what's the easiest way to reduce shaft diameter of a brass shaft without a lathe rest

[Whiterabbit]

Question is in the title. I don;t have a steady rest for my lathe. I need to reduce the diameter of a shaft by .005" across 12" of its length. precision is not needed. It takes maybe 15 minutes to go down .001 holding sandpaper in my hands while running the lathe. Seems cumbersome.

Any better way?

I've tried this in the past with a cutter, and without a steady rest it was NOT a good idea.

[M-Tecs]

Long angle lathe file would do the trick. What diameter is the brass shaft?

[dverna]

Run a belt sander over the spinning shaft??

Don Verna

[billyb]

Do you have a through hole in the spindle? Extend a short section at a time turn it down then advance the rod a little more. Bill

[jmorris]

Being brass a sharp HSS cutter and a live or dead center in the tail stock, on center drilled material, should do the trick faster and more precise than anything else.

You won't be making much of a cut going .005 on brass.

[Nueces]

billyb has it right. Use a collet if you have it, but, without a need for precision, a 3-jaw would work fine. Use a sharp tool with no back rake, to keep the brass from pulling the tool in and cutting too deep. A tailstock center would eliminate any tendency for the work to whip when extended.

[Whiterabbit]

Long angle lathe file would do the trick. What diameter is the brass shaft?

3/8". That's why I can't cut it in sections. Whip is guaranteed (I know. I tried it.)

File might work if I can support the work, like pinch the shaft between the file and...?

[Cap'n Morgan]

I have no idea if it would work, but you could try a "swiss machine" approach: Clamp the part lightly in the jaws, lock the cutting tool close to the jaws and, while the part is rotating, either pull it through past the tool tip (clamp end of shaft in drill chuck in the tailstock) or push it from behind through the headstock. You'll need to do this over several steps depending on the length of travel of the tailstock.

[smokeywolf]

You've not mentioned how long the shaft is. If the shaft is 10" or longer, you need a follow rest as opposed to a steady rest. If the shaft is less, I'd bore a set of soft jaws and turn half then flip it end for end and turn the other half. Finish with wet-or-dry.

[Ballistics in Scotland]

Whether it can be cut with a lathe tool depends on the combination of length and diameter. As it is brass you could grind a hollow in the top of a lathe tool so that the edge is as sharp as a woodworking tool, and at a considerable upward angle.

If it is a parallel shaft a travelling steady would indeed be at least as good as a fixed one, and a lot easier to improvise, since it clamps to the top slide or cross-slide rather than the lathe bed. I've even improved my results on a tapered barrel which prevented this, by putting a square bar with a spring-loaded tip on the other side of a four-way toolpost. It presses the workpiece lightly away from the tool, but that is good enough to limit vibration. An epoxied sandwich of steel sheet and 1/4in. rubber worked for me.

The use of a hand-held belt sander should be fine. But there are grades of abrasive paper which should remove quite a bit more than .001in. per 15 minutes, if glued to a long strip of wood and moved back and forth to avoid clogging. You might get the best accuracy by using two such slightly flexible pieces of wood, fixed to a 3/8in. spacer, so that you can press the abrasive to two sides of the shaft at once. With anything involving abrasive it is a good idea to cover as much of the lathe as possible with newspaper to keep abrasive dust out of the beds etc.

[marvelshooter]

Do you have the means to make something like this:
178868
The hole in the support block needs to be smooth and the adjustment is cut and try but once you get it any length can be turned.

[Blanket]

Rig a follow rest

[fast ronnie]

Abrasive strips work well if used in the correct grit for the purpose. Brass cuts easily and shouldn't take that long. I routinely take off material that way.
I would guess that you have more than one to do, though.

[Bent Ramrod]

I've done sections of barrel that long or longer between the steady and the tailstock, or between the headstock and the steady. Resting one of those orange composite deadblow hammers opposite the tool, while taking light cuts, helped quite a bit with flexing and chatter. I held the handle to guide it and the juncture of handle and head rested on the barrel as it spun.

[W.R.Buchanan]

Everyone of the above tips would work, you could even chuck it in a Drill Motor and run it against a belt sander.

The Screw Machine tool in post #11 is a way I've used in my shop many times for production runs and I have even made several tools like that.

Basically the tool has either a bushing right in front of the turning tool which supports the stock, or it has two back up rollers that support the stock in the case of what is known as a "Box Turning Tool." In both cases as the tool advances on the work, the work continues on thru the tool.

The basic problem with these methods is the setup time is extensive, and basically trial and error until you get it right. I have messed with some for hours before getting it to cut the right diameter.

For one part that is not critical I'd just chuck it in a drill motor and run it against a belt sander until I got the desired diameter. It shouldn't take even 15 minutes to get it done.

I might add that on the Guide Rods for my Hand Presses, made from supposedly"Precision Ground" O1 tool steel,,, I have had to reduce the OD of some of the shafts by using the very method described above. It only takes a minute to remove a couple of tenths of material using a Scotch Brite Wheel and drill motor.

Do be careful as the stock does get hot fast.:holysheep

Randy

[country gent]

I would mount it betweena chuck and good live center just supporting the tail stock end, Just a touch not any real pressure as this will bow the thin long shaft. You need to watch the expansion opn the shaft as it warms also as this makes it grow longer. A fine long cut lathe file or even a fine single cut file used carefully to get close ( should only take 5-7 passes with a sharp file and soft passes) then a strip of 320-600 grit paper on the face of the file to finish. There are industrial cutters out there for production that sit around the shaft and have a saw type face and short section to support the shaft. these run over the shaft and it follows the tube. One could be made, think neck turner with a hole instead of the neck pilot. This would need to be done on a length of pipe and feed with the tail stock, resetting the tails stock as needed.

[Col4570]

Make two wood Bats,hinge them with leather,put in a sheet of emery cloth and squeeze the two Bats together whilst the shaft is spinning.This will take of your few thousandths.I use this method to polish turning marks off when I make a Barrel.As follows:- Two pieces of 1"x 3",joined at one end by a leather strap either Screwed or nailed.Job Done.

[Pavogrande]

HI WR -- I think col4570 has it -- couple bits of 1x2, leather hinge, strip of abrasive cloth and bobs your uncle --

sorry I did not get to see you again for a chat before I left calif -- hallmark lane