Mini-lathe Steady Rest

January 2010

A steady rest also came on this Real Bull mini-lathe package. To match the new lathe color, all paint was removed first. Had to remove some paint from the machined slots, in order for the jaws to slide properly. Then painted to match the lathe color.

Ball bearings for steady rest fingers

After looking at some steady rest options for larger lathes, thought that adding ball bearings to the fingers would be just fine, mostly for when re-machining aluminum parts where the brass fingers may produce marks. Then saw on LMS that Sieg is already making a ball bearing steady rest for the mini-lathe, but the way they made it reduce the maximum stock size you can hold on it., as bearings will easily hit the casting.

When looking at bearings catalogs, figured out that a few dull wood router bits I had on shop may have the right bearings. Decided to use the bearings and made brass bushings to use M3 screws and with a larger end to act as a spacer to separate the bearings inner races from the the fingers. A spacer is needed to make clearance for the outer races to rotate free.

Real Bull mini-lathe steady rest ball bearings mod

After lapping fingers and removing all burrs from edges, each finger was drilled and taped to M3 thread and M3 socket head cap screws used to hold bearings in place. You can also see the small brass bushings / spacers on bearings (front and back).

Real Bull mini-lathe steady rest ball bearings mod

As the T studs were limiting fingers movement due to the ball bearings, had to cut them straight on the T end closer to the bearing. You can see the shape but the cut was painted black. This allow me to use the ball bearings with up to 45mm diameter parts. And I can always remove all bearings if the brass fingers are a better choice for some work.

Real Bull mini-lathe steady rest ball bearings mod

A quick-lock clamping plate

Steady rest quick lock clamping plate

I use many times the steady rest between the lathe chuck and carriage, to bore or thread on the end of stock. With the original clamping plate, to mount it in such position, the clamping plate has to be disassembled and inserted from the bottom into the bed casting. Not as easy to use as I would like to, so made a new one from round stock and machined to be mounted on the bed from up, without the need of removing the plate from the steady rest.


Steady rest clamping plate

To make the new clamping plate even easier to use, and to avoid the need of tools to set the steady rest on the mini-lathe, made a quick lock to clamp the steady rest in place.

Steady rest clamping plate parts

A 8mm stud threaded on both ends is attached and glued off-centered on the clamping plate in a position that the plate can rotate under the bedways and, when perpendicular to the bed, the plate is centered to clamp on both sides. Onto the steady rest hole a bushing was inserted, mostly for the lock not to run on paint. Though I know the paint will wear anyway :-)

The lever is bolted to a collar, threaded M8 through to act as the locking nut. On top a M8 threaded collar is held in position with a M3 angle point set-screw and is to act as the plate positioning knob. As this collar is to be used as a knob it is yet to be knurled. Will knurl it as soon as I finish the knurling tool holder.

Mini-lathe steady rest clamping plate

By rotating the top collar 90º CW the clamping plate will also rotate onto the clamping position. Then the steady rest is clamped by rotating the lever 90º CW

Steady rest attached to mini-lathe bed

The lever position, when the steady rest is firmly clamped to the lathe bed, was adjusted by trying washers with different thickness between the locking nut and the the bushing on the casting. The position of the top collar is adjusted so that it stops the locking nut from rotating when the lever is parallel to bedways. The M3 set-screw keep the collar in position.

This way it is even easier to remove the steady rest from the lathe, as it is done only by rotating the lever 180º. The first 90º will unlock the clamping plate and then, as the top collar will prevent the locking nut to rotate further on the stud, the clamping plate will also rotate with the final 90º of the lever movement.

This is one of those mods that I'm sure it will save me all the time spent making it.

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