All posts by Alex Hitchins

Software person with hardware ambitions.

Daily Hacks Vol. 1

During the summer, the air conditioning in my Saab decided to work on it’s own terms leaving me a little hot on my hour and a bit commute home. I got it re-gassed in-case it was low however the mechanic said they removed a fair amount of existing coolant, so it likely wasn’t that.

A little troubleshooting later and I’d narrowed the issue down to an electrical fault and then quickly found the culprit.


This relay switched two circuits, compressor and something else I can’t remember. As you can see, it’s a little mucky. Being enclosed with a metal lid carbon buildup covered pretty much the whole inside. I gave it a clean with some WD40 Contact Cleaner and tried it out. Although it was working, it wasn’t working well enough to run without tripping.

I found someone on eBay breaking a Saab 9000 and asked if I could take all the fuses, relays and other light switching units from the engine bay fuse box. From experience, the big orange headlight unit can go and is expensive to replace (if it can’t be repaired) so thought it wise to buy up the whole box and keep some spares on hand.

While I waited for the replacement relay to make it’s way to me I fashioned a temporary manual relay unit, or hard wire the AC on all the time. See below the fine craftsmanship.


The little fix worked extremely well and kept me cool until the proper replacement got delivered. One thing I did learn, was that when you switch off the engine the circuit is still on. Had to jump start one time I forgot to remove it after I parked up at work. I know the wire shown is rather thin (not sure on the AWG rating) but the switching side is at maximum an amp, which is fine for this application.


Not a particular clever hack, or fancy in any way but it simple and effective and got the job done. I like to think of Darwin’s quote “It is not the strongest of the species that survives, nor the most intelligent; it is the one most adaptable to change.“.

Mounting SSD’s Inside Server Trays

I have recently wanted to put some SSD’s into one of my XenServer boxes to give the whole thing a little boost. The boxes I’m using are some weird Dell pedigree, 1U with 4 x 3.5 inch SATA bays with varying RAM. They pack 8 AMD cores across two CPU’s. Probably too old for production environments (enterprise that is) today however for development/tinkering they are ideal. They also, collectively, don’t use as much power as my old PowerEdge 1950 on it’s own.

The bays have mounting holes in the bottom to allow for fixing 2.5 inch drives so I thought it would be an easy task to fit the new units. I was wrong. First issue was screws. I could find plenty of them on eBay but not the countersunk sort. I thought countersunk ones would tighten flush against the bottom. But no.


After going through different sets of screws I realised this plan wasn’t going to work. Next option? Easy I thought, get some conversion mounts. I ordered some and thought this was finally solved. One thing I hasn’t considered with this approach is that it seems these mounting brackets are an even width on both side mounting the drive in the middle. Fine for a PC but bugger all use in a disc tray (as the data & power ports on the disk need to be in the same place).

By this point, it had taken me about a week to not get this sorted. I just wanted the discs in so I could start having fun with XenServer. Now, what you will see below isn’t pretty, but it works. I had this foam-paper board stuff left over from another project and a good sharp utility knife. So, I cut out ‘blanks’ that fill the size of the tray the proceed to cut the area out where the SSD needs to sit. A little fancy blue masking tape in lieu of screws and you have exactly what is needed.

As I said above, this isn’t pretty and I wouldn’t do this for anything near production level stuff however I do like the hackyness of it.


Discovering ones niche

I’ve been reading stuff online to try and give me some idea on how to start writing for this fancy new blog. They all seem to start with exercises to ‘discover your niche’. What niche can I fill? There are plenty of blogs out there on software development, faffing with hardware and that sort of general technology stuff. Maybe I can break into (or even create) the as yet non-existent Saabist/Electronics/software-development/hacking/maker scene. I guess we won’t find out until I get someone reading this. If that happens to be you, welcome to my niche.