drilling and cutting acrylic blanks

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229
Location
Vernon, WI
Hey everyone, I did a search and tried to find answers before I post this, but I couldn't find anything. Just a couple of quick questions. I am not much of a pen maker and I have never tried acrylic. Can I drill this stuff with a normal sharp twist bit without it blowing up? Also, I talked to the owner of my local Woodcraft and he told me to make sure my tools are sharp and I will do this, but I forgot to ask him if I can use a parting tool on the acrylic.

I bought 2 European pen kits because they were on sale at Woodcraft. They are going to be Christmas gifts. I made one last night (will post pics later :thumb:) and realized that you need to make a tennon on one of the blanks. Can I use my parting tool on the acrylic without blowing it to pieces?
 
I just did an acrylic pen. I used a brad point bit. The parting tool needs to be sharp and it works fine. Where the chipping came was in using the barrel trimmer. The Woodcraft guy I got my stuff from showed me a small sled to sanding blanks flush to the barrel. Its what I should have done! :( I had to turn a very thin, very narrow wooden 'ring' to make up the difference in length, which is crucial. :eek:

He used a disk sander. The sled was a vee shaped holder absolutely perpendicular to the sanding disk with a slider bar that rode in the miter slot. No pics yet. I haven't built one yet. I will before I turn another piece of acrylic. The barrel trimmer just shattered the end of the acrylic, and it was the only piece I had, and the wedding was 3 days away and Woodcraft was 100 miles away!

BTW, I polished with a polishing compound for acrylics that I got from a plastics distributor. It put a very fine shine on that pen. HF also carries those compounds.

Probably more than you wanted to know.
 
I've definitely blown up a bunch of blanks, both acrylic and wood. I'll ditto what Carol said on keep your tools sharp, and using a light touch.

But when you polish those acrylics up, you will be happy with the results!
 
Wes,
The European is the pen I learned first... the tenon isn't a really big deal... key is sharp tool. I use a very narrow little wood chisel that I had laying about that I sharpened to make a mini tool to do the tenons... I use it on wood and acrylics.

Drilling, you can use any good sharp twist bit, but don't try to drill all the way through in one pass... drill a short distance, back out and clear the hole, then drill a little more etc.... some people also use a few drops of water in the hole to keep the bit and the blank cooler... it's messy and while I have done it, I don't much.... also I drill on the lathe, at a slower pace and can stop and back out more often. Also a lot of people will cut the blanks overlength, then drill to depth, but not all the way through the blank, then take the blank to the band saw and cut to length... most break out - for me - occurs when I exit the blank... so I always make the blank about 1/4 inch longer than needed and allow for the break out. On the lathe, I can slow the advance of the bit to a crawl and I get less now.

I still use the pen mills to square the ends, but you have to make sure the mill is sharp. I mill with the drill press and usually run at about 1100 rpm.

When you turn the blanks, I'll sometimes take the corners off with a scraper, but most of the time I use my big skew.... I run the lathe at about 2600 +/-, take light cuts with the skew and make sure you're doing a sheer cut... after you've done this, you'll need little sanding, but I always wet sand with the little foam pads that PSI sells... 600 through 12000, wipe with water between grits and then polish with a plastic polish. I use the HUT because that's what I have.... I've also read that McGuire's Auto polish is great.

Acryllics really aren't the bears they are made out to be... just take your time and don't rush any of your steps. You'll do fine.
 
Lot of good responses so far.
But, understand, not all acrylics (synthetics) are born equal.
Blowing up blanks while drilling is just too easy.
Best bet is to cut blank long, drill but not all the way through then cut to proper length.
Turning is different than wood but learning curve is short and quick.
Sanding and polishing can be done several ways. Micro Mesh is good. Special sanding pads, just for acrylics, work fine. But, with both, stay away from the coarsest grits. They will put scratches in so deep you might not be able to sand out. Usually, you can get a fine glossy finish without any coating.
As others have said, the 1/4" parting tool will make the tenon just fine. After you have done one you will be an expert.
Pictures are mandatory. ;)
 
Carol, Brent, Chuck, Frank, thank you very much for all of your responses. I didn't take time to write back right away, I just waited for some answers and ran to the shed to make it as soon as I could :) SO now I am responding with a thank you. I will post pictures of the 2 pens in the showcase. I don't know that I liked turning the acrylic so much. It was certainly different than the wood. Chuck, as you put it... "Acryllics really aren't the bears they are made out to be... " I would have to agree that it was easier going than I expected. I just didn't like the trail of shavings that built infront of my gouge the whole time. It made it hard to see what was ahead and get the exact shape I wanted. Oh well, still fun :) Pics are comin!
 
I have to agree with all of the post. The key is to cut your blanks a 1/4" or so longer than you need. Measure and tape your drill bit at the length you need. Don't drill all the way thru. Drill and the then cut off the end. Sharp tools are a must.
 
I just didn't like the trail of shavings that built infront of my gouge the whole time. It made it hard to see what was ahead and get the exact shape I wanted.

Doh! Forgot to warn you about that. Yeah, you can get some real nice long strings that wrap around and around.

I find when I do them I stop pretty often to clean those off so that I can see the profile.

Saw the other thread. Looks like you did a great job!:thumb:
 
I just didn't like the trail of shavings that built infront of my gouge the whole time. It made it hard to see what was ahead and get the exact shape I wanted. Oh well, still fun :) Pics are comin!

Wes,
Another trick that Ed Brown from the IAP showed at his demo.... keep a good clean wire brush handy and every so often stop and take the brush and wipe away the shavings.... they tend to wind around around the mandrel, the blank and everything else, but a quick side to side swipe with the wire brush clears them away. They are definitely a pain..... Looking forward to your pictures.
 
I have a set of brushes (like you buy at the cheap box at a gas station/convenience store) of three, a brass, a wire and a stiff plastic one. Keep one at the drill press to clean the flutes on my drill bit, and use the other at the lathe to catch and clean off these plastic shavings. Works well and safer than sticking your fingers in there (I use this while the lathe is running).
 
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