A wooden cue with a brass collar to which an aluminium extension has been addedA friend has a pool cue which converts to being a walking stick, by unscrewing the top and taking out the front part of the cue, then screwing that onto the front. The bottom of the walking stick part has a thread that needs protecting, and the cap is what hits the ground. The stick is too short for my friend, so I’m making a longer cap.

The thread on it is 3/8″ 12tpi. For those who don’t know threads, this is a weird size. It’s made for brass, which is brittle, so it’s a very coarse thread. I had to get expert help in sourcing s new tap to cut the thread.

Project: Itchy

I have just been given a lot of aluminium profile. I want to make a cnc router to allow me to engrave acrylic sheets and cut lino. The lino cutting will be the easiest problem, as it just needs a 2d movement and some human setting of the x axis. Plus a lot of glue.

So, the first thing I need to know is how the heck to build it. I don’t want to move a plate under a fixed head, if I can help it, as that makes the entire base way too big, and I don’t want to take up too much space. If I wanted to engrave an area a x b I’d need twice the run, 2a x 2b, to go from left to right. Given I might create big stuff, it’s too large for storage, and too clumsy, and I don’t want to move the platen. I think it’s called a platten. I don’t know how to spell that, so I’ve tried both ways.

So, I’m going to have to move the head, which means linear bearings and stepper motors. And stepper drivers. There should be plenty of explanations out on the internet, and I just need to find an explanation that isn’t geared to solutions I’m not using.

On the internet.


Making a better pen – success 1

A dip pen, showing the nib, a length of brass, and then the wooden handle.I nabbed some more apple wood from the same tree/friend combo, and this time I used a Stanley knife to pare it down, which was much easier than the pocket knife, both in sharpness and in the shape of the handle. I went through the same process as before, but this time I formed the far end before I started sanding down the wood closer to the join, to make sure it stayed strong there. I also sanded the brass with the fine soft pad, and then I squeezed hot glue into the brass fitting. Then the ferrule wouldn’t fit, and I had to bang it in with a hammer, which meant I had to scurry for a hammer. However, nothing broke, and now I have a pen. It’s a snug fit for pen nibs, but I’m OK with that. I’ve bent the inner springs a little bit to help the fit, and it’s all good, and I have no problems. I’m pondering making a two part top, with bits that fit inside each other, so I can get rid of the need for steel. That’s a long way away, though.

I’ve given it a coat of varnish, and I’ll give it a couple more. That’s to protect it against the horrible mess inside my pencil case, mostly. I’ll also make sure the join ends up full of varnish, so no moisture penetrates.

Making a better pen – failure 1

A brass cylinder with a wooden handle attached.  The wood has split.I nabbed a bit of apple wood from a friend. It’s soft, but that means it works easily, and I don’t have real wood-working tools, so I’m in favour of ease. I cut it to length, skimmed it down with my pocket knife to take the bark off, and drilled into the top to put the handle in, which I did with hot glue. (In case of failure. As it turned out, I was prescient.) I then carved it down further so it was almost the right size to hold, then I sanded it. I did that with a soft pre-bought sanding block, so the handle could sink in a bit. First of all I taped some rough paper over it, and clamped up the block. Then I put the metal into my drill, and went ‘vrooom’. I used the 120-ish grit to tear off most of the surface, then switched to the less brutal surface, and smoothed it. However, after I thought I was finished, I noticed my knife had left a splinter inside an otherwise innocuous dent, so I put it back in, pressed too hard, and shattered the shaft at the bottom. Pants.

I have acces to more apple wood, and I can use that. If it fails again, I’ll have to use something much harder. A friend offered me some rose wood and some lilac, and I could try either of those.

Making a pen

long aluminium cylinderI set out to make a simple dip pen. The ferrules are relatively cheap, and I don’t like the way wooden pens soak up ink and water, and split. Plastic feels wrong, and it’s too light.

I found a bit of aluminium rod that was about the right length, and squared off both ends in the mill. I used the lathe to bring it down to a comfy width, as well as put a shine on it. Because the rod was short, I had to reverse it, so there was going to be a shoulder. I made a feature out of that by notching where they met instead of trying to match exactly. I added a couple of other decorative notches as well.

The ferrule sits in a 1/4″ drilled hole, and I did that in the lathe as well, with a rather battered bit. It had been ground down to chip brass better, I think. However, it worked pretty well. Then I glued it in with araldite. It occurred to me afterwards that I should have used hot glue, because when the ferrule, which is steel, rusts, I’m going to want to get it out of there. Hot glue sounds ideal for something where metal would be involved, and the coefficient of expansion isn’t a problem in removal because the steel sheet is so thin. Whatever material it’s in, it should come out with a bit of force.

Sparky – resistor array

Sparky’s first spark-board resistor was 100ishR, 1/8W, and the magic smoke escaped instantly. The second was 50R, a couple of orders larger in wattage, and much much bigger, and made of metal. After we’d been running the spark table for a while, there was a wisp of smoke from the table, which was starting to melt. So we found four of those in an array, and we wired them up to give us 50R, and they get uncomfortably hot to touch. They’re mounted on an aluminium plate.

Today, Mat converted a lump of car radiator into a heat sink, drilling and tapping all the holes necessary to fit five waaaay chunkier 10R resistors on so we can wire them up with crocodile clips. If we need to water cool them, we can borrow some resistors from someone I know who worked in sound. If /that/ fails, he was telling me about spikes and power switching, and that’s a spare thought. However, this array ought give us a good range from 2-50R, depending on how we wire them, and if 2 Ohms doesn’t set fire to anything, we’re likely to stick with that.

Today, I helped by making tea and not getting in the way, and as a san-check on the positioning of the drill holes, and I also learned a bit about clamping. Mat helped by doing all of the work, and not fucking it up, and also by making tea.

Go to L – milling experience

A cog with a slit and an L-shaped piece that fits the slotWhile waiting for client feedback, I came across a couple of people (F. and J.) who were picking apart a broken mechanism, but couldn’t find an easy way to fix it. It had some 3D printed parts, and the ABS had twisted apart, and was jammed inside because it had a flared end. So, I milled down some plate steel while J. drilled out the broken plastic and worked out how to keep a spring out of the way, then we fitted the steel key. In place of the flared end we put in a notch and wired the steel into position. The top needed a star shaped meshing mechanism, so I cut that out of plywood on the laser cutter.

The steel cut pretty easily, but I had to be careful with the vice, as it was thin and I got to the point where I couldn’t safely hold it, and we were very lucky that was a perfect fit for the mechanism. I could take off a 1mm step with the 16mm end mill, and I did that repeatedly, with lube, and it works just fine.

We need more molyslip.