Cambrian Elan 100 Build

[Gary Clark 1]

Despite being a mainly scale warbird builder, I have had a hampering for a glider to have at the field for a while. I want to throw it up and just see how long I can keep it up (so to speak) and experience a form of flying that I am fairly unfamiliar with. I'd normally go for a plan and scratch build but to speed the process up a bit I decided to buy the Cambrian Elan 100 as I really like the look of it at George at 4 max has given me his usual excellent advice on a motor for getting it up to height so I can try and learn something about planned unpowered flight. 

 

I'm planning on this being a quick build (hopefully done in a couple of weeks) so I can get out and try it.

 

As usual, any tips, ideas or corrections are always welcomed!

 

Gary

[Gary Clark 1]

The kit arrived from Cambrian yesterday and I have to say I was impressed. Well cut kit and everything numbered clearly as well as nice plans and instructions. The balsa is a little harder than i would have picked but good quality otherwise

 

I got started straight away with the wing. Everything fitted well and went together quickly, especially since I didn't need to spend hours cutting ribs! I did trace the ribs so that I have a copy for any repairs that need done in the future

 

 

So far I've been please with how it is going so hopefully I will have the majority of the wings done today

 

Gary

[Gary Clark 1]

I've had a good day of building as the family are away for a couple of days so I've been in the garage for most of the day. The right wing is almost done, the outer panel is still pinned to the board until the 1/16 top skin drys then I will mount it to the other 2 sections. It is a solid wing and still fairly light but it is coming together well.

 

 

Hopefully I can get the wing done then get the second one started......alot of wing here!

 

Gary

 

[Gary Clark 1]

Advice required from anyone who has fitted a noto to a glider. What kind of thrust angle would you put in? Also, is there a good way to work it out?

 

Gary

[Gary Clark 1]

I decided to give myself a break from building wings as I spent most of the last 2 days building the first one! I made up the tailplane but haven't sanded them to shape yet. The rudder is a good size and both are straight forward to put together.

 

 

I made a start to the fuselage so I could plan on where to put everything inside. Clearly there isn't loads of room due to the narrow fuselage and I wanted to try and shift some of the bits backwards as it will have much more than planned in the front. I will put the servos under the brass tubes which is still accessible when the canopy is off. If the CofG is still too far forward then a little weight in the tail will solve it easily given it is such a long moment from the wing to the tail. Haven read the flying notes in the instructions, it is recommended to add some ballast anyway to help penetration so hopefully the extra weight of motor and battery will actually be beneficial

 

 

I drilled a hole in former 2 (No 25 in the kit) to allow the cables from the motor and ESC to pass backwards. I contemplated trying to get the battery in under the wing tubes but it would be too difficult to get the battery in and out so servos instead which i drew on for reference. The ply doublers make the fuse strong and rigid so it certainly won't be flimsy

 

Gary

[PatMc]

Do you intend to use a front or rear mount motor ?

If a rear mount you'll be best to shorten the nose by a little over the motor length & plan a suitable cowl. 

Examples of each type of mount below.

 

 

 

Graupner Amigo nose scan from plan.

 

 

Modified to take front mounted motor.

 

 

End result.

 

 

My RelaxE design modified for rear mount motor.

 

 

Built up thin ply cowl (the spinner was later changed for a all metal longer type) 

[Gary Clark 1]

Thanks Pat

 

I am planning on using a front mount to avoid extending the nose. The moulded canopy/hatch comes all the way to the front so saves modifying that too. I can see a a bit of a downward angle on the RelaxE so would you go for the standard of trying to point your thrust line at the CG? I was expecting some down and right thrust being a high wing but just guessing

 

Gary

[PatMc]

There's only about 1.5 - 2 degrees of downthrust on both the Amigo & the RelaxE with no sidethrust on either. Not sure what you mean by "trying to point your thrust line at the CG". 

TBH I usually don't bother with down or sidethrust at all, I like to climb as fast as possible for a timed power burst & adjust the angle of climb according to the headwind using a little down elevator. Also I would normally be steering the model towards any perceived area of lift so a natural turn wouldn't cause any issue.

The only reason RelaxE had it's nose extended was because in the photos it's just been converted from a geared 600 can brushed motor to brushless which shed about 120g of nose weight. This was in pre lipo days so it still used 8 nicads, this has since been changed to 3s lipo with a further reduction in AUW from 1814 gm (brushed motor/nicads) to 1448gm (Brushless/lipo & a couple of tweaks}. I didn't record the brushed motor power but the initial brushless power/weight was 46W/lb latest is 104W/lb.   

[Gary Clark 1]

Thanks for that Pat. I will go for 2 degrees of downthrust and see how she does with that and can use washers to alter slightly if required after that. 

 

I was told by work today that I will be away from home until Friday evening so it's on hold. Apart from the money to pay for theses planes, work really does get in the way of your hobbies sometimes!!

[Martin Hodgson]

Build is looking good. Bit late to say but Spoilers would have been useful. Will be interested to see the nose conversion.

[Gary Clark 1]

Thanks Martin

 

As I said earlier, I'm inexperienced when it comes to gliders so just went with the plan. No surfaces on the wing at all so I hope slowing it isn't too much of an issue!!

[PatMc]

2 minutes ago, Martin Hodgson said:

Build is looking good. Bit late to say but Spoilers would have been useful. Will be interested to see the nose conversion.

I agree, I thought the Elan was designed with spoilers but Gary's the build was too far advanced for a suggested mod to be made when I realised they weren't in the design. 

Best bet if necessary would be to use a very low throttle setting on approach (just enough to prevent the brake enabling) so that the prop will freewheel & increase the drag.  

[Martin Hodgson]

28 minutes ago, Gary Clark 1 said:

Thanks Martin

 

As I said earlier, I'm inexperienced when it comes to gliders so just went with the plan. No surfaces on the wing at all so I hope slowing it isn't too much of an issue!!

Slowing down is not really the issue. It is light enough to float in and small enough to be maneuverable. The real concern would be the boomer thermal and getting it down from altitude. 

Without spoilers you are left with spinning (not good on the wings if done incorrectly) or flying inverted.

 

[Gary Clark 1]

Ah OK, I get you now. Thanks for explaining.

 

I've also never flown just a rudder and elevator plane before so is getting it inverted possible?! Sorry for the ignorance! This is why I want to try this out and if it's successful (it should be!) Then building something more advanced will be on the list 

 

 

[Gary Clark 1]

I've been making progress on the other wing whilst I wait for the motor to arrive. I ordered that and a separate order for scale stuff from Mick Reeves almost 10 days ago and still not here. Almost certainly due to the royal mail strikes last week. Fingers crossed it will appear over the next few days and I can get on with sorting the fuselage 

 

[Gary Clark 1]

https://youtu.be/JoAsw2ccfM0

 

this would be fairly easy to insert now on the left wing and a wee bit of surgery on right. Is the general consensus to add them in? 

 

Gary

[Gary Binnie]

Wing loading is a consideration, adding a motor, battery and ESC has already increased it and spoilers would increase it further unless they are very light weight.

Increasing the wing loading will change the glider's ability to soar in weak thermals or light winds at the slope.

 

I'm about to add airbrakes to a slope soaring design that was designed to not have them but it was designed for reed radio gear which apparently weighed 2 lb including the 'DEAC' battery, I'm gambling that even with the airbrakes it will be under the original finished weight. 

 

To get out of lift with a spoilerless glider just fly away from the lift and speed up (but not to the point of flutter), F5J competition pilots use this technique instead of using the braking flaps, the flaps are used on the final approach to make a spot landing (within one meter for the full bonus of 50 points, F3J was within 20 cm for 100 points).

 

If you were competing with the Elan in the 100S class then spoilers would be almost essential to land in the defined area which is about the size of two tennis courts but that class died a few years ago, we all have Tracker 100S gliders that can't be sold!

 

If you really did want to add spoilers then lightweight ones can be made from trailing edge stock and are pulled open by strings running through internal tubes, airflow blows them back and they are held closed by light magnets. The servo(s) are in the fuselage nose where you will generally need trim weight for the CG anyway. The strings are connected when the wings are fitted. The string is fly fishing leader line.

 

1. My Elan.

 

 

2. My Tracker, the spoilers are quite small, later ones had larger spoilers. Fuselage is carbon/kevlar, wing is a fibreglass/balsa laminate and hollow moulded.

 

 

 

3. Chris Foss Hi-Phase spoiler.

 

 

4. Opened, using strings can result in slight asymmetry operation even when they are identical lengths but it has no effect on flying.

 

 

5. The servo end, both strings have loops that hook over a long screw with two brass servo mount eyelets. They turn 90° over dowel sections just before they pass out through the fuselage in to the wings. Spoilers are needed on this 12 ft span 'Open class' model because its glide angle is very flat, I would struggle to land it in the same field without!

 

[Gary Clark 1]

Hi Gary,

 

Thanks for all that info, really helpful.  I think I'll go without now and, if everything goes well, I can see myself building something more complex with flaps and spoilers.

 

Unfortunately my order from 4max is delayed due to a stock issue with the motor so George has said a few weeks until it is back in stock. Due to this delay, the fuse is on hold until I can fit the motor and servos to ensure everything fits where I want them to. I have the tail parts complete an I'm ready to cover them. I got on with the left wing and had the inner and middle sections joined whilst I started the outer section. All was well and the outer section is finished including tips, cap strips and final sand but only 1 minor issue......I've built a second right wing outer section 🙈 I stopped thinking and just built it on the plan the right way up rather than mirrored. I can't believe how much of a tube I've been!! The only consolation is that I traced all the ribs before I built the wings so I'll just have to cut a new set for the outer panel. Welcome to amateur hour in Norfolk...

 

P.s if anyone has a damaged outer wing panel I know someone with a spare one....

 

Gary

[Gary Binnie]

Easily done!

[Gary Clark 1]

Well I'm still hanging around waiting for the motor and bits to arrive from 4 max, hopefully it will arrive soon and I can get on with the fuselage.

 

I thought I'd give a quick run through of how I've found the kit and the build so far. First thing is the shape of the wings and general look of the glider is lovely, Fuse isn't built yet clearly but you can see why it has such a good reputation. The kit itself is very well cut and the parts clearly marked and easy to organise so saving a load of build time (except when you build 2 right wingtips and have to cut yourself another set of ribs....). The balsa is definitely a little hard for my liking, not unmanageable but trying to cut slots for hinges for example was pretty tough without splitting the wood or snapping it. One thing I don't like is strips of cloth used to strengthen the wing joints. This is thick and required a fair bit of filler to blend it back in so that I don't have a lumpy wing. I decided to use fiberglass strips on the final joint to compare the difference and it's exponentially easier to blend in and sand smooth.

 

Overall, I've enjoyed this so far and it has spurred me on to want to build a more complex glider in the future but I think I'd get the ribs laser cut first as I've realised how many there are in a big glider like this! I'll hopefully get on with the build as soon as the motor arrives

 

Gary

[Gary Clark 1]

I got a message today to say the motors will be back in stock on Thursday so fingers crossed I get the package this weekend and I can get this fuselage built. 

 

I've added a few photos of the difference between the material strengthening strip and fiberglass to show you the difference. They both need a bit more filling and tidying up but you can see what I mean about the thickness 

 

fiberglass is the second photo and very little filler to blend it in. Minor point overall but worth considering for anyone tempted to built this kit

 

Gary 

[Gary Clark 1]

Well I finally have all the parts I need to get the Fuse done. I started off by gluing in the ply servo rails then gluing the two halves of the fuse together

 

 

The slec board is great for this to ensure a straight fuselage. I wanted to mount the motor to see who it fitted/looked but it was clear I'd need to modify the very front of the fuse to allow a streamline look rather than the flat corners around the motor. I'm sure it wouldn't make a huge difference in performance but makes it look a fair bit better.

 

I place a scrap piece of balsa in front, cut a circle smaller than the diameter of the spinner and shaped it to improve the streamline looks

 

 

 

Still a fair amount of sanding to go to tidy everything up but hopefully you can see what I'm trying to achieve. I have the top deck on also but I need to sort the pushrods which means soldering the bowden cable and the threaded extenders.....I hate soldering.

 

What other options are there for securing the wings in the fuselage other than elastic bands? Surely there must be a less fiddly option?

 

Gary 

 

 

Edited September 25, 2022 by Gary Clark 1

[Gary Clark 1]

Got more progress done tonight, the back end is pretty much organised and has be dry fitted. I took all the tail parts away to be covered 

 

I have the pushrod in and roughly fitted so I can close up the bottom of the fuse then get sanding. I will try the wings and ensure the tail is set properly, ensure the wings are a tidy fir to the fuse then get them covered too. 

 

Lots of space in the fuselage for all the electronic, especially with the servos back slightly. I'll get a photo tomorrow

 

Gary

 

Gary

[Piers Bowlan]

No doubt you have seen Murat’s build blog Gary?

https://forums.modelflying.co.uk/index.php?/topic/47740-cambrian-elan-100-build-with-a-brushless-motor/

He used a spring to retain the wings instead of rubber bands.

Edited September 27, 2022 by Piers Bowlan

[Murat Kece 1]

I reverted back to a cable tie or a rubber band..