Need advise on wiring a OD Grinder

[sweettractors]

I have bought a new to me Cylindrical/OD Grinder. It was previously used in a industrial setting on 3 phase 220 volt. Here is where I need advise. It has 4 3 phase electric motors and I want to use a phase converter to run all 4. Is that going to be possible or even feasible? Ken Sweet

 

[CalG]

I have bought a new to me Cylindrical/OD Grinder. It was previously used in a industrial setting on 3 phase 220 volt. Here is where I need advise. It has 4 3 phase electric motors and I want to use a phase converter to run all 4. Is that going to be possible or even feasible? Ken Sweet

A rotary phase converter will serve you well. All that amounts to is a three phase motor of sufficient amp carrying capacity to "run at idle" generating the 3rd leg after being started via a suitable capacitor based starting circuit.

Size the idler for the Largest drive motor on the machine, (hint grinders start easily)

I have a home build RPC powering a milling machine that has four motors. Just a "Static Phase convert that starts an idler motor sitting on the floor. It works fine. As it has for the past 20 years. You can even use the spindle drive motor as the phase converter to power subordinate drives. .

cheers

 

[the old grind]

What CalG said. With spindle and hydro motors running steadily and workhead and coolant motors running intermittently (most jobs) there are few, if any simple, practical alternatives to a rotary for full power 3Ph operation w/o hiccups. btw, VFDs and similar options are one/motor, such as on a manual machine with just one for the spindle.

The ultimate would be 'Phase Perfect', but could easily cost more than a decent used ODG. At the lo-buck end, and as good as anything, source a 3Ph motor from CL, ebay, or Surplus Center and find 'Phase Craft' for the other bits, and for noteworthy assistance on all aspects of matching converter to the load/machine.

Somewhere between the extremes of investment are 'package' RPC setups, plug and play if you will, with 'box' and motor. Shop carefully, and look for reviews on sources or models. Also, Google 'phase converter' and look for anything from Practical Machinist, where us handwheel-spinners join the CNC guys in a 3ph-specific forum.

Building an RPC is only daunting the first time.

 

[LD1]

Are all 4 motors wired separately? or do all 4 go to a single point/j-box and you only need 1 power source to power the machine?

A rotary will serve you well. But I would advise that you verify the wiring on the motors that they are indeed wired for low voltage 3-phase. 480 is the norm in an industrial setting around here. Most motors are dual voltage and all it takes is swapping a few wires to get low voltage (220-240) 3-phase

 

[sweettractors]

You guys are great and thank you for your suggestions and information. I have ordered a 5 HP Rotary Phase converter. The 4 motors on the grinder are all wired to be powered from a single point. Ken Sweet

 

[sweettractors]

Update: I got the Rotary Phase converter installed over the weekend and it works like a charm. Ken Sweet

 

[Big Barn]

Update: I got the Rotary Phase converter installed over the weekend and it works like a charm. Ken Sweet

Some pics would be great, Ken.

Terry

 

[sweettractors]

Some pics would be great, Ken.

Terry

I finally got a few pics of the Brown and Sharpe #13 OD grinder. It has took a little longer than expected as I also just installed a Boyar & Shultz Challanger Deluxe surface grinder and have it wired into the same 5 HP American Rotary Phase converter. Both grinders are working very well, even when operating both at the same time. Ken Sweet

 

[Shaneard]

We have a Boyar-Schultz Challenger surface grinder here at work, it's a tad dirtier than yours but close to the same thing. The magnet is 6" X 18".

 

[sweettractors]

We have a Boyar-Schultz Challenger surface grinder here at work, it's a tad dirtier than yours but close to the same thing. The magnet is 6" X 18".

Nice looking surface grinder. Does it get much use at your workplace? Mine is a 6" x 18" as well. So far the only thing I have found that I dislike about the Boyar & Shultz is that it is a little harder than I am used to when using the cross feed manually. Ken Sweet

 

[Shaneard]

Ken, it doesn't get used much at all. Maybe 5 hours a year. We used to keep it clean but it gets forgotten, it's back near our welding area and catches a lot of grinding dust.

 

[sweettractors]

Ken, it doesn't get used much at all. Maybe 5 hours a year. We used to keep it clean but it gets forgotten, it's back near our welding area and catches a lot of grinding dust.

What type work does your shop do? Ken Sweet

 

[Shaneard]

We have 2 CNC mills, a Bridgeport & 2 CNC lathes, we do a lot of prototype work. 1 & 2 parts and do some quantity jobs but mostly prototype. That's what I like about it here always something different. Been here 21 years, I do all our mill work and all our welding.

 

[sweettractors]

We have 2 CNC mills, a Bridgeport & 2 CNC lathes, we do a lot of prototype work. 1 & 2 parts and do some quantity jobs but mostly prototype. That's what I like about it here always something different. Been here 21 years, I do all our mill work and all our welding.

I agree that having a variety makes the workplace a lot more enjoyable. I am curious about doing prototype work (1 or 2 pieces) on CNC machines. It seems there would be lots of time spent writing programs that may never be used again? Ken Sweet

 

[ruffdog]

I ran EZ Trak and Prototrak controlled mills and the programming is so quick and EZ. You can use smaller cutters to create contours and radii and the product looks better. The nice thing with CNC lathes is the constant surface speed and the ability it gives you for finish quality. You can program corner radii to eliminate stress points and also program it to break the corners (deburr).

 

[Weedy Fields]

I ran EZ Trak and Prototrak controlled mills and the programming is so quick and EZ. You can use smaller cutters to create contours and radii and the product looks better. The nice thing with CNC lathes is the constant surface speed and the ability it gives you for finish quality. You can program corner radii to eliminate stress points and also program it to break the corners (deburr).

Your mills 2 axis or 3 axis?

 

[ruffdog]

Those mills were 2 axis.

 

[Kyle_in_Tex]

We have 2 CNC mills, a Bridgeport & 2 CNC lathes, we do a lot of prototype work. 1 & 2 parts and do some quantity jobs but mostly prototype. That's what I like about it here always something different. Been here 21 years, I do all our mill work and all our welding.

You job sounds almost exactly like mine. I do the same thing at an R&D facility except I'm the only one left for the last 3 years. I have a new trainee who has zero machining experience. I like your signature.

I agree that having a variety makes the workplace a lot more enjoyable. I am curious about doing prototype work (1 or 2 pieces) on CNC machines. It seems there would be lots of time spent writing programs that may never be used again? Ken Sweet

Yes, a lot of programming, setting up, fixturing for just a couple of pieces happens frequently. Part of the job. I tell the engineers the first piece is gonna cost them a lot. The 2nd is a bargain.

 

[Kyle_in_Tex]

Ken, what do you do with your machines in your shop?