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Home-Made balance tack


Tudor

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Hey guys.

 

Been occupied by other things lathely, namely getting an old lathe up and running here at work...

It's quite beat and abused but Its a high quality Hardinge lathe. I rebuilt the compound (which clips onto the dovetail way as it's a lower-end second-operation lathe) so it has limited travel. The angle scale (which is under the top of the compound and visible through a magnifying glass built in) was completely covered in rust and grease. Now it's visible... It came in handy to set ~2 degrees of taper for my tack! I also took the excessive lash out of the compound ways so they are nice and tight now. This is a sweet lathe with a 3-jaw chuck as well as an assortment of 5C collets. I learned from a master tool and die maker on the high end version of this- the tool room lathe, with a proper apron able to cut inch and metric threads. This is it's lesser cousin.

A brass rod was tapered as thin as I could and then finished with sand paper as it was deflecting from the tool of course and not cutting as it got thin... I pressed it into a 1" slug of aluminum. A bit of tubing to keep it safe and a recycled container and we are done!

Anyway, here's the tack:

tack 001.JPG

tack 002.JPG

tack 003.JPG

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  • 2 years later...

Thanks. 
 

I think the tack is easier. Just grab the assembly with your tweezers and set it in place. It seems to just fall into alignment with the fork. That was the whole reason for opening this- I dropped it and it stopped, so I figured the balance wheel or pallet fork jumped. Pallet fork was fine, and once I set this in and lined it up, it started running before the screw was in. 
 

This kept excellent time before it hit the floor and still does now, so no adverse effect to hanging it. 
 

It was only hanging a few minutes. Just long enough to check the escapement function. 

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1 hour ago, Tudor said:

I dropped it and it stopped, so I figured the balance wheel or pallet fork jumped. Pallet fork was fine, and once I set this in and lined it up, it started running before the screw was in. 

Overbanking can be diagnosed and fixed without removing the balance. Rotate gently the balance with a brass tweezer or wood, it will move one direction but having a firm stop in the other. Loosen the cock screw, lift a the balance rim a bit and rotate in the direction where it couldn't go. It will start running, tighten back, check on the timegrapher and if no more trouble job is done.

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