Question Ball Screw replacement for wearing thread nuts

OOPS!! Typos galore.

Thanks Worldhusky for that link - fascinating how some of these oddities arise.

Peter

peterg1000 wrote: On reflection, I'm 99% certain that the ball screw used is going to be a standard off the shelf item, otherwise the tooling costs would have been prohibitive for a startup enterprise. Stepcraft were after all building down to a price so as to gain a foothold in the market.

The picture in a previous link shows the FGR ball nut on a standard Stepcraft ball screw, so I think that makes it almost certain that it's a standard item. Perhaps there is someone in the know who can confirm that.

+1. I would also be surprised if they are custom made items rather than off the shelf. They are well engineered.

Doug

Any one know the original supplier of the ball screws that Stepcraft use?

Guys - before you get carried away, on the stepcraft website, it clearly labels the item as a lead screw, not a ballscrew. The stepcraft machines would therefore not work with a ballnut, unless by absolute fluke, someone custom engineered a the stepcraft leadscrew - so that was designed to actually be a ballscrew.

I would hate for guys to waste cash fitting a custom ballnut to fit on the leadscrew, and then wonder why it ended up worse than the current arangment.

If it's worth doing, it's worth doing properly, get the ballnut matched with the ballscrew

Try Zapp automation online

R1003 C7 ballscrew
Length
300mm
R1003-300-300-C7R 1 £15.51
R1003 C7 ballscrew
Length
700mm
R1003-700-700-C7R 1 £35.31
R1003 C7 ballscrew
Length
1000mm

Grand Total (Incl.Tax) £124.03

Thanks for the Zapp link - you did me a good turn, as suitable ball nuts are on special offer there at the moment. They are specified as identical to the ones called up in this link . I've just bought a couple for X and Z axes as these are the easiest to work on.

The picture in the link shows what I believe to be an original Stepcraft ball screw (Stepcraft are as lax in their terminology as I was originally!!) with the specified nut mounted.

The adapter is no real problem provided I can persuade my lathe to cut an M18x1 thread - otherwise I will be investing in a tap of that size!

I'll update when I know if the ball nuts fit the original ball leadscrew. If it works with the originals so much the better, otherwise the screws can easily be updated with the Zapp mating parts just as you are doing. Incidentally do your quotes include machining the ends to fit existing bearings?

peterg1000 wrote: Thanks for the Zapp link - you did me a good turn, as suitable ball nuts are on special offer there at the moment. They are specified as identical to the ones called up in this link .

Could you post a link to the specific ones you got? The Moore site gave you the choice of sealed or unsealed, wasn't sure which one to try, what did you choose?

peterg1000 wrote: I've just bought a couple for X and Z axes as these are the easiest to work on.

Thats great news, fingers crossed.

finch wrote: We purchased our Miniature ballscrew from the Uk, we had a mount like that one shown, 3dprinted out of nylon which arrived, and looks great, and fits.

The stepcraft screw, is not designed to have balls in it, so you gonna have to fork out ~200 pounds for a set of 3 custom ballscrews, and then do some DIY to get them mounted

I can post pics of our one, once we have all the bits

Sorry I didn't catch this, looking forward to seeing how it turns out.

Hi,

Here is the link to the Zapp Automation ballnuts that I have on order.

This is the best price I have seen for ball nuts anywhere and beats my quote from Moore International by almost a factor of two.

Hoping the existing ballscrews are compatible!

Peter.

Doug wrote: I'm interested in this modification in the longer term. I haven't even started using my machine yet though!

I could swallow a couple of hundred pounds for a significant upgrade to improve backlash and longevity.

Doug

I totally agree with you Doug. I will also consider to replace them if someone could find a suitable replacement

Our Ballnut and Nylon connector arrived today,

and screws, but still waiting for the last screw !

That looks a really neat job.

My ball nuts arrived today, so now it's the mounting adapters to machine out of aluminium. The Stepcraft will have its first run on aluminium doing these, so any guidance on feeds, speeds, cut depth and lubrication would be very welcome.

Incidentally, could you please let me know the shank size of the old nut - I've guessed at 10mm to take the M6 screw. I don't want to disable/dismantle my machine until the upgrade kit of bits is complete.

I was at an Engineering Exhibition today and learned that CNC4YOU are integrating a wireless control pendant into UCCNC (V1.3xxx?). It will be available in a few weeks once the final bugs are ironed out and testing is completed - so they say.

Thanks,

Peter.

peterg1000 wrote: Incidentally, could you please let me know the shank size of the old nut - I've guessed at 10mm to take the M6 screw.

Just measured 10.95mm

Finch, where did you order the nylon connector?

Proto,

Thanks so much for that - I can complete the CAD now.

Peter

peterg1000 wrote: That looks a really neat job.

I was at an Engineering Exhibition today and learned that CNC4YOU are integrating a wireless control pendant into UCCNC (V1.3xxx?). It will be available in a few weeks once the final bugs are ironed out and testing is completed - so they say.

Thanks,

Peter.

I have the wireless XHC-HB04 running with UCCNC 2.26 here. The plugin seems to have some bugs (you have to disable the pendant for probing, but can be done with a modified probing macro), but it is really cool to use.
Only around 100 Euros on ebay: www.ebay.de/itm/Wireless-Handwheel-CNC-Fraser-Elektronisches-Handrad-Encoder-for-Mach3-3-4-Achse-/272319627895?hash=item3f6783c277:g:ql0AAOSwmLlX-E86

Magnus

Ever since we switched over to the UC400 Ethernet, the machine had not missed a beat. Wireless allways has the potential for disaster, a little bit of interference on a 10 hour job and walla.chaos

Hmm.

This all seems to be moving along apace.

I don't know whether the original Stepcraft screw is a leadscrew or ballscrew but the helical channel certainly looks like it will accept ball bearings o.k.

I wasn't sure what the difference is but this link explains it. You can download an engineer's guide PDF but you will have to provide some contact details.

blog.helixlinear.com/bid/224687/Lead-Screws-vs-Ball-Screws-It-s-All-about-the-Application

Doug

Doug,

I've assumed (and I hope I am correct!!!) that the original screws are in fact ball screws, since one enterprising user has already prepared the way.

Here is his original picture on what he implies is the original screw - it all looks genuine to me. I'm ordering a new Z screw from Rory anyway (my original has some runout that I partially corrected with shims) so I'll have a definite answer fairly soon.



Looking at the picture that Finch posted, it looks as though he is opting for 8mm screws and nuts rather than the original 10mm. I guess this avoids having to mill a 1mm deep recess to accommodate 21mm diameter of the ballnut.

Hmm...... dunno, I'll need to check what my mate ordered again, but I thought it was the same, our nut diam is 19mm so no recess needed

Hi Peter.

Yes, I assume and hope it's a ballscrew too. That mod looks clever; I hope that you can reproduce it.

The Zapp Automation price of £43 is ideal; £160-£170 region to replace all four is o.k. but I'm too new to this to start modifying my machine before I've even cut a piece. I read on that link that ballnuts are not ideal for vertical applications..,

I'll keep this in mind for future work after I've done a lot of cutting and can justify a strip down and rebuild.

Great stuff guys

Doug