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Wednesday, 28 February 2018

The £500 Dirty Photo

 I've been attempting to stitch together sets of photos from die shots for ages. I've managed about three so far, one of which was a big one. The latest attempt has been a failure on every computer I have, and each failure has taken hours in some cases, even overnight. The computers I have are mainly second hand and none of them are very modern or powerful.

Having a definite job to do I decided to buy a more powerful machine to do it on. So I spent £500 or so on a new (ok second hand) machine.
The result is a 386MB TIF file. I can't really post all of it here, so I've got a scaled down version:

This is an 8Mb version of the file. It's about 2000 pixels on a side, which is considerably smaller than the 10000 pixels on a side that the full image uses. The zoom that is possible on the full image is much greater than this scaled down version.
Unfortunately there's some dirt on these photos, which I'm not very worried about as I can retake some or all of the photos and rerun the panorama generation. The dirt is in the middle of the ROM so not the best place it could have ended up.

So there we have it, I spent £500 to get a dirty photograph.

Tuesday, 27 February 2018

Rainwater Harvesting Pump Controller Problem

Our rainwater harvesting system uses a pump and that pump is controlled by a, well, controller. This has worked fine for years, but about six months ago it gave a fault and I had to press the reset button to get it going again. It then ran for several months, but about four weeks ago it tripped again, and then it tripped many times.

The controller is a controlmatic E, I believe and it has a PCB inside which performs all the functions. From the symptoms I thought it might be an electrolytic capacitor problem as the frequency of occurrance is increasing. I took the PCB out and tested the electrolytic capacitors and found that they were fine. I then took the power supply dropper capacitor out and tested that and it did not look fine. I replaced it with a parts bin capacitor and the controller ran for a few days with no faults. I bought some new capacitors as I didn't want to leave a parts bin component across he mains, even though it seemed to solve the problem. It was also slightly wrong in value. I put a new capacitor in the PCB when they arrived and the controller has run ever since with no faults.

I have a couple of videos about it here:

Monday, 5 February 2018

A Different Disk Drive Teardown

There's a lot of disk drive tear-downs and disassembly videos on YouTube, but I have done another one. This one is different in that I have used some of my tools to tear the drive apart to a greater depth than I have seen elsewhere. I've decapped ICs, chopped the PCB up and chopped into bearings. There were some surprises too.

The first video is here:

 There's currently seven parts, some more may come along afterwards.

Part 2 (PCB Disassembly):

Part 3 (PCB Layers and a transistor):

Part 4:(The Tu Device)

Part 5 (Smooth Dillon and LSI Chips):

Part 6 (Flash Chips):

Part 7(The Heads and chip):

Wednesday, 31 January 2018

Maslow Chain Guide

Maslow Chain Guide

My Maslow CNC was suffering from a jumping chain, which is quite alarming when you are standing near the machine. It mucks up the calibration as well, so it is not a desirable thing to have happen. When this happened before, I used some plywood to lift the chain so that it fed onto the sprocket at the correct angle. This never worked too well as the plywood was not quite the correct thickness to guide the chain properly. After another jump of the chain I decided to 3D print some chain guides.

The guides were created in OpenSCAD, which I use exclusively for all my 3D printed objects. It is parametric, so I can type in the height I want the chain slot to be from the base of the guide and the object generated will be of that size. I need two different distances on each side of the machine, so I'll print two slightly different guides.

I had to file out the guide slot a bit in order to get the chain through the hole, but I'll print the second guide a bit bigger. It's working fine so far, we'll have to see if it has solved the jumping problem...

Wednesday, 17 January 2018

XY Table Update

The XY table project has moved on a bit. I've finally printed a couple of single axis mounts for the DVD drive stepper motors. The motors have ended up as the only part of the DVD mechanism to be used in the table. I'm planning on mounting one of the tables on top of another to give me the XY motion I need for the automating of the die shots.

Olympus BHM Panasonic GF1 Micro Four Thirds Camera Mount

Now I have a new LED lighting arrangement on the Olympus microscope I need a way to attach my Panasonic GF1 camera properly. Up until now I've used a tripod to point the camera down the camera port or just rested the camera on top. I have also pointed the camera down an eyepiece, but I end up with vignetting if I do that with a lens. I bought an eyepiece adapter which mechanically is fine, but I ended up with weird rings when I tried to take a photo. I've no idea what was going on. So I 3D printed a camera tube:

there's a taper at the camera port end and I've put some insulation tape in there to get a nice soft tight fit. The top of the tube slides in to a micro four thirds to OM adapter I bought. There's a screw I can use to attach it but the tube is such a good fit it's not necessary. It turns out that even with the thickness of the tube it is still not opaque to light, so I covered the tube in aluminium foil.

I've done a short video showing the tube here:

Tuesday, 9 January 2018

Sinclair Memory Calculator Tear-down

I've bought a Sinclair memory calculator. It's in a bit of a state, but that's good, as I bought it to tear it down. The videos are here:

Part 1:

Part 2: