txaggie08

I really don't like the awkward angle this control horn moves at on my tiger 60. Lots of up and down movement that make for an out of square linkage setup and awkward angles......



I have some 4-40 threaded ball links, could I just install one of those onto the existing horn? I've never used them as end points on control linkages like this.....

Campgems

You probably don't need #4 ball links, the #2 will do the trick, IF you attach them to proper pushrod. I like to get Carbon Fiber tubing that has a center hole that a #2 screw will not quite fit. I run a tap into the tubing for about 1/2 inch and then clean the short threaded rod and smear some epoxy in the CF tub and screw the rod in, leaving working room. Be careful your ID isn't to small as the CF will split with the tap vs cutting some very shallow threads.

The holes in the standard servo horns at smaller than a #2. I run a tap through the correct hole and the I put a flat washer under the socket head screw and screw the ball link down. Now a drop of thread locs and a nut from the other side.


Don

txaggie08

All the hardware with this plane is 4-40 already.

w8ye

My Feedback: (16)

Be sure and use the ball links like shown in the picture and not the snap on white ones. The white ones will snap off just like they snapped on.

For others reading this this is the kind not to use on control surfaces
http://www3.towerhobbies.com/cgi-bin...?&I=LXK093&P=7

Use the heavy duty kind

Edited to add URL to the kind of ball link not to use

txaggie08

Yeah these are du-bro ones just as pictured


I learned a long time ago to not by crappy hardware... poor pedro, may he rest in pieces.....

Thumbsticks

I'm also looking to beef up the rudder servo control rod on my Reactor from the stock 2-56 to a carbon fiber 4-40 setup. Campgems, can you possibly give the part number or the ID & OD size of the carbon fiber tubing you use? Again, is it simply a matter of tapping 2-56 and epoxy glueing a piece of 2-56 or 4-40 threaded rod?? Is 5 minute epoxy OK or JB Weld??
I've looked and looked to find a way to upsize to 4-40, I can find and have purchased the Dubro ball links and the Kwik links, but the 4-40 threaded rod (one end) is too small of a dia to put a thread on the opposite end....so I need to convert to carbon tubeing.
Thank you very much in advance.

Campgems

One word of cation with these ball links though. Measure the depth of the hole in the ball link for the link rod. Figure 1/2 that depth for the threaded end. IF you try to go full length, you stand a very good chance to roll the threads in the plastic link. It's hard to tell when you have bottomed out the thread and are slipping a thread. There isn't a positive stop. I was adjusting one in and after a number of turns past where I needed just a bit shorter conection, I found I was just spinning in the hole. There wasn't any noticable difference in the torque required to make another turn, so I though I was making progress, not screwing up the linkage.

Also notice that Im using the Robart ball link horns. The metal clevis on these guys are roll threaded to a very tight thread. You have to get at least 3/4 thread into the clevis before it starts to loosen up. By loosen up, I mean not cutting metal as you screw in the rod. This is one complaint I have for the Robart stuff. The #2 links are the worst. The # 4 ones don't give you much problem. I've taken to using a #2-56 gun tap and cutting the clevis threads deeper. Even then, you have a very tight friction fit. When you couple this with the plastic in the ball link slipping a thread when close to bottom, you end up with a linkage that is hard to adjust and may under a lot of stress slip a thread. Not likely the later, but the hard to adjust is a given. About the only thing worse than this setup is not using it. Nothing better that I know of though. Just be aware of potential problems and go from there.

Don

snacker

I use CF from Midwest .188"ODx116" IDx24" Stock #5722 avaliable from Tower I believe. JB Kwik set and Dubro 4-40 ALL threaded rod. Same links you use Thumbsticks. Works great, lightweight and no flex.


http://www3.towerhobbies.com/cgi-bin...?&I=LXJDP9&P=7

Campgems

I just picked up a couple pieces of Carbon fiber at the LHS. On the # 2 size, you can find one that a threaded on one end and the smooth end just fits the carbon fiber tube. Cut it so about 3/4" of the rod fits into the CF tube. I then use my 80 grit diamond grinding wheel and kiss the smoth part of the rod to roughen it up. Just a light touch to make it rough. Then epoxy it in, without cutting threads. Just make sure the ID of the carbon fiber and the rod are free of any oil, IE from you fingers..Clean it with alcohol, then epoxy. % minute is good. One thing to watch for, if you have a very tight fit between the rod and the tube, when you apply the epoxy and then push the rod in, there is some air trapped. When the epoxy starts to kick off, it heats up. The air expands and tries to push the rod out of the tube. A bit of blue masing tape wrapped around th end will hold it in place until the epoxy kicks off. Once it sets, the problem goes away. There is more than one way to get the job done. This is just one.

Don

Villa

When I used these carbon rods to make push/pull rods I found that the rods could split at the ends during a crash or rough handling. The split was at the end where the steel threaded rod was inserted. I'm not certain, but I believe these carbon rods do not have carbon thread wrapped circumferentially. The ends can "burst easily". I now wrap the ends with sewing thread and epoxy the sewing thread.

Thumbsticks

Snacker, Campgems and Villa, thank you all very much. I can now move on...I actually was stuck on this carbon fiber rod issue but had other build actions to take care. Snacker thanks for letting me know where to obtain the pieces.

Yub, yub, cmdr!

If you use ball links, take a cigarette lighter and heat up the links while pinching it with pliers. This will make them slop-free and basically impossible to snap off accidentally.