View Full Version : lathe / Slip Roller (pix)

10-17-2004, 01:56 PM
necessity the mother of invention?

needed to roll some thin stock into tubes and cones and threw together a 'lathe accessory' .. probably not the best thing for my lathe, but on thin stuff, it went easy as pie.



crossslide adjusts the amount of bend.. swinging the compound a few degrees makes cones.


Allan Waterfall
10-17-2004, 02:00 PM
Clever idea,I like it.


10-17-2004, 02:00 PM
Man, that's clever.

G.A. Ewen
10-17-2004, 02:20 PM
Excellent! http://bbs.homeshopmachinist.net//cool.gif

10-17-2004, 02:46 PM
of course, soon as i made it, i needed
something beefier. had to rolle 2 mm sheet
and the rolls were deflecting / pivoting on
my toolpost nut.

so i hammerformed the cone first, real rough, and welded the seam. heated the whole cone to deep red and quicly gave it a run through on the 'slip roller'... evened it right out.


Dave Opincarne
10-17-2004, 03:08 PM
Great idea! If it can handle knurling it should be able to handle this. Just make sure to check the speed before sending something through! http://bbs.homeshopmachinist.net//biggrin.gif

[This message has been edited by Dave Opincarne (edited 10-17-2004).]

Dave Opincarne
10-17-2004, 03:13 PM
Hey, what about a pair of roller bearings at each end riding on the drive shaft. Adjusting the gap between each pair would allow you to make both conic and radial adjustments and might reduce some of the strain on the cross slide.

Adendum: Adding a bearing to the backside of the rollers could help to relieve deflection as well.


[This message has been edited by Dave Opincarne (edited 10-17-2004).]

John Stevenson
10-17-2004, 04:29 PM
Hey Tony I like that.
That's a neat idea. I have been looking for something that can roll 1-1/2" x 1/4" into rings for bearing sleeves.
Using this idea and the big lathe down to 31 revs I could have a mandrel for each size.
If I made the mandrels out of alloy and used two ball races for the adjusting rollers I could roll it round, take it out the lathe, clamp it and weld the two ends up.
Then put it back in the lathe to skim the outside up, all on the one former.
Being in alloy would stop the weld sticking.

I'm going to the East Midlands Model Engineering show tomorrow to look at a ring roller but I don't think it will do a continuous roll and I will still have to make mandrels to skim up afterwards with the added disadvantage of matching the rolled ring to the mandrel.

At least this way it's all done off one mandrel.

Woweee I've done real good off this list this week.
A sacrificial washer for shaft repairs and now a ring roller.
Just goes to prove you never stop learning.

Thanks guys.

John S.

10-17-2004, 05:49 PM
careful, though, as you're limited to the lathe swing on rolling diameter. maybe if you take the gap out, and your ring isn't too wide.

it would be best if the follower roller (the one opposite from the side you are feeding -- ie, the bottom of the three in this case) were also driven. usually these are driven by the drive roller (which, in turn, is driven by hand or motor).

if the parts are light enough, a simple 'rubber band' might do. by rubber band i mean small flat belt. you would have to 'tension' it when the rollers are dropped into the toolpost.

make them as short as possible for the job at hand, as it will minimize the bending.

10-17-2004, 05:55 PM
I like this !!

John Stevenson
10-17-2004, 06:00 PM
I was thinking of using the TOS, it's 22" swing and the biggest ring will be about 6"

I think driving the lower roller may be hard without a lot of thought. I was thinking about using a couple of scrap ball races side by side as the maximum width I need is 2" in 6mm or 1/4" section.

It looks to be that simple to built a single side short version that it will pay me to just try it and see what the results are.

I won't have a lot of time tomorrow as I'm going to the East Mids show and I'm quite busy at the moment. I'll have to see what I can cobble up.

Thanks again for the idea.

John S.

10-17-2004, 06:47 PM
be sure to post a picture or two when finished.

food for thought: all of the big pro rolling machines use a rubber roller (urethane coated) with steel mandrel form roll.

if i'm not mistaken they might only have two rolls, urethane and steel, not 3 like the lighter versions.

press a rubber sleeve onto a bearing, load it in the toolpost like a single-wheeled knurling tool, press that against undersized mandrel (in chuck) ... load the cross slide until you reach finished size.

laser printers tend to have nice rubbercoated rollers.


10-17-2004, 07:00 PM
Well done Tony, and thank you for shareing the idea with us.

I have one thought though, and I know some will say here we go again. But please be carefull with powered rolls like this. They might be going slow, but there is a deceptive amount of potential in there.

I guess I'm a little jumpy as I have seen first hand a fellow worker put his hand through some power pipe rolls, and it wasn't a good job cleaning up and having to removing the fingers he left behind stuck to the rolls. They made quite a dong when they hit the bottom of the rubbish bin. He was rolling full lenghts of pipe and could easily have stayed 3 feet away from the rolls, but for some reason and a moments inattention it happend.

10-17-2004, 08:22 PM
Really cool! Just looking at it,if you are having trouble with the thicker material deflecting the rollers,why couldn't you back up the rollers in the middle with a set of roller bearings and use a heavier shaft between centers? Just a thought.

10-18-2004, 12:57 AM
That is really a neat idea.


John Stevenson
10-18-2004, 07:48 AM
Don't work on thick stuff.
More later - off to the show.

John s>

Alistair Hosie
10-18-2004, 04:28 PM

enjoy enjoy enjoy enjoy http://bbs.homeshopmachinist.net//biggrin.gif Alistair

John Stevenson
10-18-2004, 05:45 PM
Well i made a tee piece up this morning out of 1" square and bolted two ball races to it and put it in the toolpost.
Put a piece of 4" steel in the chuck for a mandrel and set that lathe in low.
Found out it did 22 revs and not 31 as I thought http://bbs.homeshopmachinist.net//biggrin.gif

I decided to try it on a piece of 1" x 1/8" to start.
After feeding this in about 10 times I had a curve equal to a banana but it was wanting to push the bearing out of plumb.
I could have got it bent more but it would have took a lot more pases and I don't feel it would have rolled a full circle even in 1/8" material.
As I want it to do 2" x 1/4" max it's a no goer.

Oh well not a lot lost, couple of bits of steel and about an hour.
Went to see the ring bender at the show but it was more puny than my setup and was £180 odd quid.

John S.

10-19-2004, 02:59 AM
the Ring that 3 rollers will make is more or less the circle described by the two points in contact between the 3 rollers.

if your mandrel is too big compared to your rollers, or your rollers are too close together, the ring it will roll will be enormous, no matter how hard you push against it.

for reference:
my setup uses two 30mm rollers on the turret spaced 35mm apart (5mm gap) and a 25mm mandrel in the chuck. the tightest this will roll is about a 50mm ring.

if the stock i run through is shorter than what it needs, it will roll a 'banana' with a 50mm radius.

to get a 1" ring, i would have to use a 10mm mandrel and eliminte the gap between the turret rollers.

1/4" strap shouldn't be a problem.. if your setup is rigid.. you'll need to do alot of passes, but its certainly doable.


John Stevenson
10-19-2004, 03:59 AM
It was just a test, I wasn't bothered about size of ring just the idea.
With 1" x 1/8" I was putting to much force on the lathe for what I was happy with.
If I had a big clunker I may have but this TOS although old and ugly [ I bet that describes most people here http://bbs.homeshopmachinist.net//wink.gif ] is still an accurate lathe.

Going up to 2" x 1/4" I feel is just too much.
Plus the many passes needed.
Not knocking your idea, I think it's great on the thinner sizes - just me trying to get a gallon out of a pint pot http://bbs.homeshopmachinist.net//biggrin.gif

John S.

Dave Opincarne
10-19-2004, 11:09 AM
John - Could smething like that be hot formed and heat treated after?