Google
 

Tuesday, July 27, 2010

FREE MODEL GLIDER PLAN: DOGCHEW 6" Tiny glider

The Small Flying Arts site has changed dramatically. I think they are in the process of transferring all the plans and articles over to the newly designed site. However, the plan and build notes for my DOGCHEW design are currently unavailable there. So I thought I'd publish them here. In future blogposts, I'll also publish some other tiny glider plans. Click and save the plan below. The build notes, which I wrote in 2006, are shown in full below the plan.


Build notes for DOGCHEW 6" glider

These notes accompany the plan for a simple 6" span free flight HLG. Small gliders do not have much momentum so tend not to break easily. Another advantage is that they can float on a whisper of lift. You get maximum fun with minimum fuss!

Now this is the first 6" glider of mine to fly over 30 seconds. When I was testing the prototype in a local park, there was nothing for me to do but laugh while I watched a "friendly" Dobermann Pinscher pick it up tenderly with its jaws, manouvre it about and then crunch it, very gently. I said to the dog-owner: "Well, I guess it looks a bit like a stick." He replied, "You’ll be needing a bit of glue then. A pity, cos it flew really well." I thought "yeah FLEW." At least the dog seemed to enjoy the flavour of dope on balsa. I spent the lonely walk home carefully spying the ground for other deeds by my new best mate Dobie….

That is why this design is called DOGCHEW. Its best flight so far is about 63 seconds and still air time around 18 seconds. In the 2006 Tiny Gliders postal contest (see http://www.windandwavemodels.com), average flight time was about 32 seconds.

It is a straightforward build. The plan is to scale, so you may find it easiest to use a photocopier or scanner to enlarge or reduce it in accordance with the fuselage dimensions.

Instead of laminating the fuse with PVA, you can use spots of CA – this is lighter. Alternatively, forget about the laminating completely and use hard 1/8 balsa instead. The wing is made in the usual HLG way. Make a template from the plan. Use it to cut out the whole wing planform, sand in the airfoil with the high point as per the dotted line and apply 2 coats of sanding sealer. Then cut the wing in half, sand the dihedral angle at the root chord and glue together with epoxy. Sand a “v” in the fuse for a wing seat and use epoxy here and for the throw tab. Fin and stab should be sanded as thin as you dare, so that you can breathe and bend for trim. (The prototype had trim tabs, but these were dropped in the final design because they were easy to break). Apply sandpaper or similar for grips on the side of the fuselage.

Feel free to play around with the length of the nose – e.g. chop it shorter if you like. The length shown on the plan seems to work well in calm conditions. Also, you may find it beneficial to sand a bit of washout under the starboard wing tip TE.

Using gentle glides from the shoulder, trim for a left turn, with a slightly “stally” glide. Full power throws are to the right of the wind with a slight right bank. As with most HLGs, avoid throwing with less than full power! Add left rudder if it stalls in the glide, but not too much otherwise it will spiral dive. When properly trimmed, it should transition at the top quickly and start turning nice flat left circles.

Thermal in peace….. :)

Berkshire, U.K., 2006

2 comments:

Anonymous said...

I read with great interest your web page regarding indoor free plans. I was so impressed that I would like to produce an article and plan as a free download for our own club here in Aberdeen, Scotland. Our intention would be to encourage club members to build the plane for a small indoor competition in March 2012. The plan would be free, there would not be any prize money or profit.

I would be grateful if you could confirm that you would be happy for us to do this, and in return I will gladly send you some photos in due course / an article.

Best regards


Steve Davies

Chuck Glider said...

Hi Steve. Of course you can! I'd be really interested to hear how you get on. Dogchew is an outdoor HLG, but if you build it lighter, I'm sure it will be ok indoors. There is also an article in FFQ: Issue 35, April 2010, http://freeflightquarterly.com
The plan is for all to use and hopefully have some fun - so please just go ahead.