After selling my last build I needed another Twinkle. Thought I'd throw up a build log... depron's pretty fantastic for little seaplanes so many the techniques could be applied to other designs. Depron build goes a fair bit faster than the balsa build, so I'm hoping to have a flying plane in a week or so.

First step is to make the wing. Quite pleased with the technique as recommended... put the top and bottom sheets together, and hot glue along the edges. Doing a few inches at a time, while the glue is still hot, smooth the glue out with a metal edge. This will hinge the trailing and leading edges. Then after sliding in the spars, you have a fully formed wing... run some thin CA down the spars to glue them in and it's done. After the spars set, you can set up the dihedral with a jig piece and laying the wing flat on the board. In pretty quick fashion the wing is complete save the tip floats.

my first depron version was a sweet plane, so I'll be happy if this result is anything like the first...

stole myself away from work this morning to quickly add the fuse sides. Slide them over the front spars, butt them up against the main spar... line up the rear fuse so it's straight, and apply CA.

Cut out and added the tip floats, the depron versions are much more hardy than the covering over balsa of the original.
With tips done, the fuselage sides go in next to start making the torque box to hand the loads of the fin.

and a couple of pics of the prototype horsing around on the water just for the heck of it...

did some more fondlings at lunch time. assembled the fin in a similar technique to the wing... hinge the trailing edge with hot glue, put in the ply keel assembly (ply part off the plans with two strips of depron shaped to form the fin's airfoil) trailing edge first. Then glue the front of the keel and finally close the leading edge. Pop in some motor extension wires and you're good to go.

Cut up some spruce stock for a motor stick, and bound a ground down tube motor mount to the stick with kevlar thread. The plane is designed for the CD-ROM style outrunners, so any 8mm tube mount is the ideal (others have created firewalls for their twinkles to mount firewall mounted motors).

The last pic is the sizing up of the stick to get the prop swinging in the desired location.

oh, keep it down people!!!... I'll get you the updates as quick as I can, just stop hassling the thread!!!

Hi,

You forgot one things. Can share the plans and electric setup? Hehe

Thanks

fay

For sure!

The plans can be found here for both the depron version and original balsa... http://keyboardmonkey.com/twinkle

The original was just the old CDROM conversion motors, mounting the bearing tubes to the stick is simple. These days I fly them with a single stator cool wind from [link=http://www.customcdr.com/cgi-bin/ccp51/cp-app.cgi?usr=51H5086815&rnd=5713849&rrc=N&affl=&cip =71.162.38.107&act=&aff=&pg=prod&ref=20mmsingle&ca t=singlemotors&catstr=HOME:singlemotors]CustomCDR[/link] (tube mount). You can also use LittleScreamers DeNovo or any equivalent motor... there's actually a lot of motors these days, but the ideal weight is around the 20-24g mark. Some of the motors swing big props, so I find you can feed them enough prop with the VarioProp three blade swinging 6.5" blades. The hotter motors are naturally fine as they're typically built around the 6.5" blades or less (like the LittleScreamers or ParkJet or HotWind from CustomCDR). Others have used AXI's and things up. Can use up to around the 32g mark, but you'll have issues balancing.

For batteries, I use the 650mah 15C Kokams... 2S and 3S. The 2S packs are great for general flying, and the 3S pack with the VarioProp makes Twinkle absolutely ballistic ...there's also a lot of batteries around this size these days too... 600-800mah, 15-20C are a very ideal setup. I have flown on 450mah packs, which makes a very light and floaty setup (although naturally down on power as a result too), but you need to make sure you're not over-amping them with the motor setup.

...lots of options these days for the electric power train in this beastie.

Hi,

Thanks for info.. I've few little motor any must be very fit's on this depron.
I'll order both plans.

Thank you for your info.

Next couple of pics represent the trimming of the motor stick. The top of the fin sets the thrust line, the top of the motor stick sets the angle of attack for the stabiliser.

Glued the assembly to the back of the plane. Being as straight as possible is ideal, of course, but there's a chance to correct any straightness issues when the ply keel is reinforced in the next step. This is basically packing wood/depron around the keel bottom in the second picture. Strength also comes from the keel being glued to the bottom sheet. This all makes a nice strong toque-box to take the forces of the motor both thrust and gyroscopic.

Hi Arron, great to see a new build, quick question for you, you mentioned that you use the customcdr cool windings, why didn't you choose the hot one, I new to electrics but at first glance it has more thrust at about the same weight. Anyway as I was waiting for my plans to arrive I began to order all the toys, (varioprop is in the mail) and wanted your opinion on the two motors.

good question.

in short, it's just about what I've been able to test. With the original design, I had concerns about getting enough prop on the motors to get the thrust I wanted. It worked fine for the original LensRC17t. As it turns out, you can actually over prop the newer motors using the VarioProp 6.5" blades with all the pitch wound in. So this allows the cooler motors to get their thrust numbers. I also love the results. On the cool wind, the 2S setup is simply great, but you can put 3S in there without any changes and get a ballistic setup (with some throttle management to allow the motor to cool, can't go full throttle the whole flight like this).

I think the hotter motors should work great, and I'd love to try one myself actually. In my next build I'll be trying out a LittleScreamers ParkJet motor. The hotter motors will certainly allow for the use of smaller and cheaper two bladed props. Should be a great setup, but I don't know from experience at this point (note: the hot CustomCDR equates to the LittleScreamers PurplePeril, the ParkJet is even hotter).

It's just that I can only put in an "official recommendation" on what I've personally flown. People are certainly free to experiment though

A few people don't like the VarioProp recommendation, but I love the look and the flying results I've had. If you want to try the hotter motors, start testing with the pitch wound in (or maybe smaller blades). With the cool motors, starting with the pitch opened up should get a flyable result.

I also use phoenix 10's. The cooler motors also keep the Amps well below the 10 max.


...you know, I wouldn't mind getting me a CustomCDR hot or a PurplePeril to test out and get back to you with some actual results [8D]

Well my plans just arrived and I know you must be getting pretty bruised by now, but, one more pat on the back because they are better than many of the "big name" kit packages that I have built. Now for the sad news, we just moved to our new home and the jerks that lived here before us didn't even have the nerve to build a flying shop, not only that, but there is no depron within 1500 miles of where I live. Luckily we have more water than land up here so landing strips won't be a problem. Good thing I ordered balsa plans as well, it'll most likely be two to three weeks before I can start the build but I will keep you posted. Oh ya, I ordered the hot one. If you have your camera (ie video) issues sorted out I'm sure everyone on this forum would enjoy some action shots to tide us over. (can't find the old ones of Twinkle I and II)

kinky, thanks for the kind words. I'm glad you like the plans/instructions set, and hope you enjoy the build when you get everything setup and in one place.


As far as video goes... all I have are some not-all-that-great videos of flying the balsa prototypes. They can be found here... http://keyboardmonkey.com/twinkle/movs ...they do show that it can fly in a happy fashion. Also has some snow, water and sealed surface flying. I'm looking forward to trying to get some video of a new depron build in the next coming few weeks, so I'll post them up when I get them. I also want to make a waterproof enclosure for my camera so I can get some interesting photos really low to the water surface... will see how that turns out anyway

put a little more time into the build recently... here are some pics of adding the tailplane pushrods... "dorsal" wing parts inboard of the ailerons... putting the speed controller into the rear of the fuse and then sheeting over it... and bringing the nose together at the front. Another few build sessions and it should be flying.

got stuck into some building last night. Bent up some landing gear and laminated the blocks for them to plug into... added them into the fuse with reinforcing triangles to spread the load as well as gluing them to the main spars for strength. Put on the bottom depron sheeting for the fuse, and covered the bottom surface of the fuse and tip floats with .75oz cloth and epoxy resin (this is optional, but the strength and scratch resistance is nice for grass flying). When dry, sanded the excess off the firberglass and finish sanded it a little for a nice and smooth surface. Made up a stabiliser, hinging with scotch tape with a scotch tape reinforced leading edge.

Reckon that one more build session and this puppy is flying!

Someone send out a search party for Arron[X(]

...nice to know that one person missed me.

been busy is all. my father came up to visit for a few weeks, work, etc etc. but I did finish the build and get her flying. from where I left off, all that had to be done was connecting up the gear, adding control surfaces and sheeting the top of the fuselage. all pretty boring and happened without a hiccup. I'll get a couple more pics, but here's one of her sitting in the water for her water maiden (had already flown sealed surface maidens at this point).

She's actually out of action already too... a mishap with handing and an annoying circumstance with my radio had it fall off the table I had it on. crunched the nose all up. I still have to build a new nose and get it flying again. It's just a nose shell that holds the battery only, all the gear is behind the main spar, so it's just a fix to correct the aerodynamics really... but I still have to get around to it.

Actually, pics of the repair will finish off my build pics nicely

...actually, I think the reason why it hurt me by falling off the bench was because I didn't get around to putting her flying colours on (the Twinkle logo and stickers to make her sexy)... so she had to make it known that she was unhappy. fickle things these planes.

I'm making very slow progress on a balsa twinkle. (work, life, etc.) but I think this week I can dedicate some time and get it mostly together. I'll try to get some pictures, once there is something to take a picture of.

no worries mate. It's certainly no race... just enjoy the build, that's the main thing!

have always liked the look of this little flier, What do I need in the way of depron thicknes's to build one of these?

Have you given any thought as to having pre cut kits avalable? from say, powers or some other foam shop?
( http://www.********.com/airplanekits.htm ) I know a laser is much better at foam cutting than I am, and having all the parts pre cut, properly, would really save some time and generate a lot more sales.

With the thicknesses on the plans, about 2/3 of it is 2mm, and the rest 3mm. You could go all one thickness (either way) if you wanted without too much fuss. I haven't gone all one thickness myself, but I can't imagine any great fuss in doing it... at worst, if you go for all 3mm, just take a mm or two off the height of the wing spars to account for the extra thickness... most 3mm depron is actually 2.6mm or something anyway.

I have given 'kitting' a bunch of thought, but haven't followed through with it. I had approached StevensAero with the notion of a balsa kit, but I'd need to redo some of the parts for the laser cutting, create cut files, etc etc... and it's just a time thing. I could probably do the depron beast, but haven't gotten around to it. Cutting through the template sheet and depron doesn't take too long... all the lines are straight with the only exception of the fuselage.

...maybe I'll get around to organising a kit, but due to work and everything else, I don't think it's a short term proposition.