Author Topic: Finishing Tool (Read 9391 times)

khand · « **on:** November 15, 2009, 01:41:12 PM »

Here's a tool I like to pass along. I found it on yahoos 7x12 mini lathe forum. I have been using it for awhile now and always got a pretty good finish.

dsquire · « **Reply #1 on:** November 15, 2009, 04:14:20 PM »

Khand

Nice find on the tooling tip. They use the same principle on that is used on a wood lathe. With a cut like that you shear off the material rather than scrape it off. It will be interesting to see what the response is from the rest of the members.

Cheers

Don

Bernd · « **Reply #2 on:** November 15, 2009, 04:58:11 PM »

Yeah, I've got an observation. In the pic were he says the tool is in the cutting orientation. Why does the tool look like it's upside down?

Then in the third pic down from that he say's "Here’s the finish ground and honed tool bit mounted in my QC tool holder ready for use." It still looks like it's upside down.

Now I'm having a

while I'm typing this and don't think I'm drunk yet. So could somebody explain the optical illusion to me.

Also I have to vent a bit here. Again it might be the

but the pics of it mounted in the machine all look a little dark to me. Can't make out any detail.

Ok. Enough said. Back to my

I mean no disrespect to you khand. Thanks for posting that but I just needed to ask those questions since it does look to me like it's mounted upside down. As far as the picture quality goes they are good, but a bit on the dark side.

Bernd

dsquire · « **Reply #3 on:** November 15, 2009, 05:10:33 PM »

Bernd

Look closely at the last picture on page 4. That shows clearly the position of the cutter to the work and how it will use a slicing action rather than a scraping action to remove material. This is the same idea that wood turners use when using the skew chisels. Hope this helps.

Cheers

Don

Russel · « **Reply #4 on:** November 15, 2009, 05:24:52 PM »

It appears to me that the left side of the HSS tooling is used to make the cut. It is ground at an angle, with the side cutting edge bottom closer to the headstock and the top closer to the tailstock.

Bernd · « **Reply #5 on:** November 15, 2009, 05:28:21 PM »

Don,

I brightened up the screen. I now can see how the tool works.

Thanks. I think the wife gave me to many

today.

Time for another

Bernd

khand · « **Reply #6 on:** November 15, 2009, 05:48:54 PM »

No disrespect taken. This was a file I downloaded. I have never seen this tool anywhere else so I just like to pass it on when I can. You're not using the top like on normal cutters, but rather using the side of the tool. Set the tool so the top is anywhere above the centerline and the bottom of the tool is below the centerline. If I'm turning to a shoulder, I set the tool as high as possible to I can get closer to the shoulder.

andyf · « **Reply #7 on:** November 15, 2009, 06:43:28 PM »

I've had one of those tools for a long time - it's described in my 1962 copy of "Using the Small Lathe" by L C Mason (I bet they called him "Elsie" at school)

.
It gives a nice finish on final cuts of 1 thou or so. You can't get right up to a shoulder with it, though, because the bottom corner of the cutting edge is nearer to the headstock than the part which is doing the cutting, .

Andy

joegib · « **Reply #8 on:** November 17, 2009, 06:02:06 AM »

Here's an extract from the book "Using the Small Lathe" mentioned by andyF and describing this tool:

It's different from the tool mentioned by the OP in being made from circular section tool steel. That allows you to vary the angle of attack from 45 degrees if that produces a better finish. True, you can't use the tool right up to a shoulder but you can reduce interference by packing up the tool so that only a part of the 'south west' edge is at workpiece centre height. I suspect it's easier to make than the version using square tool steel. Basically, it's a circular bit with a notch ground out using the corner of the grinding wheel. It's not a hogging tool — you wind it in until it just touches the work surface and the swarf comes off like a cobweb.

Joe

khand · « **Reply #9 on:** November 17, 2009, 01:51:26 PM »

I used a belt sander to make mine but a round tool looks like it would be easier. Scoop up those cobwebs and you got a ball of steel wool to polish the part a little more.

dsquire · « **Reply #10 on:** November 17, 2009, 02:54:46 PM »

Quote from: khand on November 17, 2009, 01:51:26 PM

I used a belt sander to make mine but a round tool looks like it would be easier. Scoop up those cobwebs and you got a ball of steel wool to polish the part a little more.

khand

Now that is being resourceful! The cobwebs that you can't use yourself you can package up and and market.

Cheers

Don

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