How to pre load screws

[graham4877]

Right i get it now,only thing i'm struggling with is how much load i'd need to put on mine,
My lathe runs real good, but theirs no way now i'd get 001" , i'm looking for as best i can get it but i'm not spending a bomb, can input the back lash in LinuxCNC just the same as mach? the work i will do with it just don't warrant that much, so its not worth spending a ton of cash now! maybe later on when i fully understand what i'm doing i'l happy plug a few ££££ into it, my main reason is i want to be-able to cut inch/mm threads , where is i can only cut mm at the minute! plus i can speed the threading time up on cnc..
I new i'd always get back lash but its just the way a member from another forum said get Class 5 and you'l have zero back lash, and he sent me to a uk site where it was going to work out 500 easy just for the x axis!


can i ask on my lathes cross slide its 370mm from the handle to the very back of the saddle
so i'm planing on doing it the way you have done it Jonathan by having the ballnut at the end as it wont fit under the cross slide, so how long would i long do i need for the ballscrew ?
same go's for the z axis , from the gear box on my lathe to the end of the bed its 900mm

Oh and i forgot to ask what sort of total cost do you thinks it will run upto, as best guess you can give me, i.m just going for 2 nema 34 900oz motors.. can any one put a link up to the best drivers and broad to use for them motors .. i've a total price but i just want to be sure!
cheers guys

[JAZZCNC]

i.m just going for 2 nema 34 900oz motors.. can any one put a link up to the best drivers and broad to use for them motors

Those motors are massive and you will get away with far smaller motors.
Seen has most lathe conversions I've seen are geared 2:1 then 3Nm Nema 23 and 75V PM752 or 50V Pm542's will easily do what you need far better than those big motors. Even 1:1 they will be fine.!

Don't fall into the bigger is better trap.!! . . . 3Nm 23's when connected to ballscrews are are very powerful and run with decent drives and decent amount of voltage will be fine for your needs.

I can put you in touch with someone who is selling some New PM752 drives if your ready to buy now.? . . . . PM quick if your interested.