Grinding Wheel Kit 505874 for Mortising Bits

[edma194]

I have the Shopsmith Mortising tools and bits along with this Grinding Wheel Kit that I assume is for dressing the bits. Anyone have manual/documentation for using this or for the mortising system in general? I think it's all self explanatory but I'd like to see if there's any important notes about the sharpening process.

[chapmanruss]

Hello Ed,

The Grinding Wheel Kit is for sharpening the Mortising Chisels. The old kit came with 2 mounted stones (white and pink) of different angles for the Chisels. It's the one you commonly see for sale in the clear plastic tube with red end caps. Newer Mortising Chisels have a single angle and use a different angled stone (gray). I don't have a specific information sheet for the stones and which uses which. I do have that information with my Mortising System itself but unfortunately it is still missing since moving. I do have the Mortising System 555810 instructions (845513 Rev. 1/01) which is 8 pages long and another older 2-page instructions 505623 (Article No. 84-3450) from 5/79. Neither includes sharpening information.

One of these days I hope to find the missing Shopsmith items.

[DLB]

Scott at My Growth Rings did an instructional video (https://www.youtube.com/watch?v=89TwGU8U0Ss) on the SS mortising system that included dressing the chisels. A standard caution for grinding any cutting edge is be careful not to overheat the edge, potentially degrading the temper. Hollow chisel mortising is not a function I love on the Mark series, it puts a lot of point pressure on the table system. In fact in the video Scott also tests an aftermarket DP handle and bears down on the chisel using two longer than standard handles.

- David

[edma194]

Scott at My Growth Rings did an instructional video (https://www.youtube.com/watch?v=89TwGU8U0Ss) on the SS mortising system that included dressing the chisels.

Thanks. I thought he had video on this but couldn't find it. So I have the old style chisels. I've had these chisels for years and never used them because it didn't seem like a great way to cut mortises. Not even sure I'm going to use them now, maybe just get a corner chisel and square an already drilled hole.

Maybe a corner chisel that mounts in the mortising bit holder could use the quill feed to drive it through a drilled hole. One corner at a time would require much less force but would need to be rotated and repeated for each corner.

[chapmanruss]

Ed,

I think David gave you better information if you watch Scott's video than what came with the Grinding Stone kit for Mortise Chisels. I have tried using both the old Shopsmith Mortise Chisels and the Japanese Type Mortise Chisels and Scott is correct the Japanese Type Mortise Chisels cut better and easier.

Before trying a Corner Chisel compare the price to the Japanese Type Mortise Chisels. There is less chance for error with the Mortise Chisel than squaring out the hole with a corner chisel.

As for sharpening them I would use a way like Scott described of putting the stone in the Drill Press with the Chisel held in a block to keep things straight in line. Free hand can be less accurate as seen in Scott's video not being able to keep the stone directly in line with the Chisel. Besides another use for the ever so versatile Shopsmith.

[edma194]

Before trying a Corner Chisel compare the price to the Japanese Type Mortise Chisels. There is less chance for error with the Mortise Chisel than squaring out the hole with a corner chisel.

I'm probably going to get a corner chisel anyway, they have a lot uses. Right now I'm looking at squaring out round thru holes 1/2" or wider. I have chisel parts from a cheap mortising set so I might try using the 1/4" mortising chisel to square out 1/2" holes. They're pretty low quality, don't have the bits for them, so don't care if I wreck them.

All be easier if someone made square drill bits

[jsburger]

Before trying a Corner Chisel compare the price to the Japanese Type Mortise Chisels. There is less chance for error with the Mortise Chisel than squaring out the hole with a corner chisel.

I'm probably going to get a corner chisel anyway, they have a lot uses. Right now I'm looking at squaring out round thru holes 1/2" or wider. I have chisel parts from a cheap mortising set so I might try using the 1/4" mortising chisel to square out 1/2" holes. They're pretty low quality, don't have the bits for them, so don't care if I wreck them.

All be easier if someone made square drill bits

That is pretty much what a hollow chisel mortiser is.

A note about sharpening. First, like any bench chisel or plane iron the chisels are not sharp out of the box. The stones do a good job, BUT... Polishing the four outside surfaces of the chisel is very important. Think of a bench chisel. Flattening and polishing the back is important in the sharpening process. The same is true of the chisel of the hollow chisel mortising bits. Once I figured that out the system was MUCH better to use on the SS.