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Heavy 10r vfd help

bridgeport13b

Aluminum
Joined
Feb 5, 2015
Hi I was wondering what is involved in using a vfd set up on my heavy 10r? Can I use the original motor or do I need a 3 phase motor? Also do I need to have three phase power or will single phase 220 work? I have no clue on how a vfd works and have been researching but don't understand it very well.
 
You may have single or three phase VFDs, and you may even purchase VFDs with single phase input and three phase output to allow you to run three phase equipment in your garage on single phase power.

Edit: further explanation

From 30,000 feet, a VFD just changes the frequency of the power to the motor. AC power comes in as a wave, varying from a positive peak voltage to a negative peak voltage 60 times per second (for the US anyway). This, along with the number and arrangement of poles in your motor determines the motor’s synchronous speed. If you change the frequency of the input power, you change motor speed. Crude explanation: The VFD does this by breaking down the incoming AC power waveform, and rebuilding an approximation of a new waveform with a higher or lower frequency. Doesn’t matter if the incoming power is single or three phase, you just need to purchase a three phase VFD, and the VFD handles each phase individually. Because the VFD is building the new waveforms “from scratch”, it may even manufacture three phases from a single phase input. Hope that makes sense.

What type and size of motor does your 10r have?
 
Whichever motor you choose make sure it has the same size shaft as the original so you can reuse the belt pulley.
 
What is the effect of replacing a 1725 rpm motor with an 1140?

And even assuming same rpm motor replacement, are belt shifts/backgear still used in the same manner, with the potentiometer used only to fine tune?
Can you set up for maximum torque optimization vs max rpm? I understand why the OP feels confused...
 
Gotta keep mind torque is only part of the equation...while torque is what moves the motor it is HP at the spindle that cuts the metal.
dial down a 1725 motor to say 30hz and you basically just lost HALF of your available HP not to mention as the internal fan slows you lose cooling too.

You can get away with overspending an 1140rpm motor to behave like a 1725 motor- more or less that's about 90hz and there will be no appreciable power loss

below 60hz is constant torque but since speed is reduced you get a corresponding loss of HP

Above 60hz you lose a little but it is made up for(to a point) because speed is increased.

Can't type much so maybe someone else will fill in the gaps, suffice to say full HP at ~30rpm at the spindle is well,just plain fun.:)
 
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It depends on your personal priorities..You should post in the VFD and Transformer section to get the pro and cons of 1725 vs 1140

Me, I had little use for anything over about 1000rpm at the spindle( tho I could certainly go beyond that)and valued low end performance over high end so the slower motor was a natural fit.




You might add what your expectations are?
 
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This is a pretty appealing deal-

1 HP, 18 RPM, Toshiba Motor with 1 HP, 115 Volts, Teco VFD at Dealers Industrial

Though my preference is the slower motor it really doesn't make THAT big of difference.The only drawback is the 7/8" shft size but that can be easily and cheaply remedied...you *could* even just buy a new standard single step with a 7/8" bore(sized accordingly),park the belt on the big step of the countershaft pulley and with the VFD you would have enough flexability to cover the original spindle speeds pretty effectively by just moving the spindle belt.

Also keep in mind that no matter what you will almost certainly have to re-drill and tap the mount OR make an adapter plate for your new motor.
 








 
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