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Wednesday, 30 January 2019

Chocolate and Orange Hot Cross Buns vs Dualit Toaster

Toasters toast things, but when the things contain chocolate then they also melt things. This is fine if you eat chocolate infused thingies (I don't), but unfortunately when chocolate melts it also tends to escape. This happened in our Dualit toaster recently when some chocolate escaped onto the prongs that lift the toast up and down.

A quick cleaning attempt and I found that it was tricky cleaning those prongs as they are down in the toasting slots. No problem, I thought, I'll take the toaster apart and give it a good clean. Being a Dualit it is made to be repaired so should be easy to dismantle. A bit later and I found that yes, you can take bits off, but not all of them. Irritatingly the bits that need to come off to free the prongs have been pop-riveted into place. This meant that I'd have to modify the toaster to get the prongs out.

So modify it I did.

The pop rivets:

were drilled out and replaced with  bolts:

 This makes it a lot more fiddly putting the bits back together, but at least now I can get the prongs:

 out (and back).

 All cleaned and re-assembled:

I think I'm going to investigate threaded inserts for the two bolts I added (and maybe some others that are a pain to fit) and try fitting them the next time I do a deep clean.

Thursday, 17 January 2019

A New Hat? For an Owl

A coworker brought this in recently. It's an owl that hides a tape measure.

The end of the tape had a bent piece of metal pressed onto the end. This eventually fell off:

I made a new end out of machined brass sheet. It's a clamp and some small M1.6 bolts clamp the end onto the tape:

 Another property of the end, apart from just being on the end, is that it is a fixed distance from the marking on the tape so it needs to be pretty accurately at the 0cm point at the end of the brass. tape measures aren't massively accurate as the tape stretches and so on, but the new end is pretty close:

The other job (perhaps it's main job, really) of the end is to stop the tape from disappearing into the body of the owl when it is fully wound in. This it does well, probably better than the original:

Is that a hat? I'm not sure what owl's have on their heads, probably nothing. I thought about making it in a hat shape, but that wouldn't have worked well as an end for measuring, so I went with a flat end.

It's interesting how complicated something like this can be when you try to make another one. It's off to the long term test of use now...

Friday, 11 January 2019

Really? That's How It's Made?

These data switches were being scrapped:

One is a Centronics printer switch and the other is a 25 way D type switch:

 I opened them up to see if there was anything salvageable inside and what I found was unbelievable. The connections between the switch and the connectors is done using discrete wiring.

I was expecting a PCB or maybe two, perhaps linked with a ribbon cable. PCBs were more expensive back when these switches were around, but the amount of labour needed to make these connections must have been considerable and, let's face it, PCBs were designed to replace this sort of thing.

It does appear to be hand soldered as there's evidence of melted connector plastic here and there:

These switches must have been tested before being shipped, and I suppose making a test rig to do that is pretty easy as all the connections come out to the connectors, but if you found a fault then it's off to the wiring to try to fix it. With a PCB it would have to be a PCB track fault of some sort which would be a PCB replacement or maybe fix. So surely fixing faults would be harder too?
It's a world away from a USB hub...

Here's a video examination of the switches: