Built a Shielded Hollowing Tool

[Raul McCai]

I’d have posted this last week, but because I’m a dummy, I snapped my only M3.5x0.6 roll form tap by mis-reading a chart and drilling undersize and my replacement tap was back ordered so I couldn’t mount the carbide insert. I almost never work metrics and have no developed memory and instinct for tap sizes like I do with inch standard so I should have been more careful but - - well - - that’s me. Always in a rush. Removing snapped taps is always a PITA.


http://i1002.photobucket.com/albums...culated Hollower/Hollower-002_zps9uolwbhf.jpg

My "milling machine" is an ancient Elgin Jeweler's lathe Between that an old Walker Turner Drill Press and a some hand held tools I got 'r dun.
http://i1002.photobucket.com/albums...ated Hollower/20151021_103829_zpsolxvrtuv.jpg

Here is a vid of the sliding hood
Inappropriate YouTube link Removed by Moderator

No inapropriate links intended. No clue how that got there.
EDIT
Lets see if this works It's supposed to be metal parts sliding together so show fitment and action
https://www.youtube.com/watch?v=-Ti-DoZoblI


Here is the very first cut on some maple end-grain that I happened to have in my lathe

https://www.youtube.com/watch?v=bObHhUXazLs&feature=youtu.be

Here is a vid after I shimmed the hood up a tad to give the chips more clearance
I think I like this better. The chips clear the hood without getting jammed.

https://www.youtube.com/watch?v=PAVxYYn3tYY&feature=youtu.be

 

[Bill Boehme]

Raul, I apologize for needing to edit your post and assume that you accidentally put the wrong YouTube link in your post above. I removed it because was political commentary which isn't acceptable. Also, check your second YouTube link because it is a broken link that needs to be fixed.

I like your shield, but are you using it with a square cutter? Also you might want to try a Rolly Munro cutter with your shielded tool becazuse it has a raised rim similar to the Hunter tools which make it a true cutter and not a scraper.

 

[Raul McCai]

Raul, I apologize for needing to edit your post and assume that you accidentally put the wrong YouTube link in your post above. I removed it because was political commentary which isn't acceptable. Also, check your second YouTube link because it is a broken link that needs to be fixed.

I like your shield, but are you using it with a square cutter? Also you might want to try a Rolly Munro cutter with your shielded tool becazuse it has a raised rim similar to the Hunter tools which make it a true cutter and not a scraper.

I Fixed the link, thanks for the edit~!!! I have No clue how the wrong link got there. It's supposed to be two pieces of steel with a button head allan screw with my table saw in the background and no commentary at all.

The carbide insert is round with ha turned up edge to get a cut and not a scrape It's a Kennametal RPHT-EN style cutter. Don't know if it's Kennametal brand.

 

[Bill Boehme]

I Fixed the link, thanks for the edit~!!! I have No clue how the wrong link got there. It's supposed to be two pieces of steel with a button head allan screw with my table saw in the background and no commentary at all.

The carbide insert is round with ha turned up edge to get a cut and not a scrape It's a Kennametal RPHT-EN style cutter. Don't know if it's Kennametal brand.

Where do you buy your cutters. I am paying through the nose for the Rolly Munro cutters.

I think that you did a beautiful job of machining the parts for your shielded cutter. It looks like it slides very smoothly. I really envy you guys with metal working lathes ... but then that might mean that I would have another hobby ... and that could mean I might get more interested in making tolls for woodturning, but spending all my time metalworking.

Comparing your shielded hollowing cutter to the Munro design, I think that you might be able to get the shavings to exit the hole a little smoothly if you use a grinding stone to remove some material at the back edge of the exit hole -- in other words make the hole angle backwards if that makes any sense. Perhaps you have already done that, but just looking at the pictures it appears that the hole is mostly vertical.

 

[Raul McCai]

Thanks for the nice words.

The chip clearance exit hole is in at a 25 Degree angle. I considered rasping it out more in the back end, but when I tried it, I liked it and decided It was good.

The cutter is not the Rolly Munro branded cutter. Or rather I don't get it from them. For all I know it could be identical. I don't know what diameter the Munro cutters are.
I got mine from Arizona Carbide along with the little screw to mount it. It's just a 12mm insert with a shear cutting edge. In that shear cutting configuration he has a 6mm, 8mm, 10mm, and 12mm

On his site they are said to fit" different manufacturers, but it is most unlikely that those wood-lathe-tool manufacturers are getting custom cutters - the cost at their volume would be prohibitive. So I am quite sure that all of them are using stock items from some carbide insert company or another.

Packard Woodworking sells the Munro branded cutters for just under $20 for a two-pack.
http://www.packardwoodworks.com/Mer...CTGY&Store_Code=packard&Category_Code=3qHllw2

That's not a bad price for a carbide insert.


I do tend to get caught up making tools for woodworking.
But then it's a nice diversion.

I just ordered the steel for a three wheel steady rest. The mane frame will be made from 3/8 " plate (to set on the lathe bed) and 1/4" thick 2" square tube.

Sooner or later I'll end up throwing a nice wet hunk of roadside mystery wood in my truck and I'll see if I can hollow something for real with my little tools

 

[Richard Coers]

Thanks for the nice words.

The chip clearance exit hole is in at a 25 Degree angle. I considered rasping it out more in the back end, but when I tried it, I liked it and decided It was good.

The cutter is not the Rolly Munro branded cutter. Or rather I don't get it from them. For all I know it could be identical. I don't know what diameter the Munro cutters are.
I got mine from Arizona Carbide along with the little screw to mount it. It's just a 12mm insert with a shear cutting edge. In that shear cutting configuration he has a 6mm, 8mm, 10mm, and 12mm

On his site they are said to fit" different manufacturers, but it is most unlikely that those wood-lathe-tool manufacturers are getting custom cutters - the cost at their volume would be prohibitive. So I am quite sure that all of them are using stock items from some carbide insert company or another.

Packard Woodworking sells the Munro branded cutters for just under $20 for a two-pack.
http://www.packardwoodworks.com/Mer...CTGY&Store_Code=packard&Category_Code=3qHllw2

That's not a bad price for a carbide insert.

That price you quoted for the Munro cutter is for the HSS cutter. The carbide is $23.95 each.

 

[Bill Boehme]

Thanks for the mention of Arizona Carbide. I agree that there is no way that any woodturning tool maker has "special" carbide cutters made for only them despite any implied advertising. The Munro cutter is 12 mm and uses a "special" Torx[SUP]®[/SUP] screw. So far, I have purchased four of the carbide cutters for a total cost of almost $100. The first time that I saw the Packard price for cutters, I was all excited to place an order until I noticed that was for HSS and not tungsten carbide.

While you are making tools, don't forget to make a big boy boring bar to hold that shielded cutter. My boring bar is made from two 1⅛" solid steel round bars welded together with one of t5he bars extending twelve inches beyond the other.

 

[Raul McCai]

So far, I have purchased four of the carbide cutters for a total cost of almost $100. The first time that I saw the Packard price for cutters, I was all excited to place an order until I noticed that was for HSS and not tungsten carbide.

Oh my~!!
I got a couple of cheap diamond wheels one is 80 grit and one is 180 ( this is the finer of the two: http://www.ebay.com/itm/100mm-Diamo...160027?hash=item233b06d99b:g:TQgAAOSwMmBVzWBm ) from the Fleabay and turned little mandrels so I can pop it in a collet or chuck it on my wood lathe to dress carbide tooling. I imagine a hard wood like oak or maple would make a fine mandrel since a small diamond wheel can be spun slowly and still work great and a little wobble is meaningless when one is holding the cutter by hand.
Put the insert on a long enough screw (with a nut to clamp it) so you can twril it between forefinger and thumb to hold it against the diamond wheel and eyeball the angle and rotate it by hand. A little oil helps. Doesn't take much to get a fresh edge.
Absent a wheel one can use a diamond dressing stone too. Pop that aforementioned screw assembly in a hand drill and spin it against a diamond honing stone.

My boring bar is made from two 1⅛" solid steel round bars welded together with one of t5he bars extending twelve inches beyond the other.

That's a lot of steel~!~!
I have some round steel tube stock 1.375" OD with 1/4" wall that may serve. I can always order heavier stuff if I get much chatter.

Happy halloween