Lamy Pico Fix

My Lamy Pico pen

that goes everywhere with me broke recently. It had been sticking when telescoping it, but I hadn't realised why. I thoughty there'd been a build up of fluff or something, but it turned out that the end had broken. You can see on the right hand side of the pen that it's at an angle. the thread has broken on the part that is unscrewed when replacing the refill. This is a shame. I could get it repaired, but even then it's likely that the same thing would happen. So I decided to have a go at making a new part.

I dismantled the broken part. There's a spring and a sliding part that holds the refill. The pen telescopes, so there's quite a bit of movement of the refill.

I realised that I could re-use these parts, although I have ordered some bits and bobs if I want to have a go at completely replacing them.

This is the sort of job that I got a lathe for, so I found some brass rod, and machined a replacement part from solid brass.

I took dimensions from the original, which gave me a starting point. The thread was 11.4mm x 0.8mm pitch, if anyone wants to do this themselves. That thread fits nicely in the barrel of the pen. I manually adjusted the part to make it work with the telescoping mechanism. This was a bit tricky as it didn't work too well at the start, but by removing small amounts of material I got it working as well as the original.

I used abrasive paper and a burnish to finish the outside, and it fits well on the pen:

I added the radius on the end using a file on the lathe. I have no radius turning tool for my lathe.

The pen when in the extended position:

The extra material is noticeable, but not unpleasant, and the brass is nice and shiny. I may remove the paint on the pen to match the new part, or I may not. I'm undecided at the moment. It may be a good idea as it is wearing off anyway in places, so would be neater if removed.


I've done a video of this, if you want to see it moving:

Tail-stock Stand

I have a mini lathe and it came with a tail-stock. This is removable and I use the lathe without it quite often. It spends most of its time on a bench somewhere, or propped up against the back of the lathe. The design of the tail-stock means that it can't stand up in it's normal operating orientation and so has to lie on it's side or lean against something. This started to irritate me. I thought of a shelf, then decided to make this:

 The tail-stock rests in it like this:

I then mounted the stand on the side of the shelf unit I built around the lathe:

It's now in a space that I couldn't really use for anything else. We'll see how good an idea this was as I use the lathe for future projects.

Vortoscope Sort Of

Vortoscope (Sort Of)

The vortoscope is an optical attachment for cameras which is similar to a kaleidoscope. I want to try to experiment with  one of these, so I decided to build a copy of the Leica universal polariser part that attaches to the lenses on the front of my M8.
The attachment is a circular ring that attaches to adapters that screw on to the front of each lens.

The basic ring:

I drilled some holes that will be used to mount various  front arrangements.

The first front attachment is a 3d printed holder for a prism from an old pair of binoculars I dismantled years ago.

The thumbscrews are used to  attach this assembly to the lens adapter disks. Using different 3D printed adapters I should be able to attach various different optical adjusters...

Bergeon Platax Punches

Bergeon Platax Punches

I've been gathering watchmaking tools for a while as they are useful for making small things, and especially useful for fiddling with watches. I have a project watch that I want to work on and having the right tools is always a good idea. One tool I recently bought is a Bergeon Platax tool which is used for dismantling balances.

Unfortunately one of the punches that it came with was broken, so I decided to make some more. These are not easy things to make, as they have various holes in the end of 0.1mm, 0.15mm and 0.20mm.

I used 3mm silver steel for the punch body, and some EN1A rod to make the stop rings. I'm using the CNC engraver/mill to drill the holes in the end of the punches using carbide drills. I created a tcl script that writes gcode with appropriate feed speeds and pecking cycles. It took a few attempts to find something that works, but I seem to have that now. And a pot of broken drills... The results are pretty good:

That's mine on the right and the original on the left. This is the broken 0.20mm punch on the left. The hole is about 1mm deep, I've no real idea if that's the correct depth, but it seemed to work on the balance I had a go at dismantling. The silver steel isn't particularly hard, but then, if it wears out I can make another punch...

One problem is the accurate positioning of the hole in the end of the punch. I think I may have to build some sort of something that I can use for positioning the CNC spindle when making small things. Trying to do it manually by poking me head round the spindle just doesn't work very well.

You can see the hole here, and the fact it's a bit off centre:

I've also ground a used D bit down and used it to create the rounded edge to the hole that the original Platax has on its punches. I may have to do something more accurate for that too. Somehow.

Second DRO Gauge

The second gauge has been fitted to the lathe. This one was a cut down 'hardened stainless' gauge I got off ebay:

I'm not sure what was hardened or stainless, this machined like butter on the mill. I'm not complaining, it made my job easier.

The mounts are 3d printed, the gauge display unit fits neatly into the metalwork, I added a copper shim to remove the last 0.1mm of movement, now there's no measurable movement.

This metal gauge works better than the plastic 0.1mm resolution one I put on the compound. Even though you can get 0.01mm resolution on the data output, it doesn't stay very stable.  I think I may use one on the compound as well, if I can buy one. I'm going to experiment with other calipers, I need another 4 for the mill and the gauge on the lathe ways.

DRO Displays

The displays for the axes of the DRO are going to be LED digits. I have some modules that use the MAX7219 chip and have 8 seven segment digits plus decimal points. One Arduino UNO and some code and we have a trial display:

So now I have a display and a gauge attached to the lathe. I thought it would be a good  idea to check the DRO gauge and see if it would be useful. It's not worth going through the hassle of building all the gauge channels if it doesn't work very well.

The first attempt was OK, but the gauge didn't slide very freely. Some adjustment of the gauge mounts might be a good idea. After some gentle filing the gauge freed up and all worked quite well.

I set the lathe dials to zero and the gauge to zero as well to check the calibration between the two measurement systems.



After moving a distance from the zero, I noticed that the gauge didn't match the scale. I finally found that when the gauge read a round number of millimetres:

The scale on the handwheel isn't at zero. I was about to give up on the DRO until I noticed that the ball on the handwheel was in the zero position.



So the dial had slipped when moving the handwheel. It looks like the DRO was more reliable than the dials in this case. Looks like it is worth continuing.

Pocket Watch

I am attempting to make a new spindle for this watch:

The spindle attaches to the knob that is used to wind the watch and also set the time. It drives the movement with a square end and has a threaded end that the knob screws on to. At some time in the past someone has opened th ecase and hinged the movement out without removing the winder and it has snapped in half.

I've attempted to find out what the thread is on the knob end, and it seems to be 10BA. So I bought a die and tap set for that thread. Unfortunately it didn't fit in my die holder. So I made a spacer for it on the lathe:

I have made a first attempt at the spindle, which was tricky as I didn't have nice easily machinable metal in a suitable size. I managed to make the spindle minus the thread, and unfortunately broke it in half when I attempted to thread the end.

Attempt 2 next...

Microscope Reflector

A few months ago I bought a couple of old microscopes from a junk shop. They were pretty cheap, but the carriages were seized. I managed to free them up and they work nicely, but on one of them the mirror used to reflect light onto the sample was missing. It was a simple disc shaped mount, so I turned one up on the lathe:

The metal is shiny enough for this to be good enough to use without a mirror. i may cut a piece of mirror to fit, or, more likely, I will add some form of LED illumination. Messing about with a mirror is a bit of a pain anyway.