New shop bot user z scale is off

[JimMetully]

Hello everyone. I believe my machine is a 2004 prt. No tool changer


I set my z zero to zero(manually using Z Z because I can't get the z zero plate to set zero at the top of mdf spoilboard). The problem is that I tell the machine to go to Z1 (should send it exactly 1" up into the air I think), and instead it goes up less than 1/4". What the machine thinks is 4" above the work surface is actually just over 3/4" above the work surface. This is obviously making my programs do strange things, but only in the z axis. I looked through the VALUES tab to see if anything was obviously wrong. Couldn't find anything that I thought was obvious. Any ideas?

Another clue is that when I try to use the z zero plate, my zero seems to be about the height of the top of the metal flat bar instead of on the top of my work surface. Is there a place that I tell the software how thick the z zero plate itself is?

Another clue is that everything seemed to work ok before I tried to run this on my new computer. The previous owner had all of the settings set up, and I just used the factory suggested settings after downloading my version from the shop bot website.

Thank you in advance for any suggestions
Jim in Seattle

[Brian Harnett]

When you hooked up the new computer did you update the firmware?

I have had to do that with computer changes not sure it it is the problem

[srwtlc]

Jim, It sounds like you're using the wrong unit values for your machine. Have you done a reset with UR and chosen the proper setting file for your machine?

Maybe we should first determine whether your machine is a stock PRT or has it been upgraded to a 4G controller. I'm not sure, but '04 may have been the first year for the PRT Alpha. Once we know this, then you can choose the proper settings file. It's also possible that the pinions could have been swapped out and you need a different unit value than stock.

Does it move the commanded distance in X and Y or is that off also? Count the teeth on the z axis pinion.

This may be helpful... http://shopbotwiki.com/index.php?title=PRTInchUnits

[JimMetully]

I will play with this when I get a chance. These are both really good leads. I will post a reply letting you guys know how it goes.

It was upgraded, and the table length was modified too. I am going to try copying the settings from the old computer too.

Thanks again
Jim 206.853.6412

[scottp55]

Jim, Z-plate dimension change is on third page of a TS (Tool Setup).

[JimMetully]

Thanks everyone for your suggestions. It was my unit values. They were off in the x, y and z axis. The x and y were within 20%. The z was set at 900ish and it was supposed to be 4000.

You guys really are the best. I have had nothing but nice and helpful people on this forum.

Now it looks like my last major project is getting a new sheet of mdf that's not all chewed up and figuring out how to level my table. Moving it seems to have messed up how flat it was.

Take good care
Jim