ThePog

ThePogs Homebrew CNC Router Build

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28 minutes ago, flyingbrick said:

Omg, you could sell quite a few of those in a heartbeat. 

I’ll take one, seriously. 

I still need to work on the feed rates and cut depths, but it's no problem to smash one out...

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21 minutes ago, Nominal said:

How much do make one without the 'not'

 

And postage to @kyteler's place

Tell you what, as I am still so shit at this; for the next few weeks I will make whatever anyone wants within reason and send it for postage costs.

This will be good for me as I can mess with setups, materials etc and maybe learn something.

Register your interest here.

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If you are keen I'd like a sign for

Te Horo Garage

Materials / size etc up to you. I'll be in Nelson in Jan for a couple of days so could collect it no problem.

 

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6 minutes ago, Nominal said:

If you are keen I'd like a sign for

Te Horo Garage

Materials / size etc up to you. I'll be in Nelson in Jan for a couple of days so could collect it no problem.

 

Deal.

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12 hours ago, ThePog said:

I still need to work on the feed rates and cut depths, but it's no problem to smash one out...

What tooling are you using? Ive got a couple of flatbeds here running ali, acm, acrylic, ply and mdf so might have some applicable feed rates etc if you needed them.

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1 minute ago, Stu said:

What tooling are you using? Ive got a couple of flatbeds here running ali, acm, acrylic, ply and mdf so might have some applicable feed rates etc if you needed them.

I may not be going about it right as I am throwing everything into the mix right now.

Also I am not 100% convinced my spindle is actually running at 24k rpm, there is some weird setup stuff I have not 100% understood.

Max spindle speed seems to be the way for most setups, I guess it clears chips best.

At the mo I have a 4mm, 10mm and 24mm straight flute endmill type bits and an ER20 collet, plus a 6mm 3 flute spiral endmill that just happens to fit. Maybe the ER20 is too light and flexing?

The mdf stuff seems happy with a 2-3mm cut depth and 2500mm/min, I overheat the Z axis servo if i go much harder than that, I may need to look at a solution for this.

I have tried ACM and it is a shitfight, it just tears the ally no matter what I do.

The sign up there^ was 2mm cuts and 1000mm/min, but i will experiment with a shallow surfacing cut and slower feed next as it is pretty raggedy around the edges. That is dry mac though so maybe a bit stringy.

Mostly I have problems with raggedy stuff at the top of the cut.

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I used to use a single flute end mill for ACM on the CNC Router that I ran for a few years. Spindle speed was up there from memory.. over 20000rpm, and feed rates were about 1800mm a minute. 

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Yeah spindle speed makes a world of difference, especially for clearing the chips.  There's a few calculators around for working out feeds and speeds but I've found all machines vary a bit so its really a case of fine tuning.

I use 4.762 O-flute cutters for ACM,  single pass, 18000rpm spindle speed, feed rates around 3000mm/min but you may need to drop back to 1800mm/min depending on how your spindle and servos handle it.  For ACM you could also try a 6mm 2 flute slow helix spiral cutter at 16000rpm and 3600mm/min feed rates.  Finish is usually perfect on the top edge if you find that sweet spot.

3mm ali I cut in a single pass using a 6mm x 12mm single flute up-cutter with 8mm shank at 18000rpm and 1800mm/min, good suction is key for holding shit down or even screw the stock down to the bed, things get really exciting if the stock moves and fires off around the workshop. My main machine runs a 14kw spindle so stops for nothing.  Thicker ali I drop back to multiple passes if using the 6mm tool, but will cut 10mm in a single pass with the bigger dia cutters.  We cut up to 40mm plate but its pretty slow going with many steps.

MDF wise we don't cut a lot, we used to make 3D vacuum mold tooling but not so much these day. We sometimes will cut 18mm in a single pass with a 9.25mm compression cutter (down/up cut) with chip breaker.  Just be careful on your entry path and speeds are slow - too fast of an  entry or direct plunge and you risk setting fire to the MDF which is super sketchy as embers can fire up into the extractor...  One of my guys didn't take this into consideration when programming a job and it was lucky I walked in just as it happened so disaster was averted.

Hopefully some of this helps.

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On 04/10/2020 at 11:26, ThePog said:

Never say I don't follow through on my promises....

Ahem...

On 08/09/2020 at 21:49, KKtrips said:

Next level challenge
 

 

 

 

;-)

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26 minutes ago, Stu said:

Hopefully some of this helps.

Yea that is all good stuff, one of my projects will need to cut ACM so my research told me to get an o flute bit. Do you use down cut or up cut?

I think I am going to be limited by the kit, it's a 2.2kw water cooled spindle and I have already pushed it hard enough to slow it down noticeably..

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3 minutes ago, KKtrips said:

Ahem...

 

 

;-)

Fuck I never agreed to that one, I may be geeky but my Asperger's doesn't run that deep.

A cock and balls is about as deep as it gets.

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The 4.762 is a straight cutter. With ACM, if the pieces are really fine and need small internal radii then you can step down to a 3.174 vortex down cutter that will push the swarf into the gaps which helps cut parts to stay on the bed rather than flying off or getting sucked up the extractor.

 

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What I hate about myself is that I am mentally investigating ways to make that happen now.

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3 minutes ago, Stu said:

The 4.762 is a straight cutter. With ACM, if the pieces are really fine and need small internal radii then you can step down to a 3.174 vortex down cutter that will push the swarf into the gaps which helps cut parts to stay on the bed rather than flying off or getting sucked up the extractor.

 

Yea it will be profiling shapes out of 2mm/3.2mm ACM. Hopefully my vac table will hold full sheets down well enough.

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At worst use some double sided tape to stick it to the bed, it scraps off again easy enough with after.

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17 minutes ago, NickJ said:

Can send you some rifle stock models if you want a challenge

That is the second mention today of rifle stocks, I can see a niche opening up, just like my chargeout rates..

Send me some CAD, I would be interested to see if I can program it.

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