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Using a roller turner on an engine lathe "video"

Ray Behner

Diamond
Joined
Mar 27, 2009
Location
Brunswick Oh USA
Got a job making (I don't know how many) coating rods for a company. Don't even know what they're for. They're made from 8mm material with each end turned down to 6mm. One end at 60mm in length, the other at 101mm. Made a prototype and silver brazed the ends in. Figured I'd get a roller turner and give it a try. What a treat to use this little rascal. It's an 00RT Boyar Shultz that has been modified by DT Tools in Tampa, Fla. He made an adapter to accept a CNGP 431 insert. This just takes all the time out of the job!
1 175 - YouTube
 
I built a similar contraption when I worked at the museum to turn a 1ft long 1/4" rod down to .200 to make a part for the Browning .30 cal we found in the nose of the Lake Murray B-25. Had to turn the first 1/4" or so to size chucked up close, then move it out, engage in the rollers and the rest was one pass.
 
Nice one Ray,.......I do the same on my 10'' SB clone, ...........in case you don't know, due to the burnishing effect of a roller box you can use a large radius tip push the feed right up and still get a fine finish
 
Got a job making (I don't know how many) coating rods for a company. Don't even know what they're for. They're made from 8mm material with each end turned down to 6mm. One end at 60mm in length, the other at 101mm. Made a prototype and silver brazed the ends in. Figured I'd get a roller turner and give it a try. What a treat to use this little rascal. It's an 00RT Boyar Shultz that has been modified by DT Tools in Tampa, Fla. He made an adapter to accept a CNGP 431 insert. This just takes all the time out of the job!
1 175 - YouTube

Nice one Ray!
 
How do you set that up? Do the rollers engage the material before the insert?

On my Boyer Schultz roller box tools, the rollers bear on the finished diameter, a little bit behind the cutter edge.

I have heard that some box tools have the guide out ahead of the cutter and guide on the stock diameter.

Larry

B-S box tool 2.JPGB-S box tool.JPG
 
I have 2, one for HSS and one that has an insert. I want to try using it in a turning center, don't want to crash it because I can't feel what's happening.
 
W&S makes a goofy looking one, where the rollers swing in, you can telescope them
out a bit on the single shaft, to set them ahead of the turned dia.
 
I have some insert tools made to fit in the place of the HSS tool
on the box tool, however I looked up the number (stamped on the side) in the Kennametal
catalog, no longer made....
It had a positive rake tool, set up to shear very nicely, much
like when you grind the HSS tool.

Ray's inserted tool looks dull, I have run a box tool on my little
logan 9" taking 3/4" dia stock down to 3/8" dia. in one nice pass.
The HSS toolbit has shear in 2 directions IIRC.
 
I have some insert tools made to fit in the place of the HSS tool
on the box tool, however I looked up the number (stamped on the side) in the Kennametal
catalog, no longer made....
It had a positive rake tool, set up to shear very nicely, much
like when you grind the HSS tool.

Ray's inserted tool looks dull, I have run a box tool on my little
logan 9" taking 3/4" dia stock down to 3/8" dia. in one nice pass.

The HSS toolbit has shear in 2 directions IIRC.

I would REALLY like to see a video of THAT.
 
I've run box tools on the turret, but never rollers.
under flood mineral oil, is there any advantage to the rollers? The seem so bulky.
 
Got a job making (I don't know how many) coating rods for a company. Don't even know what they're for. They're made from 8mm material with each end turned down to 6mm. One end at 60mm in length, the other at 101mm. Made a prototype and silver brazed the ends in. Figured I'd get a roller turner and give it a try. What a treat to use this little rascal. It's an 00RT Boyar Shultz that has been modified by DT Tools in Tampa, Fla. He made an adapter to accept a CNGP 431 insert. This just takes all the time out of the job!
1 175 - YouTube

Ray,

Those are great tools, I agree. I have two of the smaller box tools, the 000RT, one size smaller than yours.

Do you know how much DT Tool charges for the conversion kits ?

I see them on their website, but no prices. I think I may have to ping them as I didn't see any on ebay, only box tools with the conversion which is probably what you bought. Looks convenient over grinding cutters. I do currently grind HSS tool bits, into a V as I've seen them in the past, but the DT Tools looks like a better mouse trap.
 
On screw machines this was standard practice.There was(is?)one type where the tool is spring loaded so that as the tool made contact with the material it would push back against the spring. At the end of the cut the tool would withdraw and the spring would push the tool bit forward. This eliminated any return mark. In the example Ray shows it looks as if the rollers are too far behind the tool bit which can lead to a dodgy start.For a different way to get a similar result you may want to look at a pointing tool holder. This has a guide bush in front of the tool bit.

The TANGIFLOW Auto Retract Roller Box ? Auto-Retract Roller Boxes Archives - Tangi-Flow
 
So if you had a box tool with a fixed gap between the cutting tool and the rollers but could move sideways relative or "float" to the spindle axis, would it automatically centre around the bars axis of rotation?.
 
Not really sure what you are saying but the diameter is set first and then the rollers are adjusted to suit. Sorted?

Sounds straightforward, I was wondering if the whole assembly could move up and down and in and out, would it self centre along the axis bar being machined?. So if your lathe
ways are worn and drops toward the chuck end it wouldn't affect the diameter of the bar.
 
The main block of the assembly goes in a turret hole and is fixed,the only adjustment is length. The tool bit is put on centre and adjusted for size and then fixed.The rollers are then adjusted and fixed. I cannot imagine the toolholder being able to lift everything back on centre due to wear,that sounds like trouble. Sorted?

That explains a lot, thanks!. I had a bit of a look round and found photos of floating drill and reamer holders for old Brown and Sharp machines: seems they were adjusted on centre and the adjusting screws locked for use.
 
Box tools are quite easy to get your head round when you've one in your hand so to speak.

My setting method is - using the cross slide / front carriage ''conventionally'' turn a short piece of the material the dia you want, set each roller so it just touches, e.g. with the lathe running you can stop the roller by putting your finger on it, lock the rollers slides.

With the cutter of centre height, set it to the dia of the set up piece not forgetting to lock the slide / tool, .run a test cut and check the dia, ......only adjust the cutter if necessary!

The tip of the tool should lead the rollers by 1/64 - 1/32'' though you can lead by more on larger dia work say 1 1/2''+ finish dia.

DON'T use roller boxes on short chipping mats like brass and CI, the fine chips get between the finished work and rollers and mess up the job - for those mats use solid steadies which can be carbide faced.

One handy trick / tip when running brass which sprays off the tool in fine chips and makes a hell of a mess, is to turn the box tool ''upside down'' to direct the chips straight in to the pan.

Another handy dodge with brass & CI is to cover the whole chip tray and coolant outlet grid with 2 o3 layers of hessian sacking, - it stops the fine chips going in the coolant tank and makes chip removal a doddle.

Roller boxes aren't just for small work, when I was a lad I made 00's if not 000's of special 7/8 bolts, ex 2 1/4'' dia EN24T (your 4340 HT - I think?) .that 2 1/4 to 7/8 was done in one cut @ <> 0.012'' / rev feed - to finish size ......without loading a 10HP motor anything like fully.
 
Ray,

Those are great tools, I agree. I have two of the smaller box tools, the 000RT, one size smaller than yours.

Do you know how much DT Tool charges for the conversion kits ?

I see them on their website, but no prices. I think I may have to ping them as I didn't see any on ebay, only box tools with the conversion which is probably what you bought. Looks convenient over grinding cutters. I do currently grind HSS tool bits, into a V as I've seen them in the past, but the DT Tools looks like a better mouse trap.

I paid 248.00 for the RT and the adapter with insert. Oh, plus the owner is a trusting type fella and nice to talk to.
 
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