View Full Version : HmM Norton Grinder

11-28-2006, 09:18 AM
Where would you procure a manual for a older Norton surface Grinder. I am looking for dissasembly drawing ect . I recently procured one (its still sitting on my trailer haha but have a case of beer crane coming today to move it BuRp) and am planning on dissasenbling and cleaning ect. Then Im trying to figure out if its cheaper to repower it with a single phase motor or buy a 3 phase conversion.. What do you guys think buy a new motor (do they need to be specially balanced to be used on a grinder>?) or a 3 phase convertor ?? Also being a electrical (and otherwise dimwit) when you use a three phase from single phase invertor convertor whatever does it use MORE HYDRO than a normal single phase motor would. ?? Hm Questions questions always the questions. Thanx a lot Guys. MikeThanx PS Next project cnc bridgeport conversion .

11-28-2006, 09:33 AM
Yes, you want a balanced motor on a grinder. I would suggest a VFD to power the existing motor. You don't need the variable speed capability, but a VFD will give you better-phased 3-phase than a rotary phase converter does, and the motor will run more smoothly. I guess you could play around with capacitors to phase-shift the output legs of a RPC, but then you'd need an oscilliscope or something to see how you're doing. A VFD will be easier.

What do you mean, "more hydro"? More power? I assume there is some amount of power loss with the VFD, but it's not much, certainly not enough to worry about.

11-28-2006, 11:12 AM
Sounds expensive vfd now. Can a electric motor in single phase be purchased thats BALANCED/

11-28-2006, 11:53 AM
Sure, you can get a balanced single-phase motor. It will likely cost more than a VFD.

11-28-2006, 02:23 PM
madman, because I had one sitting there, on mine I used a standard unbalance 1 phase motor. One day I'll make a rotary phase converter, but in the interim it has worked fine. The motor is isolated from the spindle via a belt, and while I suppose vibrations from the motor carry over into the machine, its massive enough that they don't appear to show up in grinding. if you do go three phase, make sure its rotary, not one of the electronic converters, they need a load like a transmission or such and can be unbalanced without it.

I'd say the best advise is to keep the motor and make a rotary phase converter, guys seem to be able to pull these together fairly cheaply, one day I'll have to try to do the same.

11-28-2006, 06:52 PM
Is this a hand pumper, or does it have the hydraulic table. If hydraulic there is another motor in the base, direct driving the pump. The serial number can be found on the base under the cover, IIRC. I also think the year of mfg is there also. A picture would help.
Norton made the small grinders with manual cross feed only, or with an automatic cross feed. They also made them with plain spindle bearings, or ball bearings, V belt or flat belt, wet or dry, etc. Like I say a picture would help.

11-28-2006, 08:42 PM
If it is a belted motor a single phase 110-220 will work ok . all this ballance stuff is hog wash unless you are doing some supper high precision grinding and you aint going to do that with an old norton grinder . My KO Lee 6-18 has a single phase 110 i HP. motor i bought for $100.00 and will out grind any grinder we have at work and we have 4 different ones.

11-29-2006, 09:21 AM
I am going to just get a new motor and use a link together belt for harmonic elimination. I dont know the name but theyre red and come apart into pieces. I had bought it for my bridgeport but it wouldnt swith over the pulleys properly. I think the norton grinder is a far cry above the cheap ass import grinders. Ive done lots of manual grinding and i can flay one of those machines apart quite rapidly. When youre in tool and die mode and wound out on the grinder that poor thing takes a beating especially those cables in the table that always seem to break on those import models. I dont like chinese equipment any more. Look at out economy and whats happened.