lathe is having trouble

[JamesJmcGEE]

Hi my lathe is having trouble, I bought the hobbycnc w/ small motors 127oz, mistake maybe... anyway the in out axis works great (x?) but the left to right (Z?) seems to bind, there are no gibs to adjust, I tried everything, the binding is slight. the motor stutters a little then starts to pull but one touch from the hand stops it again. are the bigger motors 200oz alot stronger? or just a little? (I’m thinking the stock lead screw with the 2 pc. clamping nut is the problem, letting the carriage twist). I don’t want to spend allot of money on what might be the problem so any help will be appreciated.
Thanks
James

[mark c]

Hi James
I have the same lathe and Hobby CNC kit, but I got the 200 oz/in steppers. I used the plans from Ron Steele here: http://www.stirlingsteele.com/latheplans.html
this uses the supplied X axis (diameter) screw (although I have since replaced it with an Acme one) and a 3 start leadscrew for the Z axis. It works great.
If you want to keep the stock Z screw, make sure the half-nut is adjusted so it doesn't pull it one way or the other. Mine did this when I got it before I converted it.
There is also a modification to make the z carrige easier to adjust at:
http://www.mini-lathe.com
Hope this helps somewhat

[JamesJmcGEE]

does anyone know the thread size of the half nut / leadscrew?