Anyway, I was itching for some action in the shop to complete the leadscrew adaptor, but first, the mini boring tool holder has to be completed.
2 diagonal lines were scribed to mark the centre point at the end of the aluminium piece as accurate as I can using the 6" scale. The interaction was punched out to use as reference for the centre drill.
Being to lazy to setup the Sherline lathe, I removed the uncompleted leadscrew adaptor from the PD400 to work on the tool holder. The aluminium piece was clamped onto the compound using the QC tool holder and the centre drill held in the 3-jaw chuck.
To align the aluminum piece to the bed of the lathe, I put the Sherline drawbar in the Jacob chuck on the tailstock and line up the aluminum piece with the shank of the drawbar as close as I could.
The punch marked end of the job was then centered using the centre drill in the 3-jaw chuck.
The 4mm hole was drilled to about 20mm deep.
The mini boring tool is tested in its new home. It was rather tight at first but after some deburring, it slides in freely with no visible wobble.
It's time to drill & tap the 2 holes for the setscrews to hold the tool in place. The Proxxon edge finder was employed to locate the 2 edges.
The first hole was drilled.
And tested with a #10-32 setscrew.
The 2nd hole was done next. If you observed from my past posts on drilling & tapping, I tend to complete the entire process for 1 hole before moving on to the next. The right way may be to finish all the operations on 1 tool before going on the next, but I don't have the confident in getting back to the first hole after moving the dial. I may give that another shot to see if I can get the repeatability I need.
Anyway, the completed tool holder:
The tip of the boring tool was then adjusted to the lathe centre height in the QC holder using the tailstock centre.
Now I'm ready to go back to complete the leadscrew adaptor.
The compound was set to 15-degree for the 30-degree include angle. I find it rather cumbersome to have to crank the compound almost all the way out each time to set the angle. But I've no confident to implement the modification done by others on their 7x14 lathe at this moment.
The adaptor is put back into the 3-jaw and the boring tool in position to start the taper cut.
The cut completed. The tool was advanced onto the hole using the dial on the compound. The cross slide was adjusted after each pass on the compound to widen the taper hole.
Comparing the stock adapter from Sherline with the piece from Wongster's Production (Lolz...).
The hole looks wider that the stock. This is the cone tip on the leadscrew which I'm using to test fit.
Testing the new adaptor.
Perfect! At least at this stage.
I tested it next on the manual lathe with the 2 flange bearings loaded.
With the handwheel installed.
The next piece to complete the assembly will be the bearings holder that replaces the black one on the above pic. The 3 bearings will be mounted into the bearing holder from each side. The bearing holder was drawn up as a 3D model and will be the job for the next session.
I'm rather please with what I achieved in the last 2 sessions, especially with the tool holder for the mini boring tool. I did a lousy job in my attempt previously when making one for the A2Z QCTP.
Someone asked me sometimes ago why I am always making either tools or modifications to my machines but not some "end products". I thought about that and concluded that I do not have the required skill or knowledge at this point in time to start on what I want to make - clocks. All the little things I did and planned to do (or failed trying) are providing me with the needed experience and practice. In time to come, I believe I will.
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