Overdriving the spindle with a VFD on a 2J

[rogerfries]

Anyone running a VFD on a 2J head? How fast can you/do you you run it? Right now I have mine set to 75 htz and is seems to hum along nicely. How fast is safe for the motor? Where do you leave the belt speed set at?

Thanks!

[HimyKabibble]

Originally Posted by rogerfries Anyone running a VFD on a 2J head? How fast can you/do you you run it? Right now I have mine set to 75 htz and is seems to hum along nicely. How fast is safe for the motor? Where do you leave the belt speed set at? Thanks!

My machine is not a Bridgeport, but a Chaiwanese clone. I routinely run for hours on end up to 90Hz/8200 RPM with no problems whatsoever. It's a two-speed motor. In low speed, I'll run up to 120Hz.

Regards,
Ray L.

[Al_The_Man]

Originally Posted by HimyKabibble I routinely run for hours on end up to 90Hz/8200 RPM with no problems whatsoever. It's a two-speed motor. In low speed, I'll run up to 120Hz.

How do you manage that Ray?
A 2 pole motor at 90hz would be <5400 and <7200rpm at 120hz?
Unless that is the output rpm and you are geared up by belt etc.
If four pole motor it would be half that rpm.
Al.

[polaraligned]

The varidrives gear up.

How hot does your quill (bearings) get Ray.

I have run mine at 5500 and after 10 minutes it is quite
warm with no load on the bearings.

[79TigerPilot]

I run my BP at 120Hz about 5400 RPM on the spindle and it gets a little warm but not to the point I woud worry.

Ray:
The new job must be keeping you busy, not seen much from you lately.

Quill Drive is working great but progress on the rest of the mill has been slow.

Craig

[polaraligned]

Do you have the packed grease bearings?
I wonder if mine runs warmer because of the packed grease.

[HimyKabibble]

Originally Posted by Al_The_Man How do you manage that Ray? A 2 pole motor at 90hz would be <5400 and <7200rpm at 120hz? Unless that is the output rpm and you are geared up by belt etc. If four pole motor it would be half that rpm. Al.

It's a step pulley machine. With the motor in high range (2-pole), high-speed pulley, 60Hz, the spindle turns 5440 RPM. At 90Hz, that's 8160 RPM.

Regards,
Ray L.

[HimyKabibble]

Originally Posted by polaraligned The varidrives gear up. How hot does your quill (bearings) get Ray. I have run mine at 5500 and after 10 minutes it is quite warm with no load on the bearings.

I've run mine at 8200 RPM for hours at a time. After 2-3 hours the spindle will be up to maybe 110-120F - not hot enough to be a problem.

Regards,
Ray L.

[HimyKabibble]

Originally Posted by 79TigerPilot I run my BP at 120Hz about 5400 RPM on the spindle and it gets a little warm but not to the point I woud worry. Ray: The new job must be keeping you busy, not seen much from you lately. Quill Drive is working great but progress on the rest of the mill has been slow. Craig

Craig,

Haven't so much as turned the machine on since Feb, and don't anticipate being able to do so any time soon...

Regards,
Ray L.

[HimyKabibble]

Originally Posted by polaraligned Do you have the packed grease bearings? I wonder if mine runs warmer because of the packed grease.

My understanding is, for a high speed application, you want to only fill the spaces between the balls only about 20% with grease, not pack them. I have no idea how mine are setup - I've never touched them since I bought the machine about 3 years ago.

Regards,
Ray L.

[polaraligned]

Thanks Ray.