Grinders

Gorton 375 Cutter Grinder

Gorton 375 Cutter Grinder

In late 2006, I found a Gorton 375 single lip cutter grinder selling on eBay for a surprising low price, around on quarter of what these machines typically command. I could not pass up the opportunity to acquire a floor-mounted unit for a price typical of the smaller bench-top machines. This is not a glamorous machine, but it does a very good job of making single lip milling cutters. I also use this grinder to sharpen end mills.

T0717-7 Tool Head
T0717-7 Tool Head
 

The standard T0717-7 Tool Head uses 4NS collets to hold the tools, and I made a few square collets so that I can sharpen lathe tools as well. This worked so well that I designed and made an attachment to sharpen larger bits, up to 1 inch square.

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Lathe Tool Holder: Side View
The top cap screw allows 5° rotation for side relief.
The two side cap screws hold the bit being sharpened.		 Lathe Tool Holder: End View
Inverting the slot places the bearing above the holder,
allowing the holder centerline to align with the pivot.
 

What I like

  • This is a precision machine with great flexibility
  • Grinding produces excellent finishes

What I dislike

  • The flaring cup wheels that I've used quickly overheat the work.
  • There is no good stop on the main pivot. I've been using a cap screw, but someday I will make an appropriate adjustable stop

Problems

  • The on-off switch was installed in an undersized box and the cover would not fit properly. I replaced the box with a more appropriate one.

Other comments

  • I want to make a drill bit grinding attachment to handle larger drill bits.

Lisle 91000

Lisle 91000

I spent several years looking for a good drill bit sharpener that I could use on larger bits. Although my Drill Doctor suited my needs for smaller drills, mine is limited to 3/4 inch bits. In early 2013 I found this Lisle 91000 for sale on eBay. I was already packing to move when I won the auction, so I had no chance to test it until Christmas that year. Although the machine's rated limit is 1-1/4 inch bits, I was able to sharpen a chipped 1-1/2 inch core drill successfully. That is probably about as large a bit as the machine can handle. Since I have a few larger bits (nearly 2"), perhaps I can make an attachment for my Gorton 375 to handle them.

Done