[cnc1000]

Everything seemed just fine. I can smoothly run rpm up and down, according to the dial. At all speeds under 2600 rpm, everything is just fine. However, the spindle itself maxes out at 2600 rpm and will go no faster. The dial calibrations are spot on at all speeds below 2600 rpm. What the....... ?? :drowning:

[keebler303]

Sounds like the vari-drive belt is worn.

If the belt is narrower than it should be (from wear) it will not reach the very outside of the spindle side pulley and will therefore not achieve max speed.

[John Bennett]

Another thing to check. What is the rpm of the motor ? If not up to spec, you might want to check that the three phase voltage matches the voltage taps at the motor. On the motor there is a diagram to show what wires should be connected for a set voltage. Since you have just aquired the mill, it may be set at a different voltage than you have.

[cnc1000]

It is new to me, and I have not set any voltages, but in terms of rpm, both single and three-phase motor speeds are determined by frequency, not voltage amplitude. That's how VFD drives work. The worn belt sounds plausible. I'll probably let it ride until I get the cnc parts of the machine up and running. I still have to sort out the Bijur lube thing. The color codes don't match the diagrams I have. I have 4 wires coming out, red, black, green, and white. No idea what they go to. Further, the tag on the Bijur is worn. I can see a serial number but no model number. Red and black are typically the hots in a 240 single phase system, green is safety ground, and white is neutral. However, my T1 transformer puts out 125V. I guess it could be tapping off of the primary, which is 240. Hate to guess and see fireworks happen.

[John Bennett]

You could download a R2E3 maint manual off the net as it will be close. The attachment might help. As far as VFD 50 , 60 etc htz at 440 volts is the same as at 220 ?

[cnc1000]

Thanks for the image. I don't have a blue wire, unless what looks like black to me is actually blue. I'll scrape the wire a little to see. AC motors create the fields that cause the rotor to follow them, and they change phase at the rate that the AC changes phase, that being 50 or 60 Hz. The voltage, along with the impedance (or resistance at such low frequencies) determines the strength of the field coils. If you put 208 3 phase onto a 120 volt coil, you will over heat it and possibly saturate the field coil, which would cause even more heating. So the voltage is selected as appropriate for your power source. The more the current, the higher the torque. The speed is determined by the frequency that drives it. More, but gotta run. Thanks.

[John Bennett]

Some manuals can be found here
Bridgeport

Also, please note that your private message folder is not accepting incoming PM ?

[cnc1000]

Hmmm. Dunno. I have 5 messages in my inbox and can take up to 15 more. I have no restrictions on who I receive messages from. I'm flummoxed. Thanks for the link.