Has anyone tried cutting Maxmetal on a Shapeoko? One of the local sign shops near me uses it. If so any specific strategies?
I am working up a relationship with that shop to do small jobs. They are going to give me some scraps to experiment with.
Yes sir. I cut quite a bit of Composite Aluminum/Maxmetal at my shop (3XXL). For the sake of expedience I just use the CC speeds/feeds preset for âSoftwoodâ and override (increase) the feed rate when I reach the center of the substrate (approx .018 thick Al). I also typically use a downcut endmill to reduce deburring/sanding. Itâs a fun substrate but it will warp if too much material is removed. I donât have my notes with me so I apologize for the lack of actual technical data.
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Does it make a mess?
I wonder if a compression bit would work or if the stuff is too thin for that to be effective.
Sorry for the delay. Believe it or not Iâm actually making chips which are easily sucked up by the Sweepy Dust Boot. I havenât had a problem with the substrate âcoreâ melting/bonding to my endmills either. I would love to try a compression bit but I just havenât had any free time⌠that might help reduce the small amount of deburring I do on the back side of my thru cuts.
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Sound great. I look forward to trying it.
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Iâve done several projects with 1/4" (6mm) ACM. It cuts like butter. I cut them upside down with a regular upcut bit. Deburring the back was quick with a sharp scraper. A deburring tool probably would have been even easier. I also scraped the front edges. While there were no burrs, it was still a sharp edge.
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Just a quick test/example of removing the top .014 to .018 layer of aluminum, leaving behind the black polyethylene core. The picture is pre-cleanup and I did not do a final pass or spring pass (I donât mind tooling marks on test pieces). It can be a fun substrate to play around with. Good luck!
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That looks great.
I just met with the folks at the sign shop and what she really wants is for me to cut the profiles in the maxmetal. They use it as a substrate and then apply printed vinyl to the surface. So not as technically challenging. She gave me some âscrapsâ (really 24x24) to experiment with.
I will do a couple of profile cuts for her and then do some more interesting pieces like yours with whatâs left over.
She also gave me a piece of this corrugated plastic/paper material that a lot of cheap signs are made from to see if I could cut profiles in that. I canât imagine that would be challenging either but donât know if I want to try a regular bit or my plastic O flute bits.
None of that is really interesting but if so can make a few bucks it would be good. I did leave a photo album at her shop with all of my work in it for her walk in traffic to see and she has offered space on her walls for me to put samples up so I am hopeful something will come of it.
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That sounds like a great job, cutting profiles and applying vinyl is something I do regularly (most sign shops donât have the room for a dedicated CNC). As long as they can provide you with files you can use or convert with CC. 90% of my time is wasted by rebuilding artwork for the machine to interpret. When the project is larger than my CNC table (99% of the time), I hand cut the aluminum composite with an xacto knife (many passes and patience followed by a sore hand).
I also hand cut all of my corrugated plastic with an xacto knife (3mm-10mm thick Coro). In the past, I have tried a compression bit around 20k-23k rpm and many different feed rates with some decent success (not too messy). I have never tried an O flute, but I would like to. Itâs a tricky material when it comes to workholding options (very flimsy as you have seen).
For my particular situation, I hand cut a lot of substrates. Most of my projects are 6âx12â to 4âx4â It is faster and I can get the finished project to the customer quickly. Arthritis in my hands/fingers will probably start any day now!
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I am just doing some prove out tests now so they havenât given any specific files but hopefully moving forward they would. I think the plan is to have me cut and let them apply the vinyl ut we will see.
The lady that runs this shop has husband with a different shop with larger 8 to 12 foot machines and he does huge jobs. She canât get him to take the time to do her smaller work 
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That is a Great idea! People are very often looking for something more elaborate than printed vinyl on a flat surface. With your skills you might end up busier than you want to be (donât hesitate to quote a mock-up with a high price, you can always negotiate from there). Best of Luck!
Thanks.
Unfortunately I didnât get to doing the test in the maxmetal that I had planned this weekend but will try later this week.
My test in coroplast with the stingray didnât go so well. I donât think that I can get the blade protruding enough to cut the 4.5mm material. I will try that with an O flute or a compression bit and see how it goes.
The Stingray is way too short for 4.5mm thick material.
Youâll want a full-sized dragknife for that, and will then need a CAM tool which will do corner overcuts.
Yeah, that is what I discovered last night. I will try the compression bit that @wmoy mentioned in his video and the O flute.
But now I am wondering if the SharkTooth I bought for pen work would hold an Xacto knife and do double duty as a drag knife.
As far as the software, I have Vectric Desktop now, but unfortunately the drag knife gadget that is available only works in the Pro version. Maybe I can demo that to see if it would actually work.
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That is a great video. You can see how workholding options are tricky, Coro tends to move around in every direction. I donât know much about the SharkTooth pen holder, but it would be very convenient if something like that would work for Coro. I wouldnât even care about perpendicularity or runout, itâs such a cheap material⌠no matter how you cut it, it never looks great.
Ha yeah, for my first try yesterday I made sure the coroplast was âgluedâ down to my cutting mat but didnât have the cutting mat secured to the wasteboard. It wasnât an issue with vinyl, but on the coroplast it just started dragging the mat around
The second test was better but I manually held it in place. Obviously I need a better solution. I have the mat sitting on an 1/8 piece of MDF so that the T Track slots are not an issue. Maybe I will fasten that down and the use the tack it glue on the back side of the cutting mat to have it held to the MDF. Or just use tape. On the back side as the coroplast I am cutting is slightly bigger than my mat.
If I can get the shark tooth to behave with the xacto I will report back.
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Conceptually it seems like it would work although I have no experience with drag knives other than the stingray to know if there are any gotchas.
However it looks like the length of the knife handle will be an issue if the Z router is not near the bottom of the Z travel. As it spins around the handle may hit the Z plate. Seems like that could in theory be an issue with a sharpie as well but I havenât tried.
Clamping the knife in there is a little effort to keep it straight and may be a little dicey. If I could find an xacto more like me (short and fat) it may be better.
So, I bought a cheap xacto clone from HF which had a slightly thicker barrel. Then I cut the handle shorter so it wouldnât interfere with the Z plate.
It looked like it would do ok as a drag knife.
I was worried about how it would orient correctly but looking at other drag knives it seemed like it was basically shaped the same so I decided to try it on a thin piece of cardboard.
As I feared it didnât orient properly or turn as freely. I even tried a second cut after manually orienting it properly for the first cut.
I spent a good bit of time trying to get the point of the blade directly centered under the shaft of the tool.
I donât know if the blade geometry isnât good or if the angle to the surface is bad or if if doesnât swivel freely enough or maybe I just didnât plunge enough for the knife to grab properly.
Maybe the spring loaded nature of the pen tool is a bad idea.
Video of my failed attempt: https://youtube.com/shorts/Ehbguazc9gc?si=Yz6U3ZDLwdk5h7AQ
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You donât want it centered, you want it past center a little bit. Thatâs how it works. it âdragsâ behind the center point. 
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Ha, that makes sense and would make setting the knife much easier. When staring at the pictures of others out there like the SST and Donek I didnât perceive that it was offset but I do remember one of the videos talking about that.
I can make an adjustment and try again. What about the spring load? In my test cases I have a cutting mat underneath so maybe I should increase my DOC as it really shouldnât matter if I go deeper.
I guess that the zero point should still be set wherever the knife tip is rather than the zero of the spindle.