Andy Fox Posted October 11, 2014 Share Posted October 11, 2014 Am building a scaled up version of Tony's plan at 2m span. Plans arrived in the post on Thursday - Thanks Tony! - just need to clear the decks and get going. Build will mainly be depron, perhaps with some balsa here and there.... I'll be using 4x70mm fans .... I think there'll a lot adapting or 'a lot of making it up as I go along' if you prefer!! Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 11, 2014 Share Posted October 11, 2014 Just had a peep at these. They should certainly work well but they take twice the current (27A). Much bigger and heavier batteries and ESC`s required. Quite expensive also. Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted October 12, 2014 Author Share Posted October 12, 2014 Glad you received ok Andy....look forward to see the out come..... Apologies if I'm dropping in and out of the forum...time just seems to be slipping away from me....again Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 12, 2014 Share Posted October 12, 2014 Hi colin ye mine where 54.5mm. I got them in but I compounded the issue by building up the engine bearers before the fans arrived. I got them in but it's not pretty. on another subject how do you get the oval shape for the plastic tube to exit, don't say do it free hand! I have have bad arthritis at the old age of 36 and my hands are a bit digital. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 12, 2014 Share Posted October 12, 2014 Hi colin ye mine where 54.5mm. I got them in but I compounded the issue by building up the engine bearers before the fans arrived. I got them in but it's not pretty. on another subject how do you get the oval shape for the plastic tube to exit, don't say do it free hand! I have have bad arthritis at the old age of 36 and my hands are a bit digital. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted October 12, 2014 Share Posted October 12, 2014 I also stuck my finger to the ruder yesterday, that was interesting Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 12, 2014 Share Posted October 12, 2014 Message to the mods/Tony. There seem to be a few of us having a go at this. I am still chopping out bits of wood. Would it be better to keep all of it on this thread since a comprehensive guide has already been published or start new ones for individual builds? Quote Link to comment Share on other sites More sharing options...
Alan Jarvis Posted October 15, 2014 Share Posted October 15, 2014 The Vulcan is coming along Although the real one doesn't have afterburners I couldn't resist. I screwed up on the wing. You need to lock down on the rear spars and trailing edge and don't move it until you have the front edge and top spar in place. I am having to recut mine and redo it. Quote Link to comment Share on other sites More sharing options...
Steve Balaam Posted October 15, 2014 Share Posted October 15, 2014 Hi Vulcan builders To form a template for the jet efflux pipes look on the internet for a "Truncated Cone Calculator" There are many one example is depicted at **LINK** Hope this helps Steve B Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 19, 2014 Share Posted October 19, 2014 Anyone worked out a way to form the tubes from laminating film? I have cut a piece to the correct shape with 10mm overlap but it seems to have a mind of its own. May have to try making a balsa one then wrapping the film over this. Quote Link to comment Share on other sites More sharing options...
Steve Balaam Posted October 19, 2014 Share Posted October 19, 2014 I have used the program cone layout before to calculate the template required, I believe it will also add construction tabs to aide assembly, please look at **LINK** Another idea, when you have the template cut out would be to cut two ply/balsa discs separated the correct distant by a dowel and use this as a forming tool to construct your efflux tube around Steve B Quote Link to comment Share on other sites More sharing options...
Alan Jarvis Posted October 19, 2014 Share Posted October 19, 2014 A friend of mine cut this on his lathe made the job easy. The picture makes it look straight but it is tapered. Edited By Alan Jarvis on 19/10/2014 16:32:09 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 19, 2014 Share Posted October 19, 2014 Thanks for the replies. I think that I now have it sussed. I looked at several tubes etc. lying around, even the dining table legs! Pics of what I have come up with to follow. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 19, 2014 Share Posted October 19, 2014 I balsa tube was formed, with considerable difficulty. The laminating film was cut to size and wrapped around, initially sealing at a few spots with an iron. I then held it in place with Kapton tape, which is heat proof. The caps from R/C colours spray cans fit quite well so may use these for the nozzles. Edited By Martin McIntosh on 19/10/2014 17:32:19 Quote Link to comment Share on other sites More sharing options...
Colin Bernard Posted October 19, 2014 Share Posted October 19, 2014 Well like Martin I have spent most of today fighting the thrust tubes !! Eventually sorted it with a number of 'cunning plans'! Firstly as Martin found out, the film will fight being rolled into a tube - elastic bands sorted that out and allowed me to then adjust the diameter of each end, holding it with some Sellotape - enough to hold the diameter, but not too much to prevent the film twisting slightly to allow for adjusting the other end. A piece of tape in the middle then held it temporarily and I then marked the edge of the film overlap at each end to record the correct diameters. After marking slight angle for the EDF unit I then removed the tube and undo the tape. By joining the marks previously made this gave me a line to match the edge to when reforming the tube. I also trimmed the film to 1 cm beyond this line to give me an overlap. This took about 3 hrs to get this far with a lot of Anglo Saxon - but then using this piece as a template, I made the next tube in 10 mins - and it fitted !! Another problem I found was how to apply the tape down the length of the tube -obviously it needs pressing down to stick properly, but you cannot apply the pressure on the empty tube without the tube distorting. The solution was simple - fix with small pieces of tape as described earlier and then slip it over a broom handle when is then supported horizontally over a couple of chairs. You then have something firm to press down on! But then how to apply the tape inside the tube? You can't just drop a length of Sellotape down the tube. Again the answer was simple - take a length of tape longer than you need and with the adhesive side uppermost just reverse the two ends so the tape can stick to the broom handle. Put the tube over the broom handle, holding it clear of the Sellotape, and then position it so the inner overlap is over the tape and press. Lift clear of the broom handle and cut off the excess - job done! Edited By Colin Bernard on 19/10/2014 17:31:20 Quote Link to comment Share on other sites More sharing options...
Colin Bernard Posted October 19, 2014 Share Posted October 19, 2014 Another slight problem I had was getting the right shape for the cut-outs in the sheeted side. It obviously needed to be a parabola like shape and I was about to go and start plotting one then suddenly had a brain wave. I simply took a torch and used the shadow of the rear thrust tube supports to create a suitable shadow. The beauty of this method is that you can angle the torch to match the tube and get an angled shape. With a slight bit of fettling this worked first time ... Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 19, 2014 Share Posted October 19, 2014 Just beat you to it with a solution Colin by one minute. Quote Link to comment Share on other sites More sharing options...
Colin Bernard Posted October 19, 2014 Share Posted October 19, 2014 - teach me not to type so much! Edited By Colin Bernard on 19/10/2014 18:04:53 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 20, 2014 Share Posted October 20, 2014 Having got those nasty tubes done I have made up my version of the wiring. How to use up a lot of connectors very quickly. The four way esc set-up connector from a quad came in handy here. I decided in the end to use individual 30A ones. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 22, 2014 Share Posted October 22, 2014 Having got the fans and tubes glued in I decided on a final test while I can still get at everything. Guess what? Another motor wire had fractured, luckily at the 2mm connector end. This was again due to the enamel having been stripped too far back during manufacture resulting in the solder running a long way up causing the wire to become brittle. I have now run UHU POR round the wires as they exit the tube and shall secure them all together to spread any load. I initially tacked the motors and tubes with POR then flooded everything with aliphatic but since this does not adhere to the motor casings very well I have added some Evostick. Catch up time now with you cnc builders. Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted October 22, 2014 Share Posted October 22, 2014 Hi Martin Not doing this build but watching from the sidelines.. but can I ask why you ditched the idea of the 4 way ESC in favour of 4 individual ones? I would have thought that would have save a few grams....... Quote Link to comment Share on other sites More sharing options...
CK Posted October 22, 2014 Share Posted October 22, 2014 hi, I'm new but thought I would show you guy's my progress. also if anyone could help I'm planning on using 4 esc's two central fans paired with one battery and two paired with the outer's . my question would be connecting to the receiver, would I leave just 1 power wire from one esc then y lead them down to the receiver but if I lost power from that esc then I would lose everything or can I leave 1 power from each pair connected or is there another way. hope that makes sense cheers............ Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 22, 2014 Share Posted October 22, 2014 Dave, Hi. Thanks for your interest. We may tempt you into building one yet! After toying with the idea of using a quad ESC I heard about the ten blade replacement fans which if they had fitted would have drawn a lot more current so I ordered 30A units. They were incompatible and have been sent back, leaving me with the four ESC`s -------. I have been trying to save weight elsewhere to compensate, i.e. by substituting some of the ply with balsa where I see fit as I am not using the CNC pack. The ESC`s are a little heavier than the 20A ones but not too much. Meantime I have been looking at some computer cooling units which are cheap and have much more rigid seven blades fitted. These are of a similar size and design to the Dr. Madthrust blades but I did not have four the same so will just go with what I have got. Edited By Martin McIntosh on 22/10/2014 17:58:20 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted October 22, 2014 Share Posted October 22, 2014 Hi CK, That is looking great but I am not quite with you on this. It looks to have only two visible fans which could only be powered by two ESC`s but I could be wrong here. You definitely cannot use more than one ESC to power the Rx. and servos as per a quad set-up. At the end of the day it is no different to a single engine model with one ESC. Quote Link to comment Share on other sites More sharing options...
CK Posted October 22, 2014 Share Posted October 22, 2014 sorry there are four, so if I leave one power from one esc then just y lead them down from 4-2-1 that should be ok. Edited By CK on 22/10/2014 18:26:11 Quote Link to comment Share on other sites More sharing options...
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