Motor choice for mobile setup?

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knabstr

Joined
Dec 19, 2012
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2
Howdy,

I would like to build a mobile grinding station which consists of 3 tools: a belt grinder, a disk grinder, and a hard wheel. If this were in my shop I would purchase a 3phase motor and VFD & power all these tools from a common parallel drive shaft. However I am going to have my grinding setup in my truck and will be plugging in at various locations.

What is the best choice for motor and power supply?

Here are some of the considerations I have thought of:

-Single phase motors stink if I stay within the HP range that can be run at the average random plug in site available--and I don't want to go around blowing breakers. Therefore no matter what the choice I will have a battery bank and charger with power inverters/converters/something on my truck.

-A 3phase 1.5 HP motor with KBAC-27d should be plenty of power, but, I wasn't sure if perhaps a DC motor configuration would be simpler or better? I don't know anything about DC motors.


Help and opinions are greatly appreciated, Many thanks!
 
Why not use a portable generator, you can get 220 which will fix you single phase issues and allow you to work anywhere without the batteries and converter, If you have land based power, no problems. It would be nice to find out how many batteries and how large a converter would be needed to survive the voltage spike of starting a 1.5 hp motor. I am sure it can be done but could be expensive. 1.5 hp is about 1200 watts, 50% start peak you would need about 2000 watts, or less than 10 amps on 220v, very doable with a small generator.
 
DC motors are out of sight expensive compared to 3 ph and a VFD.
They are already more expensive new, and everyone wanting to build a home build windmill or other generator creates even more demand.

Maybe go DC if you get free motors, otherwise I'd stay VFD.


In terms of battery banks chargers, inverters and such, if you search the welding forums, Welding Web and others - there are discussions where guys show their welding rig and service trucks. It's not a cheap way to go.

Generators do cost fuel and motor wear, but say 6 batteries will cost $600 + and have a limited life of 3-5 years.
 
Thanks everyone for the input.

I should have mentioned that I had ruled out the generator idea due to noise & inconvenience.

Cost savings is not really a factor, I would really like to build this as best I can and be able to efficiently work out of it for a long time (20+ years). I realize that the batteries and some of the electronics won't last forever.

So what about a battery bank with a inverter charger such as the xantrex Freedom SW 3000w? does that give me enough juice to run the 1.5hp with the kbac-27d?

Thanks guys, I'll post some of my work and updates
 
knabstr said:
Thanks everyone for the input.

I should have mentioned that I had ruled out the generator idea due to noise & inconvenience.

Cost savings is not really a factor, I would really like to build this as best I can and be able to efficiently work out of it for a long time (20+ years). I realize that the batteries and some of the electronics won't last forever.

So what about a battery bank with a inverter charger such as the xantrex Freedom SW 3000w? does that give me enough juice to run the 1.5hp with the kbac-27d?

Thanks guys, I'll post some of my work and updates
Click to expand...

That's a pretty specific question that you should ask the tech service of the inverter company.

Even if the simple wattage calculation says yes, the power losses at every conversion will also be factors.

Have a look at those truck build threads.
They all have at least one generator backup to boost the battery and start the truck if the batteries have run down.

Also keep in mind, batteries will lose efficiency over time and in the cold.


and I'm really curious, why the portable grinding truck ?
 
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FWIW, they seem to be making generators quieter and quieter these days. I imagine that you can can find one just about as "quiet" as any grinder you'll be running with it.
 
knife to a gunfight said:
FWIW, they seem to be making generators quieter and quieter these days. I imagine that you can can find one just about as "quiet" as any grinder you'll be running with it.
Click to expand...

I'll second that. The portable Honda generators I've used might even make less noise than your grinder when you've got steel on it.
 
Generator seems a little wasteful to me. Why create electricity to drive an electric motor? If you really want a portable set get a small gas powered engine, like what is on a lawn mower. More power, and the variability doesn't require some fancy expensive electronics, just a throttle.
 
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