steady behind lathe

might have little project to do in new year,

got some 4.5ft 1" solid bar that needs end 8" tapering.

having long heavy bar sticking out the back makes me nervous.

i have to build a new lathe bench so am thinking of making it longer and fitting a steady about 1ft behind lathe.

will it work?

ideas and suggestions please.

No reason why not at all. I often bolt a wooden angle plate to the bed of the drill behind the lathe with a hole bored in to support long lengths.

No need to over think the idea.

Dont feel I can answer your question but I have seen Keith Fenner on you tube link use floor mounted steady to turn long propeller shafts worth a look but you will need to search his videos.

H

No mention of lathe bed size? I might just use a fixed steady, with tailstock at the end of the bed, and that would mean not a lot hanging out the back end For a 'one off'. I might tap in some aluminium strip at the rear of the spindle for extra security, proceed steadily and see how it goes. How long is your lathe?

Auto and capstan lathes have a long tube behind the headstock to support long bars, you could do the same. The bar does rattle around (auto lathe shops were very noisy), but at least it won't go out of control .
BobH

I would worry about it working against the chuck jaws as nearly 4' of bar unsupported behind the chuck has a lot of leverage. Perhaps a bush turned to fit at the back of the spindle would help as well? This could be a close fit on the bar, or more universal using radial screws to clamp the bar.

Brian

Agree - that's what I did when I machined my boat's prop shaft, and for the same reason. Made from an off cut of unidentified plastic rod and was an easy push fit on both the shaft and in the spindle bore. The tail end was supported by a bit of wood with a hole in it, clamped to the nearest bench, and was far less precise.

An extended steady is needed to stop the end of the workpiece whipping about and causing vibrations or disasters.

The two I have used are a bored out piece of wood which is okay... but later I found an old taxi propshaft bearing and jammed it over the end of the workpiece, then mounted the bearing end into the piece of wood, it was much more stable and meant there were no more "wear" or heat issues.

Once you have the far end of the workpiece shoved securely into a bearing you can mount it in anything stable you can cobble together

This works.

I also have a length of 2x4 with a V cut in the end, I intended to make a clip-on top for it as I was worried about the bar climbing out but it hasn't been necessary as the two faces at 90 degrees steady the stock nicely if adjusted to just contact it whilst stationary.

- Nick

I have done something similar to this in a bedless lathe (really a cymbal-making lathe with a temporary 3-jaw chuck fitted it) with a 3.2m length of heavy aluminium tubing hanging out of the chuck. 300rpm or so. I was actually only abrading the tube, not cutting it.

Get hold of a little laser pointer - I found a cheap one on Amazon or Ebay, fitted inside a dummy bullet for lining up rifles, etc. - and mount it in your chuck (in your case with the laster pointing into the headstock, through the spindle bore and out the back). This will greatly help you line up your steady. You can also see how well aligned your chuck is while you are at it - does it project a spot or draw a circle on the wall when the lathe is turning? Though, with a cheap laser pointer, that error may be in the pointer itself.

I made a very simple steady from a couple of casters, some dexion and a lump of wood. I clamped this in a Black and Decker Workmate which allowed easy adjustment of height and left-right position and was also suprisingly stable. Hold a 1" diameter stump of whatever on your casters and align the steady it so the laser dot (or circle!) is central on the 1" diameter face. Ideally have the casters contacting the bar at 90 degrees to each other, 45 degrees either side of the underside of the bar. You may have to stagger them to fit on such a small diameter. Though it sounds like other people's ideas for a steady with more friction would work just as well.

You might want to run your cutting speed a little slower than usual just to be on the safe side, but I don't think you'll have too much trouble with 4.5' of 1" steel whipping around too much especially if you make a steady.

I would put the steady about 1/3 of the exposed length of the bar in from the free end.

Cheers, Matt.

Been there, done that. In a brain dead moment I tried to turn the end of a thin bar with lots of metal sticking out of the back of the headstock. It was "really" exciting in that second or two before I hit the stop button!