Thanks. That is exactly the kind of info I needed. I think I wasted about $100 on 8" and 10" Freud "plastics" blades -- unless I can think of a plexiglass project. Just to see how a more aggressive blade would do, I just tried cutting some scrap 1" LDPE with a Freud 10" 60 tooth thin kerf miter blade on my TS and it did great. So then I used it to "rip" a 48" long 1.5" strip of the 2 1/4" LDPE and it also went well -- no significant melt, smooth enough (like you wrote, a few saw marks which is OK for what i am doing), and I could actually feed the stock at a reasonable speed with reasonable effort -- unlike w/ the plastics blade.
Boy, is LDPE heavy. Over 300 lbs for a 4x8 sheet of the 2 1/4". I had the supplier cut it down into 6+ sections so I could handle it.
Thanks for the detailed info re routing. No need for that yet, though I can see that it may be in the future. What I may be doing soon is using the notorious Craftsman moulding head with a custom set of cutters. (My "dado" cuts are too deep for a router or moulder.) I did a test on my RAS with the moulding head (top-down) and that was a bit too scary. The cut was surprisingly smooth with HSS cutters, and I have found a guy who will do custom cutters in carbide for the moulding head for a decent price. Problem was that on the RAS there was no way to hold the stock down as it first goes through the cutters -- and once it rode up and gouged the stock
-- while on the TS I can featherboard it all along the way.
The bottom l>Igor,
>I've been working with 1 to 2.5" HDPE as well as 7/16" Polyproplyene sheet
>and am using a Freud TK906 (thin kerf 50 tooth carbide combination blade) on
>my direct drive table saw with no issues. I find the saw motor is the
>limiting factor in how fast I can feed material ... wood or plastic. I've
>also cut the same material on my Dewalt CMS with a 12" Series 40, 80-tooth
>blade and have found I can bog that saw down if I feed too fast. I get very
>clean cuts ... and adjust my feed rate by listening to the saw slowing down
>(I try to keep blade RPM as high as possible while still making some
>progress through the material). When the lights start dimming in the shop,
>you are feeding too fast (DAMHIKT, TYVM).
>
>2.5 inch MAY require you to take several passes per cut. That's quite a lot
>of chips to be pulling out in one pass.
>
>Get a nice smooth finish (depending on how well you keep the work against
>the fence of course) that appears sawn, but is not too rough.
>
>I'm also using the Freud 8" stacked dado set to cut large grooves in the
>HDPE (up to 2" wide with a 3/4" stack ... multiple passes of course) with >great results.
>
>Don't have any experience with the Freud plastics blade ... though it does
>sound like it's meant for sheet acrylic (and other brittle plastics). > >
>I know you didn't ask about routing, but that's where the bulk of my
>experience has been lately:
>
>When routing, I try to use an "O" flute, 2-flute straight bit from Onsrud
>... more to keep from pulling the work to the router (it's mounted overhead)
>and to not pack the chips into the cut. I get fairly good results on a
>hogging pass (I only cut ~76% of bit diameter on each pass ... with a 0.250"
>bit I'm only taking 0.190" depth of cut). I have noticed I get a better
>finish if I rough cut approximately 0.10 large and come back for a final cut
>... but for the work I was doing it was more an "oh gee ... look at that"
>rather than any production change. Router speed was 21000, and cut speed was
>2.5 inches per second.
>
>Hope this helps,
>
>Rick
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