Thanks for the tips! Can you share details on the mod you did and why?
I’ll try creating a pocket down to tab depth. Also going to put in a few more test runs and see if I can optimize the higher IPM toolpaths. I might be able to get a slightly larger chip load.
I have the same issue with a 201 end mill in aluminum. It loves to get clogged. I’m only using 0 flutes now.
That’s a very good point. I’ll just take things slow and steady and not abuse the machine trying to push it past what it can handle. Upgrades will come in time. The main thing is part quality and consistency, keeping repairs to a minimum etc.
What was the stepover in your tests? If you were fully engaged & 0.004 @ 45 IPM works, then you can stepover up to the diameter of the cutter.
I like to look at the cross section of the chip and not just the forward advancement (chip load). If I can use 0.004 DOC & half the diameter (0.0625") stepover, then I should be able to switch them, 0.0625 DOC & 0.004 stepover for adaptive. It’s not an exact swap as side cutting & end cutting generate different forces, but it’s relatively close.
But either way, I’m removing a cross section of 0.004 x 0.0625 = 0.00025 in² chip area.
I started with a used S3XL and regularly wanted to cut bigger things. So I bought the expansion kit (no longer available) from Carbide 3D to convert it to an XXL but I combined the XL and XXL rails to make a machine bigger than an XXL. Linked here Shapeoko 3 XL + XXL Progress. I did this only for size. At the time I don’t think Carbide 3D offered anything larger than an XXL. I mentioned this modification only because I probably lost rigidity which would be detrimental to my cut quality especially in metal. The only other modification was to upgrade to a Z plus. This was because I saw problems (lost steps) when plunging into aluminum with the stock Z. The Z plus helps but it is not a cure all. (Probably need ramping toolpaths.) I am very happy with the overall machine and Z plus but I don’t expect it to be a home replacement for a $100,000 machine.
I did some pocket tests and half diameter or less works well.
Big thanks again for your help and tips. I managed to get a bunch of the pieces cut out today. For some reason there’s a +30% time increase when the toolpaths move from Carbide Create to motion. It took me a long time but I made around 20 and they turned out nice.
Any advice for dealing with tabs at the end of a job? I’ve been thinking about skimming them down as low as possible before clean up. Maybe I’ll trim the tabs down to 0.008" and hope they don’t break off.
That’s quite the machine you’ve got there!
I’ve got the HDZ upgrade which helps for sure. For some reason my machine hates 0.010" DOC, it makes nasty build up like what’s seen in the video. The machine much prefers taking smaller cuts and moving faster. I’m not sure why my machine is like that. Kind of confusing because it can’t even handle the stock “conservative” aluminum cutting tool profiles very well.
After testing I’m getting super clean and reliable cuts. I just need to run shallow and fast. It’s actually faster than the other profile and cleaner.
2-way tape or tape/glue should let you get the tabs pretty thin, or even through cut.
At 0.008" you might be able to remove them with a knife.
Output a single contour/profile/trim path that you can drop the Z & rerun to test it out.
Otherwise, bandsaw and sand or file, or break them off, depending on the finish req.
What are these tabs for? i.e. what are the tolerance & finish requirements?
The faster you move, the less heat you build up in one spot. This is one of the key principals of high speed machining. And since we have no choice with these spindles, embracing HSM is necessary.
As for times. I view them as a really rough estimate. I use them in a relative sense. If I adjust a path & the time in CC goes down, the actual time on the machine should also go down. But I don’t trust the time calculations in CC or CM.
Currently I’m using a fence setup. Trying to stay away from the tape and glue as much as possible though it definitely has some upsides.
The tabs are to hold acrylic (one tab for each corner). The two holes on either side are for magnets. Wanted something clean with no visible fastener and easy on / off when needed.
