Shaun Walsh Posted March 1, 2022 Share Posted March 1, 2022 7 minutes ago, Shaun Walsh said: Would a couple of Hacker 10-7L motors fit if they were front mounted rather than rear mounted, 21mm diameter? Hacker motor Presuming you are using a 2S battery Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 1, 2022 Author Share Posted March 1, 2022 2 hours ago, Shaun Walsh said: Presuming you are using a 2S battery Hi, not sure the relevance of the 2S battery question, but yes that's the primary option although others have used 3S and the 4Max kit can do either. As for the space, previous photo looks like the motor will go it although the mount might be a bit tight If the worse comes to the worse, I'll trim the X mount down and fix the screws with a smaller PCD as I'll only be scale flying I doubt they will pull out of ply. PS I thing the Hacker will be an even harder choice due to the lack of space in the front of the nacelle Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted March 1, 2022 Share Posted March 1, 2022 Yes, make a smaller x-mount if you need to, there is quite a bit of space before you hit the motor. In the extreme, bolt the motor from behind directly to a bulkhead. That would need access from the rear but might be possible. 1 Quote Link to comment Share on other sites More sharing options...
michael harper 2 Posted March 1, 2022 Share Posted March 1, 2022 I think if you mount it as a X, you need to move top two mounting holes about 4mm in and cut arms to suit to clear inside of cowl. Bottom two might be ok. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted March 2, 2022 Share Posted March 2, 2022 Chris I appreciate you already have the motors but a small diameter is one advantage of the "drum "mount as used by Emax. It is the same diameter as the motor bell,28 mm in this case, but you do have to ensure those little grub screws either side are tight. Quote Link to comment Share on other sites More sharing options...
DaveyP Posted March 2, 2022 Share Posted March 2, 2022 I've used that motor in one of my models, I replaced the grub screws with small bolts from Modelfixings. Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 2, 2022 Share Posted March 2, 2022 I'm a bit late answering the question about the fuselage stringers but I believe they are supposed to be glued on the outside of the basic frame. The Tiger Moth has a single wooden strip on each side (and the bottom rear) of the fuselage, it gives the fuselage some section but I think their main job is to raise the fabric covering off the steel tubing and fittings (stopping holes caused through fretting). The Piper PA-25 Pawnee has the same feature. I think the DH.89 is the same as I saw an uncovered fuselage under restoration which appeared to be a ply box with stringers running outside. You can simply add a stringer over the cut ones. Some piccies: 1. Our Tiger Moth, the wooden stringer (painted green) is within the red ringed area (just below the pitch trim control rod). The upright and diagonal members are steel tube. 2. My Hacker Tiger Moth (CO2). The model as designed doesn't have the stringers but I will add them (when I eventually get round to finishing it). Stringer is just taped on here and is a bit oversize. Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted March 2, 2022 Share Posted March 2, 2022 Found a photo that will help (from Wikimedia Commons). Two more Tiger Moths, both Flair, the stringer is running through the centre of the registration on the big one. The small model is the rubber powered kit, converted to electric. It has the side stringers on the plan but leaves off the lower rear one. Quote Link to comment Share on other sites More sharing options...
Ian Lauder Posted March 3, 2022 Share Posted March 3, 2022 I received the hardware from 4-Max and George included a programming card that I had not heard of before. He says it is important to set the “Low Voltage Cut Off” level to the lowest. Failure to do so could result in one ESC cutting power to one motor which would then make your model uncontrollable under power should the battery voltage drop too much. I am not at all sure what to do with it and it came with no instructions. Does any of you have experience of using such a card? Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted March 4, 2022 Share Posted March 4, 2022 Hope this helps as a start. How to setup a 4M-ESC.pdf Steve Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 4, 2022 Author Share Posted March 4, 2022 11 hours ago, Ian Lauder said: I received the hardware from 4-Max and George included a programming card that I had not heard of before. He says it is important to set the “Low Voltage Cut Off” level to the lowest. Failure to do so could result in one ESC cutting power to one motor which would then make your model uncontrollable under power should the battery voltage drop too much. I am not at all sure what to do with it and it came with no instructions. Does any of you have experience of using such a card? There is a guide on the 4-Max web site and I'll set mine up and detail a how to guide for you. PS it is a case of plug and play and so much better that trying how to do/screw it up with the TX! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted March 4, 2022 Share Posted March 4, 2022 Ian With a twin that cannot fly on one the best advice is to simply stay well clear of the ESC LVC point. In other words keep the flights short and record how long they were. The safest way to judge how much capacity you have used is to note how many mAh you have to put in to restore the battery to full. I would suggest a flight duration that ended up using using about 60% of its nominal capacity should be safe and keep the voltage clear of the LVC. It is what I do with my Bombardier airliner twin. I could set up the Tx to arrange that one motor could be cut 'on demand' so I could actually find out, at a safe altitude, if it it is controllable but so far I have not plucked up the courage to do it. ? Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 4, 2022 Author Share Posted March 4, 2022 40 minutes ago, Simon Chaddock said: Ian With a twin that cannot fly on one the best advice is to simply stay well clear of the ESC LVC point. In other words keep the flights short and record how long they were. The safest way to judge how much capacity you have used is to note how many mAh you have to put in to restore the battery to full. I would suggest a flight duration that ended up using using about 60% of its nominal capacity should be safe and keep the voltage clear of the LVC. It is what I do with my Bombardier airliner twin. I could set up the Tx to arrange that one motor could be cut 'on demand' so I could actually find out, at a safe altitude, if it it is controllable but so far I have not plucked up the courage to do it. ? I would not suggest trying spin recovery with this model from what I have found there is very little information on the subject + due to its size and construction I would say there would be undue stress and resultant catastrophic failure of the airframe if it was repeated frequently. Pick another twin to play with. Second point ESC LVC can be encountered in more ways than just duration as high load even on a fully charged battery can occur. It depends on the battery capacity, C rating and load imposed. That's why George suggests that the setting is moved as low as possible. I noted that an earlier post mentioned running on 3S as 2S didn't give the performance they wanted. Its worth remembering (for me anyway) that adding weight is not an option so going 3S would impose a reduction in battery capacity to achieve the same AUW and I'll stick with Georges suggestion for now. Thanks for peoples advice, but please keep it relevant to this build, cheers Quote Link to comment Share on other sites More sharing options...
Ian Lauder Posted March 5, 2022 Share Posted March 5, 2022 Thanks for the info and advice. I shall try to figure it all out when I have got closer to finishing the Rapide. The tiny servos for the ailerons that I received do fit easily into the end of the wings just behind the aileron so i shall give that a go. Quote Link to comment Share on other sites More sharing options...
Rapide Posted February 28, 2023 Share Posted February 28, 2023 I posted on another Rapide thread as I could not log on for some reason and have rejoined. User name and password are different but I am still Ian Lauder! After a long break to join a club and learn how to fly RC and build a Super 60 - I have returned to the Dumas Rapide build and am stuck at the engine mounting stage. George at 4-Max sold me a bundle of hardware that he recommends for this kit and it included two 2 x PPOM-2314-2400 Brushless Motors which have a mounting cross to be fixed to the rear of the motor. Offering them to the plan, they seem to just fit inside the outline of the cowl as previous posters have shown here, but I have to construct a firewall to bolt the cross to. Has anyone mastered this and can suggest the best way to do it whilst saving weight? Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted February 28, 2023 Author Share Posted February 28, 2023 Hi, My build has stalled although I will get it off the sideboard and have a look as I have the same 4Max kit. I think it will be a case of mocking something up, posting here and seeing if anyone else has a better idea although that's the point of forums like this ! 😉 Unless someone else has done it.... Quote Link to comment Share on other sites More sharing options...
michael harper 2 Posted February 28, 2023 Share Posted February 28, 2023 There's a thread on RCGroups.com about fitting a brushless motor in this kit. Might be some use. Thread is by captainborg. Quote Link to comment Share on other sites More sharing options...
Rapide Posted March 8, 2023 Share Posted March 8, 2023 That was really useful. Answered my query and other questions that I didn't know I needed to ask ....... Quote Link to comment Share on other sites More sharing options...
Nick James Posted March 30, 2023 Share Posted March 30, 2023 (edited) This is an interesting thread. My own build of the Dragon Rapide stalled a few years ago, one reason being the motor mounting. I stumbled across these , I think on ebay. There seems to be plenty of room in the cowl to allow for the dropped engine bearer to fit.... Edited March 30, 2023 by Nick James Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 30, 2023 Author Share Posted March 30, 2023 Thanks Nick and an interesting option, once I get back to it at some point. Looking at mine IIRC its tight between the ali motor mount (outside fixing holes) and the cowl so I was going to see if I could get a clubmate to 3D print something that the motor mounts to and sits directly against the existing bulkhead. The challenge will be strength at min weight, but he does like a tricky problem to solve! Quote Link to comment Share on other sites More sharing options...
Nick James Posted March 30, 2023 Share Posted March 30, 2023 Hi Chris - I spent ages (probably weeks on and off) trying to work out how to fit it using the X mount supplied with the motor. I came to the conclusion that it will only fit if the outer holes are clipped off - but then you're left with nothing to attach it to the plane. Quote Link to comment Share on other sites More sharing options...
Nick James Posted April 27, 2023 Share Posted April 27, 2023 I have 3d printed an engine mount for my build. I have omitted the mounting holes as they are too difficult to get exact so I'll drill them instead. May only be able to use 3 of the mounting holes . Feel free to try it. Engine_Mount_no_Holes_2mmBase.gcode Engine_Mount_no_Holes_2mmBase.stl Quote Link to comment Share on other sites More sharing options...
Rapide Posted December 26, 2023 Share Posted December 26, 2023 Hello after a long gap. So I learnt to fly again (after 50 years, and that was single channel) and as its 2 Christmas's since I started the Rapide kit, and the weather is lousy, I am determined to complete the model. I have mounted the motors (what a time consuming task that was), installed the servos/receiver and started to cover the tail fin. Unfortunately as the covering shrank it pulled the fragile rounded top down so I had to take off the covering and strengthen the balsa top curve. I am expecting similar problems with other fragile parts. I am about to work out how to secure the tube through which the elevator wire runs so that it is not flopping about inside the fuselage. Any tips are welcome. I bet those in the Holy lands and Ukraine wish they only had these problems! Happy Christmas. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted December 26, 2023 Share Posted December 26, 2023 (edited) Hi Rapide. The tubes for control rods can be a so and so to fix as few if any adhesives will stick to them. I wrap the ends and any midway support areas with masking tape applied firmly and then lightly coated with cyano to prevent the adhesive drying out. Just one or two winds. Then once ibstalled through the supports or the side of fuz just apply a drop of cyano and jobs done. Provided both ends are fixed securely then the control will be sound. Thr middle support if used doesnt have to be glued, just supported so as to take load off the end fixings. Same applies to control snakes on bigger models. Good luck with build. Edited December 26, 2023 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Rapide Posted December 27, 2023 Share Posted December 27, 2023 Thankyou ED. Will try it today. Quote Link to comment Share on other sites More sharing options...
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