[akasealy]

Hello All!
So... I built this Machine In which I call the Carve Fast. Its about a 28" x 28" x 3" machine area. Works pretty well used 1605 ball screws on X and Y and went with a belt drive Z for fast carving its primarily going to be used for that. At the beginning I had a design flaw in the Y axis that is carrying the z (needed to support the 16mm shafts) fixed that. It stopped the vibration issues in the z and allowed me to carve faster. But now when I carve I get these ripples. I carved at a 35 degree angle and not too bad but had ripples would need to sand. I ran the same program in the x direction and the ripples well ..... were very awful pretty much junk carve. I then switch it to carve in the Y direction had about 90% reduction of ripples. I see a lot of vibration happening in the x direction I have attached some photos of the machine and a couple older youtube links showing the machine before I suppoerted the Y rails, so disregard the Y please. Any help on solving my x vibration would be much appreciated better yet any one in the bay area of ca that has any experience in build a cnc I would be more than happy to have ya come by and check it out. Over all the work around would be to just carve in the Y but that also slows the machine down I don't want that. Its almost there just need to make a few modifications and I know this machine will be super fast.

youtube page
https://www.youtube.com/channel/UCtC...lk9j9JbYAQydrA

[daddywoofdawg]

from the video,looks like your router or Z axis is bouncing all over the place which could be the cause.

[ger21]

Which is the X axis and which is the Y?
Any pictures of the ripples you're talking about?

The short answer to your question is to never use unsupported round rails. If you grab the collet on your spindle and push and pull on it, I'm sure it moves quite a bit from the rails flexing. Any movement at all will result in poor quality cuts. There's really no way to "fix" this, short of building a new machine.

Also, the belt drive Z axis probably has rather poor resolution, but I don't know if that's part of the problem or not.

[akasealy]

Attachment 236764 with with non ripples is y direction and one with ripples is x direction

[ger21]

Which is the X axis and which is the Y?

.

[akasealy]

Again the Z axis rides along the Y the x is carrying the whole gantry. In the original post the second picture showing the whole machine x is vertical y is horizontal. So to be clear Y runs east to west and x runs north to south.

[akasealy]

And as far as the Y it has now been supported I dont get any movement (or very very little) from the z axis when pulling on the router collet. I fixed that by putting in the supported Y rails , not shown in the pics, just added those two weeks ago. now its the x that seems to have vibration when changing directions. Hope that helps, I guess I will have to order up some supported x rails and see if that will reduce it , The whole machine feels really rigid untill you see it change directions in the x axis. As far as the Z belt resolution, its pretty awesome and super fast, but major reduction in speed when carving in x direction due to vibration.When carving in Y i am getting speeds of almost 150ipm + until I get vibration .

[Trotline]

Supported rails in the X will help. You may also be getting some bounce of the stock. Hard to tell from the photos, but the cross-members that hold it up look pretty thin. Resolution issues aside, the Z speed is probably much higher than X-Y, but resolution and rigidity are in general more important than speed there. The machine will be limited to the speed you can coax out of the 1605 ballscrews. 1610 screws would be more speed matched to a high speed Z.

It's helpful to post pictures of the machine as it exists, rather than a previous iteration, when trying to figure out problems.

Luke

[ger21]

Yeah, if the Y now has supported rails and the good cuts are along the Y, then you need to replace the X axis shafts with supported shafts.