# Need Reconmendation on a bit



## Charles Wong (Jan 5, 2009)

I've been using spiral bits for most of the work I do with acrylic. The Spiral Flush trim for the final pass for a smooth finish, use either a Solid Spiral Bit or a straight bit for prepping the edge for a final pass.

I want to take down a round blank of acrylic to a smaller size(middle pic), then using my spiral flush trim to finish it off, but which can I use to *"hog"* most of the plastic off?

With the current router bit, solid carbide spiral it grabs the piece and very unsafe to use, as you can see by the chunk of plastic it tore out as it grabbed it out of my hand.

Or should I just continue to use a straight for hogging down to size?


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## bobj3 (Jan 17, 2006)

Hi Charles

Why not just use the band saw to hog off most (with in 1/8" of the true diam.) of the cir. then use the trim bit, as you know the acrylic will not cut off clean (in the chip way ) it likes to come off in strips just like with a drill bit way..once hot it wants to stick to the bit..and gull up in the flutes..

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lemonyx said:


> I've been using spiral bits for most of the work I do with acrylic. The Spiral Flush trim for the final pass for a smooth finish, use either a Solid Spiral Bit or a straight bit for prepping the edge for a final pass.
> 
> I want to take down a round blank of acrylic to a smaller size(middle pic), then using my spiral flush trim to finish it off, but which can I use to *"hog"* most of the plastic off?
> 
> ...


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## Charles Wong (Jan 5, 2009)

Thanks Bob, I do have a band saw but it's still not put together since I moved to the wife's house. (no room).

Using the setup that I have now is "nerve racking" bu it's quick. I'll go back to the straight bits and go slower :fie: to hog down the material.


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## jschaben (Jun 21, 2009)

lemonyx said:


> Thanks Bob, I do have a band saw but it's still not put together since I moved to the wife's house. (no room).
> 
> Using the setup that I have now is "nerve racking" bu it's quick. I'll go back to the straight bits and go slower :fie: to hog down the material.


Hi Charles - I've cut circles pretty much down to size with a table saw. I just cut a square, sides equal to the diameter of the circle you want, and then just nibble off the corners with a flush trim bit on the table. 
I also prefer an O-flute bit for plastics. No real chips, just plastic snow. Problem is I've only seen a couple of plastic bits in flush trim dress and they were VERY high $$$. That, and they were basically designed for fiberglass and didn't look like they would leave a very nice edge. I've had some very good results with shear angle flush trims though.


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## bobj3 (Jan 17, 2006)

Hi Charles

You must have a power jig saw it will do the job also.. 

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lemonyx said:


> Thanks Bob, I do have a band saw but it's still not put together since I moved to the wife's house. (no room).
> 
> Using the setup that I have now is "nerve racking" bu it's quick. I'll go back to the straight bits and go slower :fie: to hog down the material.


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## jschaben (Jun 21, 2009)

bobj3 said:


> Hi Charles
> 
> You must have a power jig saw it will do the job also..
> 
> =======


Hi Bob - I've had trouble with cracking trying to use a jig saw on acrylic... Wrong blade maybe? Usually use a coarse wood blade, fine tooth metal? Usually on thinner stock, 1/8" and under.


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## Phil P (Jul 25, 2010)

jschaben said:


> I've had trouble with cracking trying to use a jig saw on acrylic... Wrong blade maybe? Usually use a coarse wood blade, fine tooth metal? Usually on thinner stock, 1/8" and under.


I've had reasonable success using a downcut blade (T101BR) with the work supported near to the edge and no or very limited orbit. I find that wavy set metal blades tend to clog too easily in acrylic. Slightly slower cutting speed can also help

Regards

Phil


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## bobj3 (Jan 17, 2006)

Hi John


For me I don't let the plastic jump up or down I put it in a sandwich type jig with 1/8" or 1/4" thick MDF.
Just cut part of the sandwich at the same time thing..  just about any blade will do the job once it's clamp in the sandwich..

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jschaben said:


> Hi Bob - I've had trouble with cracking trying to use a jig saw on acrylic... Wrong blade maybe? Usually use a coarse wood blade, fine tooth metal? Usually on thinner stock, 1/8" and under.


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## jschaben (Jun 21, 2009)

bobj3 said:


> Hi John
> 
> 
> For me I don't let the plastic jump up or down I put it in a sandwich type jig with 1/8" or 1/4" thick MDF.
> ...


Hi Bob - Thanks, I was suspecting as much. I've pretty much abandoned the jig saw though. Been cutting most of it on a table saw, the thin stuff on the band saw. Didn't know what the OP had available though.
Got a question on the Rockler Louver bit also but will start another thread.


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