Workshop made Acetal / DELRIN Rack & Pinion

[Boyan Silyavski]

Can you really get such long screws with nuts for £100 including shipping? Otherwise I agree, ball screws are best, but at those lengths I think that screws, nuts and support bearings cost more than £100.

A bit more than i said, more or less "length in cm"=euro

[davo453]

All good feedback and food for thought thanks.

From what I can work out ball screw at roughly 1500mm would be around £75 plus the nut at around £60 and I have two on my x axis so it's more like £260 ish.

Guess I am mainly considering r&p because Peter that does the cncnutz YouTube blog has had a good experience with it.




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[Boyan Silyavski]

Aliexpress has better prices. What speeds your are trying to achieve with that length screw?

[JAZZCNC]

Guess I am mainly considering r&p because Peter that does the cncnutz YouTube blog has had a good experience with it.

Depends what you want from machine. R&P is much less accurate and far less efficient. Which means the system as whole is worked harder. Motors will be pushed harder which in turn works the drives harder etc etc.
Then you have the complexity of R&P compared to Ballscrews. To get decent resolution you'll 99% have to use ratio which introduces more cost/complexity. Then you have to think about backlash and adjustment vs wear,? Too much adjust and get excess wear. Too little and you get backlash. Then throw into the mix keeping rack clean and free from debris and the verly slight extra cost, if any, of ballscrews is price you should gladly pay.

Like Boyan says go to China and you'll get better price. Go to Bst automation on Ali express and tell Fred Le Dean sent you and might be surprised at the price you get back.!




Just because one person uses it and finds it's ok doesn't mean it's good.

[A_Camera]

A bit more than i said, more or less "length in cm"=euro

Yes, that's more realistic. Around 300 pounds for the OP. But of course, it is definitely the best solution even if it is more expensive and takes more time and is also more complicated than making three delrin nuts.

[davo453]

Ok I think you are talking me down and the obvious (Ballscrew) is most probably the way to go.

Thanks for the tip re BST automation.

I've never ordered from Aliexpress anything to watch out for? presumably you are likely to get hit for duty on the import..

[A_Camera]

All good feedback and food for thought thanks.

From what I can work out ball screw at roughly 1500mm would be around £75 plus the nut at around £60 and I have two on my x axis so it's more like £260 ish.

Will you be upgrading only the X? Also, don't forget to buy machined ball screws AND also support bearings and ball nut bracket, unless you plan on making those. Another thing is that I don't think you should buy 1605 in that length, go for at least 2005.

Guess I am mainly considering r&p because Peter that does the cncnutz YouTube blog has had a good experience with it.

If R&P is good enough or not depends on your requirements. Though, I think I'd personally prefer timing belt and not R&P.

[JAZZCNC]

Will you be upgrading only the X? Also, don't forget to buy machined ball screws AND also support bearings and ball nut bracket, unless you plan on making those. Another thing is that I don't think you should buy 1605 in that length, go for at least 2005.

If this is a router then wouldn't use 2005, it will be far too slow. Router needs at least 10mm pitch and at this length I'd be inclined to use 20mm pitch with 2:1 ratio to lower screw speed and increase torque.

Should get 2020 screw with end bearings and machined for about £200.

[JAZZCNC]

I've never ordered from Aliexpress anything to watch out for? presumably you are likely to get hit for duty on the import..

Only thing you'll pay is VAT and Shipping Admin fee which is about £12-15. Ask the seller to put low value on paper work and you'll pay minimum Vat.

[A_Camera]

If this is a router then wouldn't use 2005, it will be far too slow. Router needs at least 10mm pitch and at this length I'd be inclined to use 20mm pitch with 2:1 ratio to lower screw speed and increase torque.

Should get 2020 screw with end bearings and machined for about £200.

You are probably right but I mentioned 2005 because 1605 was mentioned before, which I don't think is very good at that length due to the risk of deflation. 2005 is considerably stronger but of course 2010 will be even better speed vise. I didn't know that you can get 2020 but sure that would be even better at this length.