motor type selection - laboratory instrument
motor type selection - laboratory instrument
(OP)
We are planning a benchtop laboratory product which turns a special processing device for grinding and homogenizing various tissues and plant matter. I am doing research to find the best type of motor to do the job. My experience is with direct-drive brushless motors and gearhead DC motors, but before I use one of those simply because I don't have experience elsewhere I wanted to have a discussion about (blank slate, fresh start, clean paper) how do I choose the best motor type for this application in regards to power, speeds, control complexity, and cost.
Here are the speed ranges, accuracies, and maximum torques I am working with:
200 to 500rpm +/- 10% 180mNm
500 to 1500rpm +/- 10% 250mNm
1500 to 4000rpm +/- 10% 200mNm
-1000rpm(clean cycle) +/- 10% 150mNm
Positioning is not important, all we need are the speeds to those accuracies and torques. The last speed is a reversing cycle. Cost needs to be kept to a minimum. The unit must work in 115 and 220V regions, so using a desktop universal power supply and working with DC is optimal.
so... gearhead DC? direct-drive brushless? AC syncronous? servo motors? stepper? some other motor type I'm not aware of?
I searched my heart out for this topic, and was surprised to not have found the information already. I hope this thread becomes useful for other engineers.
This is a great forum... an incredible resource to the community. Thanks to the Tecumseh Group and all participating industry professionals!
Here are the speed ranges, accuracies, and maximum torques I am working with:
200 to 500rpm +/- 10% 180mNm
500 to 1500rpm +/- 10% 250mNm
1500 to 4000rpm +/- 10% 200mNm
-1000rpm(clean cycle) +/- 10% 150mNm
Positioning is not important, all we need are the speeds to those accuracies and torques. The last speed is a reversing cycle. Cost needs to be kept to a minimum. The unit must work in 115 and 220V regions, so using a desktop universal power supply and working with DC is optimal.
so... gearhead DC? direct-drive brushless? AC syncronous? servo motors? stepper? some other motor type I'm not aware of?
I searched my heart out for this topic, and was surprised to not have found the information already. I hope this thread becomes useful for other engineers.
This is a great forum... an incredible resource to the community. Thanks to the Tecumseh Group and all participating industry professionals!
"Imagination is more important than knowledge" -Albert Einstein
www.TGWMS.com





RE: motor type selection - laboratory instrument
RE: motor type selection - laboratory instrument
In addition to the requirements stated (speeds, torques, low cost,and supply voltage), you will have to consider things such as; noise, life, size, efficiency, annual volumes, maintenance (or discard), etc.
Does one motor have to satisfy the entire range of speeds/torques?
Enquiring minds want to know...
RE: motor type selection - laboratory instrument
Thank you sreid... I am on oriental motors' site now.
"Imagination is more important than knowledge" -Albert Einstein
www.TGWMS.com
RE: motor type selection - laboratory instrument
http://
RE: motor type selection - laboratory instrument
www.miromo.com
www.microdrives.com
www.maxonmotorusa.com
www.portescap.com
RE: motor type selection - laboratory instrument
That's www.micro-drives.com
RE: motor type selection - laboratory instrument
The problem with DC motors is normally that you need to change brushes now and then. But, with that duty cycle of yours (is it really not more than 3 minutes every day?) you can run a standard automotive DC motor for many years without any brush problems. It has many advantages. Low voltage, simple drive elecgtronics (an H bridge controlled by a onechipper), mass produced, low price. In fact only advantages - no drawbacks as far as I can see. Spares are also available globally.
Go to: http://
And, you do not need a gearhead for this application. But that is something you already knew.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor type selection - laboratory instrument
can your H-brige control solution meet the 10% speed accuracy needed?
thanks clyde as well... i have app engineers for each of those manufacturers going through their catalogs.
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"Imagination is more important than knowledge" -Albert Einstein
www.TGWMS.com
contract engineering and brainstorming
RE: motor type selection - laboratory instrument
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: motor type selection - laboratory instrument
so off 'topic', but to control a DC motor closed loop to 10% accuracy do i need an encoder or can it be done with back EMF?
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"Imagination is more important than knowledge" -Albert Einstein
www.TGWMS.com
contract engineering and brainstorming
RE: motor type selection - laboratory instrument
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: motor type selection - laboratory instrument
http://ww
You can take a Microchip course for a few dollars that puts one of these in your hands and gives you a day with motor experts and lunch. I took it and was very pleased with it.
This could blast you up the learning curve!
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: motor type selection - laboratory instrument
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor type selection - laboratory instrument
RE: motor type selection - laboratory instrument
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: motor type selection - laboratory instrument
But does he really mean just once a day?
RE: motor type selection - laboratory instrument
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor type selection - laboratory instrument
thanks for the electrical hints towards control schemes... i wont be doing the design myself; we will contract that. i simply wanted to research relative complexities (costs) for the different motor control types so i can plan the optimal system.
thanks again guys!
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"Imagination is more important than knowledge" -Albert Einstein
www.TGWMS.com
contract engineering and brainstorming
RE: motor type selection - laboratory instrument
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com