Sheline cnc lathe

[Glen Hendricks]

Hello all,
Well I am going to buy a Sherline cnc lathe,
and I will be making pen and pencil sets and rings.
I will be making these out of acrylic stock.
I am going to use inserts to cut with. Now this is my question.
Which insert tool should I use? I plan on using inserts for all my cutting,
I don't like sharpping cutting tools. Any help would be great, Thanks
for any help you can give me on this..
Glen

[iDesign]

Hello all,
Well I am going to buy a Sherline cnc lathe,
and I will be making pen and pencil sets and rings.
I will be making these out of acrylic stock.
I am going to use inserts to cut with. Now this is my question.
Which insert tool should I use? I plan on using inserts for all my cutting,
I don't like sharpping cutting tools. Any help would be great, Thanks
for any help you can give me on this..
Glen

I know someone who machined Acrylic optical rods using a diamond bit and high speed spindle. His rods had a polished look when they came off the lathe. Amazing!

Sherline has a high speed upgrade that lets the lathe run at 10,000 RPM. I would consider using the diamond bit and 10,000 RPM speeds to get the smooth finishes you want.

[knudsen]

I always have trouble with it melting, but I probably wasn't doing something right. I love machining it though.

I use it for handles mostly, "one-offs", but if I did production, I would want some kind of cooling. Compressed air might be all you need. I'm pretty sure I used HSS, I'll bet the diamond cuts cooler. Maybe a slight melt contributes to the fine finish you saw.

Play around and let us know what works out!

[blades]

Diamond cutters sound a bit expensive. I'm also looking for some sort of small carbide insert cutting tools for acrylic & hardwood.

For small cutting, I would be looking for an indexable carbide insert cutter with a chip breaker. These types of inserts typically have 3 indexable sides. Some triangle inserts will have 6 cutting edges, but these are usually more suitable for heavy turning, and tend to be larger inserts, with no chip breaker. Would also look for an insert with maybe a .015" radius tip.

EDIT: Here's something from Wholesale Tool
http://www.wttool.com/category-exec/...ols_Micro_100_

[knudsen]

These guys make HSS inserts that fit cheap imported holders.

http://www.arwarnerco.com/warner_products_inserts.html

They definitely make an insert for the 1/4 and 3/8 triangle holders sold by many. Getting something that can hold a HSS might be of value for those unwanting to grind HSS. LMS carries their inserts for the holders they sell. I'm sure the Warner holders are very nice, but they are 4 or 5 x the import price, so I use their inserts on my phase II holders.

[blades]

Nice, thanks for the heads-up on the HSS inserts, Jon. Never knew there was any such thing. I will be looking into those.
I'm a bit disappointed in LMS lack of selection. They have plenty of inserts, but hardly any tool holders. Other than the ultra-cheap one, the couple others they carry are too pricey. Hobbyists don't want to pay $85 for a threading tool.

[knudsen]

It's pretty cool to be able to swap in a HSS insert for a finish cut.

I agree, their wares are not so great when it comes to index tooling. Certainly not very competitive. I think most of the cheaper holders out there are phase II knockoffs, at least the triangular insert ones, and would have a warner insert available. I suppose you could ask the seller what insert their tooling takes, but would they know?

[low_48]

I think you are going to be disappointed with standard insert tooling, machining pen acrylic. I'm a wood turner, and also turn some cast materials for pens. It can be really chippie cutting that stock with anything but a skew chisel. I can't give you any recommendations except to look at some of the polished carbide tooling, with high relief angles, used on the new design hand held chisels. I think one of them is called a Ci rougher? I think you will have a ton of sanding ahead to get a polished surface with insert tooling. Good luck.

[knudsen]

I always loved running a woodworking lathe. I didn't know the correct terminology or forgot it, so I googled "skew chissle" and found this: [nomedia="http://www.youtube.com/watch?v=cQTo1pAIpQ4"]YouTube- JET Tools - Lathe Basics - Skew Chisel How-To[/nomedia]

I remember when I first discovered that technique. It was like opening a door to a new world Well, that was back in the 70's, so there may have been other factors contributing to my excitement

Glen, I hope to see some pics of your Sherline when you get it!

[blades]

Long live the 70's!!!

[Glen Hendricks]

Thats a cool video on the skew chisle,now it would be great if they had one for a cnc lathe. and the 70's was great