K&T 307 S-12 Knee Motor Stops when I start Spindle- Help !

Any suggestions would be greatly appreciated:

Kearney and Trecker 307 S-12 Horizontal-Universal Table.
The Knee motor kicks off when I start the spindle at RPM's greater than 299. I doesn't kick off when turning on spindle at lower RPM's.

Fluids are all good, when knee motor is running upon start up the knee sight glass shows flow, but when knee motor stops upon turning on spindle at higher RPM's the sight glass flow stops, I assume because the knee motor stops.

Hope this is enough information to go on, thanks.

UPDATE:
It turns out there is nothing wrong with the machine.
I found on the electrical diagram instructions to "HOLD" the spindle start button
in until spindle comes up to speed to "prevent" the Feed Motor Relay from dropping out.

Its really great to solve an apparent mechanical issue with simple education.
Hope this helps someone else. This confused me initially because I have a K&T 205 S-12 vertical as well and you don't have to hold the spindle start button in on it, so I "assumed" something was wrong with this 307 S-12 horizontal, but glad to know everything is as it should be

I have a 2HL vertical that boggs down in really high spindle speeds. I think it may be because I'm running it on a rotary phase converter, and it might not be supplying enough power for the high speeds

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loggerhogger said:

I have a 2HL vertical that boggs down in really high spindle speeds. I think it may be because I'm running it on a rotary phase converter, and it might not be supplying enough power for the high speeds

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Click to expand...

Not sure if it's the same issue as the OP, but I have the same thing on my 2HL vertical. When i first fired it up, it struggled to hit speeds over 1000rpm, and bogged down completely if i engaged the rapids with the spindle running in those higher speeds.

I thought it was related to the RPC, as the balance between the legs wasn't great. So, i switched over to a VFD but it didn't make much difference. I took the head apart to make sure it wasn't dried grease caking everything up, but that didn't help either. It improved slowly over the next few months, and now the weather is warmer, it barely bogs down at all, even at 1400rpm. The rapids still change the tone of the motor a bit, but still very useable.

Has yours improved with time/weather?

Lee

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