Grinder Motor

Get the heatsink which is just some mass that has fins to dissipate heat attached to the rear of the unit. You'll need it to lengthen the life of the thing.
 
John L said:
Get the heatsink which is just some mass that has fins to dissipate heat attached to the rear of the unit. You'll need it to lengthen the life of the thing.
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Do you think 1HP is big enough? I also hear you lose a lot of torque with this kind of setup?

Here is my other option;

http://www.friesen.com/ipwrs/productdetails.aspx?ID=3240

About $150 more, but since it's frequency controlled there should be no loss of torque and I get 1.5 HP.
 
hey chris, I would go for a 2HP. I upgraded form a 1 HP to a 2 HP a few months ago, it makes a huge difference.
 
Hi Chris, I have a few thoughts.

My first thought is that you'll only be happy with that motor for a few days or so...then you'll wish you had more. 1 hp is only the very bottom of my my recommendation list. It really doesn't even make the list for use on the KMG.

Understandably, if that's because of your budget, I would forgo the VS and get a bigger 1.5HP constant speed motor and set the KMG up with step pulleys.

The motor and controller that you have selected are certainly compatable and will run nicely together...but there might be a better choice.

In that size, I would select a 90V motor rather than the 180V motor. The reason is that you can run a 90V DC motor on 110V AC...where the 180V DC motor must run on 220V AC.

110V AC converted to DC = 90V DC
220V AC converted to DC = 180V DC

This will give you the convinience to plug that 1 HP 90V motor into your standard wall outlet rather than a dedicated 220V outlet.

I'm not too excited about the open chassis DC controller..it will certainly need to be enclosed and protected from metal grit. Perhaps consider an enclosed model with operator controls on the front for stop/start and speed selection.

My guess is that if you buy the 1 HP VS DC setup...you'll end up buying a bigger motor and controller eventually...When that happens, then you can use the 1HP 90V dc motor for a disk grinder....so it's not a complete loss and might be legitimate way to manage your budget while aquiring machinery.

I'm not sure if I've explained this very well....let me know I'l be glad to try again. :)

2 cents poorer....-Rob
 
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Watch fleabay for a while for motors. I got a 1.5 reversible for $108 including shipping.
 
rfrink said:
Hi Chris, I have a few thoughts.

My first thought is that you'll only be happy with that motor for a few days or so...then you'll wish you had more. 1 hp is only the very bottom of my my recommendation list. It really doesn't even make the list for use on the KMG.

Understandably, if that's because of your budget, I would forgo the VS and get a bigger 1.5HP constant speed motor and set the KMG up with step pulleys.

The motor and controller that you have selected are certainly compatable and will run nicely together...but there might be a better choice.

In that size, I would select a 90V motor rather than the 180V motor. The reason is that you can run a 90V DC motor on 110V AC...where the 180V DC motor must run on 220V AC.

110V AC converted to DC = 90V DC
220V AC converted to DC = 180V DC

This will give you the convinience to plug that 1 HP 90V motor into your standard wall outlet rather than a dedicated 220V outlet.

I'm not too excited about the open chassis DC controller..it will certainly need to be enclosed and protected from metal grit. Perhaps consider an enclosed model with operator controls on the front for stop/start and speed selection.

My guess is that if you buy the 1 HP VS DC setup...you'll end up buying a bigger motor and controller eventually...When that happens, then you can use the 1HP 90V dc motor for a disk grinder....so it's not a complete loss and might be legitimate way to manage your budget while aquiring machinery.

I'm not sure if I've explained this very well....let me know I'l be glad to try again. :)

2 cents poorer....-Rob
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Thanks for the input I fully understand your explanation. I will go for at least a 1.5 HP motor. I found a good deal on the AC setup with a VFD Controller for $411, it is a 220 VAC input or I can go the ebay route and see if I can piece one together cheaper. I have 220 VAC in my garage so that is not a problem. The one I found is a tested combination that is guarenteed to work together.
 
cdhumiston said:
Thanks for the input I fully understand your explanation. I will go for at least a 1.5 HP motor. I found a good deal on the AC setup with a VFD Controller for $411, it is a 220 VAC input or I can go the ebay route and see if I can piece one together cheaper. I have 220 VAC in my garage so that is not a problem. The one I found is a tested combination that is guarenteed to work together.
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Chris,
Shop carefully. I bought a brand new KBAC 27 drive from a dealer, and a never used old stock 2hp 3 phase Baldor motor on ebay for less than 400. The KB drive is such an elegant solution with its NEMA4 case, and Rob's mount puts it in a very easy to use but out of the way location right on your KMG.
 
I actually run a 1hp 90V Leeson DC motor with the Leeson enclosed Speed controller. I agree with Rob... while it is a hell of lot better (tons really) than a craftsman or harbor freight dinky belt sander, it would still be a lot better with a 2hp+ motor. Don't get me wrong, you will enjoy it a lot more than one of the cheapies or doing it by hand. I actually just got this grinder going today and I am already thinking of upgrading the motor, but it works great for now.
 
techna said:
Chris,
Shop carefully. I bought a brand new KBAC 27 drive from a dealer, and a never used old stock 2hp 3 phase Baldor motor on ebay for less than 400. The KB drive is such an elegant solution with its NEMA4 case, and Rob's mount puts it in a very easy to use but out of the way location right on your KMG.
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What RPM motor do you recommend?
 
The one I ended up with is 3450 and on Rob's recomendation, I run it 1:1 with I think 4" pulleys.
 
I have 2, 1HP belt grinders.. I have never noticed either slowing down one bit when grinding. How hard are you guys pressing?
 
Mine doesn't slow down at all, but then again I haven't put my @$$ too deep into it LOL. I am just aware that the limitations are there, and I prefer to overkill because I'm partial OCD. Also, mine is 1750rpms and its fine as far as speed....just set your pulleys up right for your speed controller. Rob would know what ratio's work best....I just winged it, but I have a 2" pulley on the motor and a 4" on the shaft for the drive wheel and its fast enough for me, and retains good torque(those were just some pulley's I had laying around....no thought process involved, they were just there and free).
 
cdhumiston said:
OK, some of the ones I've looked at are only 1800 RPM. I beleive that's on the slow side?
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1800 rpm if fine. You would just run a 5" motor pulley and a 2.5" grinder pulley.

Bill,
I back off a little when hogging and the motor starts to slow, but I am pressing pretty hard at that point...Probably harder than I should be. With the way I do find myself pushing things a little, I imagine that I would be frustrated by 1hp though.
 
techna said:
1800 rpm if fine. You would just run a 5" motor pulley and a 2.5" grinder pulley.
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AH Math, I try to stay away from that. I stopped being able to help my kids in about 9th or 10th grade. Whose idea was it ot include the alphabet in math anyway???:mad:
 
Definately stay away from a 1hp. If you can not run 220 for a 2hp then go with a 1.5 at the least.
 
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