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Hi I am putting my CNC together again i built some years ago. It runs on two linear rails on the x-axis. They are about 4 meters long. I know already how to bring them parallel in y axis. With having a straight master rail and then align the slave with a dial indicator. But now I wonder how i could align them in z also. I don't have a flat ground plane i could adjust them to.
What I have is a straight edge, a square and two dial indicator and two semi good levels. Any recommendations?
Hi Flex - By Z do you mean to make them horizontal? If so then a good engineers level is recommended. Peter
Yes I mean horizontal. Any other options to get it fairly aligned?Quote:
Originally Posted by peteeng
Hi Flex -The usual advice is to do the best you can with what you have. I have been looking for laser alignment equipment but don't have the spare $40k to buy it :) Peter
I had one idea. But don't know if it could work. To use a water filled container as my ground plane. Then I would electrify it with a small voltage. Now I could attach a probe on my z axis and lower it until it touches the water. Don't know if that was tried already?Quote:
Originally Posted by peteeng
Hi Flex -There is a commercial system that works like that. Uses hoses and electrical micrometers. My usual issue is getting the gantry square to the rails...Peter
https://www.mmsonline.com/blog/post/...ion-and-beyond
https://www.lasertools.com.au/nivcom...-digital-level
I found an add for some self levelling water, make sure you get some :)
found the one I was looking for
https://www.precisiontools.biz/tools2/pwl/
Oh that's interesting to see it's used commercial. I wasn't aware of the fact that the earth curvature plays a role. A quick online research gave me on 4m 0.1mm that's of course significant for a commercial machine. For me that will fineQuote:
Originally Posted by peteeng
It's actually much less. 1.25 microns over 4m. My assumption prior was simply by linear adapting 1km to 4m. But instead the derivative rises by the sinusQuote:
Originally Posted by flexbex
Late to the party, but a laser pointer works. Mount the laser to your rail using the straight edge or slide carriage. Pick a wall as far away as possible in line with your rail and make a dot on it. Point the laser at the dot. Now slide the laser down the rail and as long as it is pointing at the dot, the rail is level. The further the distance to the wall is, the more accurate you can be. Just like a rifle, a small deviation of the barrel makes a large difference at the target.
You can use mirrors to bounce the beam back and forth to increase your distance. If you want to level 2 rails, then you need to lay a straight edge across them and level both ends of the straight edge, on both ends of the rail.
Even much later for a reply. But your idea sounds interesting. I might give it a go. I would adapt it by aligning the center part as long as my straight edge is. 500mm. Then put two carriers on it. Combining them on pre tension. So they won't wiggle. Then attaching the laser and move it back and forth, on the aligned part of the rail, while adjusting the laser until the dot doesn't moveQuote:
Originally Posted by excitedbox