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Building Tips and technical articles. => Building techniques => Topic started by: proparc on July 28, 2012, 12:36:55 AM

Title: Ball Links
Post by: proparc on July 28, 2012, 12:36:55 AM
What size and brand of ball links are you using in your stunter.
Title: Re: Ball Links
Post by: john e. holliday on July 28, 2012, 10:01:40 AM
I myself use the 4-40 size ball links and rods.   H^^
Title: Re: Ball Links
Post by: proparc on July 28, 2012, 10:35:19 AM
John, what brand?
Title: Re: Ball Links
Post by: Bill Little on July 28, 2012, 10:48:34 AM
I get the 4-40 size from Tom Morris.

BIG Bear
RNMM/AMM
Title: Re: Ball Links
Post by: Avaiojet on July 28, 2012, 01:31:31 PM
Tom Morris
256-820-1983
ctmorris@cableone.net

Charles
Title: Re: Ball Links
Post by: Dick Pacini on July 28, 2012, 06:25:03 PM
Dubro has some nice ones.

http://www.dubro.com/bulk/ball_links5.shtml
Title: Re: Ball Links
Post by: steven yampolsky on August 06, 2012, 10:08:28 AM
I've been using Central Hobbies for all my linkage needs. 2-56 thread for models below 600sq in size. 4-40 for anything above.

http://www.centralhobbies.com/control_linkage/link00.htm

If you want fancy, they sell titanium ends which save weight.
http://www.centralhobbies.com/control_linkage/pushrod3.htm

Their carry amazing stuff like ball linkages that are using real ball bearings! Talk about low friction and zero play!
http://www.centralhobbies.com/control_linkage/rodendadjuster.htm

On top of linkages, they have decent prices on 50mm(2in) Tetra aluminum wheels
http://www.centralhobbies.com/landing_gear/wheels.html

Title: Re: Ball Links
Post by: Howard Rush on August 06, 2012, 12:48:45 PM
I stopped by Central Hobbies on the way to the Nats.  It's in Billings, Montana. I got some metal ball link assemblies, and I got one with a ceramic ball.  I don't know what to do with them, but I'm thinking the metal sets might be good on a control handle. 
Title: Re: Ball Links
Post by: Trostle on August 06, 2012, 02:25:06 PM

(Clip)

Their carry amazing stuff like ball linkages that are using real ball bearings! Talk about low friction and zero play!
http://www.centralhobbies.com/control_linkage/rodendadjuster.htm

(Clip)


Those ball bearing ball links look really neat and the idea is great.  The problem is that they do not hold up well to the vibration and loads we expect of them in our CLPA models.  If you want to try them, fine, but I will not put them in a stunt model.

Keith
Title: Re: Ball Links
Post by: proparc on August 06, 2012, 02:41:18 PM
Keith Trostle,

Could you give me a little more detail as to the nature of the ball link failure in your Chizler,(I hope it wasn't the white and red one).
Title: Re: Ball Links
Post by: Trostle on August 06, 2012, 03:50:44 PM
Keith Trostle,

Could you give me a little more detail as to the nature of the ball link failure in your Chizler,(I hope it wasn't the white and red one).

Itwas NOT the ball link that failed.  I just did not have enough threads on the coupler into the ball link cap.  In my adjustment of the elevator trim, there were not enough threads to keep the coupler connected and on an outside turn, the pushrodd let go of the ball link cap.  (I use the titanium ball links from the race car counter and the caps that come with those.  They are bigger and sturdier than the midium DuBro Ball links but not as large as the DuBro heavy duty ball links.)  I think I am very carefull about this kind of detail, but that is a failure that was just plain my fault.  (Same system/items exactly as on my 12+ year old Bearcat with 1,000+ flights.  That Chizler lasted less than one month and maybe 25 flights.)

Keith
Title: Re: Ball Links
Post by: proparc on August 06, 2012, 04:37:31 PM
I just did not have enough threads on the coupler into the ball link cap.  In my adjustment of the elevator trim, there were not enough threads to keep the coupler connected and on an outside turn, the pushrodd let go of the ball link cap. 
Keith

Was this a 4-40 or 2-56 coupler?
Title: Re: Ball Links
Post by: Trostle on August 06, 2012, 06:38:03 PM
Was this a 4-40 or 2-56 coupler?

Actually, I use 3mm couplers that come from the titanium tie rods the race car guys use.  This gives me the reverse threads on each end of the pushrod so that adjustments to elevator trim can be made without diconnecting the ball link.  These are compatible with the race car ball link caps that are larger than the DuBro things.  Also, this allows very small adjustments to that elevator trim when a full turn on the coupler is way too much once I start getting the elevator trim to where I want it.

Keith