I like lasers, and have a couple of basic laser light show units which are a lot of fun at parties

Last time I fired them up I noticed one of them wasn’t working properly, and something was rattling around inside! It turned out to be one of the mirrors that moves the laser beam around. They are just glued onto plastic hubs on the motor shafts, so fixing it was just a case of cleaning it up and gluing it back on.

Note the missing mirror on the middle / rear motor:

As some may have noticed, updates have been a bit slow lately!

I’ve had to move a bunch of stuff out of storage and organise new places for it. The upshot is that I have retrieved a lot of my old tools and parts that are now very useful!

The workshop is getting much better set up which makes things easier - so there should actually be more interesting updates from now on!

Here’s something amusing I saw the other day - someone appears to have “fixed” a lawn mower using a pizza box. I’m not sure how well it protects the shins against flying rocks!

I was asked to have a look at a ducted house air conditioning system which had been pronounced dead by two different air con repair people - both recommending an entire replacement system at massive cost!

I was expecting the system to be under the house, so was pleasantly surprised to find that the compressor and condenser unit was actually outside like a typical split system!

On inspection, everything seemed to be working, but the compressor was covered in ice, and the condenser wasn’t as hot as I’d expect it to be.

Unfortunately this meant that the problem must be in the evaporator / fan section - which was in the house’s roof.

After finding the manhole and poking my head up in the roof, I found the a/c gear to be pretty close, but the roof was, as usual, full of insulation, dust, and was massively hot!

After removing the lid from the fan box I found that the evaporator had created a large block of ice, and the fan wasn’t spinning - but its motor was very hot.

The motor was partially seized, and probably burned out.

I suspect that either the start capacitor had died and allowed the motor to cook, or the bearings had worn out and seized.

The fan unit looked familiar, and I realised I’d seen some at the local scrap metal shop.

I was able to pick up one that seemed to be in good condition, for $10. After adding a new start capacitor ($17) and repairing the bent mounting brackets it tested out perfectly.

So, the next step was to take the new fan and install it in place of the old one!

It seemed like it should be pretty easy, but with 50+ degree temperatures in the roof I had to do it in 10 minute sections and go outside to pour water on my head in between!

Eventually the new fan was in and working - and the aircon was finally pumping cold air into the house.

It turned out that the new fan actually had a more powerful motor than the old one, so it should actually work a bit better

I just picked up an Innovate Motorsports Wideband O2 sensor / data logger kit.

It should be very handy for tuning various engines, analysing car performance, and diagnosing problems on late model cars thanks to its inbuilt OBD2 interface.

The kit comes with the meter, the oxygen sensor, and all the necessary cables in a nice carry case - but not a fitting to allow the sensor be be used in the tail pipe as is usually done with dyno tuning.

It’s better to have the sensor mounted in the exhaust closer to the engine, but it’s more convenient to be able to just clip it on the tailpipe, so I made up a clip on sensor mount using some leftover stainless steel tube.

A friend got the job of moving a large laser cutting machine from Brisbane to Sydney, and being at least a two person job I went along to help.

It’s about 7m by 4.5m with a cutting area of about 6m by 4m. It’s designed for cutting fabric for making blinds, and the cutting table has a vacuum system to hold the fabric in place.

This is how it looked when we arrived:

Due to its size it wasn’t possible to move it in one piece, so we basically had to dismantle the the entire thing, taking plenty of photos along the way!

The first step though was to make sure it actually worked before we took it apart - especially the LASER itself:

Testing the laser involved wiring up power as some of the leads had been cut, and working out how to get the control software to fire it.

Since we didn’t have a compressed air supply it wasn’t safe to run the laser through the machine’s optics (the very expensive lens can be overheated without the cooling air) so we put some tape on a steel ruler and sat it in front of the laser’s ouput hole. Firing the laser left a nice burn hole in the tape, so it was definitely working!

After the laser test, it was time to pull everything apart.

The whole machine was bolted together fortunately, so we didn’t have to cut anything. There were a lot of bolts though, and some of them were damaged due to the machine being dragged across the floor previously.

This photo shows the vacuum trays which are under the mesh surface of the table (which is held on with seemingly millions of small screws!)

The divider plates in the middle can move back and forward to section off the vacuum to the area where it’s required.

Here are two sides of the frame remaining while the last of the vacuum trays are removed by forklift.

All the parts took up an entire semi trailer, and a ute!

After a few days off while the parts came down on the truck, we got stuck into putting the machine back together in its new factory in Sydney. Note the large vacuum box in the corner:

We had to replace a few bits, and repair some damaged parts and cables.

We also pulled the laser’s optics apart and cleaned the mirror and lens, before readjusting and testing it.

Eventually the whole thing was back together and working!

Now there’s just a bit of fine tuning to do before it’s making blinds again.

Years ago I built a jet engine as a bit of an experiment, using mainly scrap metal and various leftover car parts.

Every now and then I drag it out and try some new parts or modifications.

It’s based on a small turbocharger from a Mitsubishi Starion, and currently has a combustion chamber from a Rolls Royce Dart turboprop engine.

Last week I took it along to an event called Dorkbot (http://dorkbot.org/dorkbotsyd/), which is a monthly gathering of people interested in electronic / mechanical / scientific art performances, displays, and experiments.

I fired up the jet engine, made a lot of noise - then gave a bit of a talk on how it works, how it was built, and what I have planned for it in future.

The second presenter on the night showed information and video from an installation artwork / experiment he did in California, where an earthquake simulator was set up in the middle of earthquake territory and was used to display amplified real time seismic activity from the whole state!

The event was a lot of fun, and definitely worth going to if you’re interested in all manner of crazy experimental things!

I just hope I didn’t offend the neighbours too much with the jet, and they’ll have me back to show some of my less noisy projects

For anyone interested in home built jet engines, have a look at this video: http://www.youtube.com/watch?v=4pTUeuEv8Uc

Also check out this very serious backyard jet: http://www.youtube.com/watch?v=VX5U8DlBzzk

This air compressor was frequently failing to shut off when it reached full pressure - causing it to blow the safety relief valve.

Upon inspection it was working properly, but I noticed that it was cycling on and off faster than it should.

Turning on the air valve caused a lot of water to blow out, so I suspected the tank hadn’t had the condensation drained for a long time!

The compressor also had a lot of oil on it, probably caused by spillage or over filling.

Moving the compressor made it obvious that the tank was quite full of water!

After draining several buckets of very nasty looking water, a thick oil sludge started coming out. Obviously this had built up over some time, after leaking through the compressor due to wear or over filling.

Hopefully draining the tank will stop the problem with the cutoff switch, and at least give the compressor a lot more air capacity!

This place has been a bit quiet lately, after I’ve been busy moving house and having no internet access for a while!

There are a few updates to come, and some interesting projects in the pipeline

I’ve decided to finally start a business, based around the sorts of things I’m always doing in my “spare” time, generally involving getting boats, cars, motorbikes - and pretty much anything with an engine in it - running better than they were.

I’m hoping there will be a reasonable market for someone who’ll fix pretty much anything, and not lead unsuspecting owners down a path to financial destruction like so many workshops seem to do!

I’ve also been trying to make a start in the electric vehicle industry (not that there really is one at the moment!) and have built an electric motorcycle which I use for local transport.

I’m continuing to develop the bike, and it will hopefully be the first of many electric conversions.

So, for now this site will have the usual info and contacts, as well as keeping a log of things I repair, modify, build or just find generally interesting.

Enjoy