The Evil Dishwasher

[Spiv]

Or so it has become known... It's been a long time since I've posted up in here, but I thought I should share. A long time back I was working on This and it has come a long way.

Here she is, all nekkid:


you can see I had to add quite a bit of bracing, including a truss type thing behind one of the beams:



and of course it has a proper spindle on it now. Borrowed and hacked up from an X2 (got it from LMS a while back). Results?

YouTube - Home made cnc machine cutting aluminum
There is lots of other stuff too, and I'm going to try to update my blog to reflect that. In the mean time, what do you guys think?

[zool]

Absolutely brilliant. Ditto for info shown on your blog.

[louieatienza]

Whoa... cool!

[dbc1218]

Really glad you posted because I have been designing a very similar machine, all welded steel frame, rails and bearings from linearmotionbearings2008. Here is another post I had a while back http://www.cnczone.com/forums/diy-cn..._question.html

My main question is about the shims and getting everything lined up. How hard was it? My machine will have essentially 3 different welded parts that I plan on making jigs for. Then everything will be bolted together. My z-axis and router will also be supported by aluminum plates, 3/8" thick. I plan on using low head socket head cap screws and counter boring the plate that mounts to the y-axis bearings. Oh all the steel is 1x2x0.065.

Also what diameter rails did you use for each axis?

I currently have the rails and the steel and will start building soon, any suggestions would be greatly appreciated.

[Spiv]

Originally Posted by dbc1218 Really glad you posted because I have been designing a very similar machine, all welded steel frame, rails and bearings from linearmotionbearings2008. Here is another post I had a while back http://www.cnczone.com/forums/diy-cn..._question.html My main question is about the shims and getting everything lined up. How hard was it? My machine will have essentially 3 different welded parts that I plan on making jigs for. Then everything will be bolted together. My z-axis and router will also be supported by aluminum plates, 3/8" thick. I plan on using low head socket head cap screws and counter boring the plate that mounts to the y-axis bearings. Oh all the steel is 1x2x0.065. Also what diameter rails did you use for each axis? I currently have the rails and the steel and will start building soon, any suggestions would be greatly appreciated.

Some of the alignment question is going to be about your welding, so keep that in mind. I've been doing car frames for a little while so I came up very close on most things. You may have the same luck.

For the most part I was able to get variety of washers to stick under each mounting point, and drilled the mounting holes out a bit larger to give it some play in the other dimension (I match drilled the holes I would be threading first to make sure they were as close to center as I could get). All in all it wasn't hard based on that. Just bolted things together while attached to the slides, and while everything was loose I would slide things back and forth a few times and tighten incrementally. This gave everything a chance to shift around and find a neutral spot.

rails: 20mm, 16m, and 16mm. If (when) I build another machine I'm going all 25mm. The potential for flex isn't in the rail itself so much as in the slide blocks.

[dbc1218]

Your aligning procedure sound like what I was thinking but I didn't know if it would work, its good to have conformation. I've welded a few dune buggy frames together so I'm to worried about it.

I have 20, 16, and 12mm rails. The 20 and 16 are great but the 12mm has a lot of slop in the bearings. I can adjust it with set screws on the top and side of the bearing but I feel like I'm going to need over tighten them just to get the slop out, but then the bearing doesn't slide as well. Once my machine is finished if they give me problems they'll be the first thing replaced.

[Spiv]

I had similar issues with the 12mm rails. I think they just aren't made for the kind of abuse that gets thrown at them in this kind of application. Worse than that, I think they got worse with use. Replacing them with more 16mm rails was a necessary step IMO.