KMG Drive Wheel

[cschulte88]

Hello,

I am getting ready to purchase a KMG Variable Speed Belt Grinder and there are a few options that I would like you all's opinions on...

1. 6 inch Drive wheel vs 4 inch drive wheel - It says that the 6 inch drive wheel gives you a 50% boost in belt speed. But when I am running the motor at 1.5HP (I am getting the 110VAC VFD and the 2HP motor but supposedly according to Beaumont you can set the VFD to run at 1.5HP to conserve amps and not blow my 15amp 110VAC circuit) should I worry about the decrease in torque?

2. I am thinking about replacing one of the 2 inch idle wheels on the flat paten with a 2 inch contact wheel for grinding out the curves on the handle? Does anyone see a disadvantage to doing this?

Thanks in advance for your all's advice!

 

[Ken H>]

What RPM motor are you getting? 1750 or 3600 rpm? If a 3600 rpm then the 4" drive wheel along with 1X jumper in VFD for max freq at 60 hz will give you around 3800 SFPM which should be plenty speed for hogging. If it's a 1750 rpm motor, then have them set the jumper in the 2X position so you can max at 120 hz which will still be around 3800 SFPM.

If you ask them what advice they would give for a new knife maker using a 2X72 grinder I'm sure it will be good advice since they know their equip.

To sum up, I think a 4" drive wheel will be your better option - it will allow you to slow the belt more than would a 6" wheel and you'll be surprised how much you will use those slow speeds.

Ken H>

 

[Josh Rider]

Good thinking on the contact wheel, you'll be happy you did.
If your budget allows, the small wheel holder is a great thing to have as well.

 

[BKT]

Good thinking on the contact wheel, you'll be happy you did.
If your budget allows, the small wheel holder is a great thing to have as well.

x2!! That small wheel holder is invaluable! I just use the aluminum wheels to grind against, but the rubber contact wheels left a much nicer finish.

 

[LARRYZ10]

Hello,

I am getting ready to purchase a KMG Variable Speed Belt Grinder and there are a few options that I would like you all's opinions on...

1. 6 inch Drive wheel vs 4 inch drive wheel - It says that the 6 inch drive wheel gives you a 50% boost in belt speed. But when I am running the motor at 1.5HP (I am getting the 110VAC VFD and the 2HP motor but supposedly according to Beaumont you can set the VFD to run at 1.5HP to conserve amps and not blow my 15amp 110VAC circuit) should I worry about the decrease in torque?

2. I am thinking about replacing one of the 2 inch idle wheels on the flat paten with a 2 inch contact wheel for grinding out the curves on the handle? Does anyone see a disadvantage to doing this?

Thanks in advance for your all's advice!

I am assuming that you KMG will have a 2 1/2 inch motor pulley and a 5 inch jackshaft pulley which will double the speed of your 1725 RPM motor. You should in my opinion use a 4 inch drive wheel. Second, having a 2 inch contact wheel substituted for the either the upper or lower platen wheel is a great idea. Lastly, If you can afford it have an electrician wire a 220 volt outlet for your grinder and set the VFD to 220 volt power to get the full 2 hp from your motor. Then you could use a 5 inch drive wheel for more speed without losing power at lower speeds. I started with a 1.5 hp motor and after a year put in the 220 and bought a 2 hp motor. I actually run a custom made 4 3/8 inch drive wheel for about 4000 SFM. You don't have to do everything at once though but 220 is nice to have. Larry

 

[Ken H>]

Awww Shucks Larry - I'd forgot the KMG with VFD still has those darn pulley setup. Your advice is exactly right, if that's the pulley setup that comes on it. Again, this is where the OP needs to talk with KMG folks to do exactly how the grinder is setup with the VFD. They will have the best advice.

I just don't understand why they still use the pulley/jackshaft setup rather than direct drive setup. No excuse for it.

Ken H>

 

[Fred.Rowe]

The 2" rubber contact wheels have a tendency to wear unevenly, which over time will affect the tracking. We take them off, put them in the freezer and freeze the rubber and turn them on a mill to make them round again.
There is no substitute for horse power and belt speed when using ceramic belts.

Enjoy your new machine, Fred