Levanter
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Posts posted by Levanter
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Peter
Absolutely on my build list so looking forward to the magazine. When you know which issue, will you let us know.
Another one of your quirky designs you like so much.
If I can take off and land on my balcony I will be well chuffed
LevanterEdited By Levanter on 20/03/2019 13:45:43
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Posted by brokenenglish on 16/03/2019 14:54:08:
I shall probably be a minority of one, but I disagree with some of the statements above.
CNC machining, etc. is obviously excellent for modern engines, but I don't think it gives better fits than hand-lapping, and suggesting that vintage hand-lapped P/L assemblies had poor fits and depended on using very viscous (thick) lubricant to run, is very untrue, ridiculous even.
Maybe I've misunderstood the above posts, but does anyone really think that all the ED Bees, Babies and Hunters, all the Mills engines, the Kalpers and all John Oliver's production ran superbly (which they all did and still do) with poor P/L fits?
Edited By brokenenglish on 16/03/2019 14:55:26
Maybe minority of two now but probably more. How on earth did we manage to make things with extraordinarily fine tolerances before the 70s when CNC started to be introduced? Although a fantastic development I think the applications of CNC are often misunderstood. Some amazing stuff was produced on automatic machines with air logic controls and I used to run a Conomatic six spindle auto lathe (a beast) that turned out parts - well, six times faster than a CNC lathe (I hade those as well) One of the big differences is the reduced levels of skill required for tool setting. Lots of things changed with CNC but not everything.
Levanter -
Congratulations Ron
It show what can be done with care and patience.
Levanter -
Hello Mike
I am an Oodalally builder but have switched over to resurrecting a model yacht I built 50 years ago. Your post has given me the urge to get on and finish it along with the Grumpy Tigercub which uses the Oodalally wing but designed as a twin.
You have made a nice job of the canopy. I have a balsa plug ready made for mine but struggling to find a big enough bottle. Maybe I will have to stretch one first.
Good luck with the maiden.
Tim R -
Hi Percy
That's a sad story but thank you for recounting it. I was very lucky to get it as I know there was considerable interest at the time. As soon as I saw the Ad I called Lancaster and paid a deposit for the asking price to hold it while organising full payment and shipping. They made a great job of crating it and it arrived in Mallorca without a scratch. I bribed two young lads from the ferreteria opposite to get it into my flat and onto a cabinet bench I bough from a local tool merchant. One of my better purchases and though I say so myself, has gone to a good home.
Using it for some model boat fittings right now.
Levanter -
Hello Geoff
You should look on the sister site modelengineer where this question gets asked lots of times with some very helpful replies. The link should take you directly to the mini-lathe threads You will also find it is possible to turn tapers without a compound slide by offsetting the tailstock.
There are lots of considerations and for some the hole through the headstock spindle might be too small, what diameter do you want to swing? and the list goes on.
You can easily spend as much on tooling as you do on the machine and remember you can do small parts on a big lathe but not the other way around.
I was very lucky. I picked up a Proxxon 400 being sold on behalf of a customer of Lancaster Model and Hobby World about 4 years ago. It came with a whole load of tools and the milling attachment. All for the price of the basic lathe.
About the best advice I can give is if you but new, go to a reputable dealer. If you buy secondhand, get someone who knows about lathe to have a gander.
Finally, don't be coldly practical. Once you have one you won't look back as it opens a whole new world and is immensely satisfying.
I know you have Thames Barge on the go which will need some fittings.
Levanter. -
Doh!
For attach read attack.
Levanter -
FB3
I don't know how many fuselages you are going to build given all the advice so far
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Acetone will attach both epoxy and aliphatic. If you soak the balsa side with acetone and work on an edge, you may be able to separate them bit by bit.
I suspect the ply is more valuable both in terms of money and time expended so if the worst comes to the worst you could sacrifice the balsa (some bits will get re-used) and save the doubler.
I am always making mistakes and having to work around them - part of the fun. A learned mentor of mine said to call them "features".
Levanter -
Posted by kc on 08/02/2019 16:40:14:
Actually all you really need for wing building is just the lines for the spars and LE & TE and lines for the ribs. No real detail is required so just trace those lines or draw on plain paper or the building board.
+ 1
As kc says. You only need one line for the ribs, choose inboard or outboard. One line for the leading edge where I would normally use the outside line so if there was any variation in the wood size it would not affect the planform. Likewise for the trailing edge. Really just a few lines on some blank paper. Much quicker, much cleaner, cheaper and no need to cause damage to the original.
Levanter -
FB3
What glue did you use and how long ago?
Levanter -
FB3
You will enjoy building the Isabella and it comes out at a nice size for me with limited space. Mine is powered with an OS LA 10 but has not flown yet.
To sharpen my aerial tubes I "wipe" the ends across the coarse side of my Permagrit. This raises a burr on the inside and the outside. So quick to do and the burr helps to stop the aerial binding in the hole and also make pushing the core out much easier especially if drill through thick balsa.
Thank you for the kind comments.
Levanter -
FB3
Yes it is the Isabella designed by Marco Penk from the RCM&E September 2018. I already have one Isabella so this one is Isabella II or Due in Italian. The fuselage is more or less as the plan but I used my own method (copied from Peter Miller really) for the wing. It has dihedral rather than polyhedral which made the wing simpler to build and allowed me to move the ailerons outboard. It is quite a cutie.
Levanter
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FB3
This could be for next time. What I do is drill the two ply doublers back to back at the same time. To hold them together and aligned while I drill and do other work I use a few dabs of Pritt Stick. (it wipes off with a damp cloth). You can use an ordinary drill as 3/16" is not that big and me, I wouldn't bother with a pilot hole at that size. Micro precision on position is not that critical as long as they match.
Absolutely drill onto a scrap piece of ply or wood to stop breaking out.
The doublers can then be stuck to the fuselage sides and the drilled holes make a perfect guide for a sharpened piece of aerial or suitable tube to cut out the balsa. The doublers act as a jig.
For similar reasons I do as much as I possible can on any doublers before gluing them, like lightening holes, servo rails etc.
Levanter -
I bought a second-hand scroll saw and never used it so cannibalized some parts and junked the rest. I had a Draper bandsaw (again second-hand) but it was the 3 wheel type, very bulky and also noisy so that went the same way. I now have the Proxxon bandsaw which is a peach and the Proxxon table saw and could not be without either. My favorite job for the bandsaw is tapering spruce wing spars which would be a real pain doing by hand. The combination of these two has increased the speed of my building no end as well as helping with precision.
For inside cut-outs I start by chain drilling and then smoothing out the profile with a small drum sander in a Dremel.
If I was to get another saw it would be the next size up Proxxon table saw that also has a tilt function for the blade. I would find that very useful and it is on my wish list. Are you listening Santa!
Levanter -
Hi Stephen
Your Sonata looks really nice. Congratulations! I am building an E version but the build has got stalled while I sort out a couple of RC yachts for the summer. Actually it mainly just need covering and I am a big fan of the fluorescent green as well.
Good to see the air brakes or spoilers. I would be really interested to know how you organized the servo linkage and what sort of travel you get? Also what the all up weight is. I am expecting mine to be heavier because of the motor, prop and larger battery but it is a big wing and should cope.
Levanter -
The aircraft is flying in a mass of air and doesn't know whether it is moving upwind or downwind, or across wind for that matter. If you think about it how can it? if there is wind, this mass of air is moving relative to the ground and therefore when the aircraft is being observed from the ground (rc pilot) it looks like it is going at different speeds but that is relative to the fixed point (ground) and not the moving air mass.
Taken to extreme and the windspeed is greater than the airspeed and the aircraft can appear to stand still or even go backwards! But we all know that is "impossible" in aerodynamic terms zo we readily accept the concept of a headwind. Same thing applies to currents and tides when sailing. It also explains the common and infamous stall on the downwind turn.
So Simon, I think you are being deceived by appearances and Martin is in fact perfectly correct and his explanation was spot on. It is an important subject.
Levanter -
Posted by kc on 21/01/2019 12:59:05:
SLEC advertise " plan tracing, laser & router cutting service"
Drawing boards forever!
I would love to get hold of a decent one. Not sure where I would put it but I would find somewhere. So many thousands must have been scrapped and I wish that I had grabbed one.
Levanter -
Robert
For cutting I use the Dremel diamond slitting wheel. It goes through carbon like cheese.
Be aware also that the fine black dust can "soak" into wood, especially light balsa and stain it. I learned the hard way!
Levanter
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I used SLEC from Mallorca. Everything top notch.
Next order going there too.
Not to reflect bad on the others as I have not dealt with them.
Levanter -
Erfolg
Sometimes the hardest part of a job is simply starting. I should get stuck in if you would pardon the pun.
The beauty of epoxy is that it is an adhesive so if you end up on the flimsy side you can always add another layer or two and exactly where you want it. If on the other hand you have reverted to heavy engineering then simply grind a bit off. You are going to paint it anyway??
I am a shipwright by trade and that was building steel ships up to 10,000 GT. Heavy stuff indeed with equal heavy bits. Delicate is just the other end of the same spectrum.
Levanter -
Erfolg
The more sophisticated the mould tools, the less cleaning up their will be to do and with a closed mould you can have finished edges as well. The problem with that is will make only one size and would be overkill anyway.
Looking at you photos you have got the basics and after you have finished the moulding it will be an easy job to dress the edges smooth and you have some license to vary the chord, curve the edges and even adjust it to an aerofoil section if you wanted to go really mad.
A larger number of thinner fabrics will be much better than a few thick ones. If the weave is coarse, the layers are held apart and fill with resin. This will have a poor strength to weight ratio. The other advantage of using multiple layers is that you can taper the thickness. The layers can be successively stopped short as you get closer to the wheel fixing. This will be efficient and give you a greater deal of suspension.
Your parcel tape will be fine but don't get any creases in it. It will also help achieve a good finish on both side if you could clamp boards to the outside surfaces. You could use the tape again as a release surface but wax and apply release agent anyway. The clamping pressure nd settings can be adjusted to keep the arms equal thickness and excess resin will be squeezed out with considerable benefit.
Don't use the Kevlar as it does not "wet out" easily as well as being hard to cut. If you have a diamond disc cutter then fine. Kevlar is great material with extreme toughness but needs special techniques to benefit from these properties. Carbon can be made very light but is very stiff and unforgiving. That's why I don't like it for undercarriages and I am willing to bet you make something that is well over strength anyway.
It will be messy nd I would definitely use epoxy following the good advice in earlier posts.
Levanter
It is likely to be messy -
FB3
Aliphatic is not really a gap filling glue and any that are will add unnecessary weight. The strongest glue joints are best made close fitting.
It seem your gap in the stringers is big enough to notice but not as you say enough to fit slivers of balsa which was KC's good suggestion. Your problem is quite a common one and instead of trying to fit thin strips you can easily cut small wedges. There are many ways to do this but even a shaving off the edge if an offcut will generally do.
Fit the stringer in the notch as normal. Put some glue on both sides of the wedge and slip it into place. It is best to leave them like this until the glue has dried when the joint will be stable. The extra can be trimmed off and then lightly sanded back to the correct level. Easily done in a fraction of the time it takes to describe it.
I frequently have to do this whether by accident or design.
Levanter -
Posted by SR 71 on 12/12/2018 07:00:54:
Hi Bruce i make my own tanks to fit my builds, i do them in fibre glass, i first make a plug the shape i need from blue foam, i glass it with epoxy resin and cloth, i cut the tank in half and remove the foam and the fibre glass layer, fit the connectors in and join the two halves with fibre glass, never had one fail, and i use them for both glow, petrol and in my jets
Tony
Tony
What sort of finish do you get on the blue foam using multiple coat of release agent and what release agent do you use? I am wondering is the core could be made using a foam that dissolves (in acetone or cellulose thinners perhaps) so that the tank did not have to be cut in half.
Can you explain how you make your connections. Are they mechanically fastened or do you bond them in?
I am still very interested in the 3D printing possibility but have toyed with the idea of laminating the tanks for a while now.
Many thanks
Levanter
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Posted by John Stainforth on 11/12/2018 22:01:33:
The problem is that all 3D printed objects are very porous at a macroscopic scale. To properly seal a 3D printed tank would be very difficult. There is the additional problem that all plastics and plastic fillers are permeable at a molecular level and most model fuels are very aggressive penetrants of plastics.
John
All the tanks I have are from some kind of plastic. We are probably saved from the effects you mention due to the tanks being empty for most of the time. In full sized boats, diesel and petrol tanks can be made from plastic and I suppose these are made from carefully specified materials.
Levanter
Forum members' new models: Let's see them.
in All Things Model Flying
Posted
Latest plan build from the RCME
Isabella by Marco Penk but with single dihedral, the wing spar moved forward to coincide with the thickest part of the wing and riblets
OS LA 10 up front
Just waiting for some longer bolts to fit the silencer onto the extension.
Here with bits taped in place for the cg check.
Levanter
Edited By Levanter on 25/03/2019 16:30:55