Project updates

Posted at 2017-05-14.

I thought I'd list some recent things that I haven't really documented properly.

Another knob

My brother brought me some brass and bronze. Bronze is for some bushings once the old ones are dug out for the dimensions. I turned another little knob for him from the brass. It's probably for the throttle lever of a tractor. This time I drew a quick FreeCAD model based on the dimensions and played around with the curvature of the end to get a suitable taper angle that would hit the diameters at both ends.

This time I sacrificed a bit of the 10 mm EN1A FMS to make a stub arbor and put a small shoulder and an M6 internal thread on it. I also took a bit of threaded rod and turned the ends down to work as a stud.

I hacksawed off a bit more brass than was needed and then faced and centre drilled it and drilled and tapped for M6 a little way in. The brass could then be mounted on the arbor and held in a collet.

I set the 99 degree compound angle and turned the taper and used the dials to roughly shape the end. I still don't have a ball turner. The end ends up a bit rough and I decided to try hand turning. The plain Compact 5 comes with a chunky steel toolholder block that isn't far below center height (maybe 8 mm). I used that and some shim block material as a rest and a graver I made for the Taig some time ago out of 4 x 4 mm HSS.

The finish from the graver turned out surprisingly nice (for me) and I decided to sweep it a little with some steel wool. It ended up very shiny, but there's still some waves that I think are left from the uneven compound slide movement. I should have filed the taper or used a shallower or rounder tool on that or cut deeper with the graver. Anyway, the piece was accepted and will probably be drilled and tapped to a larger size and depth to fit its place.

Of course I entirely forgot to take pictures before giving it away.


I also got some sample pieces of plastic from a nearby dealer and ordered some more EN1A. PET is just a dream to machine based on some quick tests. Even nicer than POM (Acetal/Delrin). Both are much nicer than PA6 (Nylon). I also have some PTFE and PE and some fiber phenolic sheet (might not be far off to call it Bakelite).

There's also some metal for a new Taig mount, but that will take some more planning to make sure there's room for the belts and wheels with a suitable swing for the motor as a tensioner. I'm trying to keep it compact.

Gear cutting

I ordered some reasonably priced module 1 gear cutters. I thought I would just make a suitable arbor for them.

I realised I have an arbor for the slitting saws and that might do with some nose washers. Alternatively I could make a completely new one.

The plan, in order of dependency:

I didn't have the materials at hand to get far yet, but I used some structural steel bar and brass to make an arbor and cut some teeth on a bit of PA6 scrap. The arbor was an interesting expiriment since it's my first single-point inside thread (M14x1). It would need to be made from heavier stock to have a good register at the top and the cutter hole is even bigger at 22 mm.

The dimensions on the test wheel aren't right because I didn't bother to set up and turn the piece down to right outer diameter for the wheel. Nylon is also very annoying and stringy and the edges need a lot of deburring. I'll try with POM next once I get the new arbor done. Easiest way to get the dimensions is probably to take measurements of a wheel generated with FreeCAD. So far I think I've proved that cutting is possible for me.


I upgraded my networking somewhat and the wifi no longer sits inside the steel cabinet where the uplink is. Signal is much improved.

The old tractor is running and we didn't do much about that.

For Go practice, I sketched a bit of helper to scale and archive pictures easier. Maybe it will mean some more visual pages here.

Meanwhile, outside it's snowing in mid-may.