Hi Guys,

I had need to hone/sharpen a miniature lathe boring bar recently ! I had seen an internet post some time ago of an easy to make honing/sharpening guide for lathe tools. So rather than simply copy the article I set to and made my own version.

Up to now I had just used simple guides to sharpen lathe tools on the double ended grinder. Whilst this is satisfactory for the most part, getting an accurate angle for a threading tool or a square ended, cutting boring bar. In my case a very small hole bar, needing a sharp flat end to cut a flat bottom without breaking the bar off at the bottom of the hole.

The post of an article on an adjustable hand held device that was used by rubbing the tool bit on a diamond plate or wet & dry paper fit the bill.

The device allowed adjustment of all the angles necessary to perform sharpening and honing of the cutting edges of a lathe tool.

11-03-2024-001.jpg

This picture shows the guide with a 4 mm square HSS boring bar in place. The two large screws have knurled and pinned steel knobs attached to the M10 plastic screws. These screws allow the body, made from nylon 60, to be angled both left and right, also allowing the block to be tilted to the desired angle.

A plastic M6 screw allows a lathe tool to be clamped in place. The alloy plate has a slope machined on it to match the slope cut into the nylon block. The two smaller M6 screws are used to clamp the alloy plate down on to larger tool bits. I placed a 6 x 20 mm thick washer underneath that can be removed if needed.

11-03-2024-003.jpg

This view is from the back. You can see the slope cut into the 25 mm thick nylon block and the spacing washers under the alloy clamp plate. That slope is machined at 30 degrees matching the one machined in the alloy clamp.

11-03-2024-002.jpg

This is looking at the underside. You can see the two large M10 plastic screws protruding. These screws allow the block to be set at the angles desired to match the lathe tool. I turned 60 degree points on them, simply to make them slide on the glass plate that I used, more easily.

Clamp plate.png

I made a drawing of the alloy clamp plate, showing the side and front views. All the holes are either threaded M6 or 6 mm clear. I initially drilled all holes as 5 mm and then opened the two clamp end ones to 6 mm after I had used them to set the hole positions on the plastic block.
Attached Images




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