Workshop made Acetal / DELRIN Rack & Pinion

[Paul3112]

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.

Not arguing here, but from experience .. when using steppers, the faster the screw the greater the chance to miss steps. (tool load)
I will also ad this link as Fred now ships from Germany. https://www.aliexpress.com/store/pro...612.0.0.PXFXn5

[davo453]

Thanks again.

I have costed this out (haven't asked for a quote though) and I am up around $600 ish (+VAT etc) so that kills the whole idea for the time being, cash flow is not so good right now.

The problem seems to be that the screws would need to be 1500mm long and at that length the shipping goes through the roof, so because of that using a local company such as Zapp might be cheaper anyway.

The machine does more that earn it's living so I'll save up the pennies over the next few months.

Cheers

Dave

[A_Camera]

So, back at the original idea. Make some delrin nuts and off you go.

[davo453]

So, back at the original idea. Make some delrin nuts and off you go.

As I said I have had those (for almost 3 years) and they are great but don't solve the slight problem of lash (resonant frequency) of the screw but it's not at all that bad really just a desire for my version of perfection I suppose.

[A_Camera]

As I said I have had those (for almost 3 years) and they are great but don't solve the slight problem of lash (resonant frequency) of the screw but it's not at all that bad really just a desire for my version of perfection I suppose.

But if you make the nuts it can indeed solve the backlash issue. Not an optimal solution but definitely a solution. At least until you can afford balls crews.

[njhussey]

But if you make the nuts it can indeed solve the backlash issue. Not an optimal solution but definitely a solution. At least until you can afford balls crews.

It's not a backlash problem I don't think from reading the thread, its whipping of the leadscrews because he's driving them past their max speed to get the speed he wants to machine his materials i.e. beyond the capabilities/limits of his machine. Belts, R&P or ballscrews are the only solution really to machine at the speeds he wants.

Alternatively slow the feed and also RPM of the spindle until there's no whipping......

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[Boyan Silyavski]

600$???

The link i pointed you to is much cheaper.


Also maybe your design is not good. Meaning you drive the screw directly or belted? As when belted the screwis acual length, not the length of your machine. And as that could mean 20-30% longer than actual length necessary.../when screw is end driven directly/


Dont overthink it. Buy 2 screws you need as cheap as possible as you find them. Then you will upgrade rest at a later time. Accept that there is no other way and concentrate how to achieve the best result. All else is no better than what you have now.