TC-22 How to clean shot pin mechanism?

[MetalicGlow]

I have a TC-22 1996 with transmission. The shot pin sticks while changing gears causing the shot pin time out.

Where is it located, and how does one go about cleaning it? Can it be done without removing the motor and/or transmission, or is the mechanism located within the trans itself?

[cncbpt]

I was told to use Marvel Mystery oil in the air mist unit for the shot pin to help it operate smoothly.
May be worth a try for you.
Somewhere in my files I have a service bulletin That George(Machintek)
sent me on how to service the shot pin and transmission
Will take some digging but can find it if it will help you
You can see the shot pin cylinder on the lower right side of the transmission
with the 2 airlines going to it
Never had mine out but does also stick at times

[MetalicGlow]

Originally Posted by cncbpt I was told to use Marvel Mystery oil in the air mist unit for the shot pin to help it operate smoothly. May be worth a try for you. Somewhere in my files I have a service bulletin That George(Machintek) sent me on how to service the shot pin and transmission Will take some digging but can find it if it will help you You can see the shot pin cylinder on the lower right side of the transmission with the 2 airlines going to it Never had mine out but does also stick at times

About a month ago, I ran Mystery oil through the lines and even flooded it manually at over pressure to try to free the mechanism and it did not seem to help at all. Right now, I am running all part programs below 1800 RPM because it won't shift. I need to somehow get into it physically and clean it up.

I guess I could remove the mechanism mounted on the side of the transmission and clean it without any further invasive disassembly?

I remember George posting about the transmission oil going bad and turning into thick sludge and causing this problem. If I remove the mechanism from the side of the transmission, will that expose the transmission oil thus, leaking it out?

Thanks for the response.

[machintek]

The transmission has two plates, top and bottom that sandwich two shafts with gears. The bottom plate has a holes for the shot pin. The top plate perimeter has teeth machined into the perimeter so it can be turned thus engaging either gear cluster. The turning is accomplished by a "rotac" which is air driven and has orifices to regulate at which speed it turns. When in place it is locked by the shot pin. The shot pin is also air driven but I believe that there is only one air line to it to pull the pin out and a spring to engage it. The rotac has 2 air lines. All positions are verified by switches which can be seen in the maintenance page. (As well as commands to the solenoids).
So the thing to do is pull these switches up in the maintenance page and press in on the solenoid spool and see if the shot pin status changes. If yes then maybe your solenoid circuit may be bad.
The rotac sits high on the right side of the transmission. The shot pin is below it. Yes, if you remove it, if you have oil in it, it will come out. There is a sight glass on the transmission for proper oil level.

George

[MetalicGlow]

Thank you for the detailed post Machintek.

I have tried to shift gears and when it times out, I turn the drives back on via the maintenance page and watch the switch states as you suggest. The shot pin will stick "on", when it should be "off". I have left the maintenance page up, and walked away for an hour or so, then come back to find that the shot pin state changed from "on" to "off" without doing anything but waiting. My guess is that the return spring is only so strong in terms of pulling the shot pin back into position due to the gummed up mechanism. It takes time, but does return eventually.

Cleaning it out is the next step, but I am still confused as to whether or not the motor/trans must be taken off the machine to do the job. I am not inclined enough to remove and tear into the transmission itself. However, if obtaining replacement trans oil and unbolting a mechanism from the side of the trans is all that is required, then I am game.

Can the sticking shot pin mechanism be removed from the side of the trans for cleaning purposes - without disconnecting the motor and/or trans from the machine?

Happy New Year to you and yours!

[cncbpt]

I have been watching this thread to see how you were making out.
My machine will shift from high to low no problem but shifting low to high
it will error out.
When I reset the control I find it is in high range.
Doesnt take a minute to change
I would like to check if there is a parameter that could be modified to give the shotpin a couple more seconds to change positions.
I am tempted to pull the motor and get into the trans and clean and refill it.
I havent had much time to look into it but am going to look into it today

[jmullett]

I have similar problems with the shot pin timing out the machine on a gear change. I've changed transmission oil put some air tool oil (Marvel Mystery brand) directly in the air lines and bumped up the lubrication a few clicks which has made some improvements. In fact I ran all summer long without shot pin problems until about 4 weeks ago here in Ohio.

I especially notice this happening in the winter months when the shop is cooler. The best thing I can reccommend is to run the spindle for 20 to 30 minutes and get the spindle warmed up a bit and the problem goes away for me.

[cncbpt]

I am in Ohio also.
I am going to let my mill run at about 350 rpms for half an hour or so and see if it still does it.