View Full Version : Baldor Grinder

10-01-2010, 11:31 AM
Just picked up a Baldor grinder at a local sale, its in good condition with a white wheel on one side and a fine grit light gray wheel on the other. Its the tool grinding type with the adjustable tables on each wheel. The device that goes on top to provide water cooling is missing, but otherwise in good condition. One issue, the motor is 3ph. What would be a method to use this thing on my shops 1ph electric? A small convertor work ok with a grinder? I knew it was a 3ph, but figured I could make it work. Looks to be made in the 70's I would guess. Any comments appreciated.


10-01-2010, 12:10 PM
use a vfd. Probably a better buy than any "pseudo" static phase converter @ aproximate price of $200.00 or less.

Erik Brewster
10-01-2010, 01:29 PM
use a vfd. Probably a better buy than any "pseudo" static phase converter @ aproximate price of $200.00 or less.

I totally agree on this. I've used driveswarehouse.com / hitachi drives with success before.

10-01-2010, 01:53 PM
I totally agree on this. I've used driveswarehouse.com / hitachi drives with success before.

Ok, appreciate it.....actually I forgot about the VFD route. I will look into it...

10-01-2010, 05:18 PM
That grinder is probably a Model 500. As others have said, buy a VFD that takes 110V single phase input. It's only about a 3/4hp motor. I like the TECO VFDs from dealersautomation.com myself.

10-01-2010, 05:36 PM
A 110 in - 240 x 3ph out FVD can run you as little as $100. Dealers Electric had some GE/Fuji's on sale a while back (they still may be, I haven't looked).

I bought one and it's a real nice basic drive. WAY more than enough for running a grinder and unbeatable at the price.

10-01-2010, 05:48 PM
replace the motor with a single phase one, cheapest option.

10-01-2010, 05:53 PM
I've got a 3/4 horse (I think if your interested I'll check) static phase converter that's never been out of the box. You can have it for the postage if you want. Either PM me or reply here or email me at:



Doc Nickel
10-01-2010, 06:11 PM
replace the motor with a single phase one, cheapest option.

-Don't know if this is tongue-in-cheek or not, but if not... :D


The M500's motor is part and parcel of the grinder. To "replace" the motor, you'd basically just take the endbells and bolt them to a different machine. That presumes you either have access to a parts single-phase M500 (including functional rotor, stator, wiring, capacitor and housing) or would be buying them new from Baldor. (Which would cost more than buying the complete grinder.)

And don't suggest selling the Baldor and buying an import clone- the real thing is ten times the machine the import crap is.

On the other hand, a VFD on a 500 opens the possibility of using diamond wheels on steel tools, by slowing the wheel to reduce heating of the workpiece.


10-01-2010, 06:19 PM
replace the motor with a single phase one, cheapest option.

Huh huh u huh huh?

10-02-2010, 03:54 AM
I've got a single phase reversible version of what you have, but with 2 different grit diamond wheels. First off, you're not missing anything by not having the drip pots. Basically useless for anything but being in the way and making a mess. IMO, go flood or run dry. Second, get an inexpensive VFD and forget the rest. Also gives you speed control, so you could slow it down and even use it for moderate lapping on steel (here the drip might work ok?) without damage to the diamond. But don't run it too long too low or it will over heat. Or at least put an external fan on it.

And I held out for a real Baldor, though severely tempted to get a HF at one of the many sales, and using one of the 20% coupons. In the end, I found the Baldor, looking near like new (except for mess of sludge from using the drip pots) with the near new diamond wheels for only a tiny bit more than the HF "kit" that comes with concrete wheels painted green. Nice tools are a pleasure to use. And, I'm so cheap that I often "touch up" or change the point radius on inserts. Wouldn't be without it.

10-02-2010, 09:45 AM
Russ, can I ask where you were lucky enough to find the Baldor? I looked at Fleabay, and the Baldors there are not going cheap (all $200 or so)... I would like to buy a used Baldor rather than that "heavy duty" Grizzly.



10-02-2010, 10:08 AM
Ok Doc, LOL, ur killin me here, haha....now thats a nice unit there. Mine is not as pretty. I appreciate all the suggestions here on this grinder. I think the motor will cost more new than the whole unit probably. They list this model for $1100 or something on the home page for Baldor. This is a Model 510. You know I looked at the motor plate again yesterday, and it shows both 1ph and 3ph on the plate, but there is a mark or something on the 3ph stamping. It has a junction box of some type on the back with no wiring, I will pull that off today and see if there are two wires or three wires coming off it.....maybe the damn thing is 1ph after all. It has a weird rotary style switch on it that seems to be messed up going to the reverse side, I need to get some pics and show you men for a better idea. It doenst have the toggle like on Docs pic. It spins smooth and free with no roughness so the bearings should be ok. It has a serial no. of 7/54 or something, need to reverify that. Dont tell me that this thing is a 1954 model.

How much you want for that one Doc, and I will send this to you for some compenation towards that one, hehe.....


Lew Hartswick
10-02-2010, 10:12 AM
replace the motor with a single phase one, cheapest option.
It's posts like that, that have me to point I hardly ever bother posting
on forums like this. :-)

10-02-2010, 10:33 AM
It would be a simple matter to come up with a 3 phase converter. For your Baldor grinder, you would need a 1 hp, 3 phase motor for an idler, a potential relay, some capacitors and a switch. There's nothing wrong with a 3 phase unit at all.

Here's a schematic for you.


10-02-2010, 10:35 AM
Oh Doc, was checking your page out, nice stuff. How the hell do you keep that machinery so clean and nice?? I must be a thrasher or something. I mean I dont abuse the mills or the lathes but I dont polish them either, hahah.
I like the blacksmith stuff. I want a medium anvil (old good one) myself. Hard to find now a days. I had one several years ago at an auction and let it go. Sorry I did that....whine......

10-02-2010, 10:48 AM
-On the other hand, a VFD on a 500 opens the possibility of using diamond wheels on steel tools, by slowing the wheel to reduce heating of the workpiece.


I place a CBN wheel on one side, and a Diamond on the other. One side for Steel (CBN); the other for carbide (Diamond). The problem with running diamond very slow so it doesn't heat is that it also removes metal very slowy.

IIRC, Baldor factory conversion from 3 phase on these and buffer units is just a single capacitor from L2 to L3, power fed to L1, L2 - a simple "static converter". Call Baldor...

The easiest way to run these from 115 volts is a small voltage-doubling vfd mounted in the switch housing. Open the back of the housing for ventilation.

10-02-2010, 12:19 PM
Ok, I went out to the shop and cleaned up the motor plate and took some pics of the grinder. Turns out I wasnt looking correctly at the plate, where I thought it had a "1" like "1ph" was actually just a separator slash. The motor is a 3ph unit, 1/2 hp, 1.4 amp, reversable. Notice the switch. It doesnt work that well on the forward mode. Have to get the thing cleaned up and looked over. I cant seem to post the pics I took, as Im showing not allowed to post attachments. Trying to figure out photobucket but having some issues there. Hmmmm.



http://i493.photobucket.com/albums/rr295/Mohead1/Baldor/th_DSCN0222.jpg (http://s493.photobucket.com/albums/rr295/Mohead1/Baldor/?action=view&current=DSCN0222.jpg)

http://i493.photobucket.com/albums/rr295/Mohead1/Baldor/th_DSCN0218.jpg (http://s493.photobucket.com/albums/rr295/Mohead1/Baldor/?action=view&current=DSCN0218.jpg)

http://i493.photobucket.com/albums/rr295/Mohead1/Baldor/th_DSCN0221.jpg (http://s493.photobucket.com/albums/rr295/Mohead1/Baldor/?action=view&current=DSCN0221.jpg)

Appreciate all the comments so far. I value the info very much.

Mark aka BigMo

Alistair Hosie
10-02-2010, 12:58 PM
You won't regret buying a vfd if you're serious about your hobby. These can be used for many things. I currently have one in both of my shops shops as I also have a wood shop. Thre're great to use, and as said you'll have the extra benefit of having variable speeds on all tools you put through it.
If your clever you can make it wired to anumber of machines on a board as long as you only use one at atime good luck and please enjoy your new toy err tool. :D Alistair

10-02-2010, 02:48 PM
Russ, can I ask where you were lucky enough to find the Baldor?
Local club member/friend was down sizing his shop. I had also done some machine work for him (his side $ job) that was too large for his machines. For one or both reasons, when he downsized, he sold me that grinder for a very good price. He had bought it new and mounted new good name wheels, then only used it sporadically in his shop. As he said, he uses mostly CNC with inserts (no resharps!) and had hardly used it since he bought it, not enough to justify space. His only condition was that he be able to use it on the rare occasion that he needs it. That was maybe 2 years ago, he's dropped by once to use it. And I've used it quite a lot at times, particularly when experimenting with brazed bits to get the results I want with finish or form.

That doesn't help you much, except to say make sure everyone with appropriate interest knows you are looking. They may run across one they don't want, or have one they rarely use (horse trading?). Combine that with modest diligence on ebay/craigs and patience, it'll happen. I've gotten many of my upgrades that way. That includes my 50T US made press, blast cabinet, both Baldor grinders, my SRD drill grinder, etc. All were via "word of mouth". For example, consider my 50T press. I've got a friend who put a Cummins 6BT in a 72 Suburban with the help of quite a few machined parts out of my shop. While hanging out, he heard me grumble about needing a press larger than my 20T HF (which I figure is roughly a 10T, maybe 15T at best after upgrades). Anyway, he was at a large yard sale in the "horse properties" (generally affluent real folks, often blue collar upper middle class, places that often have real shops) and called me up. "You want this?", and he described, I said yes, he paid and loaded in his pickup, delivered, helped me set up, and took his pay (refused a finders fee I tried to add).

Moral of this story? Friends are your friends... ;)

10-04-2010, 03:01 PM
Another plus with going the VFD route is that you won't have to deal with that switch...


10-04-2010, 03:51 PM
Ahhh, well... Just missed out on a Baldor 500 on Fleabay for $100. Which one of you lucky fellas got that one? :o