Browsing the Internet I came across Mikes Workshop site and he had a few photos of his slotting tool.
http://mikesworkshop.weebly.com/toolpost-slotting-tool.htmlIt was clear from the pictures that he used the same type of quick change post that I have had. I had made an over-the-top ball turner using that post a few years back. A few months back I switched to a wedge type post, but I can still mount the cylinder post easily.
The main block would be perfect to make my own slotting tool. The main block has a nice concentric and aligned set of bronze bushings pressed in and the shaft of the ball turner slides very smoothly. Quick dis-assembly and yep, it was possible. Lo and behold, all the scrap metal needed was available.
No photos of the actual fabrication process as there is nothing special about it. Milled a slot in the end of the shaft, milled down the end of the lever to fit and made little hinge blocks to hold the lever.
At the working end I made a large holder with a range of inserts for different sized tools, from 16 to 6 mm. I also added a scriber. (Left in the photo.)
I used an Allen key as a cutting tool.
There was way too much flex in the thin ground down Allen key. That gave me an idea, the flex could be used to adjust the cutting depth.
New piece of 16 mm shaft (The hole in the holder is 16 mm) and turned down to 12 mm at the business end, as I had to make a key slot for a sanding plate I made and that was 12 mm. In the 12 mm diameter part I milled a slot of 4 mm wide (the ground down width of the key) at the top and further down widened the slot to 6 mm (the width of the whole Allen key). Drilled and tapped an axial hole for a 8 mm grub screw in the bottom part and cross drilled a M4 hole for the clamping grub screw.
In the top cross drilled and tapped a M6 hole behind the cutting tool head. I had to shorten the grub screw a bit as the head and the grub screw together we wider than the 12 mm diameter.
Installed everything and now I can adjust the cutting depth by adjusting the M6 grub screw at the top. It worked like a charm and the key slot was cut in no time. In fact, assembling the slotter took more time that using it. The M8 grub screw at the bottom can be uses to adjust the cutting depth as well, because the back of the cutting tip is curved. Screw it in and the head is pushed higher against the setting M6 screw and therefore is pushed out. It all is a very close fit and I think I will need to use a much smaller Allen key if I want to do a 10 mm or even 8 mm diameter shaft.
The nice thing is that I can still use the ball turner as well. I didn't do any big changes to the main body.
Lykle
