monty2 Posted January 16, 2015 Share Posted January 16, 2015 Ta Jim, sorted from what you said, took a while, as other issues came up and delayed reply. Granddaughter not involved this time. Quote Link to comment Share on other sites More sharing options...
monty2 Posted February 3, 2015 Share Posted February 3, 2015 Jim, looked at plan and my interpretation, going to the Optician tomorrow, time I relearnt how to read drawing. Apologies. Quote Link to comment Share on other sites More sharing options...
Jim Newberry - Nuviation Ltd. Posted February 5, 2015 Author Share Posted February 5, 2015 No problem Monty, I think once a plan has been identified as having a few errors, the natural reaction to anything that is unclear is to assume it's another plan fault! Glad we managed to clear it up. Jim. Quote Link to comment Share on other sites More sharing options...
Mowerman Posted February 19, 2015 Share Posted February 19, 2015 Hi Jim I have recently bent the wire for the Jocasta U/C to the drawing but leaving the ends a bit long, The ands shown seem a bit short for binding and soldering. Any chance of a photo of how you did it? Roy Quote Link to comment Share on other sites More sharing options...
Jim Newberry - Nuviation Ltd. Posted February 21, 2015 Author Share Posted February 21, 2015 Hi Mowerman, I'm struggling a bit with getting access to models to take pictures at the moment as I am in the middle of moving house and most of my models (including Jocasta) are being stored for a while but when it comes to the length of the ends for soldering, my take on it is that I like to keep them as short as I can get away with, simply for the sake of appearance. In my experience, binding with fuse wire before soldering only requires a few mm of piano wire to provide sufficient purchase. However, the process is certainly easier with a little bit more length to play with so if you leave a bit extra you won't affect the performance at all. To my eye, the inner face of the wheel should be as close as possible to the undercarriage leg, but on a model like this, ease of construction can certainly take precedence over such a minor point of appearance. Jim. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted February 22, 2015 Share Posted February 22, 2015 Hours of fun today making the undercarriage! To those of you with a well equipped workshop I guess it's easy. My first attempts ended in disaster. The metal was too thick to bend with pliers or mole grips (my usual method) so I thought I'd bend it in my vice. Again it was too thick to make the bends, so I took to tapping it over with a hammer. I'm sure you can all guess what happened; it cracked and broke! In the end I heated each bend over the gas ring and shaped it by hand, using pliers for the bends at the end of the rods while cherry red and making the main bends by hand only while keeping the rod in the flame. I found that I could make bends quite easy this way and, by over bending and easing back I could get them reasonably tight. The hard bit was not inducing twists and getting the bends in the right place! So, on my wish list is a wire bender and a blowtorch! 😊 Soldering was fun too! I think I need a bigger iron! 😊 Quote Link to comment Share on other sites More sharing options...
Mowerman Posted February 23, 2015 Share Posted February 23, 2015 Colin No No No.- Heating the wire will make the wire much too soft even when cooled . The hardness and temper (springiness) can not be re-gained so the wire will remain too soft for the job. In the past I have managed with Vice and hammer ( or getting a fellow modeller to do the bending for me) but recently bought the HK wire bender, so much easier. The HK bender is fairly basic so would not be good for coiling nose legs but for simple bends-great but you still need a vice. Edited By Mowerman on 23/02/2015 11:26:46 Edited By Mowerman on 23/02/2015 11:28:10 Quote Link to comment Share on other sites More sharing options...
Mowerman Posted February 23, 2015 Share Posted February 23, 2015 Another thing about using vice and hammer to bend wire is that you are trying to bend the wire with too sharp a bend, this will probably be the cause of cracking.All bends should have a radius of about twice the wire diameter. I think thats right but I am relying on 75 year old memory, no doubt someone younger will correct me. Quote Link to comment Share on other sites More sharing options...
monty2 Posted February 23, 2015 Share Posted February 23, 2015 You need an engineer to tell you, heating the wire to Cherry red removes all the hardening/tempering and renders it useless. get a wire bender, relatively cheap and does the job. Mind you, if you want to spend/waste al lot of time researching how, you can restore the springiness by hardening and tempering correctly. But its a waste of time and energy. Quote Link to comment Share on other sites More sharing options...
monty2 Posted February 23, 2015 Share Posted February 23, 2015 My question, as someone who has come back to the hobby after 50+years, and got far enough forward in my build to fit the aileron servos, what is the easy/ best way to set them up to achieve the recommended throws. I prefer not to do this on my tranny but would prefer to do this mechanically. Do I use a straight, cruciform or circular addition to my servos or what? Help please Quote Link to comment Share on other sites More sharing options...
Jim Newberry - Nuviation Ltd. Posted February 23, 2015 Author Share Posted February 23, 2015 Hi Monty, Back on page 5 of this thread I uploaded a couple of diagrams to help another builder understand the servo covers and while the diagrams don't directly answer your question, you may find the information contained is useful. As for getting the correct throws, I used a servo horn that had originally been cruciform but I snipped off all but one of the arms to leave just a single one. You can move the actuating rod from one hole to the next on both the servo horn and the aileron horn until you get the required throw at the aileron. Exactly which hole to use will depend on who your servos and horns are made by so the only real solution is to play around and see what works. Hope this helps, Jim. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted February 23, 2015 Share Posted February 23, 2015 I take the point about losing the tempering on the undercarriage wire. However, the only area on the wire that was heated was at the bends. This is pretty thick wire (far thicker than that on my Piper Cub of similar size). Two bends are on the stubs, which are soldered to the axle - which does have its temper. The other two bends are at the top. Once the undercarriage is screwed to the underside of the fusalarge it is essentially two triangles, which are braced at the lower end by binding and soldering the axle to the apexs. I'm pretty confident that although the bends are untempered the undercarriage will be more than up to the job. 😊 Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted February 24, 2015 Share Posted February 24, 2015 Two quick questions: I trial fitted the motor and battery today. That battery is quite a close fit (lentghways) in the bay, which means the wires are pretty close to the motor spindle, which protrudes a little behind the firewall. How did you deal with this? Any chance of an image? Secondly: I also trial fitted two servos into the fusalarge. Did you use straight arms on the servos here or round ones? If the former, were the pushrods fitted to the inside of the servos? I can't see how they would be fitted to the outside, as the servo arms would be right up against the fusalarge sides, with the servos fitted as per the plan. Or perhaps you used snakes? I've never used them myself, so wouldn't know how or where to fit them. Again, an image would be useful. 😊 Quote Link to comment Share on other sites More sharing options...
Jim Newberry - Nuviation Ltd. Posted February 25, 2015 Author Share Posted February 25, 2015 Hi Colin, I'm afraid I can't upload any images at the moment as I am in the middle of moving house today and tomorrow and everything is packed away. The servo arms are on the inboard sides of the servos, I used a pushrod for the elevator and a snake for the rudder. In my model, the snake and the pushrod crossed over in the rear of the fuselage such that the right servo fed the slot on the left side of the fuselage and vice versa. As the pushrod exits at the rear are at different heights, there should be sufficient room to allow this to happen on your model as well. I used straight servo arms. As for the motor, just make sure that the wires are secured away from the motor shaft with cable ties. If you have room, it may be possible to construct a small box to encase the shaft although on my model I didn't bother as I was happy that I had everything secured where it couldn't make contact with the shaft. There isn't much clearance but there is room for everything! Jim Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted February 25, 2015 Share Posted February 25, 2015 Thanks Jim, The explanation helps immensely. Good luck with the move. I hope everything goes smoothly for you. 😊 Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 2, 2015 Share Posted March 2, 2015 Nothing is ever simple! Today I soldered some connections onto the esc and battery. Next I put in the receiver. And that's when I hit a snag. Neither the esc plug nor the servo plugs will fit the receiver! The esc I'm using is from 4 Max and is a PP-EESC60AU and the servos are New Power XL 16HM. The receiver is spectrum. Is there an easy way around this? I did manage to test out the wiring and the motor by fitting a Futaba receiver; both the servos and the esc fitted this! I'm glad I checked things because two of the wires needed reversing as the motor was running backwards and I had to do a servo reverse. Quote Link to comment Share on other sites More sharing options...
WolstonFlyer Posted March 2, 2015 Share Posted March 2, 2015 If the Servos and ESC plug have the extra bit of plastic sticking out of one side then that is just what is known as a Futaba style servo plug, it is there to set the orientation of the plug. You just have to carefully remove it with a sharp knife or file so that it will fit in a Spektrum receiver, it is nothing to worry about. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 2, 2015 Share Posted March 2, 2015 No, these have chamfers (the same as Spektrum), but still they won't go in. It looks like I'm going to have to shave the chamfers down, but this is daunting. I don't want to mess them up. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 3, 2015 Share Posted March 3, 2015 Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 3, 2015 Share Posted March 3, 2015 These are slight changes I made to my build. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 3, 2015 Share Posted March 3, 2015 Showing how close the battery wires are too the motor spindle. Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 3, 2015 Share Posted March 3, 2015 This morning I carefully shaved down the chamfers on the the esc plug as well as the servo plugs. In addition and to be on the safe side, I also shaved the outer edges. Thankfully all the plugs now fit the receiver. 😊 Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 4, 2015 Share Posted March 4, 2015 Current progress. Nearly there! Quote Link to comment Share on other sites More sharing options...
Colin Anderson Posted March 11, 2015 Share Posted March 11, 2015 Frustrated at present. I have begun covering the framework with Solar film, but unfortunately I ran out of material before completing the job. No problem, I thought, just pop down the local model shop and get some more. However, when I got there they were out of stock of one of the colours (black), so now I'm stuck with the model only partially covered. Damn. When finished the Jocasta will be in orange and black, as they are my favourite combination. I wish they'd sell this stuff in bigger rolls; half a metre really doesn't go that far on a model this size. I don't know if it's just me, but I actually find Solarfilm slightly trickier to use than Solartex. However, having said that, it does go around curves easier and it's also easier to hide any joins. Solartex I manage to lay down without any wrinkles and it doesn't show any wood grain that it adheres to; Solarfilm on the other hand seems to wrinkle very easily and does show the wood grain. I just have to keep practicing I guess. The next issue to address is battery power. I have one 3s 3300 mAh LiPo driving a PPO 3548-1100 outrunner through a 60 A esc. This battery (a 4 Max purple power professional 40 C) cost £35; I reckon I'm going to need at least another three, so that'll be another £105, not including the postage. I'd hoped to find some slightly cheaper alternatives, but the local shop doesn't even sell this size! I'm given to understand that the one battery I do have is probably good for 12 ~ 15 minutes; as this is rather long for my present abilities (assuming I haven't forgotten everything already) I'm wondering if it might be possible to fit 3200 mAh or even 3100 mAh batteries which the local shop do sell (and which are much cheaper). Does using a battery with a lower mAh rating just mean less running time or are there other factors? Quote Link to comment Share on other sites More sharing options...
Jim Newberry - Nuviation Ltd. Posted March 11, 2015 Author Share Posted March 11, 2015 Hi Colin, Your model is looking great! You won't suffer any problems fitting a smaller capacity battery other than, obviously, the slightly reduced running time as you mentioned. If you were looking at a high performance model that needs to draw the maximum amount of current possible from a battery then reduced capacity would have an effect as the maximum current draw is the capacity of the battery multiplied by its C rating. However, Jocasta is not the sort of model that you will be thrashing around the sky at full throttle for any length of time (at least I hope not!). Best wishes, Jim. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.