The carriage lock is then engaged, and case that needs trimming is inserted into the bushing by hand. I used a scrap of aluminum, angling it at 30 degrees and then adding a V to the 30 degree face.
The bolt has a stainless hose clamp brazed to the head, and is used to hold the form fitted case bushing. I came up with a crude scheme which works for making a small number of dovetails. I didn't use lock nuts, just a bit of dental floss in the threads for friction to simplify adjustment. Once the fixture is assembled and mounted on the lathe compound, the process of alignment and trim length adjustment is started.
T slot fixture retracting tool holder is a combination boring bar holder and threading tool holder which includes retraction as well as flip up to allow easily inspecting the bore being worked on. The trimmed length never varied over a couple of dozen randomly picked cases by more than 0.
The bottom holes of the Incra T-track are not countersunk, so we recommend that you use 3 mm panhead screws to fix the T-track in the slot of your worktop. The tangential is different than normal QCTP toolholders because the bit is so close to the toolholder, making it harder to see from some angles.
The carriage is adjusted to bring the neck of a case inserted into the bushing to a point where it is almost touching the end mill.
To complete this tool holder family a tangential will be needed along with more holders for normal bits. I placed a Phase II toolholder in the mill's vise and positioned the stopped dovetail cutter so it touched one side of the dovetail, then set the mill's horizontal stop for this point and similarly for the other side of the dovetail.
I much prefer the original design so eventually I shimmed the Rockwell QCTP up to match the 7x12 so all my holders now work on either lathe without tweaking height. File the corners as needed if they interfere with the fit; I found that looking along the length of the dovetail with a light at the opposite side helped to detect any interference.
Experience showed that it was difficult to see the bit in use so the area above the bit was milled away to improve visibility this could be done more elegantly with a tilting vise. It is possible to make toolholders with a mill, given a dovetail t slot fixture. This required adding a hole to Cleeve's grinding jig with a 7 degree angle, of course.
The mill's vise is precise, allowing this trial-fit technique to work nicely; of course, the holder being machined was re-installed in the vise with the same orientation each time.
The frugalmachinist had the answer for both the dovetail cutter and the toolholders. Dovetail Cutter The cutter was turned from a 1. My retracting tool holder a variation on Cleeve's design is shown under construction, where the major pieces are partly complete.