pipemakersforum.com

A quick questions regarding turning ebonite. I'd turned a small length of delrin (at around 950 RPM ) and it polished as it turned. I then turned a length of ebonite and the finish left a little to be desired. It seemed there were areas where it rubbed and/or pitted. Anyone have some constructive input on this subject?

Thanks,

Mark

Sharper tooling and better tool profile/tool angle. You are probably burning the vulcanite.

Delrin is about as easy as it gets for turning. Vulcanite is more difficult, but not bad.

You'll figure it out.

Yep - sharp, sharp sharp. Also, grind a bit of a radius on the leading edge of the bit if you're using a HSS bit. Be sure to set the bit height correctly as well - I find setting it slightly above the center works for me, but others have found that setting just below works also. Once you get it figured out you will have tenons that need absolutely nothing in terms extra finishing steps.

Chalk it up to being an impatient newcomer to turning I suppose. I was using a 1/2" carbide tool bit that was pre-formed. Upon closer inspection of the tool break, I noticed a small chunk out of it's face. I assume this is not part of the design, since I don't account for it when I sharpen a blank. I freshened the tool faces on a belt sander with an aluminum oxide belt and took the lathe again. Better finish now. I then tightened down the tool in the tool post and better yet. At about 550 rpm and the right feed rate I can achieve a good finish.

When turning along the length of the piece, the finish is good. When I take to the face of the ebonite, I can't seem to avoid pitting no matter what I change ( feed rate, rpm, sharpness etc.) What do you use to face the stem/tenon besides a forstner? Since I'll be turning and drilling on this lathe, I'd like to be able to take advantage of it's precision.

Thanks,

Mark

Ixnay the carbide. HSS all the way. Facing the rod should be a breeze, no Forster necessary.

This subject has me totally enthralled- I'm about to go try this exact procedure for the first time tomorrow.

Tyler wrote:Ixnay the carbide. HSS all the way. Facing the rod should be a breeze, no Forster necessary.

Tyler,

To save an hour of scouring these forums, would you mind explaining what advantage HSS might have over a carbide cutting tool? I'm very green here. I do have quite a few 1/4" HSS bits that I've ground but they are for my Taig and I'm not sure if I can use them in the tool holder for my larger metal lathe.

Thanks.

HSS can be ground to a much keener edge than carbide bits typically have. Also, if you grind the bit with a generous radius, you can get a perfectly finished tenon with no need to do any sanding or polishing. They can also be ground to unusual shapes as necessary and can be sharpened in seconds.

Mark Beattie wrote:

Tyler wrote:Ixnay the carbide. HSS all the way. Facing the rod should be a breeze, no Forster necessary.

Tyler,

To save an hour of scouring these forums, would you mind explaining what advantage HSS might have over a carbide cutting tool? I'm very green here. I do have quite a few 1/4" HSS bits that I've ground but they are for my Taig and I'm not sure if I can use them in the tool holder for my larger metal lathe.

Thanks.

What Kurt said.

As for 1/4" tooling, if you can get it to the right height it will work. I use some 1/4" in my 9x20. It takes either shims or an adjustment of the QC tool post.

Soooo what exactly is this radius supposed to look like? I'm trying to grind one that'll get a good finish on my practice Lucite rod... yeah. It'd leaving a pretty shaky finish.

Tyler wrote:

Mark Beattie wrote:

Tyler wrote:Ixnay the carbide. HSS all the way. Facing the rod should be a breeze, no Forster necessary.

Tyler,

To save an hour of scouring these forums, would you mind explaining what advantage HSS might have over a carbide cutting tool? I'm very green here. I do have quite a few 1/4" HSS bits that I've ground but they are for my Taig and I'm not sure if I can use them in the tool holder for my larger metal lathe.

Thanks.

What Kurt said.

As for 1/4" tooling, if you can get it to the right height it will work. I use some 1/4" in my 9x20. It takes either shims or an adjustment of the QC tool post.

Thanks. I shimmed a 1/4" HSS bit that I have for my Taig in the tool post. It works great. I just had to take some time align it correctly but it cuts great. A little more practice is needed to cut the correct 'break' in it though as too 'generous' a break rubs the stock and too little scratches it, but all in all, the HSS is working great. I'm finding that it's leaving a very nice finish on the acrylic but still needs some work on the ebonite.

The Smoking Yeti wrote:Soooo what exactly is this radius supposed to look like? I'm trying to grind one that'll get a good finish on my practice Lucite rod... yeah. It'd leaving a pretty shaky finish.

I'll try to remember to take a picture of one of mine when I get home.