Alan Jarvis Posted September 21, 2014 Share Posted September 21, 2014 Hi Tony It would have been nice to know which EDF's you used. I have ordered 4 of the following which states a thrust of 450g. However reading some blogs people are saying they only give just over 200 g. Although I haven't received them yet I am beginning to think I have wasted a good bit of money. **LINK** I am thinking 4S may have been a better choice Alan Quote Link to comment Share on other sites More sharing options...
Alan Jarvis Posted September 21, 2014 Share Posted September 21, 2014 Ref my previous post, have just re read the forum again and see that they are they same EDF you used. So happy now. In stock EU warehouse. Alan Quote Link to comment Share on other sites More sharing options...
David Pearce 4 Posted September 21, 2014 Share Posted September 21, 2014 With reference to your forthcoming Hawk Tony, is there any chance that the plans will include the single seat Hawk 200? I've always thought that this fighter version with its radar nose and single canopy is a really attractive little fighter. Its only different from the 2 seater in the forward fuselage so I would hope that a little extra work would expand the choice of aircraft that could be modelled. There are some good colour schemes including the BAe sales aircraft in this version. (I always thought it confusing that the two seater was the 100 series and the single the 200 series!) Cheers, David Edited By David Pearce 4 on 21/09/2014 10:34:13 Quote Link to comment Share on other sites More sharing options...
PeterF Posted September 22, 2014 Share Posted September 22, 2014 Did you measure the thrust with the fans in situ (nose down onto some scales for a rough test) as the inlets may well cause some loss in thrust. Even so it will still be well powered even if it does. Some of Chris Golds early EDF planes from 15 years ago flew with 2kg of thrust for a 4.5kg plane on brushed motors and NiCads. Weve never had it so good for EDF. I have some carbon fans that are only 1mm larger in OD and will put out >800g of thrust each on 6S. I am thinking about scaling it up to around 64" (30% larger) to give an all up weight of around 3.6kg (double) for the same thrust:weight ratio. The thrust tubes would then be a little more scale. Quote Link to comment Share on other sites More sharing options...
Steve Adams Posted September 27, 2014 Share Posted September 27, 2014 Hi Tony, Would designing a edf Harrier jump jet be out of the question in the future? Showing all variants would be a plus obviously most people wouldn't expect it to be vstol just nice scale detail on what is yet another iconic beautiful and undermodeld British aircraft.....go on you no you want to Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 6, 2014 Share Posted October 6, 2014 So how much progress have people made? This is my first ever build! i have made up the body as far as I can until my fans arrive, about 4 hours work is that about right? Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 7, 2014 Share Posted October 7, 2014 I have been laboriously cutting wing ribs for a couple of days now but I like to build; not just assemble! I have been experimenting with the fans. Crudely suspending one from a gauge I got 8oz of thrust. I have now added 0.5mm of acetate to the inside of the body to reduce the gap between the blades and this. It gives another 1oz and I am about to fit another layer to reduce the gap to almost zero. Will report on the results of this soon. The stated static thrust is 12oz so my measurement method may not be that accurate. I have a question. Exactly what `rear part` of W2 is balsa as stated on the plan? I would have thought that the elevator bits on all inner ribs would be balsa but not having the CNC pack I don`t know. Quote Link to comment Share on other sites More sharing options...
Dennis Holmes Posted October 7, 2014 Share Posted October 7, 2014 Martin in answer to your question w2 in the cnc pack is all ply. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 7, 2014 Share Posted October 7, 2014 Have now decreased the fan blade gap by a further 0.5mm. Huge (2oz) increase in thrust and there is still a gap of just under 0.5mm so may experiment a bit more. Very time consuming but it will probably be worth it. Thanks for the info on W2. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 7, 2014 Share Posted October 7, 2014 Really, did you just shim the inside of the fan? i had to order mine from world wide, have you picked retracts? Also I don't really understand the aileron arrangement. care to,explain? Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 7, 2014 Share Posted October 7, 2014 Found this. http://en.m.wikipedia.org/wiki/Elevon i assume you mix the two together 50/50? Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted October 7, 2014 Share Posted October 7, 2014 Hello Martin, you asked about the control of the elevon's and that it could be 50/50 - well my learning and experience of building and flying wings like the Vulcan is that good control will come from a different set up. If you look up a build I did of a Vulcan very similar size the control was from the prime movement being elevator low 6mm high 10mm - aileron low 7.5mm high 12.5mm. To see the details type in - Avro Vulcan B2 on here top right, its on page 11 1st paragraph. I've designed a measuring mechanism to help set-up the elevon's when I'm on the laptop tomorrow I'll show the details and pictures, I'm sure it will help. Quote Link to comment Share on other sites More sharing options...
Alan Jarvis Posted October 7, 2014 Share Posted October 7, 2014 I ordered the Hobby King 50mm fans and when they arrived they had DRMAD stickers on them so I thought of ordering the following. Anyone tried them? **LINK** Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 7, 2014 Share Posted October 7, 2014 I cannot quite see yet how the wire coupling to the outer and inner elevons would work which is why I would prefer to use four servos but Tony says (above) to keep it simple. This would probably give the correct deflections. Yes, the fan body has been shimmed with 2x 0.5mm acetate using Evo Stick. Each was held in place during setting with suitable cylinders (alloy can, spray can top). I may try using 0.4mm ply to reduce the gap even more. The information on keeping the gap as small as possible was gleaned from Marcus Norman`s Epee many years ago but I never did pluck up the courage to run a home made 5" fan on a pylon racing 40! He sent me lots of info on the ideal intake and efflux areas but this has been lost long ago. I have sussed out the retracts used but will not reveal the type since Tony is selling them. Don`t know what mods. were done though. Still wing rib balsa and ply bashing. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 7, 2014 Share Posted October 7, 2014 Alan, Just looked at those and they could be of interest but wondering how much load they will put on the motor, what would be the current increase and will there be a significant increase in thrust? At that price I may be tempted to try them. Martin. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted October 8, 2014 Share Posted October 8, 2014 As I promised Martin Rowe 1, to help you understand how elevon's can be set-up on this kind of wing, and a mechanism to help with setting those movements up. As you can see from the picture's I've pre-marked on paper and card a grid that has the movement's for each prime movement which is provided via you elevon mix from your transmitter, so it was elevator low 6mm - marked as on the grid -E 6mm - so on and so forth. If you notice my elevon's are 8 mm wide at the edge so that's why there is in the middle a drawn on gap and the elevon movements are marked either side of that, I've shown picture's with 6 mm and 12.5mm deflections. Below the tool is slipped on the engine and the elevon is in the middle. Martin with this set up it makes than very control-able and you can fly close in with another one. Of course there may be different movements on Tony's design and on the plan he's got Elevator and Aileron both at 10 mm each. Kind regards Mark Kettle. Looking forward to seeing the build results. Edited By Mark Kettle 1 on 08/10/2014 07:27:05 Edited By Mark Kettle 1 on 08/10/2014 07:28:13 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 9, 2014 Share Posted October 9, 2014 Just received four of the ten blade fans from the UK warehouse (last ones). Don`t bother, they do not fit the Dr. Madthrust units and do not even resemble the five blade fitting although they are much better quality. Now starting a ding-dong with HK to get them returned at zero cost to me. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 9, 2014 Share Posted October 9, 2014 Dennis, should it have read W1 since the plan shows a join on this? Quote Link to comment Share on other sites More sharing options...
Alan Jarvis Posted October 10, 2014 Share Posted October 10, 2014 Martin Sorry I mentioned those fan blades and put you to some trouble. I have now finished the fuselage part and moving on to the wings today. Alan Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 10, 2014 Share Posted October 10, 2014 Hi Alan, Not your fault about the blades, which HK apologise for and have agreed to take them back. Just sent them but at my cost! Still experimenting with the originals and am waiting for the glue to set on the final layer, this time 0.2mm GRP. This brings the total gap fill to 1.2mm and the blades are nearly touching the case. Now getting difficult to measure the thrust. Will post the results later. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 10, 2014 Share Posted October 10, 2014 Martin it might pay to have a read of John Ransons foray into EDF, he is very pragmatic and his findings are interesting regarding thrust and intake shape. The interesting part of the thread starts here Cheers Danny Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 10, 2014 Share Posted October 10, 2014 Danny, found the bit about the fan unit on test but nothing yet on intake percentage. Will have a further look later, thanks. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 10, 2014 Share Posted October 10, 2014 Thank you that awesome. Progress has been slow,this week. I was also caught out by the diameter of the edf units mine were a fair bit bigger than the cnc holes. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 11, 2014 Share Posted October 11, 2014 Tried a fan with the extra 0.2mm fill and it is not worth the bother so will just mod the rest with 1mm. Quote Link to comment Share on other sites More sharing options...
Colin Bernard Posted October 11, 2014 Share Posted October 11, 2014 Re Martin's comments on the EDF diameter being too big for the pre-cut holes,I found the same and it would appear that Hobbyking have changed the specification of the EDF units since Tony bought his. At the time his EDF units were 53mm outside diameter, but the ones I have, and I guess Martin too, are 54.5mm - hence the problem. Discussing this in an email conversation with Tony he pointed out that the 10 blade Dr MadThrust is still at 53mm - so if you have not bought them yet this would be the one to go for, (Product ID 9107000193). Quote Link to comment Share on other sites More sharing options...
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