Parting Tool Holder Mod

So a while back I decided I'd had it with HSS parting tools and picked up a SECO indexable blade. Unfortunately the tool holder I had, even though this is a larger KDK size, wouldn't hold this size parting blade.

What to do?

Note: the piece of shim stock is in there for two reasons. First, I only had a .125 end mill and the blade is actually something like .115 wide. I also have another blade that is .125 wide and takes slightly wider inserts...so this will hold both blades.

Here is the original blade clamp. Time to make a new one. I squared up this chunk of steel (bottom) to make a larger clamp.
Here I'm setting the dimensions by measuring the height of the tool holder.
A quick scribe and some work with my 2" indexable face mill got it down to size.
I forget what I'm doing here but I found some tricky way to measure the position and width of the blade slot.

Next I had to drill and tap the holes for the mounting screws. I clamped the new holder blank and the tool holder at the same time.

Using an over size drill bit I "roughly" located the existing holes by adjusting the table and working the quill up and down until I couldn't feel any rubbing on the drill bit.

Then I swapped out the right tap drill size and...drilled and tapped.

This is the bottom of the clamp and you can see the clamping screws juuuust shy of sticking out. Since there was a lot of extra depth to my larger clamp, I needed to cut some clearance to it didn't hit the top of the compound when it was mounted.

I just eyeballed it, test fit, and then milled some more off.

You can also see the little lip that allows for the clamping action. I measured this off of the existing clamp. It was pretty important to get the depth right so the clamp wouldn't bottom out...and thus not clamp. Clamps that don't clamp aren't very useful.

I know some people swear by HSS, but an indexable parting tool is the only indexable tool I'd own if I was limited to one. It will part anything, no questions asked.