How fast can I cut PVC foam-board??

[dhunt]

We have a time-consuming project coming up
that will involve cutting many square holes in 3/4 inch PVC foam board.
1 inch holes spaced 1 in. apart.

We cut a 24 x 24 demo on Friday
please see photos at
http://www.talkshopbot.com/forum/album.php?albumid=63


I used a quarter-inch spiral upcut to do this, but I ran the file at a too-slow speed of 0.35 ins. per sec.
with the Porter Cable set at 10,000 rpm.
Five passes (-too many).

Sure, I got nice cut-quality but it took forever :cool:
and seeing as these objects are nothing more than duck-boards for shower stalls in a local hotel
quality is not that important...plus the size we need to cut is going to be bigger than just 24 x 24
so I need to cut down the time spent cutting each item.

I'm thinking I might up the forward speed to somewhere around 0.5 - 0.6 ins. per second
and three passes this time.

What do you guys think? Too fast? Too slow? More passes? Less?
.

[knight_toolworks]

with a 1/4" bit 2ips is fine 8k or so. it cuts like butter. with that many holes hold down may be an issue.

[jerry_stanek]

I cut .25 deep with a .25 bit at 10000 rpm and 4.5 IPS

[dhunt]

Thanks for the 2 responses so far..
You guys are quoting me i.p.s. waay above what I thought possible for PVC! :eek:

Given the 1 inch squares to be cut, I'm thinking that i.p.s. speeds as suggested
might result in too much 'herky-jerky' on this old PRT-96 of ours
when she turns quick tight corners, but we'll see.
Given what y'all have said, I shall def. try a first cut at 1 ips and see what gives.

Our P-Cable can't go lower than 10K rpm, and no higher than 21K
but seeing as it's plastic, 10K will be the rpm. Less noise too.
.

[steve_g]

David
I'm surprised they are using the PVC foam... if it's actually solid PVC those speeds will be to fast. On another note... aren't the edges a little sharp for bare feet?

SG

[knight_toolworks]

Don't push past what speed your machine can cut. but you can take deeper cuts. I have cut .5" with a 1/8" bit in one pass at 1 and 2ips.

[dhunt]

David
I'm surprised they are using the PVC foam... if it's actually solid PVC those speeds will be to fast.
On another note... aren't the edges a little sharp for bare feet?The client originally thought we should use Teak, and then paint the Teak white
but knowing Teak...not only does Teak not take paint easily but
how the heck are we going to get two coats of paint into those little square holes??
Clients don't think about manufacturing practicalities like that! :)


Which is why the boss suggested bypassing all woods entirely
-and since 'White' was essential, why not just go with white PVC foam
which we are already fairly familiar with.

The boss used the duckboard over the weekend (presumably in his shower? ..not sure)
and declared it just fine on the bottom of his tender feet!

...........................

The PVC foam board available locally has a tough shiny 'skin' on either side
with a less-tough filling making up the rest of its thickness.
The core stuff is tough enough,not squishy, like a softer wood but very consistent.
.

[knight_toolworks]

I would think the foam would feel good but it will mash down I would think over time. may be best to get the real sintra as it is denser then the generic brand.

[dhunt]

Don't push past what speed your machine can cut. but you can take deeper cuts.
I have cut .5" with a 1/8" bit in one pass at 1 and 2ips.1 to 2 ips is the daily range of forward speed I use
so I'm comfortable with your comments and suggestions.

[dhunt]

I would think the foam would feel good
but it will mash down I would think, over time. ===> So we sell them new ones in five years time?

may be best to get the real sintra as it is denser then the generic brand.-if available here on the island.
Will ask if it's in local warehouses.



Sintra huh? Must ask about that by name.
What is it? a hi-density PVC foam?

The stuff I've been working could qualify as a hi-density foam in the middle.
I can't stick a screwdriver into it more than maybe 1-3 mm. using all the push I can muster!
It has a thin clear-plastic film to be peeled off, on one side- but not on the other.
I looked on the bill of sale and all it said was PVC foam board, and the thickness in mm. -from a European source?

[letterman7]

All pvc is measured in mm. Sintra is just one brand and I've not known it to be denser than another. My concern would be the cut edges over time - if they aren't bleached a couple times a week, you will get dirt and mold growing in the small pores of the board.

[dhunt]

All pvc is measured in mm. Sintra is just one brand and I've not known it to be denser than another.

My concern would be the cut edges over time - if they aren't bleached a couple times a week,
you will get dirt and mold growing in the small pores of the board.OK, thank you for that caution! ;)
.

[Greybarn]

We cut Starboard with a 1/4 spiral O Flute at 2 to 3 ips. We go to 2 when we need better edge quality.
I think we cut PVC and SAN foam with a 1/4 2 flute up cut bit at 2.5 ips.