Hi there, I was considering getting a KMG grinder in the new year but was wondering first what kind of Motor and Variable Speed Controller combination should I use ? I was thinking about a 1720RPM 1 1/2 HP motor but I don't know much about matching the specs to a controller. Does anyone have any ideas on this ? Thanks.
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What kind of Motor and Variable Speed Controller ?
- Thread starter texasnewf
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Buy the one straight from Rob.
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If you want a 2 HP DC Motor I've got a few Baldors.
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Tex the Penta drives that Rob sells are the best around its all about the NEMA 56 enclosure I think that right? anyways you can find lots of drive really cheap but if steel dust or any dust for that matter gets in the unit poof up in smoke it will go. Rob will help you get the dash pots dialed in as well so your machine will run at its tip top, if you can spring for the 2 HP. I have 2 hp on both of my kmg's and will be upgrading everything to 3 soon.
Remember as well if you plan to run a VS rig you will be getting a three phase motor with a 56 frame also buy the mounting plate that Rob sells it really does aid in getting everything lined up and takes the hassle out of getting thing going.
Good luck
Spencer
Remember as well if you plan to run a VS rig you will be getting a three phase motor with a 56 frame also buy the mounting plate that Rob sells it really does aid in getting everything lined up and takes the hassle out of getting thing going.
Good luck
Spencer
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The 2 HP I got from Rob is doing a fine job!!!
I know Rob at KMG has some nice motors and controllers but they are a little expensive for me. I was looking for a much cheaper alternative. I can buy a 1 1/2 HP motor from surpluscenter for around $30 I just need a relatively cheap controller ? What about this one ? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=330130463715&ssPageName=STRK:MEWA:IT&ih=014
As Spencer and Mete have said, if you don't get a sealed controller it will eventually short out, if you do not install it in a "clean environment".
The AC Tech/Lenze unit that Texasnewf has found has very impressive specifications. It can work with 240V single-phase inputs with no derating. Most importantly, it has a NEMA 4X enclosure meaining that it is dust-proof and splash-proof. It looks like this family of drives was developed with applications in places like food processing plants where they wash everything down at the end of the day. The one in the auction is rated at 1.5hp with a price of $299. Drives with similar electrical ratings that are NOT NEMA 4 sell for $200 and up. The premium for the NEMA 4 enclosure is typically much greater, say 100% or more. The e-bay seller also has an auction for a 2hp drive with a BIN price of $349.
www.actech.com
www.lenze.com
Lenze is a German industrial electronics company with a pretty solid reputation. I have run across them in the past but have not actually been able to get my hands on any of their stuff. It is not clear if the US-base AC Tech subsidiary designs and manufacturers the drives here in the US or if they are a sales organization.
Good find Texasnewf!
Phil
The AC Tech/Lenze unit that Texasnewf has found has very impressive specifications. It can work with 240V single-phase inputs with no derating. Most importantly, it has a NEMA 4X enclosure meaining that it is dust-proof and splash-proof. It looks like this family of drives was developed with applications in places like food processing plants where they wash everything down at the end of the day. The one in the auction is rated at 1.5hp with a price of $299. Drives with similar electrical ratings that are NOT NEMA 4 sell for $200 and up. The premium for the NEMA 4 enclosure is typically much greater, say 100% or more. The e-bay seller also has an auction for a 2hp drive with a BIN price of $349.
www.actech.com
www.lenze.com
Lenze is a German industrial electronics company with a pretty solid reputation. I have run across them in the past but have not actually been able to get my hands on any of their stuff. It is not clear if the US-base AC Tech subsidiary designs and manufacturers the drives here in the US or if they are a sales organization.
Good find Texasnewf!
Phil
I have another dumb question.. sorry... I am not sure why one could not get a 110V motor to work with a variable speed controller ? .. I have a Grizzley grinder with a 1HP single phase 110V motor. Is there any way I could get a controller to vary the speed on this motor ?
Texasnewf
The only dumb question is the one that is not asked.
There are two types of motor controllers available for the hp range of interest here. There are the DC controllers that work with DC motors. They vary the voltage applied to the motor. The physics relating to how the DC motor works causes the motor speed to follow the voltage. There are the 3-phase controllers (AKA VFD. ASD). They vary the frequency of the voltage applied to the motor. The physics relating to how the 3-phase induction motor works causes the motor speed to follow the input frequency.
I don't believe that anyone has come up with a practical way to control the speed of a single-phase induction motors of this size. It would be quite a lucrative breakthrough for whoever does it. There are controllers but they are only for small, fractional-horsepower single-phase motors, like those found in hand held appliances. These controllers will not work on induction motors like what you would have on your Grizzly.
Phil
The only dumb question is the one that is not asked.
There are two types of motor controllers available for the hp range of interest here. There are the DC controllers that work with DC motors. They vary the voltage applied to the motor. The physics relating to how the DC motor works causes the motor speed to follow the voltage. There are the 3-phase controllers (AKA VFD. ASD). They vary the frequency of the voltage applied to the motor. The physics relating to how the 3-phase induction motor works causes the motor speed to follow the input frequency.
I don't believe that anyone has come up with a practical way to control the speed of a single-phase induction motors of this size. It would be quite a lucrative breakthrough for whoever does it. There are controllers but they are only for small, fractional-horsepower single-phase motors, like those found in hand held appliances. These controllers will not work on induction motors like what you would have on your Grizzly.
Phil
Fred.Rowe
Knifemaker / Craftsman / Service Provider
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I finished my upgrade from 11/2 horse to 3 hp with the 6
inch drive wheel today on my kmg. SWeeeeeeeet. I use a 3 pulley system on the drive and driven shafts.
I worked with the 11/2 hp for 2 years and don't think it had enough butt.
If you are running the ceramic belts the faster [sfm] speeds improves the cutting action of the belts.
It could be just me, I am a kid of the 60's and hp is in my blood.
Fred
inch drive wheel today on my kmg. SWeeeeeeeet. I use a 3 pulley system on the drive and driven shafts.
I worked with the 11/2 hp for 2 years and don't think it had enough butt.
If you are running the ceramic belts the faster [sfm] speeds improves the cutting action of the belts.
It could be just me, I am a kid of the 60's and hp is in my blood.
Fred