[Rick Madden]

I'm a new member and hope I am posting in the correct category.
As the title says, I am wanting to route a T-slot in some 3/4" plexiglass, but before I do, I'm looking for advice. I have a Rockler T-slot bit, 5/8" dia. x 3/16" H x 1/2" shank that I have used in wood with good results, but using in plexiglass has me wondering if it's safe, and doable. This bit requires a 3/8" slot cut before the T-slot. If I start with a 1/8", or 1/4" slot working my way up gradually to the height needed and then making the 3/8" slot, could I then use the T-slot bit to finish? I have a router table with a 3 hp Milwaukee router with adjustable speed. I assume a slower speed would be best, but I'm concerned about melting and chip build up. Any advice would be appreciated.

 

[Stick486]

Welcome to the forums N/A...

tooling plastic is safe but is the application of the finished product...
what do you intend to do w/ the finished product???...

you need to hog out as much as you can before run the T slot bit...
I'd do the hogging out in one pass w/ a dado blade...
3/8" slot cut before the T-slot - ??????
cut the plastic the same as you would wood...
as you cut have all of the suction you can muster to keep the chips cleared of the cutting operation...
use slower motor speed and moderate feed... too fast a feed and you'll get load up and melting... too slow and you'll get a lot of melting...
practice on scrap 1st...
wax your bit before ya get started...

how do you intend to polish the inside of the T slot as Acrylic is extremely nick sensitive (will easily break/crack) and your finale won't have much in strength......
I'd use polycarbonite instead of Acrylic...

there's some attached PDF's that you might find useful...

.

 

[Nickp]

Welcome, Rick...and best of luck with your project...

 

[Rick Madden]

Stick,
What I'm hoping to make is a gripper style push block with an adjustable block in the center. The T-slots would be on the ends of the 3/4" plexiglass allowing T bolts and thus adjustability. I could use T track...and I may wind up going that route, but I thought if the plexiglass could be routed safely and use toilet flange bolts with knobs, that it would be a good idea. I may just use wood for this with the T slots. Just looking for advice and/or suggestions if I do go with plexiglass. Come to think of it I'm not certain if it is plexiglass...could be polycarbonate. How can you tell the difference?

 

[PhilBa]

How deep and long is the slot going to be? Acrylic and polycarbonate gets wonky when you cut more than half way through. I've seen it cup when cutting less than halfway through - though a lot wider than 3/8".

Do you have scrap of it? You can flame polish acrylic, poly just burns. Poly is somewhat softer than acrylic though I can't really tell. Poly is supposed to be bluish when viewed on end but I've seen acrylic that does too.

 

[Stick486]

in that case I'd use hardwood and T track...
use polycarbonite, acrylic may impact shatter and produce sharp shards of shrapnel...
However, BY FAR, the best choice of plastic to use would be a Polyethylene.. (PE, UHMW, HDPE, etc.)
tools super easily, holds fasteners well, super tough, cheap, solid colors, won't break, won't shatter, smooth, slick, and a bunch more pluses...

Is it Acrylic or Polycarbonate???
The easy way is by burning....
You will not need to burn a whole piece, just an edge, corner or a small scrap.....

Acrylic:
no soot or charring
smells like garlic
burns slow
bubbles

Polycarbonate:
self extinguishing
lots of soot
carbonizes on the burned area
stinks

included is a PDF for a shop made Gripper...

.

 

[Stick486]

How about some light reading????
we have some PDF's at this here link that help you six ways to Sunday...

 

[Bstrom]

I brought the 3D brand Gripper knockoff for $38 shipped on eBay. Works beautifully.

 

[ranman]

Could you cut the parts individually an laminate them together? I did that for a base for my offset laminate trimmer. I use an cyanoacrylate instant glue. Clear and no bubbles.

 

[Stick486]

Could you cut the parts individually an laminate them together? I did that for a base for my offset laminate trimmer. I use an cyanoacrylate instant glue. Clear and no bubbles.

w/ exposure to the blades and bits, I believe acrylic and polycarbonate would be poor choices...

 

[Cherryville Chuck]

I recall some pictures Herb Stoops posted a year or two ago when the plastic push stick he was using hit the blade by accident during a cut. The broken pieces did some nasty looking damage to his hand. I believe it was one like this one: https://www.amazon.com/POWERTEC-710...ds=table+saw+push+stick&qid=1584343798&sr=8-7 which is some type hard plastic. I have one too and I'm more careful with it now, switching to a home made plywood one when the gap between blade and fence gets too narrow. Something to think about when choosing a material. Wood or UHMW PE would both be safer choices.

 

[sreilly]

Welcome aboard Rick. Great starter question and your quarry resulted in some very sound advice. Using test scrap pieces always help and one of the reasons I have a vast amount of scrap.....that and a few mistakes. Lets us see how your project turns out as we really enjoy pictures of projects and shops. You can simply drag and drop in the area below the message when posting.

 

[Bstrom]

I recall some pictures Herb Stoops posted a year or two ago when the plastic push stick he was using hit the blade by accident during a cut. The broken pieces did some nasty looking damage to his hand. I believe it was one like this one: https://www.amazon.com/POWERTEC-710...ds=table+saw+push+stick&qid=1584343798&sr=8-7 which is some type hard plastic. I have one too and I'm more careful with it now, switching to a home made plywood one when the gap between blade and fence gets too narrow. Something to think about when choosing a material. Wood or UHMW PE would both be safer choices.

I built a plywood guide while waiting for my 3D knockoff to come from China. I agree plastics pose a potential danger but a flying chunk of wood that doesn’t splinter is just as scary. The trick is to have a tool that fits the procedure best and do a little dry run practice using it to avoid the unknown. I press down and against the fence with my saw guides to maintain control in the rare event the blade could snag the guide, which I make sure to catch before the blade does! Just shut off the saw and reposition...

 

[TallPaul85]

Here is a good website to go to for information or search “Ridout Plastics”

https://www.eplastics.com/?gclid=Cj...z-M7FZYTq1W-rl7sdBaKDbHm4ya-bz1caAuZDEALw_wcB

Make sure you take it easy when removing stock. If you go to fast the plastic will get hot and melt and trap your cutter.

 

[Cherryville Chuck]

My favorite is very close to the design of this one one except I make it out of 1/4 to 3/4" ply: https://www.youtube.com/watch?time_continue=23&v=W9oyt2gj0ek&feature=emb_logo

The reason I like this design so much is that it provides push force while also exerting down force and by pushing a little bit towards the fence eliminates the need to use a feather board when sawing short pieces. I usually make the hole so I can put all my fingers in it and not just a finger or two and be able to put my thumb on top for down pressure and that gives me more control over it. And even better from my point of view is that they are made from scraps and cost nothing.

 

[Stick486]

My favorite is very close to the design of this one one except I make it out of 1/4 to 3/4" ply: https://www.youtube.com/watch?time_continue=23&v=W9oyt2gj0ek&feature=emb_logo

The reason I like this design so much is that it provides push force while also exerting down force and by pushing a little bit towards the fence eliminates the need to use a feather board when sawing short pieces. I usually make the hole so I can put all my fingers in it and not just a finger or two and be able to put my thumb on top for down pressure and that gives me more control over it. And even better from my point of view is that they are made from scraps and cost nothing.

there are a zillion designs out there..
a few...

.

 

[Stick486]

However, BY FAR, the best choice of plastic to use would be a Polyethylene.. (PE, UHMW, HDPE, etc.)
tools super easily, holds fasteners well, super tough, cheap, solid colors, won't break, won't shatter, smooth, slick, and a bunch more pluses...

Kitchen cutting boards are made from variations of Polyethylene..
see your dollar type stores or big lots for them...
really cheap too...

 

[roofner]

there are a zillion designs out there..
a few...

.

I like the J Bates push stick at the top of this post.

 

[OldCurmudgeon]

I would use all-wood construction, not even a metal t-track. Cut the t-slots in the wood. You don't want any metal getting too close to whirling blades...

 

[Cherryville Chuck]

I would use all-wood construction, not even a metal t-track. Cut the t-slots in the wood. You don't want any metal getting too close to whirling blades...

Or screws, brads , or pins either unless they will be more than 3 1/4" above the table. The blade can go at most about 3 1/8 on a 10" saw.