Milling vinyl records

[andrew]

I sure wouldn't call this a total success, but not a total failure either.. 
Cutting silhouettes into vinyl records.  This was a first shot at it.  Thinking pretty sweet clocks

Besides the kids fishing line breaking off, there are some small spots/holes where the vinyl (or whatever a record is made out of) got pretty gummed up, and as you can see the cut itself got hot on the edges and took on a bit of the spoil board dust as well..  The endmill was a 1/32" two flute down cut.  30 ft/minute feed rate, 0.025" per pass, and the dewalt 611 on its lowest speed. 

Any advice on how to minimize the heat and melting? shallower passes, slower/faster speed rate, faster rpm, different mill?
The endmill ended up with a pretty good glob of hard plastic on it too but she kept on cutting and didn't break.

[kevin]

That turned out pretty good. I was checking these out on Pinterest last night, and other than the mentioned broken fishing line, yours looks as good as their's.

I can't give you any useful advice on the settings, so maybe Derek or Aforww will be along here soon to share some of their wisdom.

[Derek the Admin]

That looks cool Andrew. Your projects are always neat.

We can definitely improve the finish and stop some of the gumming. Please post all your cutting settings. How many flutes on the end mill? Any air blast or coolant applied?

[mp4doggie]

Awesome as usual way to upcycle . Also that looks like a easy fix with some superglue or if you want to get crazy run real fishing line down the pole ( black thread)

[aforww]

Very cool. You can handle the melting two ways. Either slow your RPM dramatically or increase feeds. On plastics I'm generally running at 30k RPM and close to 2000 mm/min depending on DOC and bit size. The faster you run, the more accurate your chip load, the better the finish.

Like Derek said, post your speeds and feeds, type of operation, and cut settings. We'll get you where you need to be.

[andrew]

Thanks guys. I think some pretty neat stuff could come out of this. Need to hit up salvation army for more practice records.. And pick up a Carve King (Christmas can't come soon enough!). A 12" record doesn't quite fit on the M3 for full diameter cut

The mill was a two flute 1/32". Not sure on the exact rpm of the router, but it's the slowest setting on the Dewalt 611. Feed rate was 30 feet per minute, depth per pass 0.025" it took three passes to get through the record, the operation was just a simple profile (I think that's what it's called) the mill just followed the outline path. No cooling or air blasting short of the air coming out of the router.

Do you think blowing some air on it from an air compressor would help much? I can't slow the router rpm down any lower, It's as slow as it will go. Wasn't sure if speeding the feed up would create more heat, sounds like that would be something to try.

[breslinmr]

Jul 7, 2017 23:35:35 GMT andrew said:

I sure wouldn't call this a total success, but not a total failure either.. 
Cutting silhouettes into vinyl records.  This was a first shot at it.  Thinking pretty sweet clocks

Besides the kids fishing line breaking off, there are some small spots/holes where the vinyl (or whatever a record is made out of) got pretty gummed up, and as you can see the cut itself got hot on the edges and took on a bit of the spoil board dust as well..  The endmill was a 1/32" two flute down cut.  30 ft/minute feed rate, 0.025" per pass, and the dewalt 611 on its lowest speed. 

Any advice on how to minimize the heat and melting? shallower passes, slower/faster speed rate, faster rpm, different mill?
The endmill ended up with a pretty good glob of hard plastic on it too but she kept on cutting and didn't break.

just make sure not to be cutting any rare vinyls lol 

[aforww]

Think the DeWalt bottom end is 12k RPM. So, with a .0312 mill, estimated good chip load of .002, you would need to run it at 120 IPM at 30k RPM. I'd do a ramping operation with a maximum step down of .019. If you hear chatter, or it sounds like it's beating the record instead of cutting, reduce feed rate slightly.

Remember, heat is our enemy. We get rid of it in chips and not having the cutter dwell too long. So with that small of a bit, and such small flutes, you have to run super fast. I Mill my ABS at over 2000mm/min. Realize though, your spindle needs to be dang near perfectly plum at these speeds. If it's off, the tool pressure will increase, cutting efficiency will decrease, and probably break with a quickness

If you want to go slower, Turn it down to 12k RPM and 48IPM.

Side note, I use single flute cutters in the micro sizes ESPECIALLY in plastic and aluminum. Single flute is better at evacuating chips ergo, evacuating heat. Inspect the chips. If they look like they were shaved off cleanly and are uniform in size/shape, then you are on the right track. You don't want chip load to be so small you're almost burnishing but you don't want to be too high that the cutter can't keep up. To little, you get chatter and curled/melting edges. Too much and you will hear it struggling and chips will look like they were cut with a lawn mower.

[Derek the Admin]

Good post, aforww. One correction is that the DWP611 is 16k to 27K, so you can adjust those numbers proportionately.

[aforww]

Jul 10, 2017 15:59:11 GMT Derek the Admin said:

Good post, aforww. One correction is that the DWP611 is 16k to 27K, so you can adjust those numbers proportionately.

Thanks for correcting. I probably should have looked it up instead lol.

So, at 16K feed rate should be around 64 IPM. At 27K would be 108 IPM.

Another thing to note, if you run it at mix speed, you need to adjust your GRBL max feed rates. $110, $111, and $112. If they are set to values lower than what your Gcode is requiring, it won't machine that fast.

I'd also recommend using something other than Easel to run really fast. In Fusion I can have it slow down on corners to avoid any over travel from momentum that results from rigidity variables.

[Derek the Admin]

Max feed shouldn't be too limiting though. The M3 is really fast (8000mm/m max in the XY plane) because it's belt driven. You'll never machine that fast on a hobby level machine. The Carve King has a default max of 3500mm/m (138 IPM) in the X direction and 4400mm/m (173 IPM), so the practical max is 138IPM. You can increase the feed on the X to perhaps 4000mm/m but depending on how much pre-load you've put on the anti-backlash nut you'll be close to stall speed. Since we all pretty much stay with a 1/4" cutter or smaller on these machines (that's my recommendation), you can get about any chip load you'll ever need with that RPM range, feed rate capability, and a one or two flute cutter.

[aforww]

Jul 11, 2017 13:22:36 GMT Derek the Admin said:

Max feed shouldn't be too limiting though. The M3 is really fast (8000mm/m max in the XY plane) because it's belt driven. You'll never machine that fast on a hobby level machine. The Carve King has a default max of 3500mm/m (138 IPM) in the X direction and 4400mm/m (173 IPM), so the practical max is 138IPM. You can increase the feed on the X to perhaps 4000mm/m but depending on how much pre-load you've put on the anti-backlash nut you'll be close to stall speed. Since we all pretty much stay with a 1/4" cutter or smaller on these machines (that's my recommendation), you can get about any chip load you'll ever need with that RPM range, feed rate capability, and a one or two flute cutter.

100% agree. Though for some reason, a long while back I had to go change my $$ because it was set at 2000mm/m.. maybe I reflashed GRBL from GitHub and never changed it lol. Who knows.

[andrew]

Thanks for the tips guys!  Speeding things up dramatically (30 ipm to 95 ipm) solved nearly 100% of the melting problem.  Have noticed that the plastic does still build up on the mill.  When that happens the "glob" rubs the top and the melting starts.  Temporary solution..  Use Aforww's handy dandy stop button and clear the mill when it gets clogged up

Now to figure out how to "clamp" down a thin record...  the cutting pulls it up off the bed in spots.  The kids fising line didn't break, but you can see it's deformed and not thin..  this was because the lifting of the record while cutting.   I tried carpet tape on the first try which worked good, but was a real pain in the ass to get off the plastic.  Maybe a down cut mill would help with that..  or some less sticky carpet tape.

Anyway, onward and upward!  Thanks again for the tips

P.S.  no collectable/rare vinyl has been destroyed in these experiments...  unless Ronnie Dove's Greatest Hits counts as collectable?

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[aforww]

Jul 12, 2017 1:00:33 GMT andrew said:

Thanks for the tips guys!  Speeding things up dramatically (30 ipm to 95 ipm) solved nearly 100% of the melting problem.  Have noticed that the plastic does still build up on the mill.  When that happens the "glob" rubs the top and the melting starts.  Temporary solution..  Use Aforww's handy dandy stop button and clear the mill when it gets clogged up

Awesome man, glad it helped! Occasionally I'm right about something! Lol.

As for it building up, thats a constant battle. If you watch my videos you probably see a tooth pick come into picture. I keep them (now wood skewers) in my drawer. It starts to stick at the top, just break it up before it globs while the machine is still going.

So, at 95 IPM, what's your depth of cut, step over, and are you still using the same bit?

[Derek the Admin]

Looking good man!