How do I make the X and Y axes exactly perpendicular?

[petruscad]

Hi,

I've built a JGRO-type gantry router out of MDF. I'm in the alignment stage now! I know how to make the spindle perpendicular to the table (tramming), with a dial indicator mounted in the spindle. The open question is, how do I align the X and Y axes so they are precisely perpendicular to each other?

If the axes are not at a 90 degree angle then the machine will not be able to cut an exact square, for example.

Thanks,
Dumitru.

[TommieK]

Dear Petruscad,
Exact and precise are not synonomous with the JGRO type of CNC machine you are attempting to build. Roller skate bearings and gas pipe are at the best of times only ever going to get you close. However, to give you a small amount of encouragement, the adjusment blocks (you either made these out of MDF or Delrin or perhaps HDPE) with the four 1/4" all thread bolts are what is used to adjust the alignment of the machine. Hope this helps. Tom

[badmoonrizn]

Tram the y axis to one extreme with a pencil chucked in the spindle and make a mark on the cutting bed by lowering the z axis. Raise the z, and tram to the other extreme, and make a mark the same way. Take measurements of the marks to the edge of the cutting bed, and make your adjustments from there.

Do the same with the X axis, and it should be pretty darn close. I have made the JGRO machine myself, and it is precise enough to do some fairly detailed work even with the roller skate bearings and gas pipe.

No, it will never be as stout as say an aluminum framed machine, but at least it will do just about anything your imagination can dream up. It's a fine machine for the money spent.

[Broken Balsa]

This may sound very simple but it worked for me... I put a rod in my router and used a small square up aginst the rod on both axis. That seem to work just fine. When I change routers occasionaly I just repeat to make sure nothing has changed. Mine works very well and I enjoyed building and using it. I used squares on all axis and mark my sacrifical board when I replace it with lines in both axis. Makes it quick and easy to lay a sheet down and get it very close. I mostly make camera mounts for model aircraft and cut a lot of G 10. I think you will be very happy with your machine. Ron ..Broken Balsa