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Author Topic: Only X-axis motor is working  (Read 11647 times)

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Offline rcaffin

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Re: Only X-axis motor is working
« Reply #180 on: April 07, 2018, 08:30:27 PM »
Hi Inferno

Frankly, I would prefer to first update the drivers, then the power supply, and only at the end would I look at the motors themselves. But that is just my bias - partly due to the fact that when I did finally update the drivers, everything else worked so much better.

Cheers
Roger
Re: Only X-axis motor is working
« Reply #181 on: April 07, 2018, 08:47:18 PM »
Hi,
I strongly support what Roger proposes. By far and away the weakest link you have is the drivers. Replace those with good ones you may well find everything else
is good enough, and no matter what motors or powersupply you use is ever going to make up for poor drivers.

I use Vexta 5 phase steppers, 5 phase is somewhat esoteric but they have a few advantages. When I first got them I used a homemade, home design driver, quick and nasty. I was
somewhat disappointed at the motors particularly as I paid a real PREMIUM to get good quality. Eventually I bought the genuine Vexta Drivers that are specifically intended for these motors,
they have an open circuit voltage of 150V!. They are absolutely superb, they spin my motors at 2400rpm all day and have not missed a step in four years. Without those drivers the motors
are really very average.

Craig
My wife left with my best friend...
     and I miss him!
Re: Only X-axis motor is working
« Reply #182 on: April 07, 2018, 10:54:28 PM »
I understand what you guys are saying and if finances worked that way, I would go that way.
I don't need a perfect table at the get go. I need proof of concept. Once I have proof of concept I can justify adding funds to the project. Any upgrades, that take funds, before proof of concept will delay the project.

The drivers will be easier to swap out than the motors will which is why I decided to do motors first. The power supply is something that I know isn't adequate for the proof of concept.

Re: Only X-axis motor is working
« Reply #183 on: April 07, 2018, 11:18:19 PM »
My wife left with my best friend...
     and I miss him!
Re: Only X-axis motor is working
« Reply #184 on: April 08, 2018, 12:57:39 AM »
Hi,
this is a capable driver:

https://www.ebay.com/itm/Leadshine-AM882-Stepper-Drive-with-Sensorless-Detection-Up-to-80VDC-8-2A/121235083471?hash=item1c3a2c90cf:g:Gd4AAMXQOT5Q~Sn9

Try one and see, you want a path to a solution, this is a path...

Craig
Thanks for the link. I'll have to wait for an Ebay 15% day and then place an order. (They've been having a lot of those days lately)
I think it might be a good idea to buy one and see how it performs compared to my TB6600 based driver.

FWIW, the current driver still loses steps even on 800 microstep setting. It just seems to be less actual rotation is missed. Load on the motor or no load on the motor seems to yield the same results.
Re: Only X-axis motor is working
« Reply #185 on: April 08, 2018, 01:05:30 AM »
Hi,
ditch the TB6660, they are rubbish. Even if you get them to go right the moment you try to decelerate your motor hard the back EMF will blow the driver chip.
Get a decent driver, there are some experienced CNCers who recommend these Leadshine units and plenty more who recommend Gecko.

Craig
My wife left with my best friend...
     and I miss him!
Re: Only X-axis motor is working
« Reply #186 on: April 08, 2018, 01:34:46 AM »
I was looking at VEXTA drivers and it seems I need to watch the ratings on them. The motors I'm going to use will be 3A so I can't be getting a 1A driver.
Re: Only X-axis motor is working
« Reply #187 on: April 08, 2018, 01:55:33 AM »
Hi,
Vexta make two and five phase steppers, don't confuse the them.

My steppers are 23 size and fitted with a low backlash 10:1 planetary gearbox. Even second hand they were over $250 each and the drivers were another $200 each.
The motors and drivers are matched at 1.4A per phase. With a five phase steppers four phases are active at any given instant. Thus the total current in the motor
is 4.6A. I run them at 1A per phase so they run a little cooler.

The gear reduction means my machine is quite slow, rapids of 1200mm/minute but great torque, the stall thrust through 5mm pitch ballscrews is over 5000N. I got what I wanted but paid
a premium, knowing what I know now I think I could have spent more wisely and still achieved a good result. I would think long and hard before getting five phase steppers, they are good
but somewhat rare and all of them are expensive.

Craig
My wife left with my best friend...
     and I miss him!
Re: Only X-axis motor is working
« Reply #188 on: April 08, 2018, 02:15:18 AM »
I'm looking at these.
https://www.ebay.com/itm/THREE-CNC-Gecko-G-201X-ONE-YEAR-WARRANTY-stepper-motor-Drivers-WITH-EXTRAS-G-201/330679891164?epid=1726495475&hash=item4cfe0eb4dc:g:NtoAAMXQk-FRFA7r
Gecko G-201. They should be able to handle the finished platform. I like that they have built in anti-resonance.
Re: Only X-axis motor is working
« Reply #189 on: April 08, 2018, 02:32:10 AM »
Hi,
yes very good value for money and Gecko is the leading brand.

Did you note that there is only one resolution, that is to say micro stepping is fixed at 10 per full step or 2000 step per revolution.
This is good in most circumstances but not all. Provided your design is good with 2000 step/rev then go for it.

Craig
My wife left with my best friend...
     and I miss him!