long roller question

I have small machine shop in rural area. Most of work I get is smaller work. I have two manual mills and a 17X 80 Clausing lathe. I have about 3 times a year a order for a 101 1/2" low speed roller.

I have been making them on the mills, by laying tubing across both table and using right angle attachment and then counter boring ends. This is a very awkward way to do it but it is the only way I can think of to do it here.

Does anyone have any thoughts on a better way?

I have a pretty rough idea of what you have going on here, I'm guessing the c-bore is for a bearing?

These wouldn't be for a rolling tailboard would they?

What is wrong with using a steady rest and C-boring them on the lathe?
Are they longer than your lathe?
What is the diameter?

Cheers Ross

Fixed steady rest on lathe, vee or clamp block (on centreline) in the tool post, cutter in chuck - tube in rest and clamped in post & feed in to cutter - like shelling peas.

The rolls are 6" dia. and about 2 foot longer than lathe bed. My steady rest will not go around them. The rollers are for a converyor that removes wood chips.

Are you boring the ends to accept a bearing?
If the rollers have shafts on the ends, you might try DOM tubing and just shrink ends into it with the shafts already turned to size. I do many rollers like that.

Think Sami has it....If your steady is too small buy a cheap "V" block and make a riser to mount it to the lathe bed in place of the steady.
Better would be a pair of ball bearings mounted like the fingers of a steady, but large enough to support the tube. The bearings would be fitted so that the tube could roll forward or rear along the lathe axis (bearing axles ar right angles to the bed of the lathe)...of course you have to remove the tailstock to use all this.

Mount the boring head on the spindle and cut the c-bores. Once you make the support and clamp for the cross slide the setup would be quick and accurate without having to screw with tramming or jacking your BP all out of whack....
Cheers Ross

charis said:

The rolls are 6" dia. and about 2 foot longer than lathe bed. My steady rest will not go around them. The rollers are for a converyor that removes wood chips.

Click to expand...

Make up a vee block - hard wood will do - that sits wherethe tailsock rides, make a vee block for the tool post / cross slide and clamp with a chain?? - bore from chuck as before.

IME a bit of time spent in preparation for jobs like that pay dividends.

OR.... Take the job to a shop that is equipped to do it, and work on things more suited to your machines. Remember, the bottom line is making money, not making parts. I like to do as much in-house as I can, but some jobs just aren't worth the time spent on them.

Charis, if you use your lathe as sort of a boring mill, then the steady would be unnecessary.

Fabricate a cradle to secure the tube centered, attached to your carriage and a second support that is placed near the right end of the lathe bed, that has some mass and is confined to slide on the ways, like a loosened tail stock.

The cradle could be as simple as a 1/2" or greater thickness, V'ed plate, drilled to bolt against your carriage, like most follow rests do, a locating shelf milled across, to solidly seat on the carriage, the top corners of the cradle drilled and tapped vertically, to tighten down a cross bar, use padded vise chain....or...

A cable or tie-rod, between the carriage and tail stock, the part secured in the carriage cradle and a pipe center in the tail stock advanced into the part, tensioning the cable/rod 'til the assemblage is ridgid. A little extra way oil....

Then a boring head mounted on a shank that matches your lathes spindle taper, (#5MT on my 17") or a straight shank that you can mount in a chuck, carriage feed doing the work.

I think that I'd arrange the seats of the cradle(s), as non-marring, smooth-topped brass bolts, say 1/2", radiating inward @ 120° and 240°, (top being 0°), with lock nuts, making centering on the lathe easy and making the fixture adjustable for other diameters.

A fixed stop, say a downward projection of the cradle that stops against the front or back way, could be incorporated to quickly center then lock the cross feed each time the fixture is mounted.

I have several shop-built fixtures for my 17" lathe that require removing the compound, no problem, just 2 bolts. That should easily provide for a 6" + swing over the carriage.

My shop is not nearly big enough for all the machines it would take to equal the versatility of my fixtured lathes and mills, while my investment is a tiny fraction. To me, the way to go for seldom but repeated jobs.

A V-block fixture secured to the table and the boring head in my K&T horizontal would quickly set up the job for me.

Bob
Edit: see what happens when you type too long......

Conveyor roller applications may not be all that precise. What we usually do is make dual flanged spools, with the stub shaft sticking out one side. (A full length shaft through the roller is not required). For a six inch roller, the flanges might get spaced 6 to 8 inches apart. Both flanges get welded to the shaft (or if you want, you can fabricate removable hubs), and the flanges get OD turned to a close/tight slide in fit in the pipe. If you go loose with the fits, the stub shaft could end up wobbling so you need to take a series of measurements inside the pipe to get an average diameter, ignore the distorted area right beside the seam, as you should grind the seam smooth anyways. To the average inside pipe diameter, add about .005 to .010" to obtain an OD value for your flanges.

Heat shrink is a good method to get a more snug fit of the flange in the pipe, since pipe can be wavy, particularly near the weld seam. Make sure to turn the flange ODs so that they run exactly true with the stub shaft. Then after assembling the spools into the pipe, weld the outer flange into the pipe. Typically, the pipe does not need any boring at all. If you need to crown the roller afterwards, you'd have to machine the OD regardless of how much pain you took to install the shaft and flanges.