June 16, 2018 at 6:18 am #61706
Hi Ryan, Hi fellow MPCNC users. Here are some things that I did on the MPCNC I have mounted in my basement.
This first batch is mostly “exercises” projects, for me to learn the basics, and maybe decorate my home a little.
The Rose Knight was made with a sharpie when I wanted to see what this machine was capable of (not disappointed! Again, hat off to Ryan for this nice design)
The dragon and the dalek were made using a Dremel 3000.
The Cthulu was made with a Makita router and a pointy bit.
DISCLAIMER : I am not the author of the images I used for these design and have no intention to make any commercial use of these. I just downloaded cool images from google and mapped them with ESTLcam. Christian, if you read this, your program is hell of a neat thing, and I am really impressed by your work.
Attachments:June 16, 2018 at 9:40 am #61719
That is a whole pile of nice work right there!June 16, 2018 at 11:22 am #61728June 16, 2018 at 11:33 am #61729
RyanKeymasterJune 22, 2018 at 7:10 am #62060
They know !
This was made using a 6mm flat mill for roughing, and a pointed bit (90°) for carving. I still get somme levelling issues (notice the artefacts aroud the carves ? Nothing too ugly, but I am sure I can do better on this). If you have advice on how to properlly level the bed and the machine, and then zero the “z” between tool changes, I would be happy to learn from you. I am thinking about using a probe, but I want to max my accuracy to see how far I can go before that. Thanks in advance guys, keep on being awesome!
Attachments:June 22, 2018 at 8:40 am #62062
To get a proper level, you have to start with a repeatable squareness. Nothing you’ll do will be consistent if you’re not starting from the same spot.
Your feet should all be pretty much the same height, you should enable the motors when both x rollers are the same distance from the ends and the y rollers are the same distance from the ends. You also need to check that the router bit is perpendicular to the work surface. Ryan made a printable part that attaches to the dw660 chuck and can check this, but you could also put a piece of bent wire in the router and slowly spin it to see if it’s always the same distance from the bed. (Does that make sense? The tip of the wire would make a >6″ diameter circle when you spin it, and if it’s off perpendicular then some parts of the circle will be closer to the board).
After that, you really care that the bed is parallel to the gantry, not really level. The sure fire way is to surface the spoil board. You can also surface your workpiece (workpieces are rarely the same thickness everywhere). If you surfaced your spoil board, you can just run workpieces through a thickness planer. Also make sure you’re getting good clamping.
To set your Z, at the start, or after a tool change, you can use the 3d printer trick of putting a piece of paper over the spot you’re zeroing on. Jog the z down until the paper has some resistance, but isn’t stuck. That’s like a cheap feeler guage. This is the only way I’ve done tool changes, since I haven’t bothered with a probe. If you want to see if your workpiece is parallel to the gantry, you can do this in several places and look at what the Z value is at each place. This is a very manual way of doing mesh levelling :). If you measured 5 spots, one on each corner and one in the middle, you would have a very good idea of just how off it is. Then you can try things like resetting everything to find your repeatability or you can surface the board and try again. You’ll end up with a very scientific approach to this, I hope.
W.r.t. v carving, a sharper pointed bit will also be less sensitive to z errors. If you’re using a 90degree bit, then 1mm error will end up being 1.4mm wider. A sharper bit would be only 0.5mm.
Take the parts of all that that work for you. You can easily spend a whole day on this without cutting anything. I would enjoy that, but aome poeple might not :).June 22, 2018 at 10:26 am #62075
All of this is making lots of sense. Looks like I have some work. Thank you !June 22, 2018 at 1:11 pm #62097
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