Thread cutting in chinese ballscrew

**Neale** · 11-01-2017

Originally Posted by noyloj

Is squareness going to be a massive issue in this case the nuts only serve to retain the ballscrew in the fixed bearing holder?

Ta

As the man says, squareness is absolutely important. The bearings typically come with a retaining nut with an accurately (one hopes...) machined face specifically for this purpose. From memory, the nuts on mine didn't look like standard M10 - aren't they a much finer thread (like 1mm pitch, not 1.5?). Might be interesting to find a die of that size.

**noyloj** · 11-01-2017

Originally Posted by Neale

As the man says, squareness is absolutely important. The bearings typically come with a retaining nut with an accurately (one hopes...) machined face specifically for this purpose. From memory, the nuts on mine didn't look like standard M10 - aren't they a much finer thread (like 1mm pitch, not 1.5?). Might be interesting to find a die of that size.

Ok, though Hoss's plans don't specify any machining of the nuts in so far as I can see. I think he must rely on single point of contact being adequate to prevent axial travel since the bearings are held captive radially by the housing, but point taken the squarer the better!

Neil I agree... 1mm pitch would be much better as less material would be removed meaning easier cutting hopefully and I could buy lock/jam nuts specifically, good idea!

Perhaps if I set up my rotary table in the vertical position I could work out some way to hold the die somehow with the tailstock and allow it to slide forward as I turn the ballscrew in the chuck? Crazy or totally crazy?

**komatias** · 11-01-2017

Originally Posted by noyloj

Ok, though Hoss's plans don't specify any machining of the nuts in so far as I can see. I think he must rely on single point of contact being adequate to prevent axial travel since the bearings are held captive radially by the housing, but point taken the squarer the better!

Neil I agree... 1mm pitch would be much better as less material would be removed meaning easier cutting hopefully and I could buy lock/jam nuts specifically, good idea!

Perhaps if I set up my rotary table in the vertical position I could work out some way to hold the die somehow with the tailstock and allow it to slide forward as I turn the ballscrew in the chuck? Crazy or totally crazy?

So if you are following the usual dimensions you will find the a M10x1.5 does not pass over the 8mm section. We typically use M10x1.0 as it also allows you to get a finer adjustment on the locking nut.

In answer to your original question, if you have rolled screws, then yes, you can use a die. I have done this with a M10x1.0 and as long as you are square on, you will be fine. You may need to use more lube than usual here.

**noyloj** · 11-01-2017

Originally Posted by komatias

So if you are following the usual dimensions you will find the a M10x1.5 does not pass over the 8mm section. We typically use M10x1.0 as it also allows you to get a finer adjustment on the locking nut.

In answer to your original question, if you have rolled screws, then yes, you can use a die. I have done this with a M10x1.0 and as long as you are square on, you will be fine. You may need to use more lube than usual here.

Thanks a lot! That's great news as I do have rolled ballscrews...

I knew if asked long enough someone would give me the answer I wanted!

Also my whack idea about the rotary table as screw cutting lathe ain't gonna work as the 2MT small end in the table is smaller than 16mm...

So carefully by hand with plenty of lube it is... sounds familiar!

**Clive S** · 11-01-2017

I knew if asked long enough someone would give me the answer I wanted!

That's the trouble if you ask enough people you will eventually get the answer to want to hear.

**noyloj** · 11-01-2017

Originally Posted by Clive S

That's the trouble if you ask enough people you will eventually get the answer to want to hear.

Well our man Komatias has actually done it... soooo.... I'm gonna have to give it a shot!

Thanks everyone I'll let you know how I get on in my build log if I ever manage to find a M10 x 1mm HSS die in the wilds here!

**Jonathan** · 12-01-2017

Post it to me with the nut you want to use and I'll cut the thread on my lathe for the price of return postage.

Edit: Sorry I'm retracting that offer - I don't think this will help you as much as it might at first appear.

John S hit the nail on the head with "They can be screwcut with tipped tooling but I wouldn't fancy my chances with a die.".

**John S** · 12-01-2017

Because John S has done it hundreds of times with his own compact design for mounting the motor, bearing, nut and coupling.

Patented that is as well.

No sticking the motor on two plates and 4 pillars. Its a CNC machine not a fcuking clock.

**noyloj** · 12-01-2017

Originally Posted by Jonathan

Post it to me with the nut you want to use and I'll cut the thread on my lathe for the price of return postage.

Edit: Sorry I'm retracting that offer - I don't think this will help you as much as it might at first appear.

John S hit the nail on the head with "They can be screwcut with tipped tooling but I wouldn't fancy my chances with a die.".

Thanks anyhow, but I've gone ahead and bought the die already on ebay... Looks like Old Skool rules for me!