[DistortedDesign]

My hobby cnc pro controller board quit working, that i never fully had running. I have had it a while so can't turn in, no support from dave on his forum. So i am just going to have to get something else. I just saw the thing about optimal voltage for steppers. Not sure if my math is correct.

I have keling 425oz motors. 8 wire so it can be bi or uni. If bi parallel needs 4.17v, 2.8A, 1.8ohms, 6.8 ind = 425oz
If uni needs 6v, 2A, 3ohms, 6.8ind = 305oz
According to the math i need 90+ volts feeding the controller because of the inductance...?

I don't have much money right now, i am just trying to get my joes 2008 up and running. I can upgrade controllers in 6 months but don't want something that will be missing a ton of steps, but is still reasonable in price. The voltage for the steppers is throwing me off. I was looking at aquick cnc, TB6600 or TB6560, or hobbycnc pro...again..sigh. I will buy geckos in time but not right now. I still need to buy bits, and software as well. Any recommendations?

Thanks,

Jason

[ger21]

Get a G540. It'll still run better than the HobbyCNC, and it's a cheaper option. When you can afford it, sell the 425's and replace them with 381's.

[DistortedDesign]

Uhhh G540 is $300 hobbycnc pro $105... How is G540 the cheaper option? I only have around $100 for new controller, i will move to geckos eventually. I still need mach, design software, router bits, and possibly a power supply as well as a new controller i hadn't counted on with no budget. Which is why i was looking at the above models.

What supplied voltage do my steppers need? Square root of inductance x 32? .....83v ? Seems really high.... Is my math wrong?

Sent from my SPH-D710 using Tapatalk 2

[lucas]

Those motor's aren't the best as others said, but you only need the high voltage power supply to obtain the max power available at very high speed.
It depends on your machine design if you need this, torque at lower speeds is the same even with a lower supply voltage.
I'm running 3Nm motor's well below the calculated supply and still have up to 10K mm/min rapids with a 10mm/turn ballscrew using THB6064 drives with a 42V supply.

Forget the TB6560, it only works reliable at 24VDC.

[ger21]

Uhhh G540 is $300 hobbycnc pro $105... How is G540 the cheaper option?

It's cheaper than the 3 G201x's and 72V power supply that you'd need to get optimum performance from those motors.

I didn't realize you had a $100 budget/ I thought you were looking to upgrade. Just get another HobbyCNC and run the motors at 36V. It's what Joe and many others did when they first built their machines.

[DistortedDesign]

Yeah it's what i was thinkin, my issue is Dave isn't supporting his product on his own forum. I don't know.

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[lucas]

What's wrong with the board?
There are only 3 driver chips and a few passive components, should be easy to fix.

[DistortedDesign]

What's wrong with the board?
There are only 3 driver chips and a few passive components, should be easy to fix.

Basically I have a dead short on the board that I can't find or two of them. I have a dead short on the 5v tab and the y axis vref tab also has a dead short. Here are the links to those threads
http://www.cnczone.com/forums/hobbyc..._question.html

http://www.cnczone.com/forums/hobbyc...ing_wrong.html

I could use any help, just pm me or respond in those threads, thanks

[lucas]

Basically I have a dead short on the board that I can't find or two of them. I have a dead short on the 5v tab and the y axis vref tab also has a dead short.

That short on the Y Vref is a good indication.
I would guess that the Y driver chip is shorted internally and pulls both the Vref and +5 down.
You could compare the resistance of all chip pins with each other, if one or more pins of the Y chip is different then it's probably blown.

To be sure you could cut the 5V pin of the chip or the PCB trace to that pin (do it in such a way that you can resolder them back) and then measure again.
What supply did you use, you mentioned 42V IIRC, this may be on the limit.

[DistortedDesign]

Lucas, I am going to copy your last post over to my other thread here so not to hijack the thread off topic. Thanks for your help and interest.