nigel newby Posted December 8, 2018 Share Posted December 8, 2018 Hi Chaps, I am now having problems connecting the throttle to the servo. I have a steel snake cable running through a plastic tube that I cannot think what it's called. Anyway there is very little room between the firewall and the carb. When I put a link on the cable, the link takes up most of the room. I therefore get very little movement. The hole coming through the firewall and the throttle lever are also not in line. Now I am wondering if I can somehow solder a rod to the snake cable. I could then put a Z bend and a swinging set in the rod, and connect all up. I have included a couple of photos to help you see the problem. |I know you chaps are good and will come up with a simple wheeze to do the job. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted December 8, 2018 Share Posted December 8, 2018 Bowden cable Nigel There is never much room You need a piano wire pushrod with a Z bend That way no connector is taking your space Then a 90° bend at the other end with a swing keeper Quote Link to comment Share on other sites More sharing options...
Colin Bernard Posted December 8, 2018 Share Posted December 8, 2018 I had a similar problem and my solution was to fit a spare servo arm on to the front of the engine bearer arm on the side of the throttle lever. The cable from the servo was attached to the arm, and a pushrod then ran back from the servo arm back to work the throttle arm. Quote Link to comment Share on other sites More sharing options...
Stearman65 Posted December 8, 2018 Share Posted December 8, 2018 Use a ball link & put the adjustment at the servo end. Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted December 8, 2018 Share Posted December 8, 2018 How about these Quote Link to comment Share on other sites More sharing options...
John Tee Posted December 8, 2018 Share Posted December 8, 2018 Nigel, DuBro due a small kit for 4 strokes to get the throttle connection. Works the same way as Colins suggestion. A lever pivoted in the centre is mounted nearer the front of the engine mount, connected to the throttle cable and a wire pushrod comes back from the other side to the throttle. Get mine from SMC in Worthing John Quote Link to comment Share on other sites More sharing options...
Paul C. Posted December 8, 2018 Share Posted December 8, 2018 Hi Nigel I had the same problem with a ASP 52 in my CAP. Along with there being little room the throttle lever moves in and out as it opens and closes, I used wire with a 90° bend to give room and allow the lever to slide. Will try to add photos. Paul. Quote Link to comment Share on other sites More sharing options...
Paul C. Posted December 8, 2018 Share Posted December 8, 2018 Photos worked for once Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
cymaz Posted December 8, 2018 Share Posted December 8, 2018 Nigel, have you tried undoing the grub screw on the throttle arm body and moving that around for adjustment? Quote Link to comment Share on other sites More sharing options...
nigel newby Posted December 8, 2018 Author Share Posted December 8, 2018 Thanks for all the great ideas. Yes Cymaz have tried that. Was ok for moving the linkage more in line but that was all. The Dubro Four Stroke throttle linkage is a great idea, but as the plane is already built will not be able to fit it now. Not quite sure on your solution Denis. The distance from the servo to the throttle is about 10 inches, there is also a drop between the two of about 2 1/2 inches, hence the Bowden cable set up. Not to sure how a ball link would work, so I think I will try Pauls suggestion but with a slight difference. I will pick up some smaller piano wire than I have at the moment so that I do not have to drill a bigger hole in the throttle arm, and use a brass collet as he has done. Then join the wire and Bowden cable together that way. A nice big Z bend should solve both the rocking and moving in and out problem.Have tried it out with a allan key and they gripped together well. It looks like it will work. If all ok should be able to solder the connection for a belt and braces approach. Will let you all know how it goes. Nigel N Quote Link to comment Share on other sites More sharing options...
nigel newby Posted December 8, 2018 Author Share Posted December 8, 2018 Just been looking at the dubro system again, and I could fit the part that connects to the throttle arm and run the wire straight through that. That should work, If I can find one small enough to go through the throttle arm. Nigel N Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
nigel newby Posted December 8, 2018 Author Share Posted December 8, 2018 Thanks for that Tom. I had moved the arm out a little to try and get it to work. Have now moved back to where it was. Cheers Percy, will see what the model shop has tomorrow morning. I don't realy think that I could fit a Dubro as I am unable to get to the engine mount with out quite a bit of work. Although I could possibly fit it to the fuselage. But I like the small connector idea. Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted December 8, 2018 Share Posted December 8, 2018 Use one of these **LINK** Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 8, 2018 Share Posted December 8, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted December 8, 2018 Share Posted December 8, 2018 Yep, I use the small ones where space is tight. Quote Link to comment Share on other sites More sharing options...
Caveman Posted December 8, 2018 Share Posted December 8, 2018 Nigel, I use the same system as the Dubro linkage shown by Percy. However, I make my own from pieces of aluminium angle. This one is a little 'Heath Robinson' and really needs re-working, but it does the job. I've just finished another one for my CAP20L which uses ball-joints and is a lot less embarrassing, but this shows the basic scheme. Note that the base angle is held in place by the engine bolts which means that no additional fixings are required. The blue 'washer' between the throttle arm and actuating rod is there to take up a bit of slack!! I would have used a ball link fixed to the throttle arm, but I didn't want to enlarge the hole in the throttle arm. Hope this is helpful. GDB Quote Link to comment Share on other sites More sharing options...
nigel newby Posted December 9, 2018 Author Share Posted December 9, 2018 You chaps are all putting me to shame!! But in my defence, I must admit I do not always have the tools or odd scraps to do the jobs like you chaps. One of the things I have noticed is that nothing seems to fit. I have had to drill out a few holes on servo arms to fit linkages etc. Can the manufacture's not get their act together and all agree on what size the holes should be. Also what size pins and rods go through them. In the case of the throttle arm, I could drill it, but there would not be much meat left on the bone after. Same with servo arms etc. Anyway on the morrow will see what treats the model shop has in store. Perhaps the cave man should make a real non Heath Robinson system using his design, that bolts down on the engine lugs and make his fortune that way. If not perhaps I will do it and make mine Ha Ha. See you all soon Nigel N Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted December 9, 2018 Share Posted December 9, 2018 You have more control with your fingers Nigel With pin drills and pin drill vice, like these Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 9, 2018 Share Posted December 9, 2018 [This posting has been removed] 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.