Tapping Set with chucks for or Mill Drill Press

[Ralphxyz]

Strange re: " The previous motor was a brushless variable speed DC motor.
The lathe is now much improved due to the increase in torque especially at low speed."

One of the most common criticism of VFD was that they lost torque at low speed.
My Brushless DC motors have lots of torque at low speed.

Ralph

[jjr2001]

Strange re: " The previous motor was a brushless variable speed DC motor.
The lathe is now much improved due to the increase in torque especially at low speed."

One of the most common criticism of VFD was that they lost torque at low speed.
My Brushless DC motors have lots of torque at low speed.

Ralph

Well I guess it all depends on the frequency you are feeding the motor.
The old motor was a 750 watt brushless DC for the MicroMark 7x16 mini lathe. I replaced that
with a 1HP 3 phase inverter duty motor and VFD..Why?
Well the original motor replacement cost $335.00. For that cash I was able to pickup
on Amazon a 120v VFD with 240V 3P output rated at 1HP and a matching motor and it was less cash for the pair
than just the cost of the replacement motor alone! Crazy isn't it?

New VFD plus 1 HP Motor for Mini Lathe or any lathe

Ok the new motor is much larger, I had to mount the VFD and Motor external to the lathe but
I have a much superior lathe system compared to the way it operated before. How much of
that "new power/torque feel" is due to the mass of the new motor and how much is related to
the reduction in speed I now have since the new motor is lower in rpm and I also added a jack
shaft and reduction pulley set. I never used the old motor past 50 or 60 percent of speed.
This one I will on occasion push it up to 75 percent of speed. (more than enough for carbide
and nice blue chips)!

Now the effect that I see is that this new setup does not choke at low speed when cutting off or
taking a large cut in steel like the old original little motor did. I keep the load on the lathe down to
about 1HP by setting a current limit on the VFD and would never think of going back to that
brushless original equipment motor even if it were free!

Here is a little torque/rpm chart with an explanation for KKurtz engineering:


Cheers, JR

[jdurand]

My new mill comes with a 2hp, 380V, 50Hz single phase motor. Are VFDs available for less than a kings ransom for these?

I will have a 380V, 20A outlet to power it, the wires have already been run.

[greenie]

Tapping on Bridgeport or Bridgeport clone is dead easy, especially reversing the tap out of the hole.
All you do is set your drill depth stop to whatever depth you want the tap to go to and as the tap is going in, watch the stop.
When it's about at the stop just hit reverse and out comes the tap with NO smashed taps in the blind holes.

Easy as fallin' of a log, eh. :-)

[jjr2001]

My new mill comes with a 2hp, 380V, 50Hz single phase motor. Are VFDs available for less than a kings ransom for these?

I will have a 380V, 20A outlet to power it, the wires have already been run.

I found this at Amazon but have no idea of the quality. It 380v in and 380v out 3 phase 2 HP. Might just work for just a kings supper!

Cheers, JR
https://www.amazon.com/dp/B08934PX94...NsaWNrPXRydWU=


oops, I missed the single phase!

Edit #2

Ok, it may be possible but it will be a case of experiment and maybe don't drop the speed below the speed that the motor's
centrifugal switch cuts out on startup. Going to be trial and win or loose. (even more money to the king).

https://sawmillcreek.org/showthread....-3-phase-input
Cheers, JR

[jdurand]

I think I'll just stick to the 5 speed gear head, safer. Or, I guess I could check on an upgrade to a 3 phase motor and a 1 in 3 out phase vfd. I'll be sitting when they reply.

[jjr2001]

Sounds like a good plan. New Mill. New Motor. I would stick with that too.
Cheers, JR

[Ralphxyz]

I used the Consew 3/4 hp brushless DC motor
on my 12x36 lathe and Clausing 8520 Vertical Mill. For $99.00 I can live with any shortcomings, which I have not found yet.

Ralph

[jjr2001]

Nice, Thanks for the info. I searched for Consew on the net and found their website.
If my MiniMill motor/speed controller ever bites the dust I will certainly look at the Consew.
Looks like a perfect fit. Looks like it would work as well for the MiniLathe.
Great tip.

Cheers, JR

[Ralphxyz]

One problem people have is that the Consew controller is a closed box there are no schematics if you wanted to fix or modify something.

I did add a 10k potentiometer in place of the hall effect foot switch and that works, I am planning to utilise a DS1803 programmable digital pot
for automated spindle control.

The 3/4hp might be a bit much for a mini lathe but certainly would work, actually I have a 4x12 lathe that I have thought of powereing with the Consew motor.

Ralph

Ralph