Pee Wee / Thimble Drone 0.020 piston reset

Just bought one and at TDC, it feels like the piston is not moving but I am able to turn the crank through it. Sorry I don't know how to describe it better.

I purchased a piston reset tool from Cox International but before I use a tool I have never used before, I wanted your input.

Some of my questions:
1) How do I know I'm done?
2) When "tapping" the reset tool, I'm worried that if I don't tap it hard enough, it won't do anything. If I tap it too hard, it will be asymmetric. Is this a real concern? Or put another way, I think it will be best to push in all around the socket.

Thanks in advance!
Harjit

As with any resetting, do this on a solid surface. Either on a concrete floor on top of a piece of steel or on top of a anvil. Make certain the joint is clean of oil. You want to transfer the shock to the joint and not into everything else. Use a small ball pein. This isn't a job for the 24 oz. hammer. Make certain that your setting tool is as square as you can make it to the work.

You don't want to over do this. Each shot should be accurate and not hard. I like to give it a shot, rotate the tool 180 and give another. Keep rotating the tool on every shot making certain the rod is properly engaged in the tool allowing for full contact on the socket. I check repeatedly for play. Just keep tapping accurately and not hard. Obviously , you don't want to overdo this and the .020 is quite small so being cautious to how hard is critical. After a few taps you should note that the clearance is tightening up. This process can take a few minutes. This shouldn't be rushed due to heavy hitting not to mention the difficulty in obtaining spare parts should something go awry. Heavy hitting or out of square shots can result in the crown of the piston mushrooming. The piston should go back into the cylinder as smoothly as it was removed. The piston is harder than the cylinder so if a problem occurs, your going to be in search of a piston.

Don't concentrate on removing all the clearance in the rod joint. Having a slight bit of movement is better than none. Assuming all went well, you should be able to rotate the piston without binding on the rod went the rod is splayed to either or side.