Itchy: motor wires

I really hate crimping wires into DuPont connections. I tend to do it with pliers through hatred of the crimps in question, but that’s not serving properly. So, time to redo some of the ends of wires on Itchy. This time, without fucking it up.

On the other hand, randomised direction for travel along the Y axis is funny. But so is leaving bricks under hats on the pavement.

Itchy: X axis motor mount

Today I milled the motor mount for the X axis (as opposed to the motor mount which moves the X axis. I hate that nomenclature).

Ahem.

Today I milled the mount for the motor that powers drive along the X axis. It was a stepped piece to allow it to butt up against the aluminium extrusion of the axis. It has mountings to attach the motor and the two cable tracks, and a dip for the registering surface of the motor to sit in.

Because I am a numpty, it also has a dip on the opposite face of the plate, where the motor doesn’t sit. This came about in part because I was being taught how to clamp it so my mind was elsewhere, and in part because I was not thinking enough. I don’t k I would have got it right even given the chance.Today I milled the motor mount for the X axis (as opposed to the motor mount which moves the X axis. I hate that nomenclature).

Ahem.

Today I milled the mount for the motor that powers drive along the X axis. It was a stepped piece to allow it to butt up against the aluminium extrusion of the axis. It has mountings to attach the motor and the two cable tracks, and a dip for the registering surface of the motor to sit in.

Because I am a numpty, it also has a dip on the opposite face of the plate, where the motor doesn’t sit. This came about in part because I was being taught how to clamp it so my mind was elsewhere, and in part because I was not thinking enough. I don’t k I would have got it right even given the chance.

Balls.

Itchy: Google API and image search

Google’s search API is deprecated. For image searching, I used the Google Python CSE API client. That meant setting up my own custom search engine. For a perplexing long time I couldn’t get any decent results out of it, but then I blanked out the list of sites in which to search (I had google.com and nothing else) and, importantly, found a dropdown menu that gave me the option of searching elsewhere. So now I’m finding 0 results from my first tier non-sites, and then all the results that google can give me, from the second tier. It’s a strange way of doing it, and I couldn’t find it in any of the docs, but that’s how I did it.

Itchy: software and sobbing into my keyboard

For the Pint of Science festival, I’m paired with someone working in machine learning, primarily with text. He’s giving me the results of a search that finds common names – or sometimes fails to find things that are names, but look a bit like them. I use those for an image search.

I hate hell, all Capulets, and Google Custom Search API.

Itchy – no longer Wobblebot!

I now have parallel* twin lead screws to move the X axis. They are belt driven from a single motor, with an acrylic brace at one end and aluminium blocks at the other. I should really be tensioning them by moving the motor up and down, but that’s now gone to the bottom of the list after getting the software working, getting the cut-out switches on, and making the machine actually produce art.

*mostly parallel

Itchy – how the nuts work

I was going to make myself a tap out of steel and try to make an aluminium nut from it – after discussion I decided to make that a delrin nut. After further discussion, I used polymorph. And by further discussion, Roger came into the room ten minutes after I’d explained the problem to him, and said, “The other thing you could do…” and then I did what he suggested.

NB: do not use a drill to move the screw back and forth in polymorph to clean it out. It gets hot, and polymorph melts below 100 Celsius.

Fortunately it’s not hard to warm it up again and recast it. It’s all trapped inside a bit of inch square extrusion.

Iterating Wobblebot (and a side project)

I’ve laid the cable track, planned the new screws and bought another identical to the second…

So, as it turns out, not all lead screws are the same, even when they are supposed to be. The first one I bought has a thread that’s at the right pitch, and the right height, but the trapezium shape is too narrow. This was leading to a huge backlash problem, which I thought I would have to deal with by making anti-backlash nuts. However, the other lead screw, which I had bought thinking it was a pair, doesn’t have that. There’s more metal, and it fits snugly in the nut I have. That means there’s hardly any backlash at all.

I’m still interested in making the anti-backlash nuts, and I have other uses for a tap for that shape of screw, so I’ve ordered a length that I’m going to try to tool into a tap, with the lathe and the mill. Clamping it is going to be a right beggar – I might enclose it in a thermoplastic and clamp that instead.