Richard Harris Posted December 28, 2012 Share Posted December 28, 2012 Hasn't the weather been rubbish? I have been waiting for the right day to get outside so I can carve/hack and sand my bigger version of the Fire Fly, but to no avail! So to keep my finger in I have started on a smaller version for some light hearted indoor flying or calm weather (if and when this may happen) Those who have followed my madness will know that I have tried this before with my Hobblite, mini Ceirva C30 and Stllleto designs with varying degrees of success. So ging back a week or two I had this itching thought that I know works but I just have never tried and that is elevons on an autogyro. Basically as you would expect, fixed rotor mast with elevons on the tail. The photo shows two models I have built, the first is simple profile type model. This I can get to fly but only in a straight line so I built the second model to try some other ideas which I am sure will work....but this is all work in progress whilst waiting for flying weather. Mini Fire Fly is just a reduced scale version of its larger counterpart but I will be building 2 versions. The first is an elevon version and the second is a normal type, then it will be back on to its bigger brother. A quick photo of what I have done so far, not a lot just depron and very light! Edited By Richard Harris on 28/12/2012 22:27:30 Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted December 28, 2012 Share Posted December 28, 2012 Wow Rich that Vapor has really put you into micro weight mode , not sure if the elevons will recover a high bank angle but it will be interesting to see what happens at such a low weight it may just work ! Tom. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted December 29, 2012 Author Share Posted December 29, 2012 Not quite that small Tom! I gave the depron a coat of balsa loc then covered it with solar film on a very low heat, the film has gone on better than expected. Rich Edited By Richard Harris on 29/12/2012 00:05:20 Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted December 29, 2012 Share Posted December 29, 2012 Ah!.. the secret process , give the model a drink and then shove it in the microwave. lol . Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted December 29, 2012 Author Share Posted December 29, 2012 To right Tom!! Made up a pair of boots this morning, not alot to them really just 4 layers of 6mm depron sandwhiched together with the 2 inner sheets scalloped out. 5 mins with the sanding block and then covered in solar film, just need to cover the second then add a bit of decoration t help with orientation Mods......can you re title the thread, I have a dodgy 'o' button on my lap top and it missed one of them out, thanks in advance Rich Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 29, 2012 Share Posted December 29, 2012 Title changed Rich how do you get such a good finish with film over depron? Whenever I've sanded depron I get a very uneven finish indeed. Sometimes it will sand and sometimes it sort of pulls the surface. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted December 29, 2012 Author Share Posted December 29, 2012 Chris, Cheers for that When applying the glue (UHU por) to each face I leave the very outer edge free from glue , a gap of around 3mm ish. It seems it is the glue that can rip the depron as it picks up on the sanding block, I always just sand in one direction, seems to work out ok for me. I start with the sanding block and finish with just a piece of fine sand paper as it is easier to create curves with no flat spots. If there are any lumps after that have been missed when covered you can flatten them down with the covering iron Rich Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted December 29, 2012 Share Posted December 29, 2012 Rich. Nice work , and it looks light enough to fly on depron blades with a cf leading edge .I recently flew a flat blade set out doors and they worked well on a model weighing over 1 lb . Also tried some flat balsa blades with a tapered t/e and they also produced a surprising amount of lift . At the risk of sounding boring , the flat wing on one of my models lifts 12 lbs and will fly very slowly ,but adding some trailing edge taper does improve the L/D considerably. Will look forward to seeing this one fly , as it's a great simplification than could be built with or without the added touches that make it look good. Tom. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted December 29, 2012 Author Share Posted December 29, 2012 Tom, Same here , I had good results with 3mm depron blades a few years back. I did try 6mm but they didnt spin up too well. Best I found for a 20" span model have been balsa LE blades with a depron TE or as on the Panther cub built up balsa blades. I prefer the added touches for two reasons the first is I do like my models to look as if they 'could have been' a real one. The second is for more preactical reasons ,spats and colouring (especially cheques) are all good orientation aids I have found. Lighter colours as a base colour with darker colours over the top as a contrast. Spats are the best I think, especially with my eyes! Decorated the back end with solar film and black 10mm squares, no mean task I tell you applying these puppies! culd all go with one strike of a blade too Rich Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 1, 2013 Author Share Posted January 1, 2013 Have made the blades up this morning and they are a mighty 300mm in length each, this should give me more than enough lift I think. Also made a start on a very small dummy radial to hide the brushless motor, this is made from depron. I will post some more photos of this when it is completed. Rich Edited By Richard Harris on 01/01/2013 14:40:16 Edited By Richard Harris on 01/01/2013 14:41:07 Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 1, 2013 Author Share Posted January 1, 2013 A photoo of the head, very simple to make by just two lite ply hexagons with a 0.4mm thich FG sheet in the centre as a blade holder. I have done away with my normal triangular plate idea purely for lightness. I have also a Polypropylene blade holder that came off the Hobblite, this works well and will be used as a back up if the new head doesn't work out. I think it was made from a Jacobs cracker lid! Rich Quote Link to comment Share on other sites More sharing options...
Richard Elliot Posted January 1, 2013 Share Posted January 1, 2013 Very innovative Rich, is the bearing just brass tube slid over a bolt or is there more to it ? Like the c/f film a lotCheerRich Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted January 1, 2013 Share Posted January 1, 2013 Cool Hi Tech finish Rich . Plain bearings work well on these light weight jobbies ,and as you show makes the plate nice and simple . Tom. Edited By Tom Wright 2 on 01/01/2013 22:27:06 Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 1, 2013 Author Share Posted January 1, 2013 Rich, It is just a brass tube that is a tight interference fit, this is glued into position. On the Hobblite head I used the little brass top hats used for servo mounts, these work well too. The Gimbal itself is a length of piano wire which doubles up as the spindle, the head control arms are 1.5mm carbon rods sandwhiched between a round servo arm and a disc of balsa and FG sheet. Heat shrink tube is used as the flexible joints between these arms and the control rods, I generally double up on the heat shrink tubing as added security with a drop of CA for safe keeping. Silcone fuel tubing is the heads flexible joint. Tom, Yes, simple and light Rich Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 4, 2013 Author Share Posted January 4, 2013 Apart from adding the rudder servo/radial and a pilot I am ready to crash test this thing. Just hoping that the weather may improve soon. Rich Quote Link to comment Share on other sites More sharing options...
Gyrocopter Posted January 4, 2013 Share Posted January 4, 2013 Neat idea with the silicone tubing, as usual looking smart, good luck with the maiden. Chas Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 6, 2013 Author Share Posted January 6, 2013 Thankyou Chas, I didn't get to maiden it as the wind felt a bit to strong for my liking so I will wait until it is calm. Did manage to finish the stand off radial dummy engine to hide the brushless motor, if you squint your eyes and look away it isn' too bad! Will leave it off for the first flights A photo next to the standard Fire Fly's dummy. Rich Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 6, 2013 Share Posted January 6, 2013 Stunning work, Rich! You should be marketing those dummy engines in their own right. tim Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted January 6, 2013 Share Posted January 6, 2013 Posted by Tim Hooper on 06/01/2013 22:38:34: Stunning work, Rich! You should be marketing those dummy engines in their own right. tim I agree they are fantastic This is another one i am keeping my eye on . Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted January 6, 2013 Author Share Posted January 6, 2013 Cheers chaps but they are really nothing special and very very easy to make, just a bit time consuming. Would be good if I could get the parts cut from depron but I wouldnt know where to go for that? dont even know if depron can be laser cut? Rich Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted January 6, 2013 Share Posted January 6, 2013 Yes , depron can be Laser cut Ricard Looks even better in your hand . Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 2, 2013 Author Share Posted February 2, 2013 In preperation for last nights indoor flying session I manage to maiden my Mini Fire Fly yesterday afternoon, it did fly but roll responce was pretty poor. So I reduced the height of my mast but didnt get chance to try it again outside. First flight in the hall and it went pretty well but a little under powered with the fitted 2 cell Lipo, so a 3 cell 240mah battery was fitted and it was far more respoonsive. Left hand circuits weren't a problem and I did manage to keep it well within the walls of the gym, but right turns were not so pretty I think I was fighting the prop torque. I will add some right thrust in time for the next session. Pretty pleased with the results. Rich Edited By Richard Harris on 02/02/2013 13:09:51 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted February 2, 2013 Share Posted February 2, 2013 Looks Very promising Richard Keep up the good work , Quote Link to comment Share on other sites More sharing options...
Richard Franks Posted October 22, 2013 Share Posted October 22, 2013 Hi can you tell me what the rotors are made of? they look black? Thread says balsa and depron. New to electric flight what size motor is on the indoor model. Its brilliant Confused Richard Quote Link to comment Share on other sites More sharing options...
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