Thread: Shaft & Linear Bearings

Good score, love over engineering. Do it once and don't have to worry.

Think i’ve found a good use for the shaft and linear bearings you tagged

AB478A7E-FEE6-43F8-A988-26E8F20C246D.jpeg

Originally Posted by Lappa

Think i’ve found a good use for the shaft and linear bearings you tagged

AB478A7E-FEE6-43F8-A988-26E8F20C246D.jpeg

Why not this? I have no experience with these but would my link work for the lift Set 2x Linear Guide Rails Shaft 400mm Chrome + 4 SBR8UU Blocks Bearing For CNC | eBay

There are heaps of them on eBay keep looking.
I'm sure I've seen them on 20 mm shafts.
I agree for home builds if your not sure over engineer it.
It only hurts the cash flow once.

Cheers Matt


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Originally Posted by Chris Parks

Why not this? I have no experience with these but would my link work for the lift Set 2x Linear Guide Rails Shaft 400mm Chrome + 4 SBR8UU Blocks Bearing For CNC | eBay

You might get a bit of flex with 8mm shaft, but the concept would certainly work.

They will be vertical so I don't think flex will be an issue.

Originally Posted by Chris Parks

They will be vertical so I don't think flex will be an issue.

Ye but over engineering looks cool to some times.

With the router bit cutting at 90 degrees to the shafts and trying to push the bit sideways, flex could be a problem.
I’m with Simplicity - over engineering is cool

Seeing that the blocks will be near the ends of the shaft no way will 8mm flex.

Originally Posted by Lappa

With the router bit cutting at 90 degrees to the shafts and trying to push the bit sideways, flex could be a problem.
I’m with Simplicity - over engineering is cool

There's also quite a lot of weight hanging off those two 8mm shafts. I'm no engineer, but I'd be concerned about it. Others with more of an engineering/design background probably know better. If the 8mm shafts are of sufficient size to perform the job it would certainly be very cost effective.

I grabbed a set of the 16mm shown in the first post. Will work equally well in both horizontal and vertical mounting, I agree with Chris that the smaller ones would be fine on a lift because of the dual sets of bearings, limited travel involved and the closeness of the spaced slide mounts to the bottom and top rail mounting points, but these 16mm things are seriously heavy and seriously strong.

FYI Because they are so strong and so easy to mount, I tried a test set up using them as fence rail slides on the Router table, simple to fit and absolutely zero play - in other words - the fence could be moved to any position across the table and remain 100% at right angle to a mitre slot, or even better, a second set used for a sliding table set up, again with 100% tracking between the fence and the sliding table section and smooth as silk movement. If used for a fence slide then the fence position DRO could simply be attached underneath one of the side rails - completely out of the way and with 100% positional tracking of the fence. Oh and of course they would work (cut down) as the basis for indestructible router lift guide rails.

Thanks to aldav for the heads up

Just more random thoughts and rambling - but I've been looking at different ways to use these CNC rails and bearings.

With this type of guide and mounting design it's actually simpler to make a CNC motor lift, not only that, they can easily be used on a typical Router and remove the need for the Router guide tubes and mounting plate. Like the motor lift shown in previous posts, the lift and CNC motor / Router mounting adaptor do not need to be attached to the table top, this makes a hinged top for complete access even easier if desired. You can get a Stepper motor with an inbuilt Lead Screw Rod and Nut - the motor shaft is a lead screw, comes in various lengths - this removes the need for any coupling adaptor and any possible associated play.

So one of these rails either side of the motor, a mounting block / frame between them for what ever motor you use, and a Stepper with lead screw centrally positioned between the rails and offset to the side (front or back) of the motor housing.

FYI The bearings on these slides have two adjusting screws for removing any play, and from what I can find, it looks like these bearings have a dynamic load rating of 175 lbs each.

Originally Posted by MandJ

Just more random thoughts and rambling - but I've been looking at different ways to use these CNC rails and bearings.

With this type of guide and mounting design it's actually simpler to make a CNC motor lift, not only that, they can easily be used on a typical Router and remove the need for the Router guide tubes and mounting plate. Like the motor lift shown in previous posts, the lift and CNC motor / Router mounting adaptor do not need to be attached to the table top, this makes a hinged top for complete access even easier if desired. You can get a Stepper motor with an inbuilt Lead Screw Rod and Nut - the motor shaft is a lead screw, comes in various lengths - this removes the need for any coupling adaptor and any possible associated play.

So one of these rails either side of the motor, a mounting block / frame between them for what ever motor you use, and a Stepper with lead screw centrally positioned between the rails and offset to the side (front or back) of the motor housing.

FYI The bearings on these slides have two adjusting screws for removing any play, and from what I can find, it looks like these bearings have a dynamic load rating of 175 lbs each.

A vertical 10mm Aluminium plate mounted on these and use the mount that comes with the spindle and it would make a simple indestructible lift, as if I haven't got enough to do already! You could use some 80/20 extrusion for the table frame if you wanted to go totally overboard.
80/20 Australia

And here they are even cheaper from I suspect the same seller https://offer.ebay.com.au/ws/eBayISAPI.dll so I couldn't resist and bought two sets.

Sorry Chris. eBay link doesn’t work.

My 16mm shaft and bearings arrived. Whoaaaa!! You were right Chris - probably, no, most definately, an overkill for the lift

Tying this and a thread in the CNC section together, I’m thinking of attaching a stepper motor to the micro adjustment on my Triton as a trial/precursor to a lift - bits should be here this week.