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View Full Version : Ball screw fixed end DIY support ideas needed.



ccmarco
05-12-2010, 11:44 PM
I'm wondering if exist a way to build in a simple way the equivalent of a flanged mounting block for the fixed end of a ball screw.

Unfortunately cheap commercial models are for 10mm shaft, ergo 7200 ball bearings, while a need a support with 12mm bore diameter, so 7201 ball bearings.

These items are quite expensive for low budget projects and i'm considering to try to build a couple for X and Z axis of my DIY XYZ pantograph.

Of course i do not pretend same strenght and precision of metal ones, but something that would be OK for a wood machining CNC device.

The first problem is :

i do not own a lathe ...

but maybe with a quality forstner bit, some delrin slices, a couple of 7201 bearings and a collar ....

Has someone managed to get something similar to work good ?

Marco.

Swarfing
05-12-2010, 11:59 PM
Marco you could always go with a bronze bush (oilite bearing) and a couple of thrust bearings at each end as a cheap option?

ccmarco
06-12-2010, 12:08 AM
It could be an idea, but i still have to find a way to build a main assy that carry all parts.

Do you have a photo of a similar implementation ?

jonm
06-12-2010, 01:34 AM
ccmarco
i had the same prob as you , i had a 12mm diameter trapezioid screw , so i turned the screw down to 8mm using a grinder and a drill as a lathe , threaded the end for a locknut , used a 100mm x 100mm x 10mm plastic shim with a 22mm hole drilled in it( to take a skate bearing) as a bearing block. so it went , thrust washer - bearing block (with skate bearing ) - thrust washer - locknut , tighten locknut to preload assembly , solid and cheap i have no lateral movement in screw ..... phew!!! maybe a pic would have been better

ccmarco
06-12-2010, 09:16 AM
Hi John,
yes, a pic would be good.

It's all clear thrust washers aside.

Unfortunately the screwballs machining requires a good lathe and proper skills, any other attempt will fail unsafely.

Here in Italy, lathes are quite expensive, anyway i'm thinking to buy a little one at least to work small parts.

Could you take a shot of your assembly ?

Thanks,
Marco.

M250cnc
06-12-2010, 01:02 PM
Marco surely there must be someone local to you who can do the screws.

Phil

ccmarco
06-12-2010, 04:14 PM
Hi Phil,

sure that, i already have a deal with a professional lathe worker for ballscrews machining and ball bearings flange build, but it would be more funny to make my own screw supports, at least.

About ballscrews, i have space only for a small lathe and as far as i know, hardened steel is too much for similar tools.

Or i'm wrong ?

Marco.

M250cnc
06-12-2010, 05:30 PM
Marco i have never tried turning ball screws, i have a cylindrical grinder and did mine on that.

But a small lathe would struggle with hardened screws

By all means make whatever you are capable of making, but it is false economy to make something that you cannot make accurately.

Phil

ccmarco
06-12-2010, 08:34 PM
Phil,

i'm not looking for a way to machine ballscrew's ends by myself with improvised methods.

Instead, my purpose, for non critical applications, is to build, only, ball bearings support flanges.

Of course, for professional high quality CNC machine making, this does not make sense.

Marco.