# tapping/inserts in acrylic/plexiglass for jigs



## vjeko (Feb 5, 2009)

I'm planning to make a router base and attach
a knob to it for better control. As far as I can see
the manufactured router bases are just tapped -
is this better than metal inserts from the perspective
of stressing the plastic less ?

What type of insert is best (a specific product would be
a appreciated) ?


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## bobj3 (Jan 17, 2006)

Hi vjeko

They make many types of inserts for plastic ( pem for one ) plastic will take on a tap hole but because plastic is hard ,so to speak ,it likes to break off the tap threads, the one I like to use is the tee-nut, that's to say a reworked tee-nut ,I chuck the tee-nut on some threaded rod and remove almost all of the flange so I end up with a small flange stand-off type ,so to say,then I put in a 1/8" deep pock hole one the bottom side so the flange part of the tee nut can just set right in the pocket hole. it's easy to remove most of the flange off the tee nut with a battery type drill and the belt grinder..
Tee-nuts come in many sizes ( 6-32 to 1/2-13 thread ) but if you just want to buy some inserts here's a link that will have almost all types..

The one I like best for plastic, in the insert type is the one you put in with a pop rivet gun,in that way you don't need to use a hammer on the plastic to get them in place..

http://www.mcmaster.com/


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vjeko said:


> I'm planning to make a router base and attach
> a knob to it for better control. As far as I can see
> the manufactured router bases are just tapped -
> is this better than metal inserts from the perspective
> ...


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## GBM (Dec 18, 2007)

" Plastic " is such a generic term. LOL
I would like to recommend a book I got from my local Woodcraft store... 
" Ingenious Jigs and shop accessories" by the " Fine Woodworking " people..
Taunton Press... 
It has a guy with a router on the front.. or my 1999 edition did... bought within the last year...

It has a chapter on Plastics for jigs and woodworking in general... 
An eye opener for me... 

For tapping and threading in plastics they recommend being more careful with acrylics due to brittleness... and thus recommend using a coarse thread being sure you lubricate while tapping.. like with wax... 

The chapter covers acetals, acrylics,polycarbonates,ultrahigh molecular weight plastic,phenolics,machining plastics, safe working practices, rough cutting,routing, drilling, sanding, gluing, tapping and threading...and sources of supply.
Highly recommend the whole book... ( but would you expect anything less from " Fine Woodworing " mag people ? LOL


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## Microsuffer (Aug 7, 2008)

Acrylic, wood where the grain has become so fine it disappeared. I see no problem with calling it that.


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