i would glue the thermistor to the underside thou as it would be hotter than the top of the chip
has there ever been made FLIR pictures of the duet in action?
I stuck it to the top because when the fan comes on, I blow cold air on the underside. If the thermistor were stuck to the underside, it would sense that cold air and turn the fan off prematurely.
the U axis (wich was initially E0), had upper and lower software limit of 0 (checked with "M208" command).
That was probably causing the trouble.
Ok I didn't know that the "G1 U100 S1" command (once the endstop is activated) is acting just like the G92 command. Good to know !
Thank you for your answer
I suggest you measure the voltage at the gate and at the drain of TR3. The part number for TR3 is BSH105. With the heater commanded off, the gate should be at +3.3V and the drain should be at 0V.
If that's how they are, then TR4 (the main E0 mosfet) is shorted
if TR3 gate is at 0V then either TR3 or the microcontroller is faulty, or the firmware is turning the heater pin on. Check that you don't have a M307 H1 A-1 C-1 D-1 command in config.g to free up the pin for another purpose.
if TR3 gate is at +3.3V but TR3 drain is at 5V instead of 0V, then TR3 is faulty.
Is the motor vibrating loudly instead of rotating? If so, that usually means that you haven't got the wires paired correctly.
That's absolutely right. I connected one old motor and it was running. Then i checked for the wiring. New motor's Red and Green wires were swapped (from the supplier itself). So, I corrected the wiring. Now all the motors are running.
Thanks for the suggestions.
Also spec'd out the openbuilds steppers
openbuilds nema17 54 1.8 1.68 2.8 1.65 25.51
openbuilds nema23 123.58 1.8 2.8 3 1.1 14.29
openbuilds high torque nema23 243.62 1.8 3 4 1.2 10.00
I use those on a different bot ( well, the 17 and regular 23 ) and like 'em.
My recommendation is to use a twin-entry ferrule for the ground side of the VIN terminal block on the Duet. From it, one wire goes to the power supply, and the second one goes to the DueX. This second wire should be kept short.
It might help to check out my build log where I spent a fair bit of time with the SSR and how it was configured with lots of photos and decription. http://forums.reprap.org/read.php?178,702599,page=1
In short run small/low power cabling between the Duetwifi heated bed output and the DC inputs to the SSR make sure to get polarity the right way around.
On the AC side, use mains cables rated for at least the power rating of your heater preferably double that power rating . I.e. a 700w heater running at 240v pulls 2.91 amps, use 5A cable at least. If in doubt cannibalise a main cable of suitable rating. Take the neutral wire and run it to your heated bed mains heater, preferably adding a thermal fuse between the heater and the neutral wire, and ensuring you tuck it under the bed between the mains heater and whatever is above it (presumably aluminium plate), make sure its secure.
Now bring the live in from your power socket to one side of the SSR AC connectors. The other AC connector on the SSR goes to the live on your bed heater.
When a DC PWM or bang-bang "signal" is generated by the duetwifi, when the bed is on, the ssr will connect the AC. If its bang bang then it goes ON-OFF at full power in cycles lasting a second or two each when maintaining the bed temperature, if you send low frequency PWM (default setting for duetwifi) then it will pulse power at up to 10 hz to the bed for more precise control, the SSR will pulse connect the mains to the bed correspondingly..
The important part is the earthing. Make sure there is an earth wire from the aluminium bed, to the frame, and the to the SSR backing plate, and then out to your AC mains supply (preferably with an RCD/GFI) device. Ensure that all metal parts of the machine are grounded together, check this with a multimeter, aluminium frames are covered in aluminium oxide which is not very conductive so scratch the surface with the multimeter probe and check. The resistance between each of the metal parts should be low i.e. as close to 0 ohms as possible. Any poorly grounded or ungrouned metal parts need to be electrically joined together, you can use ring crimp connectors and mains wire and a drill and tap, with some m3 machine screws to earth bond the frame components together if needed. I didn't need to the tnuts and bolts created good connections.
If it stops controlling it for any reason the thermal fuse will trip permanently disconnecting the power, I chose 150 degrees, which allows a little headroom but should cut the power before anything melts or catches fire. If there is a wire break or the silicone heater (I assume you are using one) gets penetrated by anything, the RCD will trip.
As for your confusion, at any point that the duetwifi commands the bed to heat (that can be started by a gcode file, the paneldue, the web interface) then the heated bed output switches the SSR ON. When this signal goes off the SSR goes off. How it is wired doesn't affect how you tell it to come on/go off.