siclick33

A simple problem that is driving me nuts.

I am setting up a model (Eurosport) with ball links between double horns; I'm not sure about using the supplied links as they are for 3mm rod and I'm using 4-40. I was considering using the Dubro Monster ball links but I am not sure if they will foul the horns as the control surface moves. They do come with one conical standoff washer but I would need 2 (one each side). Dubro don't seem to sell the conical washers on their own so one option would be to buy twice as many ball links as I need just to get enough washers, but that seems like a waste of money. The Kavan ball links would solve this problem but they aren't that easy to get (even in Europe) and I'm not sure how strong they are.

My question are therefore:

1. Is there a problem with Dubro Monster links fouling the control horns when used in a double horn setup?
2. If so, how do you get round this problem?
3. Are the conical washers readily available to buy without the ball links?
4. Are there any other ball links that work better the the Dubro Monster links in this setup?

Thanks,

Dieselman1220

My Feedback: (25)

Im assuming this is on a Comp arf europsport? If so why re invent the wheel? Carf gives you very good quality hardware.
3MM is slightly larger than 4-40, you can thread the 4-40 ball links on the 3mm rod if you desire. I have done it on my carf hawk and ultra flash.
Hundreds of flights with no issue.

Dave Wilshere

Just about everyone will use the perfect supplied 3mm units. Sleeve the rod with 4mm od 3mm i.d carbon tube.
Secraft do 4 40 ball links if you insist

siclick33

I would use the supplied hardware but I need it to match my imperial servo arms. I'm not too happy about using 4/40 rod with the supplied (metric) ball links.

It looks like the Secraft ball links are similar to the Dubro ones so I would still potentially have the problem of them fouling the control horns.

Dave Wilshere

Secraft comes with lots of cones. But won't work as cross bolt is 4 40 too and control horn holes are 3 mm.
So Toni Clark links are your choice they come with undersized holes for rod

Chris Nicastro

My Feedback: (3)

The diameter of the Dubro monster 4-40 link matches the radius of the control horns. When placed between the horns there is a slight amount of range of movement without the cones. The alignment of the servo and control horn should be that there is no lateral movement. When that's aligned right you don't need the cones anyway.
The smaller normal 4-40 links have more lateral range of movement when placed between control horns. For smaller control surfaces that would be fine too.

To to increase the lateral range of movement just use thin washers between the link ball and the horns on both sides. Bolt this together prior to gluing the horn in the surface so the spacing is correct.

mr_matt

My Feedback: (10)

It depends on the sweep angle and whether you want the linkage to run parallel to the slipstream.

The more the linkage is at an angle to the hinge line the more chance of fouling.

I don't like using washers to expand the clearance around the ball, I normally drill the ball out for a brass or copper spacer tube and solder it on then drill the spacer for the bolt. I use combinations of Dubro adjustable and normal plastic links