Simple horizontal grinder

Hi PT Doc, I do not understand your question but thanks for the compliment. Larry
 
Larry, you did good with the grinder - I'm in the final stages of a KMG clone with 2hp 3ph and a cheap Chinese VFD. I've been impressed how much smoother and quieter a direct drive is than with pulleys. I'm still working out the vertical to horizontal flip - you did a good simple method.

Ken H>
 
JG, I was wondering when someone would comment of the gunpowder behind the grinder. I am fully aware of the danger and have not ground so much as a pine stick with the grinder. I just finished it and took a few photos. I just bought all that powder from a man who wanted it gone and it will be put away this week.

PT Doc. The original grinder design had the pivot hole inward of the center of the bar and a long spring was fastened to the end of the arm and the base of the grinder frame. I read that a lot of grinder builders had trouble with the amount of tension on the spring and had difficulty getting it right. I then saw a photo of a grinder where a hole was drilled at the back end of the arm which also put the tracking wheel location quite a bit further from the pivot. I thought the tracking arm would have some play from side to side that way. Lastly I saw a grinder with the arm reversed and the handle hole was enlarged for the pivot and a new hole drilled and tapped for the handle at what used to be the rear of the arm which puts the tracking wheel close to the pivot which I liked. I also drilled a 9/16 hole for the pivot because the laser cut parts were so rough. The grinder tracks perfectly now but I have only tried two belts . The machine is steady though . I can't take full credit for any of the mods I made to the grinder.

Ken H, My main grinder is a KMG which I wouldn't trade for anything. If you absolutely don't have to make it horizontal then I think there are some benefits to using pulleys and a jackshaft. Number one is that you can use a four pole 1725 RPM motor . The guys that know everything about motors have stated that the 1725 RPM motors are better in some ways than the 2 pole 3450 RPM motors like I used on this grinder. The second advantage is that it is easy to put a 5 inch pulley on the motor and a 2 1/2 pulley on the jackshaft and double the 1725 RPM speed to 3450 RPM and have the power to select a 3 1/2inch, a 4 inch, or a 5 inch drive wheel to get the surface feet per minute that you desire. These supposed advantages may not be that important (and probably aren't) but most us type of guys like to plan the heck out of everything and theoretically build the very best machine. I have seen A KMG with a direct drive motor where the jackshaft used to be and I have seen a KMG with a direct drive motor right under the tool arm. If you flip the KMG clone you still have the problem of how to configure your tool rest which is a major concern in my book. I would use the jack shaft method and hold your blade vertically to profile the underside.


Thanks to everyone for the comments. If anyone is going to build a Polar Bear forge/GIB/EERF type grinder send me a message and I will tell you what the surprises were in putting the thing together and try to help if I can, Larry
 
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