Berd Air Max v2 Motor Running Hot

[wdmarine]

I just installed the Berd Air Max v2 on my Rostock Max v3 and noticed the motor is running very hot to the touch at about 150F.

The board is a Duet Wifi and I am running the motor at 75% through the Duet's PWM E0 output through the provided eSwitch. The motor is mounted on top of the printer with the ventilation holes free and clear, so proper cooling isn't the issue.

I am using about 8 inches of the smallest diameter yellow tubing, but then the rest is the larger diameter. The metal ring tube is the original length with a gradual bend without any kinking, so I do not think there are any unexpected obstructions to the air flow. That said, blowing into the tube shows that the air flow is very restrictive, however I would expect this is normal. I will run the motor without the tubing attached to see how hot it gets.

I did ask Glenn, the maker of the Berd Air, and he said his motor doesn't run hot. Has anyone else run into this? Any ideas?

Thank you!

[gchristopher]

Mine's running pretty hot to the touch, too. I haven't measured the temperature because it's not melting anything. I'll check it with the crappy IR thermometer on the next long print and let you know what my imprecise measurement gets. (Other than yet another reminder to set up a good thermocouple.)

My EZStruder motors used to get pretty hot, enough that I worried a bit about the ABS printed brackets holding them. I slapped NEMA17 sized heat sinks from Robotdigg on the back of them, along with a 40mm fan, and they rarely get warm to the touch.

None of this represents good or well-informed engineering! Hopefully the competent people here have experience, too.

[wdmarine]

Thank you for the reply, gchristopher! I appreciate knowing I am not alone.

The maker of the Berd Air, Glenn said his motor ran at 120F once it warmed up. Well, it turned out the reason I was reaching 150F was, as is too often the case with me, user error. I wasn't thinking clearly about it when I wired the motor circuit up and used the wire I had on hand, which was 22awg. Glenn pointed out this was a bit light and so I rewired the motor with 18awg. This change, alone, is responsible for bringing the motor temp down by 30 degrees.

I've got to say I absolutely love the Berd Air. It cools the just-laid layer perfectly and I love how it helps to clean up the effector assembly.

Between switching to FSR and so being able to lose the accelerator PCB above and losing the three stock layer fans below, my effector assembly is beautifully uncluttered now. I am using the 713Maker mount for the E3D v6 hotend along with the bowden adapter lock ring so I could extend the otherwise recessed PCT connector. Its light and open for easier viewing of the print.

To be clear, while I do like the aesthetics of an uncluttered effector assembly, I was driven more by the practical desire to make it easier to disassemble the hotend in case of a jam.

[img]http://s3.amazonaws.com/3dPrint/hotend%20assembly.jpg[/img]

[djarmag]

I recently changed the tubing to use 4.5 ID flex tubing from an aquarium store and a 5mm aluminum pipe from hobby stores. The motor runs cooler (before the white plastic housing was too hot to touch, now it is cool to the touch but the metal housing is still slightly hot) but the reason the motor is hot is because the airflow is too restricted. By using the larger diameter piping, it allows the motor to have less work and load plus you get the benefit of running less "fan power" for more airflow to cool your part if you restrict the nozzle a little.

I designed a mount specifically for the 713Maker platform and I will post my design on Thingiverse when I can. The triple output in conjunction with the vinyl tubing makes for a nice semi-rigid support structure in itself!