Where do you get your ACME screws?

[kolias]

On my 1st CNC I bought the 3 ACME screws (1/2”-10 one start) and bearings from a machine shop in Florida. This shop however does not normally make 5 start screws. Looking on different places, McMaster for example only sells the screws without turning the ends to fit the bearings and my local machine shops charge too much to do this work or the majority will not even bother with this work. In addition, McMaster sells only 3 ft lengths and up and I need one 3 feet, one 2 feet and one 12” long screws all ½”-10 5 start.

Anyone knows a good place in US or Canada to buy ACME screws the way I want them?

[JJJJJ]

I bought my ½”-10 5 start at BDI Canada. They are Nook screws. About 100$ for a 6 feet length. 25$ shipping for 2 screws.

[ger21]

Try Roton or Kerk.

[kolias]

Originally Posted by JJJJJ I bought my ½”-10 5 start at BDI Canada. They are Nook screws. About 100$ for a 6 feet length. 25$ shipping for 2 screws.

Price sounds reasonable, did they machine the ends for your bearings?

Nook does not supply less than 3 feet so what did you do for your Z axis?

[kolias]

Originally Posted by ger21 Try Roton or Kerk.

Roton is good but they dont machine the ends to fit the bearings
I will try to call Kerk tomorrow

[Rotax91]

Great topic! I will need my ACME soon. I also will be running 1/2-10 5 start. Is Roton or Kerk any cheaper than McMaster? I checked them and they were about $14/ ft. for the better 4140 steel ACME (Part# 98940A204). Maybe that's just what the going rate is but it seems high. Let us know who you think is cheapest.

Thanks.

[kolias]

So far my opinion is that McMaster is the least expensive at $14.12 / ft for the 4140 but although not a big difference cost wise with the 1018 carbon steel, I will choose the carbon steel. See the link below.

Frequently Asked Questions

My problem is that McMaster does not supply anything less than 36” and doesn’t turn the ends to fit into my bearings

[ger21]

Are you aware the McMaster Carr doesn't ship to Canada?

[kolias]

Originally Posted by ger21 Are you aware the McMaster Carr doesn't ship to Canada?

Thanks Gerry I know about it. If I decide to buy from them I will have them shipped to a friend in PA and he will re direct to me.

Have no idea why they don't ship to Canada anyway since there are 100's of US companies shipping to Canada. Perhaps just to make life more difficult for us?

[Rotax91]

kolias- thanks for the link explaining 4140. That's great news for me. My Y axis is 42" and the only reason I thought I'd need 4140 is because I thought it would sag less than 1018. Perhaps it has nothing to do with that though. My nuts are plastic from dumpstercnc so wear shouldn't really be an issue. That takes it from $14 down to $9.58 per foot. A substantial difference. Being that my Y drive is dual drive, that really helps.

[LTHOMPS]

Kolias:

Buy the screw and cut it to length yourself (if you have the tools or you can borrow them from a friend). A cut-off wheel will do the job in seconds. You can also grind the end to fit your bearings with a table top grinder. Attached is a photo of a ball screw I did yesterday. The grinding down to size takes a little practice, but chances are if you can build a cnc, you can grind a piece of metal.

[kolias]

Hey LTHOMPS thanks for the info, I have no problem cutting to length but I doubt that grinding the ends to fit my bearings will be good enough for a precision job.

If the ends are not machined properly to fit the bearings I will have a wobble on the screw which it will affect the accuracy of the axis