Tony F Posted February 8, 2014 Share Posted February 8, 2014 OK So I'm getting my models ready for Mojo to return and am still fiddling...I would love some help on this little problem please = My A1 Skyraider Foamie. I have wire's set up for the tailwheel movement and find these very poor...keep getting caught up even though they are taut. They go through the airframe and seem to get hung up all the time. What other way can I use other than those flimsy wire's ? As you can see the tailwheel has it's own servo for retraction but when retracted the wire always get's caught. I would prefer something solid wire like ??? Any ideas please ? Tony Quote Link to comment Share on other sites More sharing options...
GrahamC Posted February 8, 2014 Share Posted February 8, 2014 What about.... Running them through a piece of plastic straw or snake outer just in front of the retract unit. The straws might need to mount on a piece of ply or something. It might even be possible to fix the tube to the fuselage side. I'm presuming the wire gets caught around the tail wheel? That would mean that they would only have a very short run, and therefore much less play in the area where they are vulnerable. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Cheers Graham...Good idea for the rear but it seems to happen from the full length...servo to linkage....was hoping to replace the whole thing...maybe cutting the foam open....putting another servo down the rear with a shorter link ? Might work but I don't fancy butchering my plane Tony Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Nope forget that idea...see in pic 2 the rudder is shoehorned onto the same servo as the wheel. Tony Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 Do I take it that the wires are going slack when you retract the tail wheel. If that is the case, I would try and introduce a couple of light springs at the steering servo end and when the tailwheel is retracted, set the springs to the minimum tension that will keep the wires reasonably taut, then when the wheel is lowered, there will be more tension applied by the light springs, which should help to avoid the wires getting caught up. The previous suggestion of running the wires through plastic straws will also assist the smooth operation of your steering. something like springs from a biro or springs from a steerable tailwheel set. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Hmmm cheers Handyman....can you think of any other way to do things not using the wire ? Tony Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 8, 2014 Share Posted February 8, 2014 Presumably the problem you have Tony is that in the retracted position the distance between the servo and the steering arm is shorter than when the wheel is deployed? This means that you can't use any sort of rigid linkage, like a rod, or the tail-wheel will be unable to retract because it can't compress the rod. Wires are the classic solution here - because they offer no resistance to compression - they'll fold - but they resist tension - they won't stretch. I really can't see a better solution than Handyman's with the springs. Unless you do away with the steerable tail-wheel all together and just make it castor? Then you don't need the wires! Works fine on most models. BEB Edited By Biggles' Elder Brother - Moderator on 08/02/2014 14:05:52 Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 I used to do some Fly fishing some years ago and I kept a few yards of fly line, the fluorescent type which had quite a good breaking strain, 7lbs I think. I have used that quite successfully for closed loop rudders in the past, but you still need to maintain some tension throughout the retract operation. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 OK guys thanks for the input...I'll try with the wire option, springs and straws...see how it goes... Tony Edited By Tony F on 08/02/2014 14:16:49 Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 8, 2014 Share Posted February 8, 2014 Fishing trace has my vote everytime - cheaper than the 'closed loop wire' you get online or at LMS. Route it with snake outers if you can. So good to see your mojo has made a welcome return!! Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Easy Stevo... Tinkering is back because I've put these jobs off for ages...only flown this beast once lol.....errr what's snake outers mate ? Tony Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 8, 2014 Share Posted February 8, 2014 These - **LINK** Or buy the larger ones, and use the inners, as they hav an i.d. of just under 2mm ! Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 OK I feed the fish line through the outers yeah ? Then connect line as before to the servo and the other end at the tailwheel ? Tony Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 8, 2014 Share Posted February 8, 2014 I use these if there is no direct route between servo and horn.. it does help thread then throug the airframe. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Cheers Stevo.....snakes ordered Tony Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 Hi Tony, another Tony here. After having a closer look at your tail wheel steering problem, I noticed that you had a crimp on the one side and what looks like just a knot on the other side. Your crimp could be a major problem here, with it being so large, it will obviously catch somewhere during its operation, "Sod's" law says it will happen. If you got rid of the crimp from that end of the model, perhaps double up the operating wire and bring the crimps near to the steering servo where there is more space. then some plastic snake outer, glued to the sides of the retract servo housing, should keep those wire from fouling up. There does not have to be a straight run of wire from the other servo to the steering horns for it to operate smoothly. But I still maintain that two small springs at the steering servo end, will remove the problem of wires going slack and fouling up. Tony B. Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 It would work the same if you used fishing line, although I think that Stevo is referring to plastic covered fishing trace wire here. When I used the fly fishing line, I doubled it back through the servo horn and used some small diameter heat shrink tube along with a small squirt of super glue, then an application of heat to shrink the tube and you have a strong flexible connection which should work very smoothly. I tend to used 3mm strimmer cord on a lot of my models with a Kwik link adapter super glued on the ends and then give the adapter a light crimping with some side cutting pliers. Never had one pull out in 20 years of flying. Tony B Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Hi Tony....crimp fell off when testing model...couldn't re crimp it so just tied a knot on that side. When the tail wheel is retracted I seem to get a large amount of "slop" and moving the rudder servo that's when the wire fouls. I'll try some springs when I can get some and post here with a new picture so you can advise. "just seen your follow up post....this is why I only had one flight because nerves got hold after rudder froze in flight with the fouling" Tony Edited By Tony F on 08/02/2014 16:41:58 Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 Tony, when this blessed rain and wind eases up, I will go and have a look in my shed. I seem to remember a pair of ideal springs hanging around in my bit box. If I can find them, and if I can lay my hands on the fly fishing line, I will make a mock up so that you can see what I am talking about. I will then let you know and you can PM me your address and I will put them in the post, if that's ok with you. Tony B. Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 Just a thought, before you remove the old wires, and in case of any problems fitting the new stuff, use the old wires to pull the new ones into place. Just a tip from a 73 years old modeller. Always try and find the easy solution!!!!!. Hee,hee,hee. Tony B. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Lol nice one Tony....If it's ok with you I'll wait to see the mock up before my ham fists get in there !!!! You are a gent and a scholar Sir Tony Quote Link to comment Share on other sites More sharing options...
Handyman Posted February 8, 2014 Share Posted February 8, 2014 Hi again Tony. Been to the shed and found some springs that will show what I was getting at. They are too short for your aircraft, but ideally you need springs about 4-5 cms long or in old money,1.5 to 2 inches long, close wound. I will make up the example tomorrow. If you PM me your address, I will get it off to you on Monday. I will include a good length of the fly line that I have used on several models and a sample of the heat shrink tube that I use when I join the line together. Heat shrink tube from Maplins. Cheers...Tony B. Quote Link to comment Share on other sites More sharing options...
Tony F Posted February 8, 2014 Author Share Posted February 8, 2014 Thank you Tony, your very kind !! pm on the way.Tony F Quote Link to comment Share on other sites More sharing options...
Tony F Posted March 17, 2014 Author Share Posted March 17, 2014 Hi Handyman...sorry it's a bit late.....but here is the fix you sent me and safely inserted in my Skyraider.... Once again....many thanks....works a treat now. Tony Quote Link to comment Share on other sites More sharing options...
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