MakerGear Forum

So here is the thing.

I just got my printer out of storage, set it up yesterday. it worked ok, but the temperature on the extruder was being a little erratic, so I autotuned it, which failed, went into config h and altered the PID MAX value, which allowed it to complete its autotune, applied those setting to the config file.

Cool. First time I had done such a thing. Felt accomplished.

Went to do yet another 20mm test cube and now S3D seems to either move the bed/extruder half distance or it thinks the bed is twice the size? The print was 50% the size too, so something has decided that 1mm=0.5mm in its little world.

I have checked the settings, the bed remains the same size etc.

I have no idea why fiddling with the PID settings would cause this, but its the only thing that I have changed...

I will say I did solve my erratic extruder heating. Which is nice.

So any help??

Since you changed PID MAX, you would have had to flash the whole firmware.

My guess is what happened is that you flashed a firmware that was for one RAMBo board revision with the 8-microstep steppers, while you have a RAMBo board with 16-microstep steppers.

Look in Configuration_adv.h for MICROSTEP_MODES. Old RAMBo boards (v1.0) need
while for the newer boards (v1.1 and v1.2) need
Unfortunately, nobody has been smart enough to change the board identifier number between the 1.0 and 1.1, making incompatible RAMBo boards indistinguishable in the firmware, which is the root cause of this headache.

While comparing MICROSTEP_MODES against your RAMBo version number is a good indicator of whether or not you have a version mismatch, changing the MICROSTEP_MODES doesn't solve the problem. . . you need to go to the file Configuration.h, where the old RAMBo boards need
and newer RAMBo boards need
You can also correct for the general silliness of the "/2" and "*2" corrections in the code above; I just copied what was in the downloaded Marlin source files. . .

I believe that between the two definitions above and the PID settings, that covers all the discrepancies between the older and newer firmware on the M2s.

Tim,

Huge thanks for your reply.

I thought it would be something along those lines, but no matter what I did, it didn't alter.

Untill you came along. now the key thing here was, I think, the Microstep modes code, as look and look it was not to be found in either of the config files. So I added it my self and hey presto...

Back up and running! And bang on scale as well. Makes the modelmaker in me happy...

Thanks again!

Glad I could help! The computer programmer in me is happy that my advice was sound. . .