I just did my first carve using King ColorCore material. Overall, it came out great… but I did have a couple issues and I was wondering if anyone might have some advice. One thing I learned, do not use a down cut bit. I knew that… but I needed a 1/16" clearing pass and I didn’t have a 1/16" up cut on hand. It worked, but spent alot of time cleaning out the grooves afterward.
The other two issues I had was that anywhere the machine moved x / y at the same time when cutting a pocket toolpath for numbers / border, so in other words anywhere there was a curve in the pocket… I got noticeable chatter / rippling on the sidewall of the cut. The second issue was noticeable tool marks in the bottom of the pockets. I suspect this is a speeds / feeds issue? My settings for the text and profile were:
1/4" O-flute upcut (Oh Jenny), 200ipm, 18000rpm, .25 pass depth, offset / conventional… on Foreman Elite w/PWNcnc 2.2kw spindle
I have attached some photos…
Mike
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Looks cool. I haven’t cut any colorcore on my 1f yet, but I have done a fair amount of acryllic and other materials on a bigger machine in my professional past. I’m looking forward to getting some hdpe soon.
I’m curious, are your steppers set at the stock resolution (400) and acceleration settings? There’s a thread or two about changing the settings, I’m on my phone but they should be easily found. The stock 400 resolution is very rough, in many people’s opinion. Mine as well. The acceleration can be set lower to increase smoothness of motion, also. Makes the whole machine less jerky. I went ahead and changed these settings pretty much outta the box. Something to consider.
I would definitely try a feed somewhere lower around 120ipm, and if you feel that the chips are too small or they’re in danger of melting, slow down the rpms if necessary. An airblast in the cut to clear chips can help keep things clean and cool.
Yeah I’d definitely slow down to start and then bump it upwards as you go.
I’ve been cutting cured epoxy with my increased resolution settings, and I’ve been pleased with my curves.
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I’ve got an order for an outside sign similar to your build. I’m glad I stumbled across your post! Can you tell me where you purchased this material. Thank you.
Bunkstaff,
Thank you for the reply… and funny you should mention the stepper motor resolution… as that is exactly the rabbit hole I have gone down in an attempt to improve the cuts. I had stumbled across some forum discussions about the issue some time back… so I decided to look into it further. Trying to get concrete answers is difficult… it seems to be a touchy
issue for 1F… and my understanding is that if you do change the PPR on the steppers… 1F won’t offer support unless you change it back to the original setting. Another issue is that some say it will reduce torque… others say it won’t (or at least negligibly). I submitted a support ticket with Masso asking the question, and they basically just referred me to the already existing forum discussions. Masso did, however, suggest that 800 to 1000 PPR ‘may’ work. That said, it would seem several users have gone as high as 4000, and report noticeable improvement with no apparent down side. I’ve decided to try 800 and see how it goes… I’ll update here once I’ve had a chance to experiment with it.
All of that said, I do think it is a combination of issues (feeds / speeds, bit selection, material, and PPR). They make special bits for cutting plastics, which I don’t have. I was using an Oh Jenny (1/4" up cut O-flute), and I may have went a little too aggressive because I was worried about heat buildup causing melting / re-welding.
Todd,
I ordered it via BuyPlastic.com. I believe you can also find it on Amazon and several other online suppliers.
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FWIW - I went straight to 2000 resolution and I’ve been happy. I haven’t made many very challenging demands on my machine yet, but I’m not too worried. I went down the same rabbit hole regarding torque etc, not super clear… My gut says that even with a 2.2k spindle the stepper torque won’t be a huge issue until I start trying to cut some metal more intensely. Changing the resolution is easy enough though, and you can always go back to stock if you need to for service or whatever.
My experience with aluminum cutting bits and plastic cutting bits is that they’re super similar- I’ve had/used both, but I haven’t had any problem cutting plastic with a bit intended for metal. As long as you’re rocking with a single flute upcut, I expect that it’ll be fine with HDPE. I suppose one possible reason to drop extra cash on a plastic bit would be if you want to keep your bits segregated/quarantined. As in, this bit has only ever touched plastic, never any other material. That would be good practice for preserving the edge, but I dunno how great the value prop with that is at a hobby level. I only loosely followed that practice in a professional context, tbh.
Good instincts with the aggressive speed tho, most everyone goes too slow. Myself included, until I started getting bored 
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Bunkstaff… I upped mine to 2000… so far very happy. Time will tell I guess!! Thank you for the advice.
Mike
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I have not carved by HDPE project for a friend yet, but I did move to 4000. Cuts so far are much nicer, but it does come at a cost of time. Since I just do this as a low volume Side Hustle and have not tried to dial in the best bang for the buck. I shoudl be starting my HDPE cuts in the coming month so will report what I find out…
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Interesting… I’m not clear on how this would affect time? For example… I moved all mine to 2000 (later ended up moving Z azis down to 800… but that’s another story…), and there was a noticeable improvement in quality / smoothness of movement, but I did not see any time difference. If I set my speed at 150 inches/min, for example, it’s still moving at that same speed it’s just the stepper driver is using more PPR to get that speed.
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