I have a 20-year old Burr King 2 x 72" grinder with a Baldor 1 hp 110/220 single phase motor that just shot craps. I've put quite a load on it over the years and it's never batted an eye. The other day I was using it with just a feather touch smoothing out the ripples/flats in a knife handle. It slowed and quit and I thought for a naive minute I'd tripped a circuit breaker. Then I notice the wisp of smoke coming out of the motor.
Back to files and sandpaper for a bit until I get the motor rebuilt/replaced.
Any of you know if I could get a rheostat added to give me variable speed, or do I lose a lot of low speed torque that way? Sure would be nice to make my mistakes at a slower pace.
if you have to go with a replacement motor just go up a few HP, it will be worth the extra money. I have a 2hp Bader variable, and can readily bog it down without effort even with sharp/new belts.
If you decide to go the variable route, the best price will be had through this place, they have the NEMA 4X controller fro $160. http://www.electricmotorwholesale.com/9338-KBPC-240D/
At some point this year im going to buy a KMG chassis, I have a heavy duty 5hp motor that will be running it, im TIRED of not being able to really get after it when I grind.
This may be an opportunity Ron. I agree with Matt. But I think you expected to hear this. Up your horse power and get variable if there is any way possible.
I agree-bigger motor and variable speed. I got a 2hp, 3 phase motor off the auction site for a great price. Saved up and got a KBAC 27D VFD to go with it. Once you get the variable speed, you'll love it.
Jeremy
Also with variable, you will likely need to get a 3phase motor. My controller converts it from single to 3ph. I found 2hp 3ph motors cheaper and easier to find on the auction site. I kept shopping and found a brand new Baldor with those specs for $100.
QuoteOriginally posted by Lamey:
At some point this year im going to buy a KMG chassis, I have a heavy duty 5hp motor that will be running it, im TIRED of not being able to really get after it when I grind.
A 5 hp grinder. Just one more way that you're more of a man than I am. I'm going to start marking my knives "Diet Matt".
Matt Toms
I'm going to take your advice (all the advice seems consistent) about getting more horses in the stable. I never even looked at 3-phase motors, even though I knew they were cheaper in the large sizes, because I have only single-phase 220V. Am I reading correctly the controller will provide 3-phase to the motor from single-phase source?
Having said that, I've never loaded the grinder down significantly with the coarser grits when I'm leaning into it pretty good. With the fine grits, I learned not to put too much pressure on the blade or I get hot spots and warps.
Bottom line, if my old one-pony motor can be rewound cheaply, I'll keep it. If the price gets up there too high, I'll junk it and go with a variable speed controller and bigger motor.
Come on tax refund :)
I hear you on the grinder woes. Mine is not very good. I hope to be able to make and sell enough knives this summer to get a KMG chassis and outfit it with variable speed.
Mine was worn out when I got it, but I plan to make it better and pass it on to a fellow that is wanting to start out then upgrade.
Keep us posted on developments.
Chris
Yup, the controller plugs into my 110 outlet and wires into the 3 phase motor. I got my 2hp motor for I think it was $80.00. Just be aware that different models of VFD's are compatible with certain hp motors. So if you go that way, planning which size for what model will keep aggravation down later on :) .
Jeremy
And another great option once you get a variable controller is to run the three phase out wire to a toggle switch. From the switch you can run a line to your belt grinder and another line to a motor with a disc. If you plan to do this from the start, you should order the forward/brake/reverse switch with your controller. I added my switch later once I obtained another 2hp, 3ph motor for my disc.
Lots of great ideas here. I got my Burr King for $900 new and for another $300 or so, could have had their variable speed setup. Oh well, live and learn. I'm still happy with the grinder and I think I will really love it when I get the variable speed. Meantime, I've rediscovered files :)