Thing-o-matic moving too far on y axis

[pdunwin]

Hello,

I acquired a Thing-o-matic from a friend. He had been able to do good work with it, but I'm struggling even to get a halfway decent calibration cube out of it.

Recently, I unhooked it from my computer and took it back to his house, where we were able to make some progress. After I brought it back home, hooked it back up and ran it through a calibration, I tried another calibration cube. All was well until the print began, at which point the bed flung itself forward, out from underneath the nozzle. Some experimentation found that the bed was moving about 10 times further than it was being told to in the y direction (towards and away from the front of the machine). What could be causing this? Nothing had changed except that I had moved it between houses.

Of note, however: during out trouble shooting, we opened up the bottom to check all the connections. We didn't change anything, but could a dipswitch have been flipped or something?

Thanks,
Paul

[pdunwin]

Has no one else had this issue, or something similar?

I've asked the friend I bought it from for instructions I might use to check that the Arduini dip switches are set correctly, but does anyone here know if those are available online?