turning acrylester pen blanks

[CORY FETZER]

is there a special turning tool or trick to turning these composite blanks i have no trouble with any wood or deer horn but when i try to turn these with a harbor freight 1/2 in gouge or round nose scraper they just shatter even tried the benjamins best bowl gouge still no luck

[Keith Christopher]

is there a special turning tool or trick to turning these composite blanks i have no trouble with any wood or deer horn but when i try to turn these with a harbor freight 1/2 in gouge or round nose scraper they just shatter even tried the benjamins best bowl gouge still no luck

Cory,

when turning these you have to make sure of a couple of things.

1) make sure the tool is sharp and cutting not chattering it away
2) make sure you have a VERY good fit between the tube and the acrylic
3) take your time and don't ride the bevel too much as it will heat up the acrylic (see step 1)
4) slower is better for these. From drilling to spinning.
5) Go with even speed and pressure when turning them DO NOT try to take too much off at once.


ok more than a couple, but I have shattered my fair share of these believe me. Good luck with future turnings.


Keith

[Dennis Peacock]

The best tool I've used on them is a 3/8" spindle gouge. The key thing is making sure your tool is "sharp" and I use a finger as a guide against the toolrest as with the bevel rubbing will generate heat and that's one thing you do not want with the composite pen blanks. I do turn them rather fast on the lathe but use a lite touch with the tooling.

I also wet sand them while on the lathe with water as the lube. Works good. :)

[Frank Fusco]

Even though I eschew synthetics for pens, I have done a couple. Blow-outs, whether with wood or plastics, usually occur for two main reasons.
One: The lathe is not fast enough. A pen blank can be turned from square at very high speed. This avoids catches almost 100% of the time.
Two: Glue is not applied evenly on the tube/interior. Be sure to rough the tube and be thourough about distributing when placing inside the blank. Some folks treat the inside of the blank with CA prior to glueing the tube in.
Other causes are tools not being sharp and just plain not being careful when starting your turning to round. Light touch is the key.

[Daniel Heine]

Hello,

I ruined several of the acrylic blanks before I finally developed a method that works for me. I took one of my Harbor Freight roughing gouges, and reground it to a much longer bevel, about 25 degrees, then honed it on a paper wheel impregnated with chromium oxide, and buffed it on a floppy wheel with floppy compound. This created a tool that was very sharp. I turn at about 800-1000 RPM's, and take very light cuts. The key is to shave the edge off until you get it round. Once it is round, you can be a little more agressive, but still not like wood. Once I have the shape I want, I smooth it first with a round nose scraper that is very sharp, and finally with a skew.

For finishing, I sand with 120, 400, 600 grits, and then proceed through the micromesh grades. Next, I apply tripoli directly to the blank while spinning on the lathe, and buff it off with a clean, soft white cloth. Repeat this process with the white diamond, and you have a beautiful pen!!

I am still trying to figure out the crushed velvet blanks, they break at any moment, and with out warning. I think I'm done with those, however.

Good Luck,
Dan Heine

[Bill Boehme]

A bowl gouge certainly won't work very well because the bevel angle is much too large and it is hard to keep a bevel angle that large sharp enough. I would strongly recommend using a skew chisel. A skew can't be properly sharpened on a dry wheel bench grinder -- if you can't pull a sheet of paper across it and have it cut cleanly then it is not sharp. I would suggest a wet grinding system or if you have lots of time on your hands, the monoctystalline diamond whetstones.

Bill

[Mike Vickery]

I am with Frank on this
I turn these at a very high speed. Highest or second highest on my Jet mini (not sure the RPMS's but I thinl highest is 4200 and 2nd is 3600).

Freshly sharpened tools. I use a 3/4 roughing gouge then move to a skew chisel light cuts with both.

[CORY FETZER]

thnks for all the suggestions ill get some more blanks andd trt try again