Table Saw Selection help for cutting acrylic accurately.

[Drew_Y]

I am using a table saw to cut acrylic sheet to create boxes for a number of purposes. The technique is to usually run the front back pieces together over a jointer or fenced router to smooth the edges prior to making a 90 degree seem.

The set up will need to cut very easily upto 3/8" cast acrylic and easily to 1/32th inch repeatability. I was considering a basic set up of the Jet Contractor saw 1 1/2 HP with an upgraded Beis fence or Incra fence. Anything I should look out for or good I really need to go higher end on the saw to get the precision I want?

[gpdewitt]

Blade selection is important, especially if you'd like to be able to skip the jointer step. It's possible to get a joinable cut with the right blade. Generally, the higher number of teeth means the better the cut in acrylic. As for rake angle and tooth pattern, check with the manufacturer. Some plastic companies sell blades they find best for the task. Also, if you can fit it into your costs (it's a bit more expensive), cast acrylic is more machine friendly than extruded, as it has a higher melting point. Ever try to cut or drill plastic only to have it melt back together? Wrong type of acrylic. Hope this helps... Gary

[Drew_Y]

I have the correct cutting blade and use cast materials already.

I am really more interested in not wasting money on second rate machine equipment, as well as not wasting money on overkill equipment for my needs.

I really have two basic questions.

Is a Jet Contractor saw stable enough to get reliable precision to

1/32th of an inch with the proper set up equipment ect?

Is the Incra fence recommended over the Beis fence for such purposes?

[B a r r y]

Yes.

Any stock Bies style fence should cut to 1/32" precision without spending more money.

Many woodworkers consider 1/64" "standard" precision.

Barry

[James "Cubby" Culbertson]

My Jet Contractor's saw will easily meet those tolerances. I use the stock fence. Honestly, just about any saw will work provided you set it up properly. I'd avoid the bench top units but a decent contractor's saw should work fine. For only 1/32" accuracy, I wouldn't run out to buy a special fence. Cheers, cc

[Andy Dingley]

I call 1/16" standard precision, and 1/64" standard accuracy.

A simple Incra is only precise to 1/32" (the smallest adjustment you can make), but its accuracy (how well-spaced these arbitrary points are) is much better than this.

[Morris Dovey]

Andy...

Not sure I have the Incra you're talking about (photo near the bottom of ) but using the micro-adjust feature allows me to adjust more finely than 1/64" with good repeatability.

I've been thinking of using a length of parachute cord to attach a magnifying glass to the fence...

[Drew_Y]

How much flex is in the fence?

I can't understand how a 1/64th inch can be standard realistic accuracy when I can get more than that in the tail end of the fence with a little bit of pressure of standard fences.

Is there any flex in the fence of the Incra. Local shops here do not have them set up on display.

[Andy Dingley]

That's why I don't use my Incra any more.

[Morris Dovey]

Not sure what (if anything) to say. I can calibrate the Incra by sliding it to the blade and adjusting the scales to read zero at the cursor. That part, at least, seems fairly straightforeward.

Once calibrated, I can use the scale to position within a gnat's eyelash of where I want the fence to be.

If I'm being more fussy than usual, I lock the fence at both rails and at the slide - which effectively prevents flexing.

[B a r r y]

Any Bies copy I've ever used could repeatably rip a board to a given measurement, within 1/64", measured with calipers. 1/64" is half a

32'd, which is the smallest mark on the scale.

I don't get all that worried about pushing fences unless I see it in the results. The pressure is realistically spread along the face of the fence. In all honestly, I've NEVER pushed on the far side of my General Bies copy, so I don't really know if it'll move. I am, however, very familiar with the results I can get.

Barry