Sherline lathe question

[bnalls]

Hi everybody. Quick question about my Sherline lathe. The Slide screw insert on the lathe table requires the motor to be turned many times before it changes direction. Is this an understood design characteristic or is this a problem w/ my lathe. It would seem like an incredible amount of backlash, but it looks like there's no way to combat it so I figured I'd reach out and ask. Thanks for any and all responses.
Brian

[lfbrown]

Hi Brian,

Sherline is legendary for backlash. I assume you're using the power feed, hence your reference to the motor turning.

I don't have the motor but there is always .25+mm backlash in the saddlenut. Even with a brand new saddlenut I routinely get .12mm which quickly wears out to the .25mm mentioned.

Sherline now offers, however, a leadscrew backlash lock. See the following link for more info and a part number. I bought one for my mill but haven't installed it yet so I can't tell you how well it works.

http://www.sherline.com/4417Zpg.htm

Les Brown

[zephyr9900]

Originally Posted by bnalls The Slide screw insert on the lathe table requires the motor to be turned many times before it changes direction.

Hi Brian, something is definitely out of adjustment with your lathe. It should be possible to get .003-.005" (.08-.12mm) backlash with the stock lathe.

My lathe is a stock 4400 with CNC, and I can regularly turn parts to .001-.002" tolerance (backlash measured and compensated in TurboCNC.) If your lathe is CNC, are you sure that the leadscrew support bearings are adjusted with no play?

Best regards,

Randy

[bnalls]

Thanks for the replies! The table was indeed not tightened towards the center of the screws is a nut apparently but I have yet to fix it. Thanks for the responses!
Brian