Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: GRAYHIL on November 28, 2011, 12:12:32 PM
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Hi All
I want to have more powerfull motors than 263oz I have presently.
I have seen these
http://www.ebay.co.uk/itm/Stepper-Motor-4Nm-Nema23-566oz-1year-Warranty-cnc-parts-/120811893754?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item1c20f333fa
and want to know will the TB6560 drive them? and are there any other problems?
thanks Graham
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I perhaps should have said it is a 4 axis machine
Graham
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Preformance depends on the delivered voltage and amps available from your power supply and driver specs. Not sure if those drives are limited to 3 amps and 24 volts.
If you had a motor curve you could get an idea of motor torque and speed you will have. Also depends on how you wire the steppers.
So yes they will work but maybe you won't get more power than you have now.
RICH
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Rich
Can you explain a bit more?
According to the data sheet for the board it is 24v 1.5amp to 3amp.
The motor supplier says
"Yes this driver will work with our steppers, you can use them in series to give you better torque but slower speed or in parallel lower power but higher speed."
So I presume I would have to wire them in series.
Why wont a bigger motor 566oz against 263oz not produce more power?
New to electronics and all these terms >:(
Graham
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You haven't given the specs of your present motors but I suspect that your *real* problem is the drivers.
According to the data sheet for the board it is 24v 1.5amp to 3amp.
Doesn't mean much without motor specs.
The motor supplier says
"Yes this driver will work with our steppers, you can use them in series to give you better torque but slower speed or in parallel lower power but higher speed."
Doesn't mean much - but it might get him a sale.
Why wont a bigger motor 566oz against 263oz not produce more power?
Beacuse (very simply put) motors don't *produce* power, they convert electrical *power* into mechanical *power*. If the electrical power isn't there in the first place, *more powerful* motors arn't going to improve anything.
Not a lot to go on but my guess would be you'd be better off replacing your drivers than your motors.
Ian
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Graham,
Difficult to compare preformance without motor curves at different voltages and amperages . So one would need to see what torque can be had at 3 amps for each motor.
Maybe you will only get half the torque out of the 566 in comparison to the 263 which may have full torque. Additionaly depending on how they are wired that torque value
will change. The max speed of the motors are voltage dependant and also influenced by the motor characteristics. As speed is increased torque will decrease and that also varies
depending on how wired. In general the higher the torque rating the slower the max speed. What you are are interested in is power which is max torque over some speed range.
So the motor power range will vary depnding on voltage and amperage available and you are limited by the driver and possibly the power supply also. So in general
one would need four different motor curves showing preformance, two for each motor which shows different curves depending on how wired. You need to use curves specific to
the motors and not compare to other manufactures information.
The general statement "in series to give you better torque but slower speed or in parallel lower power but higher speed" are true, but, one needs to consider / compare
more than that when comparing different motors for an amplication since other things come into play.
RICH
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Rich
This is what I originally bought
http://www.ebay.co.uk/itm/CNC-Kit-3A-4-Axis-Driver-Stepper-Motor-Power-Supply-/260901875466?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item3cbef6af0a
Do you still think a better board is required to give more power or bigger motors?
Is there anything else I can do.
One of the motors is geared down but I can stop machine movement in that axis by holding the machine cross slide.
Same with all the others.
It cuts wood and plastic resonably (cut some 48tooth 8" Dia 1/8"thick plastic gears) well but I want to cut steel/ally.
Am I expecting too much?
Graham
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Rich
Where will I find "motor curves" thats a new term to me.
Graham
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at the risk of being ignored again I'll give it one more shot. According to your link your motors are rated at 3.6mH. That means that for max speed/torque combination the optimum voltage is 60V. Your power supply is 24V max - way too low. Plus the blurb on your link states "High voltage will burn up the chips or stepper motors!!!". This is misleading at best. With a decent driver 60V would NOT damage your motors. However with THAT driver it WILL damage the driver and MAY damage the motors. Motor curves will help you to understand this but won't change the facts.
Ian
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Stirling
I did not ignore you, as i said i am new to electronics and have a lot to learn and try to understand.
So it seems what goes in from the power supply via the board gives you more power at the motor, that I understand now.
Seems like my whole system is underpowered for what I expect it to do.
Graham
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Where will I find "motor curves" thats a new term to me.
The seller may have them for the motor. Most name brand motors have motor curves and usualy they are done for 24 or 36 volts along with
the different winding configurations. As a prep on your learning curve you may want to have a look at the first few threads of this link which is
about a lathe retrofit i did.
http://www.machsupport.com/forum/index.php/topic,12484.msg80823.html#msg80823
Then go to the Gecko Drive site and read all the info that they have posted. Then maybe read Jones on Steppers, if you want to get into more detail,
and you will have a good understanding of the power supply, drive and machine relationships.
So it seems what goes in from the power supply via the board gives you more power at the motor
Not quite right in the big picture. If you were to design a cnc system you would define the machine application, then select a proper machine,
then analyze what the axis needs to do along with the machines physical aspects and after some rationalization select the approriate motors
and power supply to do the task. Computer may also come into play in all of this. Once you have determined what is required and selected the
item off the shelf you then pay the price...or...... go back to the beginning of the design and make comprimises.
You are ask backwards in the approach, let not your heart be troubled, since most of us do the same thing and the saying "doing it right the first
time is echoed".
RICH
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Hi All
I want to have more powerfull motors than 263oz I have presently.
I have seen these
http://www.ebay.co.uk/itm/Stepper-Motor-4Nm-Nema23-566oz-1year-Warranty-cnc-parts-/120811893754?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item1c20f333fa
and want to know will the TB6560 drive them? and are there any other problems?
thanks Graham
No problem, just make sure the motor is rated at or under 4.5A. The TB6560 can handle that draw and up to 36V.
You will need the proper power supply, it will need to provide the Voltage required by the motor used and the Amperage for the motor used. Do not supply more voltage than the motor needs or heat will be generated, and the power supply will need to have the proper wattage to run all three motors at once.
So for a three axis machine with one motor per driver the required wattage is dermined by the following:
These motors require 2.8V and 4A in parallel plus you will have three of them so Wattage needed is 33.6W.
You will also be under the max rated Amperage and supplying 2.8V is no problem, you will probably want to supply 5V. Just remember the Logic power!!
Cheers,
Rob
Http://www.whatisacnc.com
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From memory, the TB6560 chip has a peak output current availability of 3.5 Amps.
The imported controller board (sold as TB6560) recommends stepper motors drawing 3 Amps max.
It may be that connecting stepper motors rated at 4.5 Amps might just be asking for trouble.
Tweakie.