Topics created by sebastien

@sebastien said in ATX PSU and 200W 12V Heat Bed:

I assume a MOSFET would work as well

As long as it's rated for the current, yes. It would basically be replacing the mosfet on the Duet.

@sebastien said in ATX PSU and 200W 12V Heat Bed:

what I should do with the Duet EXT_5V GND

connect it to ground.

Your diagram looks ok.

Make sure your cables are thick enough to handle the DC current and make sure you have good strain relief.

This page shows all the pads that contain electronics, clearances, etc. The surface mount stuff is all MUCH shorter than the various connectors.

Also, at the very bottom of that page is a link to github. The T3P3/SmartEffector/SmartEffector_v2.0/SmartEffector.kicad_pcb file is literally the board file that can be loaded in KiCAD so you can see the PCB layout. I don't use KiCAD, and therefore don't have it installed, or I would screen shot it for you.

The strain gauge itself is a set of very fine traces in the circuit board etch. They form a "tri-spiral" around the center.

You can actually see the traces that form the strain gauge in this photo (also linked from that same page).

@sebastien said in MinebaMitsumi 17PM-KA39B steppers not moving (Atom 2.0 upgrade):

Replying to myself here, but basically the wiring was OK and that I thought there was a problem because the movement was too brief. I was using G1 S2 X1, but using a higher value such as G1 S2 X10 makes the movement more visible.

The main thing that made me think there was an issue is that the motor produce a sound after a G1 S2 command even when they're not moving, while I thought they would power off after the movement is complete. Issuing a M1 command does stop the noise from the motors.

So it's working after all?

When you first power up the printer, the motors are not powered. After you first move a motor, it remains powered at the end of the movement, in order to hold position. The motor current will be reduced to the idle value (default 30% current) after all motors have been idle for the idle time (default 30 seconds). The firmware assumes that the motors will still hold position at the idle current setting. On some printers (mostly deltas), you need to increase the idle current percentage to make sure of this.

You can disable the motors (i.e. reduce current to zero until they are commanded to move again) using M18 or M84, but then they are not guaranteed to hold position, so the associated axes will be flagged as not having been homed.

HTH David