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Hi guys,
I have cncusb mk1 chines copy and i connect it as you see in the attached photos, its turn on well when i using the jogging but the stepper motor temperature increasing with short time and the fan of power supply start turn especilay when using low step/rev setting.
Is this normal or not ?
And what the best setting u are suggest for step/rev dip.
What's the current setting on the drive? And what's the rated current of your stepper? Voltage?
The driver is set on 3.32ampQuote:
Originally Posted by louieatienza
the motor amp rate is 3 amp/ 6.3 volt
Sorry the pics don't show up on the phone... You should set the current of the drive at 3.0A or below. Over current will give you more torque at the cost of more heat. Also you can have choppy motion and non-linearity with microsteps. If you have current reduction for standby option on the driver I'd set that too.Quote:
Originally Posted by CNCsector
Note : i didn't use any resistors inside the connections between the driver and controller as wantai site guide said.Quote:
Originally Posted by louieatienza
You can check this http://www.wantmotor.com/ProductsView.asp?id=257&pid=82
Stick a CPU cooler on the motor. It's amazing how much that helps.
Again... If you set the drives current above the rated current of the stepper it will get hot fast, and you'll have less linearity in the microsteps...Quote:
Originally Posted by louieatienza
If you can keep your hand on the motor it is still OK, but if you can not, then reduce the current on the drives. Also i do not trust the chinese drives since i had experience with some and they do behave strange to say the least. On one type of drives ( 5A rated TB6600 ) it would not lower the current on idle, and the max torque i would get at the motor would be at /16 microstepping, everything else on the setting was useless, and nowhere near 5A so i had to modify them to make them usable by adding some resistors. They are still working after over a year.
The motors should get warm after 15-20 minutes normally, but not hot.
Tom
50-60C isn't unusual for steppers and is no cause for concern. They run hot especially at idle. More recent drives have idle current limiters to reduce the heating effect.
bob
Just to reiterate, summarize, and add to what has been said here:
1. Stepper motors (depending on the driver used) can actually heat more while NOT moving than they do when moving. rowbare and tommylight make very good points about idle current reduction. That's why we love our THB6064AH and Linistepper V3 driver kits: They include an automatic reduction of drive current when the drive isn't stepping. (This is new on the Linistepper V3). Luc's version of the TB6600 driver also has that added by an external circuit, so if you go that route, get it from him, not China... NEVER from China.
2. It is true that stepper motors can get very hot (60'C isn't unusual) and still work, but they DO lose torque when heated (any permanent magnet will lose strength as it heats). Depending on the quality of the magnet, that can be significant. I've seen systems that start to skip steps after long periods of being powered on and not moving. One example was a machine (NOT using one of our drivers) that would fail to move the Z axis up on a job where most of the work was cutting down a large interior area, and then cutting some holes in the remaining edge was done later in the job. When the large area was being removed, the Z axis wasn't moving very often and the Z motor got hotter than heck. When it tried to pull the bit back up out of the interior to make those final holes, it just didn't have the strength to move... Really nasty bit crash into the wall. Now, that same machine could pull of the Z axis no problem when it was cold and other jobs didn't cause motor heating enough to cause problems. The fix? We put a CPU cooler on the Z motor and all was well. The motor temp dropped from ~150'F (~65'C) to 102'F and the motor was fine.
Demagnetisation through heat, temperature resistance magnets - supermagnete.de
Magnet Experiments: What Happens When a Magnet is Heated / Magnet News & How-To's
3. Chopper drivers produce more motor heating than the old school linear drivers. That hummmmm and hiss and screech you hear is the motor vibrating due to the chopped drive power and that comes with eddy currents which cause heating. Linear drivers are limited in terms of how much amperage they can deliver because the /driver/ will overheat, but the motors will run cooler on a linear driver. If you are driving up to 75 watts (e.g. 24 volts, 3 amps) then the Linistepper (or other linear driver) will result in a cooler motor than the THB6064AH (or other chopper driver). Of course, that really isn't a fair comparison, because the Linistepper is a unipolar driver and the THB6064AH is a bipolar, but the basic idea holds true. Choppers cause motor heating. Not a lot, but some.
4. As louieatienza points out, running your motors past their rating is going to cause problems. You can "cheat" by adding cooling to the motor, but it better not fail or get dusty or whatever because if it does, that motor is going to loose power, melt, or just short out internally taking the drivers and everything else with it. Andrey did that on his concrete 3D printer on a hot day when the extruder jammed. He bumped up the drive to try to clear it and fried ALL the electronics in one shot. I do this weird thing that may or may not help: I drip just a touch of my wifes essential oils on the driver heatsink and motors at the start of a new run. If it suddenly starts smelling really good in the shop, I start checking for overheating.
Damn, that is a nice idea, it usually smells on hydraulic oil in my shop. Tomorrow is a new day......and a new smell!!!Quote:
Originally Posted by James Newton
Thank's a bunch.
Tom
Why are they called essential oils when they are not actually needed for anything? :)
Because if she says she needs them and you say no, you'll discover WHY they ARE essential oil. In the mean time, just assume that any oil smooth's friction and a certain 'joy' can be found with their application.
Friction bad, a well oiled machine good.
BUT; .Please don't tell my wife I said all this.;)
Larry