Need a ball link for a Great Planes PT-40 MKII (must fit the control rod that came with the plane) the great planes ball links come in two sizes 1/16” and 2-56 does anyone know the one I need?

What's it for? (purpose.. you alerady said the plane)

CGr

Hey CG did you hear anything about your trip to the south. Tenn/Ky ??

Throttle linkage for my Evolution .46NT

Hi Gene. No yet. We had a meeting late on Friday I think it was, and there is a problem with our timing. We are still working it out. There is an air-show scheeduled for SDF (Louisville) plus the Derby and it's their busy time. I should know more this week.

I took at the manual for the PT-40. It just says ball link. I would have to assume it's a 2-56 size, which would make sense for that size plane. It would not be smaller because it would become non-standard with the rest of the linkage and they just wouldn't do that. So, I would have to assume 2-56.

CGr.

I use a z-bend on the throttle... not chance of it coming off... but you need a stright bind free connection.

The almighty z-bend. Hopefully you don't use that on the throttle arm at the carb, unless the thottle arm is plastic. Most carbs have metal throttle arms. You don't want a metal to metal contact, such as a control rod touching a throttle arm. You are asking for radio problems.

This is an easy question. Both Nylon ball links fit a 2-56 rod. The difference between the 1/16" and 2-56 is the threaded part on the metal Ball. If you are using it on the throttle arm i would use the 1/16". The 2-56 being a bigger diameter than 1/16 would require you to drill out the throttle arm.

D

Good point. I didn't realize that there was a 1/16" size, I've just bought the 2-56 and drilled out the hole. I guess I just assumed that the ball links only came in what size I get. Live and learn. Either way, the manual just says "ball link" without specifying a size.

I think I will just getboth they are under $2.00 each
thank's

Glad we could help.

❏ 7. Once you have finished setting up the nose wheel
steering, snap the nylon retainer on the connector under
the servo horn. Remove the 4-40 screw, then reinstall it
with thread locking compound and tighten it down. Cut off
the excess wire, leaving about 1/2" sticking out of the
connector.
❏ 8. Snap the nylon ball link at the front of the throttle
pushrod onto the metal ball previously installed on the
carburetor arm. Pull the throttle control stick and trim lever
on your transmitter to the fully “back” or closed position.
❏ 9. See the photo at step 4, then insert the pushrod
through the Screw-Lock Pushrod Connector if you haven’t
already done so. Install the horn on the servo so it points
toward the tail of the model at about a 30-degree angle as
shown.
❏ 10. Pull the throttle pushrod toward the tail to fully close
the throttle. Install a 4-40 x 1/8" socket head screw in the
connector and tighten it. Move the throttle trim lever and
watch the carburetor to see if it opens slightly. If the servo
does not move (just sits there buzzing), flip the “Servo
Reversing Switch” on your transmitter. Open the throttle all
the way with the main control stick. If the throttle opens all
the way but the pushrod bends (or the servo buzzes), move
the connector one hole in toward the center of the servo
horn
wattmeter

❏ 7. Install a threaded ball stud in the bottom hole of the
carburetor arm of your engine and secure it with a 0-80 nut
and a drop of epoxy or thread locking compound. Fasten
the engine to the mount with four #4 x 5/8" screws
included in this kit (or your 4-40 screws). Hint: Add a drop
of household oil to the #4 sheet metal screws to make them
easier to screw into the mount.
Here is the proper post for the ball link,got out of manual.
I 'm building the same plane.
wattmeter

That way you will have a spare if you ever need it, and you probably will. Put it somewhere you will remember where it is.. Why do I say that?? Guess.