Thread cutting in chinese ballscrew

[noyloj]

Thanks for the quick response...

I am doing a CNC conversion on a Warco WM16 and I'm following Hoss's design (more or less) I've had the screws machined in China but they neglected to put a thread for the Ballscrew retaining nuts on the Y axis... with this plan the 1605 screw is reduced to 10mm for bearings and then tapped at M10 x1.5 and finally reduced to take the motor coupler...

Hadn't even considered squareness to shaft...

[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

[njhussey]

the nuts only serve to retain the ballscrew in the fixed bearing holder?

Only?? Its what gives the ballscrew its rigidity and stops backlash etc. etc....needs to be square and true to put equal pressure all round on the bearing race.

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[Neale]

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]

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]

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]

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]

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.