Hello
I realize that the heated bed has different limitations based on the size of the plate.
Is this based on the heating mechanism itself or the power supply?
Seems like something that could be upgraded without much trouble if its the power supply…
In one of the kickstarter updates ages ago they explained it was due to power supply limitations. However, due to this limitation, the heating circuit is designed to not draw current that would exceed the power supply. I’m not sure putting it on a separate power supply will allow it to get hotter.
I went with a 750W 120VAC heater. Haven’t gotten far on that project, all the pieces are still in the box. But someday…
I don’t know how you could control it via gcode in that circumstance, but surely it cant be that difficult to swap out
Furthermore, I know you have a not level bed, seems like one could be made from some plate without too many problems.
I am very interested in over time the modifications people come up with to make the machine better, especially in this forum where everyone seems like an engineer!
AKA: relays.
Drew a schematic over here: Snapmaker 2.0 A350 Power Supply Requirements - #11 by brent113. In this case, the 2nd PSU is not 24VSC but 120VAC.
Yea, have a borosilicate sheet in a box too.
Communications are not my strongest area. I am starting to tinker around with modbus on a very limited basis at work. I guess if you had a controller to decipher the gcode it wouldn’t be too hard, but sounds like a challenging thing to do without a PLC with a serial port.
I will check out your information tomorrow, and also wonder if there is any merit to adding a heater to the enclosure
Oh wait, the heater is PWM controlled… does that mean the plug just carries voltage and an analog PWM signal? Possibly two, one for input power and one for temperature value output?
That’s definitely doable!
Also new to that but I have had some successful implementations into products at this point
0-10V or PWM is ez street, I was way over thinking this.
The cable has 4 wires. +/- DC power to the heater. +/- to the thermistor. The heater circuit gets 24VDC PWMd to it. The thermistor is just part of a larger circuit. As long as an NTC 100k thermistor makes it back to the controller, the controller is happy. The output from the controller for the +24V heater power needs to be intercepted to control a relay. It’s not an analog PWM, it’s using bang-bang temperature regulation now. I plan on changing the firmware to add PID control if necessary, but that also wouldn’t be PWM, but slow switching.
I understand over half of the words you used!
Hehe, keep us posted, I could get to the relay easy enough but the balance is a lil tricky for me
Edit: On further consideration, I think you are saying it is simpler yet than I thought. The heated bed is either ON or OFF (not a variable power) based on the thermister value being sent to the controller yeah?
Additionally: Wow, Simplify 3D vs cura - its amazing how well this print came out (not the circle from before, something else) against all the tinkering and crap I was doing to try to force it to work on Cura. Definitely worth the money…
Yep! Switches slowly, only turning on or off when it crosses the temperature setpoint.
Glad to hear you’re having good results with s3d!
Man I was just gushing at my print 15 minutes ago, suddenly the layers are not sticking! Oof, i jacked the heat up we will see how it goes.
This stupid circle thing is just going to be the death of me. My 10th attempt!
@brent113. If you wanted to get really fancy, you would use an hvac temp controller and convert the pwm into an analog signal the temp controller could use. Then You have temp control pid at 120vac with minimal effort.
Or…I would just enabled the bed PID controller in the firmware that should’ve been enabled by default. But I’ll measure the swing first, might be stable.
@brent113 @MooseJuice
The limitation is because of the controller.- I had email contact to edwin long time ago because of the told “powersupply is too weak”. The email contact should be here in the forum A350 heat bed mod