sx3 Spindle Speed

[rwskinner]

Does anyone know if the KX3 pulleys and belt will work on an SX3 in order to get the RPM up?

[cjdavis618]

Yes, these are the factory pulleys that will update your speed to 3600rpm. It takes you from a 1:.5 ratio to 1:1

The down side is that your torque will be cut in half as well. You will not have any problems though, even with large facing tools with shallow cuts (.020 or less on AL with 2.5" face mills)

[rwskinner]

Thanks. So I just need the belt and motor pulley right?

[cjdavis618]

Correct. The size of the belt is a 5m-460.

[rwskinner]

The KX3 belt and pulley came in. The pulley fits fine but the top retaining washer needs to be modified (redrilled - Pin doesn't line up).

LMS sent a 5M-450 belt which is no where close to making it over both pulleys.

The KX3 motor pulley was 53 grooves and I'm unsure what the KX3 spindley pulley is but it must be different than the SX3. I have to look, but I think the spindle pulley was 42 grooves on the SX3.

I there a belt length calculator for the timing belts or are you pretty certain the 5M-460 will fit?

[cjdavis618]

The KX3 belt and pulley came in. The pulley fits fine but the top retaining washer needs to be modified (redrilled - Pin doesn't line up).

LMS sent a 5M-450 belt which is no where close to making it over both pulleys.

The KX3 motor pulley was 53 grooves and I'm unsure what the KX3 spindley pulley is but it must be different than the SX3. I have to look, but I think the spindle pulley was 42 grooves on the SX3.

I there a belt length calculator for the timing belts or are you pretty certain the 5M-460 will fit?

On your SX3, the motor pulley is 18 tooth. The spindle from factory is 45 tooth.

If your new motor pulley came in with 53, then the 460 would be a bit tight. My 475 almost worked with the pulleys both being 45 tooth but it was still to loose tighted all the way out. the 460 worked well with the motor pushed about halfway through the adjustments to tension.

I would say that since you have the 53 teeth, that the 475 would be just right.

I can't use mine and probably never will if you want it. PM me your address and I will send it to you.

( edit: I just dug the belt out and it was actually a 5m -475, oops)

[rwskinner]

I just went and doubled checked.

For reference (future searches), mine is a Grizzly G0619 SX3

My original motor pulley is: 1.335" OD x 22 groove
The new KX3 motor pulley is: 3.275" OD x 53 Groove

The SX3 stock spindle pulley is: 2.775" OD x 45 groove.

With the factory pulley and belt installed, center line between the motor and spindle is 4.550"

Motor RPM 3600 actual - Motor is marked as 5000 RPM????
Factory Ratio: .4888 RPM 1760
New Ratio: 1.177 RPM 4240

New Belt Size: 5M-475

Richard