window. I go into more detail in this thread.

 

I found these notes and thought I should post them. With the undersized and often misplaced servo windows making it all but impossible to reach all the servo mounting lugs. This often drives the external bearing from being a secondary mounting feature to a primary mounting feature. Please be aware of this when setting up your servos.  Note, that I'm still using the full contact area of the servo tray. I think that the bonding area is the Achille's heal of this type of servo mounting. I'd have still liked to have used all the servo mounting lugs. I have concerns with the servo mounting as shown in the Aeroic manual where only 2 screw mounts are defining the load path into the frame. (I'm at a loss as to why the bearings were removed) This may be fine for low non-catilivired loads but at the size and weight of the Alpenbrise this is just unacceptable in my opinion.

Here you will see that while I too am forced because of the window placement to only use 2 of the 3 mounting lugs. I'm using the external bearing mount to keep the output shaft stable but to also keep the servo body from flexing (rotating) in the mount. Both the smaller x08 mount and the larger x10 mount are doing this. 

As a side note I found that the Servorahmen X08 frame would benefit from the chamfer of the corners adjacent to the servo lug (both with the frame and the hold down bar).

[Konrad]

I just received 2 PMs asking for my opinion on the Aeroic Alpenbrise. I thought I had stated that in the first post but as I received a few question on this it is obvious to me that there is still a lot of ambiquity in my statement. I need to be clear I'm not a sales of marketing shill for my local Hobby Shop Aloft Hobbies. Nor am I or have I evere been tied in any way with Aeroic, even if you might have seen my name in some of their documentation. With that out of the way here is what I hope will help folks spending their holiday bonus. Here is my responce to the PM's.

 

YES, the Alpenbrise is a great value at under $2000 USD. It is not of the best quality, again it is under $2000. There are a lot of failures in the implementation of systems. I think this is because the designer hasn't built or flown any of his designs in over a decade (health issues). I also don't think he knows how to model systems in a CAD program. It shows in the end product.

 

If you have experience with molded model (2 or 3 builds) and have the skill, time and inclination to rethink the installation of systems then I heartidly recommend the 4 meter Alpenbrise. If your radio can support the 6 servo wing I strongly recommend it, you will love the roll rate and flap performance!

 

Do NOT follow the manual. Do let Aeroic (Hammond) know that you would like to see manuals that actually work. 

 

And tell Aeroic that I sent you.

https://www.aeroiccomposites.com

 

All the best,

 

Konrad

 

That's as close to any ad copy you will likely get from me.😇

[Konrad]

Moving back to the nose, it is my experience that fuselages with this configuration, flangeless tub cockpit area, are prone to buckling. This is because the there is little or no side support on the sides, no upper flange like we got with the Tangent models of old.

Aeroic is now supplying their model with a rather heavy awkward glass tray that the user is suppose to epoxy in place. This is left up to the customer to install, as it leave the option as to what application one wants to use the model.  Aeroic is concerned that a full flange tub might hurt sales to the GPS triangle racing crowd (powered warm liner?). That's their marketing concern and as such I'm not going to second guess their solution. Other than to say I like to bring my full length servo tray from the nose, past the fuselage hoop and into an area that will support the fuselage against the forces trying to crush the fuselage on my landings. My factory supplied tray did not reach aft under the wings.

I also take this opportunity to make as large a fillet between the tray and the fuselage. Here I've used 8 strands of heavy cording saturated in epoxy. This results in a good bond with the tray and adds a lot of glass to mimic the strength we would normally get with a flanged tub.

[Konrad]

Engineering is the science of compromise. The preceding posts where generally about why I thought the compromises made by the designer with the servo installation and nose were in error. I hope I gave sufficient reasons to support my conclusions. I also tried to offer enough detail to allow anyone purchasing the Alpenbrise to solve the problems as I demonstrated.

 

What follows are generally things that show quality issues. Whether they are tooling or process problems they are a still problems that should have been addressed through proper engineering and culture.

I need to reiterate that my model was from a late 2022 production run. The owner of Aeroic has since visited the factory and claimed to have made improvement on the order of magnitude. I can’t comment on that but what I originally received appeared to be in line with the quality we originally received from Aeroic’s previous OEM.

 

And here is where I have to step up on my soap box.
I hate it when folks use stereo types (even positive if such a thing exists) to imply something.
The owner/designer of Aeroic time and time again uses the term European Quality or that the picky Europeans find the quality more than adequate.
First the Europeans are no more demanding to exacting standards than anybody else.  What, the peoples from the other continents are happy go lucky slobs that wouldn’t know quality if we held it in our hands? We all want the products and services to perform as described and intended regardless of our continent or origin .

In one of my engineer positions I was tasked with assessing quality escapes in aerospace. I can say that every skilled craftsman I’ve dealt with, regardless of the continent they are on or from,  has tried to produce the best product they can with the tools and materials management supplies.  I can say that ALL quality issue can be traced back to management, or lack there of! 

Firms like Apple and Boeing are having many of their components/products manufactured in China and Asia. These are of the highest quality because the management has clearly defined in the contracts what is expected and has placed resources (spent money) to ensure that these requirements are met!

Few firms are producing models of the quality we see in Vladimir’s model. Not because Vladimir's model is based in the Ukraine  but because Vladimir’s model is run by a world class modeler that uses his products. As a result he supplies his team with the best tools (time being one of them) and materials to produce the best models. 
http://f3j.in.ua

Stepping off my soap box.

 

The key problem I had, was that the wings and the fuselage did not line up. My wings had cracked wing roots as a result of the factory trying to force the wings on to the fuselage.  I suspect that the wings cracked in the area of the connector window when the wings were first mated. I measured the holes to be out of round by over 0.30mm when I first got my model. I tribute this fit problem to the inability of the tooling to place the fuselage and wing pin bores in proper relationship to each other.   The wing fairing on the fuselage showed extensive damage from the subsequent attempts to separate the wing and fuselage as the builder tried to fit the wings to the fuselage. 

 

Next I see that the fuselage has an excessively wide wet seam. This adds weight and results in a fuselage that will perform much like the fuselages of old when we used fiberglass tape to join the fuselage halves together.  I also see where the seam did not lay down properly as a result of too abrupt a change from the thick layup as the halves tried to over lap each other. I suspect the rough seam is as a result that the fuselage bladder failed in my fuselage layup. (I’m assuming Aeroic uses a fuselage bladder during the layup. If not they should as it will help with the seam and limit some of the voids found in the fuselage part line).   There are some very rough trimmed edges around the fuselage openings as a result of post cure trimming of the kevlar layup. These seam and trimming issues may be as a result of the price point. Aeroic models don’t carry a European price. So it wouldn’t be fair to expect European quality, whatever that is.

 

Now to move on to the real quality issues, the wings!

 

Edited December 25, 2024 by Konrad

[Konrad]

You might have noticed that in the above photo with the green text has much nicer looking cutouts compared to some of the earlier photos of the same area.

This is because I spent some time cleaning up the Kevlar fuzz.  Let mebe  blunt Kevlar is horrible stuff to work with, as sanding and grinding (abrasive rework) results in a horrible yellow fuzz! (This is one way to test if the fibber is Kevlar). 

 

To clean up the Kevlar fuzz I re-saturate the fuzz with thin CA. Then I come back with a sharp blade to CUT, not grind, the fuzz off. I may need to repeat this several times.

 

Please remeber that the CA offers little or no strength. It is used to allow the fiber to try to resist the blade. Allowing the blade to actually cut the Kevlar fibers. 

Edited December 26, 2024 by Konrad

[Merry Mark]

Good reading and useful posts, Konrad.  Thanks.

[Konrad]

12 hours ago, Merry Mark said:

Good reading and useful posts, Konrad.  Thanks.

I need to apologize for my writing.

 

I need to stop posting from my tablet with its small key board. Add to that that I have autocorrect active and I'm far too often mistyping correct words. I should type into a word processor and come back 2 hours latter and edit my posts prior to posting, but that's too much like work. So I apologize for making it so hard to read my posts, even if they are generally informative.

[Konrad]

The original set of wings, late 2022 manufacture, had a lot of problems with the installation of the control horns. The installation of these horns result in the binding of the control surfaces at around 22°. This is because the horn laid across the hinge itself. 

I attribute this to the fact that the control horn barb (leg) is too thick to fit inside the control surface. These control surfaces are unusually thin as a result of the “high energy” double cusped airfoil* Hammond usually is using. For reasons I don’t understand these control horns are not cut/supplied to fit into the space made by the control skins. It is clear to me, by the slight distortion of the top skin, that the technician tried to seat the control horn aft of the hinge line. But because the horns are too large they sat across the hinge. You can see this in the bulge in the bottom skins when the surfaces is deflected upwards. This is another example of the persistent problem Aeroic has with system integration. I think is comes from the lack of understanding of the fit function in most CAD programs. This kind of interference problem can easily be found by proper modeling of all the components being used and then checking for tolerance stack up. To me this was another classic engineering failure, not as Hammond so often likes to claim a “Friday Build”. 

 

No, issues like these are directly traced to the lack of proper tooling and process needed to hold/place the control horn in the proper position  This isn’t an issue with the technician  rather a lack of foresight by the designer and management. I really wish OEMs would leave off the control horns on all but the most basic entry level model. Particularly if the OEM doesn’t have the installation process well under control. Removing improperly installed control horn is much worse than starting with a clean slate! 

Another system integration failure is that the standard 10mm thick servo will not fit the pocket for the outer ailerons. This is forcing the user to use an 8mm thick servo if the builder wants to stay within the airfoil profile and not use bulged servo covers. I’m having concerns about using a small 8mm servo on such a large control surface for a model that will weigh over 5KG and has the speed potential of the 4 meter Alpenbrise. I've found that proper mechanics is key to a nice handling and safe RC aircraft. I might even go as far as to say that proper mechanics is even more important than well balanced aerodynamic forces. 

 

 * The airfoil used on the Alpenbrise 157 is a proprietary airfoil and is only using a single bottom cusp. This is because the model is designed for alpine soaring.  I’ve attached a photo of what this looks like using a real Eppler 205. This is why we old timers in the glider community call this feature (aft loaded airfoil) the Eppler cusp. Please don’t confuse this feature with the under cambered airfoils that look like bananas used in many free flight models.

 

Edited December 28, 2024 by Konrad

[Konrad]

I see that the photos of the aileron servo window NOT fitting  (standing proud of the the surface) with the classic 10mm x 30mm x 30mm servo didn’t post.

 

It is because the aileron window is sized for the 8mm thick servo that I asked that my replacement wings be cut for the 3/6 surface wing. As stated earlier my concern is for the durability of the 8mm servo gearbox. With the 3/6 surface wing I’m able to spread the aileron load across two 8mm thick aileron servos per wing and one 10mm thick servo for the smaller flap. This has worked great in practice.

 

There is some misleading information on the Aeroic team build thread on the sales forum. First the wing control surfaces length are not generally to be thought of as being adjustable by the end user. If you were to cut in the third surface from a wing that was cut as a dual control surface (blue) it would be rather small. The 3/6 surface wing needs to be ordered at the time of purchase.
https://forum.alofthobbies.com/index.php?threads/aeroic-alpenbrise-4m-build.3968/#post-52049

There is also some conflicting data on the size of the control surfaces with the 3/6 servo wing. The original sales sheets showed the values in red. The wing I received as a warranty/upgrade had the surfaces cut as called out in green. This really is a personal preference thing. Since I plan to use my Alpenbrise as a gag F3F racer I want that middle flap to act more as an aileron than as a flap. This is to help get the roll rate I need to turn the bases (pylons).  Now in landing mode this middle surface will be rigged as a flap. I get the best of both worlds, a high roll rate and great braking action!
https://alofthobbies.com/collections/slope/products/alpenbrise

And last, Aeroic is using some terms I think inappropriately. An IDS (Internal Drive System) is different from an external bearing support servo output shaft.
The IDS is an actuation system where the linkages are kept inside the wing (structure) lowering the aerodynamic drag. There are generally 2 types of IDG. The now more common Linear Drive System (LDS)  such as I’m using from Servorahmen. And the Rotary Drive System (RDS) sold by MPJet and made popular in Dr. Drela’s designs.

Most IDS use a bearing outside the servo case to support the servo output shaft. This is needed as deflection of the servo output shaft will have an exaggerated effect on the control surface as a result of the small levers (servo arms & control horns) involved. 

As designed the elevator drive (pin) system is an IDS as the actuation system is inside the structure. What is shown in the manual lacks an external bearing support for the servo output shaft. This places an inordinately high demand on the internal servo bearings from the cantilevered servo output shaft. 

As the space available for most of the servos is lacking in the wing of the Alpenbrise most of us will be going with mechanically ”undersized” servos. As a result I strongly recommend that all the servos use an external bearing supported output shaft. Yes, even if using the traditional surface control horn. I’m appalled that the Aeroic manual actually shows the destruction (elimination) of the external bearing supports. I don’t know what constraints the author of the manual was under, but it is high time that the manual was re-written!

Folks when dealing with a model of this weight and speed please put a detailed focus on safety and use sound mechanical practices.

 

P.S.

I need to show how I clear the epoxy and control horns that fowl the hinge line. I use a very small burr and remove the epoxy and/or re-profile the horn to allow the control surface free motion. This is a lot like building a ship in a bottle! (No space to work in)!

 

Edited December 29, 2024 by Konrad

[Konrad]

Circling back to the control horn for the classic control horn and clevis push rod. I see a persistent problem with Aeroic products, the supplied clevis does NOT fit the hole  in the control horn. It would be much much easier to test and adjust the control horn size prior to the OEM installing the horns in the wing. I'm just appalled at the utter disregard and contempt Aeroic is showing for its customer. Here a customer was complaining that the supplied parts don't fit. This has cost the customer a few days of valuable hobby time and given him a shock particularly as he wanted an easy build. 

https://forum.alofthobbies.com/index.php?threads/aeroic-alpenbrise-4m-build.3968/page-5#post-56040

This is unacceptable!!! Aeroic knew the parts supplied don’t fit! Yet Hammond did not offer a solution to his supply problem in the manual or with an addendum. This is just showing the contempt he has for his customer's time.  Really, one needs to make up a 1 meter long 1.5mm drill bit, to fit the control clevis? 

 

It is these persistent fit issues with both in-house and vendor supplied the components that really relegates Aeroic models to a less than stellar status. Actually it is these fit issues if only looking at the physical product that drops Aeroic to a sub standard provider of molded composite gliders. ( I make this statement based on at least 6 years of experience with Aeroic products ending in the production date 2023 and comparing them to European manufactures.)

This is just ridiculous, Hammond always has an excuse that it is somebody else's problem/fault. No, this control horn problem rests squarely on his shoulders. Aeroic needs to instigate a sub-vendor quality program or make these horns in-house.

[Konrad]

I did not have to deal with the clevis to control horn problem as my original wings had a manufacturing flaw in the lay up of the sine wave spar.

Aeroic warrantied these wing with a replacement set, made up of a six servo wing set up for IDS.

 

I recently learned that the wings of the Alpenbrise are fault tolerant. 

I had intended to keep these manufacturing findings between myself and Hammond. But as has seen fit to take this issue public I thought I try to set the record straight
I’m saddened that Aeroic (Doc J) didn’t take the opportunity to show that the wing was fault tolerant rather than questioning the expertise of their customer.
https://forum.alofthobbies.com/index.php?threads/alpenbrise-rocket-launch.4186/

As I stated earlier the original wings of this model suffered from a manufacturing defect. Aeroic replaced them and allowed me to upgrade them to the 6 surface wing I’m now using. There is some mis-representation of what happened in that post. I did not reject the wings. I did bring to the attention of the OEM and dealer a manufacturing issue I found in the original set of wing. I wanted Aeroic to be aware that there is a manufacturing and a quality issue. I could see that the OEM knew of the misplaced web as they burned through the paint when buffing the wings. These wings should never have left the factory for retail sale. As I felt that the original wings as delivered were suitable for my application and I didn’t want to see these wings end up in the land fill prematurely I did NOT reject or ask for a warranty adjustment. Aeroic, Doc J (Hammond) did the right thing and offered me a replacement set under warranty.  I took up his offer as he was willing  at the same time to upgrade the wings to 6 surfaces at no cost to me. 

 In this thread we discuss the issues with the manufacture of the Sine Wave Spar. Key is the binding of the web to the spar caps. With the Alpenbrise it looks like the designer is using at least 3 webs for the added bonding area this affords. As was mentioned in that thread the webs are manufactured straight. It is in the lay up of the wing that that the webs are preloaded to follow the apex of the wing profile. It was as a result of this pre-load that the web popped out of position as the two halves of the wings (top and bottom) were being brought together.  Please note that the ALpenbrise wings are sporting 3 sine wave webs. This is negating much is not all the weight savings compared with the classic box spar. With the box spar it is easy to wrap fibers to tie the top and bottom spar caps together. Please see how Boeing ties the top and bottom elements together with fibers.
https://forum.alofthobbies.com/index.php?threads/sine-wave-spar.1626/

Here are some photos of the manufacturing defect I brought to the attention of the designer. Was I justified in bring these issues to the attention of the OEM/designer and his dealer?

Seeing  some of the fundamental (first principle) engineering issues I’ve been dealing with in assembling this Alpenbrise. I really shouldn't be surprised that Hammond would rather question the expertise of his customer, rather than practice continued product improvement. I’ll leave it up to you, the potential customer base, to determine if my findings are relevant to the build and suitability of the product. I’m saddened that Aeroic (Doc J) didn’t take the opportunity to show that the wing was fault tolerant rather than questioning the expertise of their customer.

Edited January 1 by Konrad

[DaveB1]

Konrad,

You have provided a number of detailed and undoubtably excellent engineering solutions to raise the standard of this glider, but I observe that there are virtually no comments on this thread commenting or responding to your postings - I wonder why that is ?

I rarely post, but can't help it this time - I don't know if it is just me, but I resent the direct public criticism of a respected designer (not doubting the claims you're making).

I won't be following this thread any further

[Konrad]

Thank you Dave.

 

I post to help others make the best of their purchasing power. Not to be involved in any kind of love fest. 

(I've had a few PM asking for clarification and details with regard to purchasing the Alpenbrise. So I think there is some interest in my position. This forum heading has been very dead prior to my threads. So I don't think it is wise to read anything into the fact that there is so little exchange inside this thread)

 

The designer(s) need to be held accountable particularly if they don't learn from their mistakes. I hope to give ammunition to perspective customer to both hold the designer's feet to the fire to make better products prior to purchase but also to aid those perspective customers in getting the most (value) from their purchase. (Please note, I try not to say "XYZ" is junk and then runaway. I try to give supporting arguments as to why I think as I do and to offer work arounds. It is far too easy to call something junk and not offer a solution.)

 

While I think I make it clear what I see as short comings in the product. I hope I've shown where Aeroic /Hammond has actually stepped up and done the right thing in support of his customer (me) with an unsolicited warranty adjustment.

 

I'd like to see Aeroic have a more robust engineering review process prior to the release of a product. I'd also like to see a culture instilled at the factory that would allow these many flaws to be caught and brought forward prior to release to the public. This model was not sold as a seconds or prototype. Rather it was sold* at full retail as such I hold it to the same standards I hold any other product I buy.

 

As to public criticism I see I left off some key words in one of the sentences corrected in red. My apologies for not making it clear as to who made this issue public.

"I had intended to keep these manufacturing (2022 production date) findings between myself and Hammond. But as Hammond has seen fit to take this issue public I thought I try to set the record

straight."

 

Also if you follow along, I hope you will see that after I define all the issues I find in both the product and the firm as it applies to the product. I hope to post some of the few strong points I also found. (I hope I hinted to some of those in the first post).

But I need to show the short comings followed by the my solutions, as I think this has much more impact on the perspective member's purchasing decision. If the perspective customer is leaning towards a purchase, any glowing comments (if there are any) will have no impact on their purchasing decision. But if the customer is on the fence I hope I give him some information to make a informed decision, nay or yay

 

I hope hope I haven't used any derogatory terms to describe my interactions with the designer. If I have I apologize. I do point out what I think are some questionable if not serious engineering and management omissions. 

 

Yes, much of what I post is to try to offer a balance to what we see in sales hype. I'm making a concerted effort to foil sales hype to offer the customer an honest assessment of the product and support service.

 

To be clear, with the Alpenbrise 157 (post 2024 production) if one is in the market for an alpine soarer I think the product falls on the side of a good value at the current sales price all factors take into account.

 

Happy New Year,

 

Konrad

 

*After having looked at all the Aeroic products imported into the USA in the first mounths of 2023 the importer felt he had to but them on sale at a deep discount to help offset the many quality escape I'm showing here with my example of an Aeroic 2022 production run product.

 

 

 

 

Edited January 2 by Konrad

[Konrad]

Now this is squarely on me for not giving the warranty replacement wings a through going over. Ok, yes I did but I forgot to weigh the replacement wings!

learned that the warranty replacement wings are in fact of the "SS" lay up. I feared that they might have just been heavy as they were the first 4 surface wings. I got this impression as the wipers were just grossly oversized. (Later I'll post more on how this manifested itself and how I corrected this manufacturing flaw-mid 2023 production run).

I learned that Hammond thought he was doing me a favor offering me the upgraded "SS" layup as part of the warranty. (This accounts for why my Alpenbrise has a mass of 4.6kg empty).

I'm sure Hammond must feel that no good deed goes unpunished, as I'm sure I'm one of the few folks that would be more than a little annoyed getting a set of heavy upgraded wings for free (warrantied).

As mentioned earlier this Alpenbrise was to be built to the FAI F3F racer spec's. The heavy wings limit the performance at the low end of the F3F allowed wind speeds. And as I don’t think I can get much past 63g/dm at the 5Kg FAI limit I couldn’t possibly use the benefit of the SS lay up. So as nice as the "SS" wing are they are not suitable for my F3F application. 

I have to thank Hammond for try to improve the customer experience by offering what most would have thought was an upgrade.

[Konrad]

Yikes!!!  I found a major failure in Aeroic’s QA program, mid 2023 production! 

To recap, the first set of wings that I received with my late 2022 build had the Sine Wave Spar’s web misplaced. Such that part of it had totally slid off the spar caps. I saw this as the web had made a slight protrusion into the outer skin. Not only could you see the discontinuity in the skin but in spots you could feel it. As this happened in the outer 1/3 of the wing span I wasn’t too concerned as the wings really are of a stress skin construction and the skins are made up of heavy carbon cloth.  

As I thought this was a problem with the factory/engineering process and I had seen much the same issue with Aeroic's previous OEM. I contacted my dealer and Aeroic to discuss my concern with the build process and suggest that Aeroic examine their molds as I feared that the web might have left an impression in the molds.

I hate to put stuff into the land fill prematurely and as I thought that the wing even with this misplaced shear web would be more than adequate for my intended use (Front side slope and F3F racing all low speed stuff. No, DS loads) I planned to use them.

Much to my surprise Aeroic (Hammond) offered to supply me with a replacement set of wing under warranty.  Please recall that I didn’t ask for a warranty adjustment as I thought the condition of the wings would meet my performance criteria. In another step, ether to support his dealer or his customer, Hammond (Aeroic) allowed me to make a custom request for this replacement wing at no additional charge.

I asked that the replacement wing be supplied as a 6 servo wing. This is becoming so popular that the USA dealer (Aloft Hobbies) now only carries the Alpenbrise as a 6 servo wing.

The problem I just found with the replacement wings (June 2023 DOM) is that the gap seals as delivered are so large as to limit the upward direction of the aileron and flaps. This is easy to do as the addition of the gap seals is done by hand after the wings have been released from the molds. My concern is, that with my set of wings, nobody did the inspection/adjustment to ensure that the control surfaces would move adequately after the gap seals were formed.

We the customer shouldn't have to have a fully set up composite shop to assemble these high dollar molded models. Luck would have it that I have some of the basic skills and tools to accomplish this. 

My set of wings only allowed the control surfaces to move upwards 13°. After cutting back the gap wipers with a vibratory saw I now have my ailerons moving in the upward direction 33°. I left the flaps alone as I think 13° is adequate for any of the camber changing I’ll be wanting to accomplish.

To be clear this was a failure in the Aeroic’s QA program. This issue would have been caught had Aeroic actually had a robust QA program to find fit and function issue prior to reaching the customer. There is no excuse for this, heck Covid 19 happened a while back. This is clearly a management problem. If the release inspection form would have given a minimum required range of motion the inspector would have seen this issue and had the wings reworked at the factory. I know this would have added cost, as the management would have to supply the inspector with an inclinometer. But how much did it cost, with a hit to Aeroic's reputation having the customer make the adjustment? 

If you have any model from Aeroic, please check that the control surfaces will move the amount stated in the manual prior to doing any of the build!

 

 

[Konrad]

Now to be fair most folks don't know how to assess properly designed and manufactured composite models. As a result they are often just concerned with the shine and price. That's on us! In my builds I try to show what to look for and the why I think XYZ is important.  Yes, I also try to cut through what I see as sales hype.

Aeroic is in that uncomfortable position of not being anywhere near the quality (engineering and finish) of the top end firms. Nor are they priced with the bottom tier manufactures like RCRCM or RGMCN
https://www.rcrcm.com
https://www.rgmcn.com/h-pd-51.html

I don't know why Aeroic uses the statement European quality. Honestly I have no issues with the Asian composite worker. If given the tools and materials by their management they can and do produce exquisite work. The key is management, the contract and the effort put into QC & QA. 

I'm again jumping ahead a bit. But since my photo in the above post showed is so well I need to level set expectations a bit. This has to do with surface finish and fidelity to the airfoil. Aeroic's products are nowhere near the top end of the quality scale. They are in the USA only about 60% the cost of the high end models. While I really have problems with Aeroic's poor engineering when it come to system integration and mechanics. I can't really fault them for the finish as I'm not paying much for the model. Here we get a 4 meter composite model for under $2K in the USA. But even for $2K if a product doesn't work it is still a waste of one's money. Again that is why I go into such painful detail to help those get the best from their purchase. I'm not trying to help or hurt sales just level set expectation.

The Aeroic line is using a heavy weave in their layups. One can be see this as this bleeds through the finish (the small dots around the light source). This is so pronounced that you can actually feel this and some of the under skin support structure (spar caps). Now any aerodynamicist will tell you this will destroy any hope of maintaining laminar flow over the wings. Unfortunately this nullifies most of the benefits we gain from the molded model. As a result of the surface finish, those wiz bang airfoils aren't performing as the charts would lead you to believe. Also with molded wings you should not feel any of the sub-structure as again this will disturb the airflow destroying any hope to reaching the described performance from the selected airfoil.

Aeroic is using the heavy weave as a cost cutting effort. The higher end OEM are often using "spread tow" cloths to try to eliminate the weave bleed through and the resultant poor performance as a result of the surface finish.
 

[Konrad]

I’m almost becoming nostalgic for the days of the Zhou* builds (the previous OEM for Aeroic)! 

 

More quality issues.
Maybe I was under the wrong impression that the paints used in high quality molded (painted in the molds) models were catalyzed paints?

Here I was cleaning off the gum from the shipping tape with IPA and much to my shock the red paint was coming off my mid 2023 Alpenbrise set of wings!

This issue might be from type of paint used (chemistry). Or a problem with the mix ratio if Aeroic is in fact using catalyzed paints.

I did a control test with the 2017(?) Zhou built Redshift wings (green) and the paint was robust against the alcohol cleaner.

What happened to the paint quality? What does Aeroic recommend to clean the painted surfaces? I didn't see it in the manual. This is going to be a real problem here in California when the guys start to clean off the Ice Plant blood!

Really starting to have concerns with Aeroic’s quality!

 

I now see (2025) that some of the Aeroic manuals mention the paint might be damaged with the use of alcohol cleaners. I don't see this warning across all the manuals nor do I see an approved cleaning process stated in the manuals.

 

While this doesn't effect the function of the model much if at all. It does have a huge effect on pride of ownership! Luckily for me I was able to buff back the surface finish shine.

 

*Zhou (RGMCN) was the previous OEM to Aeroic and was shown to be the source of a lot of quality escapes with the older Aeroic product line.

 

Edited January 2 by Konrad

[Konrad]

I think we are coming near the end of the configuration and system integration issues with the Alpenbrise's wing. This has to do with the servo covers.

Aeroic is now highly recommending the use of IDS. Unfortunately the supplied jelly been servo covers do not encapsulate the forked servo arm of most IDS's. 

A lot of this might be a result of nomenclature. I think that what Aeroic is calling and IDS is really just an external bearing support of the servo output shaft. If this is what Aeroic is thinking then their Jelly bean servo covers might fit the standard servo arm can be used in conjunction with the external bearing and classic high drag control horn. 

But what is generally thought of as an IDS (LDS or RDS) is a system that keeps most or all the linkage inside the airfoil profile by the use of rather short lever arms. To keep a reasonable amount or bearing area for the pivots the servo arms are rather wide generally being forked arms.

 

What I do like is that the jelly bean servo covers are NOT fitted to the window. This allows you to position the jelly bean in the optimum position over the servo prior to fitting the cover to the window.

Here I'm showing that the supplied jelly bean servo covers are far too narrow for most forked arms . 

Luckily in my set up I was just able to keep the inner flap servo arm small enough to stay inside the profile of the airfoil that the use of a simple flat servo cover (supplied) was adequate. The center flap servo is the one most likely to need the jelly bean servo cover as this surface needs to move close to 120°. This means that the servo arm is the longest of the three servo. As I'm using the Servorahmen IDS I was able to use the flat servo covers for all six wing servos. (Actually the inboard flap and center flap appear to use the same length servo arm. As the inboard flap is thicker I can set the spoon to have a longer lever and the fact that the wing is thicker near the root. I can get the 105° of flap motion with the same length arm as the one used to get the 120° of motion on the center surface. I can get the inboard flap motion needed easily with the servo motion being close to the 150%).

But if one is going to use the conventional surface horn you will need a large jelly bean servo cover for at least the center surface and more likely all three servo covers. I'd like to see Aeroic supply the servo covers with the jelly bean being about 1.5 times wider to accommodate today's forked servo arms. I'd also like to see a bulged servo cover offered for those that need to use the classic 10mm x 30mm x 30mm servo for the outer aileron window. (I'm using high performance 8mm thick servos as aileron servos so the flat covers work)

Here I show that I make up a set of wide jelly bean covers with a simple glass lay up. 

I'd like to see Aeroic offer servo covers to actually cover the components they recommend. While it is easy to make up your own set of covers. The fact that the ones Aeroic supply (jelly bean) aren't useful for today's system just looks like a waste of resources, both Aeroic's and your money.

 

 

 

Edited January 3 by Konrad

[Konrad]

At the risk of being labeled an Aeroic fan boy I need to point out some highlights with the new factory and processes.

 

Both sets of wings, heck all surfaces, show nice separation lines with the control surfaces.  The hinging of the surface actually has a bit of relief. This should take off some of the stresses from the kevlar cloth hinges.

 

I don't know if what I'm seeing is just a byproduct of sharp tooling (I think there is much more to it than that). But the separation line for all the surfaces is very sharp and well defined. This is really difficult to accomplish with materials that have heavy weaves (fibers) in them.

 

I think, don't know, that Aeroic is using carbide PCB cutting bits for this. This in itself is difficult as the wing and router need to be held rigid and to close tolerances.