Y axis prox switch and end stops

[gg_haskell]

I am setting the prox switches for my shopbot . X axis went well , but I have questions about the y axis. The table is centered between x- rails. The end stop to the right of the y motor stops the bot at about 3/4" past the edge of the table. I had to set the prox switch inside the stop so I now have 1/2" clearance. That is with the stop pushed as far right as it can go. On the other three sides I have a clearance of 2". I am concerned that with a large cutter head I will not have proper clearance.
Also are proximity switches used to set a home position , are there any suggestions of other methods?

[dana_swift]

Greg it sounds like you have thought it out, I put my limit switches just outside the cutting envelope for the same reason.

Another good way to find home is to "center in a hole". That routine is in the C:\SbParts directory named "S_Center_inHole.sbp". That depends on you creating a small hole at the home position in the spoilboard. It also requires you have a probe, or a superzero to make contact with. (look up the superzero devices in the forum). You can also set Z from the bottom of the hole.

I am working on a simple method of setting zero using a shoulder bolt. So I have written a routine similar to what comes with the shopbot I call "center on bolt". I will be posting more on this technique later, when I have a list of parts written up and have done a lot of repeatability testing.

Other common methods are edge finding, and lasers centered manually on zero. Look up lasers elsewhere on this forum.

When I start my bot, I always use C1 to find the "home" prox switches. Then if I have a part mounted on a vacuum fixture I will often use the lasers, or "center on bolt" to set the zero relative to the fixture, or the part.

And then if I am cutting an oddball part that is just clamped down to the table, I intentionally put it on a part of the bot that doesn't get used as often, then the wear and tear on the rack gears gets a little more evenly distributed.

Hope those suggestions give you some ideas to get going with.

D