Direct or belt drive grinder????????????

J

J. Hoover

Joined
Jul 2, 2006
Messages
1,782
I have been looking, reading and reviewing grinders lately a lot. My current grinder is a direct drive grinder (homemade) with a 1 1/2 hp dc motor and variable drive. I purchased it from the estate of a knifemaker who passed away in Florida several years ago. I upgraded it to the variable drive as he used this particular grinder to profile with I believe. Tool change is another matter and I want to upgrade.
I like he direct drive on this grinder and have no experience with belt drive grinders other than cheap 4 X 36 type grinders.
I have been leaning toward the KMG but before I pull the trigger just wondered what the pro's and cons were of each type if any.
 
I like the belt drive on my KMG. It allows the use of step pulleys to control speed (if you aren't ready to invest in VS)... or - if you are using VS like me, but want hide the motor away - you have more options for motor placement with the belt-drive. That being said, I certainly wouldn't turn down a nice direct-drive grinder like Travis's TW-90. ;)
 
I think both styles are proven. With the belt hook up, there're many more motor options. Sometimes folks can get started with something they already have on hand or luck into for a deal. If you're worried that a belt won't transmit the power efficiently, maybe take a peek under the hood of your car. Tons of great setups out there, but don't scratch the KMG off the list because it uses a belt. Weigh all the features.

Good luck with it, Craig
 
Thanks for the input fellows, my main concern is the loss of power transmitted when using a belt, and added vibration of the shaft. I have everything I need to make the kmg run with step pulleys which is why it appeals to me.
Down the road I would upgrade it to a vfd as money allows. My current grinder uses a dc motor and vfd, I have found that I basically use the speed control on about 3 different levels and wonder if I would be just as happy with the step pulleys. Of course the speed control makes changes those speeds much nicer I imagine.
 
Last edited:
If you are upgrading, can you re-use your current motor and drive on the KMG? That would solve the step pulley issue...

There should be no real issue with loss of power from a belt drive, unless you really lean into the belt when hogging. And then, honestly, perhaps belt slippage is protecting you from yourself....or at least protecting your motor

Vibration is another matter...link type belts really help, as will using machined rather than cast pulleys. But it's a bit harder (and more expensive) to find machined step pulleys. Not hard to find single speed ones... Mass in the stand can smooth out vibration too, especially if it's something that can move a bit like sand or lead shot in bags or in the frame.
 
Thanks Mahoney those are some good ideas on the stand, and swapping out the motors. I will definitely make the stand to be filled. I plan on keeping both grinders although I could swap out the motors so the kmg would have the vfd. Doing so would make the other grinder a dedicated hogging machine as it really turns. It has a 6 1/2 inch drive wheel and coupled with a 2hp 3450rpm motor makes the dust really fly.
thanks again
 
The TW90 grinder is a square frame machine that has a direct drive. In my opinion it is the best of both worlds. The square design makes tool changes a snap and the traking and drive are unsurpassed. At first glance it seems a might expensive but if you take a KMG, Bader Or wilton and add up the cost of motor, vfd,small wheel adapter platten attachment and multiple workrests the prices equal out. the TW grinder also comes powder coated so no need to paint to avoid rusting. it also runs smooth and quite and the tracking is unsurpassed.
 
Bill I wish I could afford one, but unfortunately 3400.00 for a grinder is just not in the budget at this time. I agree that they are a fine machine, I drooled over them. I don't have my back up against the wall and could wait until I have the funds for the TW90. I have been weighing all options and the one thing I don't want to do is buy something that I am not happy with down the road. Thanks for you comments, I do appreciate your thoughts on this.
 
If budget is a concern, I just finished a belt driven Grinder In A Box. I already had the motor, so I think I spent arount 550 total. The belt gives plenty of power from the 2 HP motor.
Jason
 
You must log in or register to reply here.
Back
Top