Home Made Control Horns

Would some of the members who are experienced in making their own control horns share their expertise on how to do this properly? For example, are the pushrod bushings brazed in at the same time the upright is brazed to the wire? Also how do you go about queching the unit, and so on?

I am working on a Brodak Pathfinder II and I can't bring myself to use the nylon R/C type control horns that were supplied with the kit.

Sounds like a Sig kit, DO NOT use those horns.
Chris...

P.S. I buy my horns,Tom Morris, Windy, etc, sorry I have no expertise in the fabrication area.

Eggy,

Unless you are just wanting to do it for the heck of it, I would buy mine. Much more precision than the average modeler can achieve and if you value your time at all just not worth the effort, IMHO.

However, if you insist, use the low temp silver solder. Unbelievable strength and I have never had a problem with system failure. I put the bushings in first and clean them up before attaching the control arm to the horn. When complete, clean with acetone and an old toothbrush to remove any residue. I have made some in the past for older planes but quit a couple of years ago when I realized that for me it was a true case of "the law of diminishing returns" I use Tom Morris horns and systems now but there are other suppliers who also have quality products for almost any application

LAST EDITED ON Aug-02-04 AT 09:57 AM (CDT)
 
I've also used Tom and Windy's excellent control components. However, with a profile model like the Pathfinder, you are talking custom horns because the control arm is offset from center to clear the fuselage. Custom means expensive. I live in Canada and when you add currency exchange, money order & import fees plus P&H, custom horns get to be a bit pricy to say the least.

I have no problem brazing neatly with a flux coated brass rod or using high silver content "solder". I just need some tips on how/when/if to quench the horn properly, when to add the bushings etc. so that I don't wind up with something that snaps in the air because it is brittle or somthing that is too soft because of the heat from the torch.

I too live in Canada and because of the high cost of cross border shopping for most of our control line supplies am forced to be self sufficient in most of the mundane things. I make my control horns from 1/16" ground stock (01), after I shape to specification I heat to cherry red with the torch and Quench in cold water, you could use old engine oil but it usually leaves quite a bit of residue on the surface which must be removed before silver soldering. After attachment to the wire reheat the horn with the torch to a light straw colour and Quench again in the same medium that you hardened it in (Water or Oil) and it should be at the right degree of temper for use. Never had one fail yet.

jonuck