Ball Screw replacement for wearing thread nuts

What is the benefit of a high quality ball screw (with hardened balls) on a unknown lead screw with technically unknown specs and profile?

The backlash goes almost to zero?
Maybe the wearing will progressively augment the backlash, but I think it will be limited to few cents of millimeter, IMO.

At the moment I cannot see alternatives. Buying new "professional" leadscrews will rapidly overcome the value of the machine itself, and it is like firing at a small bird with a big naval gun.

The backlash goes almost to zero?
Maybe the wearing will progressively augment the backlash, but I think it will be limited to few cents of millimeter, IMO.

The backlash with the new nuts is very low and the cost of replacing them is very low. Also it ensures the wear is on a cheap components, as replacing the rods would be very uneconomical. Bronze nuts has been used as a wear component in machines for ages and has a very reliable record with regard of wear. The new nut with adjustable pre-load seems like the best solution.

The balls in a ball bearing is very very hard, and running those on a regular hardened rod will quickly wear down the rod. To me it seems like risking a high replacement cost for a short-lived joy, and there is no going back when you get wear on the rods.

The new nut with adjustable pre-load seems like the best solution.

You missed the point here: the new nuts are not available for old SC1 steppies. The old machines use an 8 mm leadscrew instead of 10 mm.

The balls in a ball bearing is very very hard, and running those on a regular hardened rod will quickly wear down the rod. To me it seems like risking a high replacement cost for a short-lived joy, and there is no going back when you get wear on the rods.

Two guys of the forum made this mod before, they are quite satisfied.
I'm available to buy new rods/leadscrews one time per year, when it pays in terms of precision. Also, one has to look to quality of the steel used from Stepcraft. It seems good to me, so (maybe) there will be no so huge wearing by adopting ball-nuts...

You missed the point here: the new nuts are not available for old SC1 steppies.

Ah, sorry. I missed that.

Also, one has to look to quality of the steel used from Stepcraft. It seems good to me, so (maybe) there will be no so huge wearing by adopting ball-nuts...

Doing a hardness test on the rod would probably be a good indication.

The original Stepcraft leadscrews are made from Eichenberg, so the quality should be not an issue in this case.
But I agree with you: we need a volunteer to make a duration test....

Yesterday I made some measurement: the leadscrews on the old Steppie (8mm diameter, 2mm step) seems to be perfect to accomodate the 1,59 balls of the KGT 8x2 FGR RH N A G miniature ballnuts from Moore International.

Any volunteer here?
We could collect some money and share the costs of purchasing a couple of that stuff for a test. 🙂

I have installed SKF Ball Screws in my Stepcraft 2-420, and I am not sure what lubricant I should use? :dry:

My best regards
/Mika+

Anleitungen sagen Öl auf die spindeln, aber ich bin sehr sher skeptisch.
Du solls ein öl mit sehr sehr stärke Klebeeigenschaften finden.

Ich benuzte OKS 402 Lithium-Fett:

Schmierung von Gleit-, Wälz- und Gelenklagern, Keilwellen,
Steckachsen, Gewindespindeln und Gleitflächen aller Art
bei normalen Belastungen und allen für die Fettschmierung
üblichen Gleitgeschwindigkeiten

https://www.stepcraft-systems.com/en/forum/betrieb/5758-reinigung#55463

What do you think about PTFE Grease?
PTFE Grease.

I will order on of OKS 402 and try it.
Can I use OKS 402 to the rollers as well?

My best regards
/Mika+

What do you think about PTFE Grease?
PTFE Grease.

I love Teflon, but I never tried it on the Steppie. The main problem are the adhesive properties of the grease. The product shown at the link you posted says nothing about that. 🙁
Here below there is another PTFE-grease, they claims "excellent adhesion", it will be true? There is no datasheet to make a comparison... mmmmh...
https://www.motipdupli.com/en/INT/products/motip/professional/technical-sprays/ipg-1301/tm-1301.html

I will order on of OKS 402 and try it.
Can I use OKS 402 to the rollers as well?

Absolutely.
Viscosity of the OKS 402 (110 mm2/s) is somehow in the middle between an oil and the Microlube GL 261, so you can use it for nuts/spindle and the rollers as well.

Density 0,93 g/cm3 (DIN51757)
Viscosity NLGI 2
This is on the grease in my link.
Data sheet PTFE Grease.

My Best Regards
/Mika+

I made same SKF ball screw (SH 10 x 3 R) holders.
Firstly I tried to thread the workpiece by hand, but the result was not acceptable.
The best result came with 4th axis and thread mill.

Now i can do these holders for others too:)

I think that POM-C plastic should work also, but I still used 6082 T6 Aluminium.

Uploaded some videos to WiseParker facebook site:
https://www.facebook.com/WiseParkerEE/videos/484377495768269/

Thanks to everyone who shared pictures and ideas.

Hi I had a question I also have a Stepcraft D840 version 2 and have quite a lot of backlash on my Y axis and tried the new anti backlash nuts from stepcraft but this one fit very badly and I sent them back. Now I read this message and am very curious if this works well. Do you have the correct dimensions of the Y lead screws and maybe a link where you bought the new bullet screws. I am very much looking for a better solution.

Hi all,
I'm also interested in the modification. If quite some backlash on my Y and Z axis.
I don't have the gear to cut these alu holders myself. I can image that more users are interested. Maybe someone who's better equipped can help another SC user out?

Hi!

I just got some original FGR 10x3 RH ballscrew nuts if someone is interested. I have 10 brand new FGR ballscrew nuts available. I will send from Estonia.

Best wishes!
Martin