New to me Vertical Rotary Grinder

Hello!
Just received my Gallmeyer and Livingston vertical spindle rotary table grinder...7 1/2hp with an 8" wheel. It lists the spindle voltage as 240/480...and it is currently wired for the 480 volt application. I need to know where the change-over wiring is located...behind the 6 prong plug common to these beasts, or is it located at the mounting point to the vertical column on the machine? I would like a heads up before putting a wrench to the machine...anyone ever worked with one of these grinders? Any help appreciated.

Not familiar with your grinder but have swapped voltages on plenty of other equipment. Likely you need to re wire the motor(s), fit new heaters or adjustable overload for motor starter and re wire the control transformer. Probably the wiring in the machine can handle the higher amperage of 240v but it is a good idea to verify this.

Google did not show me that machine, sounds like a flywheel grinder in my world, got any pics?

Agree with above from Rob.

Just so

Likely you need to re wire the motor(s)

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Almost always the terminal box ON THE MOTOR - which contains the several wires coming OUT of the motor - each with its identifier tag

Motors and transformer are easy and no cost, heaters or overloads can be tricky to source if old or odd mag starters are used in your machine. This should be the only thing needing "new" parts. Also a good idea to keep the 480v stuff in the electrical cabinet, next guy may go back to 480v.

Thanks for the replies. The machine has a motorized Boneham and Turner spindle, so no change out possible on the spindle/motor. Most of the electronics are 110V, and the two transformers can be easily rewired. The issue is that the spindle data plate indicates 230-460, so it should be easily rewired, but I cannot find where the wires are bunched internally...I have done dozens of changeovers, and even memorized the usual 1-7, 2-8, 3-9 and 4-5-6 pattern for low voltage conversion...I just cannot find where the wires are located.

The machine is a production model grinder with auto down feed adjustable in .0001"...no flywheel grinder. Only model indication I can find is listed as VRT-6...and I cannot find anything on the net as yet. Will try to get some pic's up soon.

Motor has no electrical box on it for the wire connection?

Rob,
Exactly. There is a 3" long, six prong plug that runs the spindle...I can take the male component of the plug apart with 4 screws mounting it to the spindle and see if the bunching is behind the plug, or the other option is to remove 4 large cap screws that mount the spindle assembly to the column and see if the bunching occurs at the mounting point...everything else on the spindle is sealed. There appears at the terminus of the plug wire in the electrical box no facility for a change over. If, I cannot find the bunching, and the spindle requires a motor shop to accomplish the changeover, I will instead buy a transformer that will produce single-phase 460 and artificially produce a starting leg with capacitors, and, when running, the spindle should carry the other components at voltage...If I can find how to convert the spindle to low voltage operation, it would be much easier....

dalmatiangirl61 said:

Google did not show me that machine, sounds like a flywheel grinder in my world, got any pics?

Agree with above from Rob.

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Similar process but different application. The Gallmeyer/ Livingston, like Mattison and a couple others, capitalize on the Blanchard vertical rotary design. I've had plates ground nearly 7' across corners flat within -.002 overall. More common use is things like die shoes, sub-plates, and tooling. Far more effective than milling same area; and BOTH sides.

" Boneham & Turner " that's a blast from the past. I worked on a few of their tool post grinders although they were more famous as a manufacturer of jig drill bushes.

Regards Tyrone.