Acrylic Base for Dewalt 621 Router

[Tom Bain]

I have/had a large circular acrylic base for my DW621 plunge router from Pat Warner (may he Rest In Peace), but I recently broke it in a moment of bumbling stupidity. Does anyone know of a good source for a replacement base?

[George Bokros]

Make yourself a replacement. I made an offset base for my 611. If I remember right I bought the material at McMaster Carr. Machines easily.

[Lee Schierer]

Making your own isn't difficult. I would not use acrylic as it cracks and breaks too easily. Use Lexan (polycarbonate) which is considerably stronger and crack resistant.

[Osvaldo Cristo]

Making your own isn't difficult. I would not use acrylic as it cracks and breaks too easily. Use Lexan (polycarbonate) which is considerably stronger and crack resistant.

I recommend polycarbonate instead of (standard acrylic). Actually I have made four or five (if you consider one of them made wrongly) bases in the last one year.

[Doug Garson]

I know a lot of bases are clear but is it really necessary? All the action happens in the opening, when would a clear base have an advantage over say MDF?

[Jim Becker]

I know a lot of bases are clear but is it really necessary? All the action happens in the opening, when would a clear base have an advantage over say MDF?
Lexan over MDF is an easy choice based on durability...it just happens to be clear. I suspect there are some circumstances where an oversize base that's clear can have an advantage relative to seeing the workpieces more clearly, such as when routing edges and needing to adjust/stop/start relative to changing grain direction to avoid tearout.

OP, I'm also in the "make your own" camp for this kind of thing.

[David Stone (CT)]

I know a lot of bases are clear but is it really necessary? All the action happens in the opening, when would a clear base have an advantage over say MDF?

MDF can work OK, but a significant disadvantage compared with a plastic base is that it's much thicker--which often means you can't get enough bit projection to accomplish the task.

[Michael Drew]

I know a lot of bases are clear but is it really necessary? All the action happens in the opening, when would a clear base have an advantage over say MDF?

I dunno about necessary, but it is handy. My Milwaukee router came with a clear base, and I really didn't give it much thought. But after using it several times, I was wanting a clear base for my other routers.

[Thomas McCurnin]

Universal acrylic bases for the 621 are available on line at Infinity and on eBay.

[Don Peters]

I totally agree with you all that polycarbonate is superior to acrylic in most respects. However it has an Achilles' heel in very particular circumstances: It chemically stress fractures upon direct exposure to somewhat unknown concentrations of mineral spirit. This is noted in most spec sheets, but no-one reads them.

In plain language, this means don't cleanup caulking or coatings with paint thinner. And paint thinner has a bunch of other chemicals in it, so my rule is to only use water - never hot solvents - around Lexan. I have personal experience with the problem, and it's convinced me of a very real, if arcane, concern.

I have no knowledge if this being an issue with acrylic (Plexiglass et al), but then I've used it vary little.

[Richard Coers]

I totally agree with you all that polycarbonate is superior to acrylic in most respects. However it has an Achilles' heel in very particular circumstances: It chemically stress fractures upon direct exposure to somewhat unknown concentrations of mineral spirit. This is noted in most spec sheets, but no-one reads them.

In plain language, this means don't cleanup caulking or coatings with paint thinner. And paint thinner has a bunch of other chemicals in it, so my rule is to only use water - never hot solvents - around Lexan. I have personal experience with the problem, and it's convinced me of a very real, if arcane, concern.

I have no knowledge if this being an issue with acrylic (Plexiglass et al), but then I've used it vary little.
Could you please provide a link to showing stress cracking from mineral spirits. I only find issues with acetone.

[Dan Hahr]

Google Jasper router base plate. Drilled very accurately for use with bushings.

Dan

[Don Peters]

Sorry Richard, but those days are behind me by about forty years. I can relate the story that prompted the post though. A long time ago I owned a small company specializing in building high-end cold molded sailboats. One of our creations was a 40+ foot race boat.

The boat was stunningly beautiful with bright finished topsides, and it did quite well in early races. However there were some changes to the rating rule that made it advantageous to install a "feathering prop" to both reduce drag while sailing and also reduce the boat's rating. The prop shaft was driven by a hydraulic motor, emerging horizontally out the trailing edge of the fin keel about 18" below the bottom of the hull. The problem was that the new prop only reduced drag if it's two blades were aligned vertically in line with the trailing edge of the keel; if not, the induced drag was much higher. And the problem was that there was no way to easily ascertain if this was the case.

So the "fix" was to install a window in the bottom of the boat directly above the propeller. This was a simple job: haul the boat, cut a hole in the bottom about 8" square, rout a rabbet around it and bed a piece of 1/2" Lexan flush with the outer skin. We used 3M's #5200 urethane to bed the Lexan and cleaned it up with either paint thinner and lacquer thinner, probably both, but I don't recall. No worries, Mate - launch the boat, call the owner and send him a bill.

So the next thing I know is that he's on the horn, and he's major league pissed. Seems he got a call from the harbormaster informing him that his half million dollar race boat was sitting quite low in the water, and would he come around and deal with it? Like right now?

Upon hauling the boat again (at my expense), we had a look. That polycarbonate window looked like broken glass, fractured in several places. We did the research, wiped the egg off our faces, and did the job again without the solvent cleanup. Why is there never enough time to do it right, but there's always time to do it over?

dp