Lyon
Well-Known Member
Hi all,
I finally got my new grinder built. I went with a 21 inch wheel for hollow grinding and added a KMG tool arm on the opposite end. My reasoning was that if I was going to build a variable speed grinder and invest in the motor and controls I may as well stretch my money as far as I could. My current grinder is a grizzley 2X72 so there wasn't anything that I could salvage for the new build.
The 21 inch wheel is a pair of 1 inch repurposed bandsaw wheels that have been rubber coated by sunray. My plan was to make it a convertible 2 inch or 1 inch grinding wheel. I am not done fiddling with it but it looks like that probably won't happen any time soon. I will need to get setup with a lathe cutter and true the wheel as it is spinning so that I can get it to run a little more true. I had made assumptions about the process that sunray would do when coating them and when looking at the wheel after I got it back I noticed that it wasn't as prefectly true as I had thought. In summary, I did save about $300 on the wheel vs buying a new one that size from sunray but it is going to take some extra work to get it like I would want. I did get the wheels usable in the 2 inch configuration with some shimming for now so at least I have that going for me.
Some of the design considerations that I settled on:
You will need to use a 2 X 132 belt. Because of the extra length over a 2 X 72 belt and needing/wanting a variable speed controller, adding the tool arm was a natural continuation. It only cost me an extra $15 for a forward/stop/reverse switch in the controller to change the belt direction depending on the side of the grinder I was working on. While 2x132 belts don't have as big of a variety of belt types it is still the second most popular. That being said they are not as easy to track down and will require some more effort to find the supplier you want and you may end up ordering from a couple of online stores to get everything you need which is what I had to do.
I went with an air cylinder for the tracking arm mainly because it sounded kind of cool. It also allows you to get a good range of precise adjustments for the belt tension. I went with a 3/4 bore cylinder which is too small so I will be stepping up to 1.5 inch bore.
Because of the length of the grinder and me being 6 feet tall without my work boots on there was no way for a bench mount to work. I was lucky to find a 10 inch piece of well casing for the post. The top piece is 12 X 34 X .5 inches and the bottom is 20 X 24 X 3/8 inch. I went ahead and bought them new vs dumpster diving at a scrap yard. The quality of the cuts are also WAY better than I could have done and that alone was worth the cost to me. I also didn't want the top to warp from welding or vibrate so I went thick which let me drill and tap directly into the plate for mounting the pillow block bearings. The bottom plate I drilled holes for a 7/16 bolt at each corner so that I could stabilize it vs bolting it down. Seams pretty solid so far :biggrin:.
I mounted the 1.5 horse motor under the top plate and stepped it down 2-1 so it has plenty of power and a max SFM of 4300.
Next week I will post up a pic comparing the grind vs a 10 inch wheel.
I finally got my new grinder built. I went with a 21 inch wheel for hollow grinding and added a KMG tool arm on the opposite end. My reasoning was that if I was going to build a variable speed grinder and invest in the motor and controls I may as well stretch my money as far as I could. My current grinder is a grizzley 2X72 so there wasn't anything that I could salvage for the new build.
The 21 inch wheel is a pair of 1 inch repurposed bandsaw wheels that have been rubber coated by sunray. My plan was to make it a convertible 2 inch or 1 inch grinding wheel. I am not done fiddling with it but it looks like that probably won't happen any time soon. I will need to get setup with a lathe cutter and true the wheel as it is spinning so that I can get it to run a little more true. I had made assumptions about the process that sunray would do when coating them and when looking at the wheel after I got it back I noticed that it wasn't as prefectly true as I had thought. In summary, I did save about $300 on the wheel vs buying a new one that size from sunray but it is going to take some extra work to get it like I would want. I did get the wheels usable in the 2 inch configuration with some shimming for now so at least I have that going for me.
Some of the design considerations that I settled on:
You will need to use a 2 X 132 belt. Because of the extra length over a 2 X 72 belt and needing/wanting a variable speed controller, adding the tool arm was a natural continuation. It only cost me an extra $15 for a forward/stop/reverse switch in the controller to change the belt direction depending on the side of the grinder I was working on. While 2x132 belts don't have as big of a variety of belt types it is still the second most popular. That being said they are not as easy to track down and will require some more effort to find the supplier you want and you may end up ordering from a couple of online stores to get everything you need which is what I had to do.
I went with an air cylinder for the tracking arm mainly because it sounded kind of cool. It also allows you to get a good range of precise adjustments for the belt tension. I went with a 3/4 bore cylinder which is too small so I will be stepping up to 1.5 inch bore.
Because of the length of the grinder and me being 6 feet tall without my work boots on there was no way for a bench mount to work. I was lucky to find a 10 inch piece of well casing for the post. The top piece is 12 X 34 X .5 inches and the bottom is 20 X 24 X 3/8 inch. I went ahead and bought them new vs dumpster diving at a scrap yard. The quality of the cuts are also WAY better than I could have done and that alone was worth the cost to me. I also didn't want the top to warp from welding or vibrate so I went thick which let me drill and tap directly into the plate for mounting the pillow block bearings. The bottom plate I drilled holes for a 7/16 bolt at each corner so that I could stabilize it vs bolting it down. Seams pretty solid so far :biggrin:.
I mounted the 1.5 horse motor under the top plate and stepped it down 2-1 so it has plenty of power and a max SFM of 4300.
Next week I will post up a pic comparing the grind vs a 10 inch wheel.
Last edited:
