Squaring x to y

[paul]

i found my bot to be a little out of sqaure. to improve it i turned off/unplugged one of the x motors and moved the in the x direction a small amount 1/16 in the direction needed to improve my squaring. did a rectangle measured diagonally did not notice an improvement. repeated above procedure moving x another 1/16 still no better!? did it again this time by an 1/8. same thing. what am i doing wrong??!! thanks guys!

[Mayo]

It's likely not the motor/gear position that you need to adjust.

I would loosen the top 4 bolts that hold the Y carriage to the pieces that ride on the X rails. Use a large carpenters square to make sure you have square between the Y carriage and the X rails. You will probably need a second person or some clamps to hold the square in place while making adjustments. Make sure things do not shift when you re-tighten your bolts.

[gordon@shopbottools.com]

Paul,

The best way to square a tool is with an actual cut. This is the recommended method for squaring the Y to the X that is used by most of our installers. First thing to do is determine the how much out of square the carriage is. To do this, cut a straight line in the X direction. Then one in the Y direction towards the zero end of the table. With a framing square measure how much the cut is out of square. If, you used the 2 ft end of the square in the Y direction you'll need to multiply the gap by 3 to determine how far to move the end of the carriage into square. Now the carriage can be adjusted. Place clamps on the X rail on one side of the table against both sides of that X car. This will keep that end stationary as you adjust the other side. Place your framing square against the X rail and slide it up to the X car on the side that the carriage needs to be moved towards, using the scale on the square mark the distance the carriage needs to be moved. Next, loosen the 8 bolts that hold the Y rails to the X cars, place the square back in the position you used to mark the offset, and move the carriage over until the corner of the square reaches the mark you made earlier. Finish up by tightening the bolts that hold the Y rails to the X car, being careful not to move the end of the carriage. I've found the best way to do this is to tighten by pulling the wrench towards the sides of the table and not the ends. IMPORTANT, make sure that the clamps you put on earlier are taken off before trying to move to tool. Now you can make another pass in the Y direction and check the squareness. If it is still out repeat the process above until the cut is square.

[Wdyasq@yahoo.com]

I have an older - originally a cable ShopBot I have converted to rack and pinion. Once I got it square and running 'true', I placed masking tape under where my 'zero' is and reset the carriage to make sure my machine was on 'zero'. I cut the tape using the 'y-carriage' as a guide. I pealed off the tape to the cut line, marked it with a 'marks-a-lot' and checked again for square.

Now, if I wonder if my cuts are square or my machine is still on register, I have a visual check.

I may take a piece of 'double-sided' tape and stick a tape down on the 'uni-strut' so I can see where I am without looking at the screen. I would also be able to see if the machine 'jumped phase' on the motors due to one problem or another.

Ron Brown - wdyasq@yahoo.com

If Stupidity got us into this mess,
then why can't it get us out? - Will Rogers

[beacon14]

When we finally got our machine as square as square can be, we adjusted the hard stops on both ends of the table so that they would be contacted simultaneously whenever the x tried to go past working limits (yes it happens more often than I would like to admit). The two advantages of this are that when the machine hits the hard stops, instead of hitting only one and forcing itself out of square, it hits both and stops, but stays square. Also, we can easily check squareness by bringing the y carriage right up to the stops and measuring or sighting the gaps between the carriage and the hard stops. Equal gaps means square ShopBot means happy ShopBotters.

[gerald_d]

This old topic may be useful. It followed after this thread.

[gerald_d]

Deleted double post