Sciencemadness Discussion Board - Slow high torque electric motors for stirrer?

Slow high torque electric motors for stirrer?

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MJ101 - 25-6-2018 at 03:57

@Magpie: I found this. Hope it's helpful.
https://www.sunrom.com/p/stepper-motor-driver-module-a4988-h...

P.S. I'm glad you got it sorted out.

Magpie - 25-6-2018 at 07:32

Yes, thanks, I have used an A4988 driver also. I'm now using the Toshiba 6600-4.0 driver as it came with my Zyltech NEMA 23 stepper motor. When I get my tachometer hooked up the system will be complete.

Edit: Tachometer is hooked up, speed = 470 rpm at 24vdc.

[Edited on 25-6-2018 by Magpie]

MJ101 - 25-6-2018 at 14:24

@Magpie: I was thinking...

With the length of time and amount of stirring you'll be doing, you might want to consider heat sinking that driver chip.

If you do, using silicone heatsink compound may interfere with reactions, or get eaten by them.

Forgive me if my statement appears dumb. I honestly don't know.

Just in case, there's this: https://en.wikipedia.org/wiki/Arctic_Silver

Just a thought.

Magpie - 25-6-2018 at 17:58

A heat sink is an integral part of the driver.

Magpie - 26-6-2018 at 11:33

I just finished running the motor for 2hrs at load. The driver was too hot to touch. I will take it out of the box and add a fan.

MJ101 - 26-6-2018 at 12:15

That heatsink is really tiny. It looks like it's epoxied in place, so changing it might be difficult if not impossible without breaking the IC.

In case you need it for reference, here's the spec sheet of the IC itself.

https://www.allegromicro.com/~/media/Files/Datasheets/A4988-...

Magpie - 1-10-2018 at 17:47

I finally have the large OrientalMotor stepper motor running using the Toshiba 60 driver. In the attached video it is driving an agitator in my autoclave with a homemade mechanical seal. The motor sounds rough but that's its nature. It is running at 418 rpm using 28.9 vdc. This is the Avast HTML file that I could not convert to a YouTube compatible format. My Apple iPad converted it for me.

https://www.youtube.com/watch?v=5K9WpnZ7W7s

morganbw - 15-10-2018 at 14:38

Quote: Originally posted by Magpie

I finally have the large OrientalMotor stepper motor running using the Toshiba 60 driver. In the attached video it is driving an agitator in my autoclave with a homemade mechanical seal. The motor sounds rough but that's its nature. It is running at 418 rpm using 28.9 vdc. This is the Avast HTML file that I could not convert to a YouTube compatible format. My Apple iPad converted it for me.

https://www.youtube.com/watch?v=5K9WpnZ7W7s

Your homemade mechanical seal is of interest to me. If you feel the urge, share what you have done.

Magpie - 15-10-2018 at 17:52

I modified the top of my autoclave to install a port for the 5/16" shaft. Attached to this port is the mechanical seal that I designed. It uses an 1/8" square packing. It works well.

When pressurizing the vessel, say to 1000 psig, the shaft must be restrained with a counterweight of 81 lbs to keep from ejecting the shaft. This happened to me shooting the shaft into the top of the hood. It then bounced off that and hit my arm, bruising it. I then made a beam that holds 16 bricks to supply the necessary counter weight.

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