I have a fairly unique situation but I don't think I'm putting the right search terms in.

I have a smaller (I am a semi professional welder, owned/own everything from large engine driven welders to back pkc ot industrial oxyacetylene welders, college educated and almost 3 decades of experience.) welder that I adore, due to its very light weight, very small but also very potent (IGBT rather than low frequency transformer design. I have experience with large, heavy, current demanding welders. Jsvig to mess with cooling, upgrading diodes, capacitors, etc)

I prefer the 120v unit because it offers enough current without the need for large generators or heavy extension cords

The issue is, with all the welding I do, I have fitted a 10lb spool onto the holder where a 2lb spool would go. 5 times the weight

I have modified the welder to accept this larger spool, and it works *great*

I am almost on my 3rd spool

And I've only hit the thermal cutoff *once* while welding continuously

Not bad for a used welder I bought for $115

(It's become my favorite welder. High frequency for the win)

Anyway, the issue is with the 10 lb spool, due to friction, it can drag ass while welding, the 390 brushed DC feed motor isn't torquey enough (just needs a little more.)

So, I discovered you can get brushless 3 phase 390 form factor motors

This motor should bolt directly up into the feed mechanism

With a lower kv rating, it should have ample torque to drive the feed mechanism

(Again, cannot stress how anemic the feed motor is)

The issue is,

The welder is 120vac driven

The DC power supply for the brushed DC 390 feed motor is likely minimal and anemic by design (I will likely have to abandon it)

That leaves me with a 120vac power supply,

With the need for a "regular" potentiometer for speed

To control a 390 form factor brushless 3 phase motor,

That seems to only be offered with DC motor speed controllers,

That seems to only want a pwm pulsed input to control speed (I would prefer a regular potentiometer or even a rotary pulse generator, but that leads me to my problem,

I COULD,

Wire in a high current 120V to DC power supply, powering a BLDC speed controller that powers the 390 motor, that uses a separate pwm speed controller, that I removed the RPG/potentiometer and installed it into the control panel of the welder, to drive the brushless motor, to push/pull the wire,

But then the circuitry would be larger and more complicated than the entire welding circuitry (there is maybe enough room in the welder)

However, I am certain there is such a thing as a 120vac brushless speed controller, with the DC power supply, 3 phase motor speed controller, and pwm pulsed output variator to control the controller,

All built into one (hopefully compact!!) unit (!!!) that isn't a large industrial programmable motor controller

Does such a thing exist? Or do I need to piece together 3 separate things to make this work...




Tl;dr

Is there a small self contained 120vac powered small brushless motor (390 form factor) speed controller with a rotary style speed control knob commercially available that's inexpensive

 

I just scanned over the post, but is it possible to use a VFD they will control the typical 3ph motor using 1ph power.
And a LV DC control level for RPM.
t

 

I suggest checking with a larger motor supplier,

 

Probably there is such a device BUT I am not familiar with it. The problem with a welding wire feed is that the burnig of the feed wire is not always constant. At least not for me.

 

So, far the only 120vac brushless controller that's cheap and compact is for a brushless sewing machine

I don't know what the voltage output is.

Ironically I DO have a heavy duty sewing machine that I DO want to convert to brushless so I suppose it wouldn't be a big deal to measure voltage across one of the phases

 

I have a unique situation where I’m searching for the right terms. I have a small, lightweight, and potent welder (IGBT design) that I adore. I’ve experience with large, heavy welders and have modified it to accept a 10lb spool instead of the 2lb spool it’s designed for. This modification works great, and I’ve only hit the thermal cutoff once while welding continuously.

However, the 10lb spool drags during welding, and the 390 brushed DC feed motor isn’t torquey enough. I discovered brushless 3 phase 390 form factor motors that can bolt directly into the feed mechanism. These motors should have ample torque to drive the feed mechanism, given the anemic feed motor.

The welder is 120vac driven, and the DC power supply for the brushed DC 390 feed motor is likely minimal and anemic. I need a 120vac power supply with a regular potentiometer for speed control of a 390 form factor brushless 3 phase motor. However, speed controllers that only want a PWM pulsed input are only available for DC motors. I could wire in a high current 120V to DC power supply, powering a BLDC speed controller that uses a separate PWM speed controller. This would make the circuitry larger and more complicated than the entire welding circuitry. Is there a 120vac brushless speed controller with a DC power supply, 3 phase motor speed controller, and PWM pulsed output variator all built into one compact unit? Or do I need to piece together three separate things?

TL;DR: Is there a small self-contained 120vac powered small brushless motor (390 form factor) speed controller with a rotary speed control knob commercially available that’s inexpensive?

I agree with Max:

It possible to use a VFD they will control the typical 3ph motor using 1ph power.
And a LV DC control level for RPM.

I believe VFD can be used on AC motors as well as DC motors. This should open some options you haven't considered. Oh, and I took the liberty to condense and consolidate your opening post. I hope you don't mind; it's an easier read for me.

 

might you consider a DC geared motor.

 

Since I have no information about the wire feed motor or it's controls, I cant make many suggestions. BUT based on what I have seen of wire-feed welders, reducing the friction in the wire feed system could be helpful, and not require a different motor driver.

 

Since I have no information about the wire feed motor or it's controls, I cant make many suggestions. BUT based on what I have seen of wire-feed welders, reducing the friction in the wire feed system could be helpful, and not require a different motor driver.

Reducing friction isn't possible outside of temporarily greasing the friction surfaces which only lasts so long

The motors I referenced usually take 3v/phase to achieve 3000 rpm so not a lot

A geared motor may work but would require re designing the entire feed mechanism (it is already geared)

REALLY what I need is a small, inexpensive, AC 120v powered, 3 phase, 1-10v~ per phase at maybe 10 amps (?) controller with a simple potentiometer that I can desolder or simply mount where the old potentiometer is for the variable DC power supply

Similar to the brushless sewing machine motor controller (but I don't know what the voltage output is for that.)

 

Three phase driver circuits do exist, as well as 3-phase variable speed drives. Not much of it is new, either.
A variable frequency oscillator driving a three segment shift register controlling a three section "H-bridge " output stage could do the job. BUT likely at three volts.

 

Is there a small self contained 120vac powered small brushless motor (390 form factor) speed controller with a rotary style speed control knob commercially available that's inexpensive

Depends on what fits your definition of "inexpensive". Just the IC for a VFD, without complete circuit is gonna cost about $15. A low-power VFD begins from $70 and goes up.

 

Depending on what part of the world the TS is located in, there will probably be electrical supply houses that cater to industry, and can provide exactly the 3-phase controller to serve the TS requirement.

 

Depending on what part of the world the TS is located in, there will probably be electrical supply houses that cater to industry, and can provide exactly the 3-phase controller to serve the TS requirement.

I never thought there would be a residential with 3-phase outlets. Never seen any domestic appliance running on 3-phase, unless it takes single phase and uses some inverter or something to get 3 phase out of it. but regardless, the TS says something about " 3 phase, 1-10v~ per phase at maybe 10 amps " which is not the industrial voltage.

 

Certainly an inverter drive could use a 3-phase scheme and avoid an output transformer. AND it would make direction switching simpler.

 

Certainly an inverter drive could use a 3-phase scheme and avoid an output transformer. AND it would make direction switching simpler.

yep, especially with the BLDC that TS is aiming for, inverter ( any SVPWM) works well with PMSMs

 

I never thought there would be a residential with 3-phase outlets. Never seen any domestic appliance running on 3-phase,

Depends on what part of the world you are in!
e.g. in the UK I had several off peak storage heaters in my house fed off a 3ph supply .

 

Depends on what part of the world you are in!
e.g. in the UK I had several off peak storage heaters in my house fed off a 3ph supply .

Do all houses in the UK get 3-phase or only certain areas? And i think your voltage is 240. TS seems to be in NorthAmerica

 

Do all houses in the UK get 3-phase or only certain areas? And i think your voltage is 240. TS seems to be in NorthAmerica

No, only if needed, as in large loads such as storage heaters,
BTW, I am a Canadian now!

 

Just spitballing here:
https://www.amazon.com/Brushless-Controller-Forward-Reverse-Function/dp/B0DBSNV86J/ref=sr_1_3
https://www.amazon.com/Diameter-4000rpm-5000rpm-Brushless-Phase/dp/B07D6JJFCM/ref=sr_1_5
Don't know if these are available in your local. Don't know if you have the necessary voltages. Don't know if you can fabricate a motor mount.

 

Just spitballing here:
https://www.amazon.com/Diameter-4000rpm-5000rpm-Brushless-Phase/dp/B07D6JJFCM/ref=sr_1_5

Just another nit-pick.
Those ads make a common mistake of mixing two types of technologies, 3ph AC and BLDC (Brushless "DC")
Pretty much the same motor, but totally different in resulting commutation.
Gennerally higher torque avail, using BLDC.
No transformer required in N.A.