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:

Die Holder

I have no way to hold dies on the lather. I have just bought a collet chuck for the lather tailstock so it seemed sensible to try to make a die holder for the collet chuck. The collets I have only go to 20mm and the dies are 25mm, so they can't just go in to a collet.

One end was turned to 19.5mm so it will fit into a collet. The other end is bored out to hold the die.

The final die holder has four tapped holes around the edge to hold and align the die.

I have some smaller screws coming...

Vice

Up until now I've been using a large vice that I bought to use on the drill press. It's just too big though, and uses up too much of the Z axis travel when milling. So I bought a small machinist vice.

It's a quick release vice and is tightened by the knurled knob. Tightening by hand isn't enough to firmy grip, fortunately there's a hole for a bar in the knob. Unfortunately one wasn't supplied. Fortunately I had some bolts so I made a tightening bar:

It was a good chance to try out my new knurling tool. The knurl came out OK, but didn't quite mesh properly on the larger diameter.


The bar works well though: