House breaking with a cheap Chinese laser cutter

First I do not condone house breaking, unless you own or are permitted to enter the property anyway. But there are instances where house breaking becomes a necessity.

We were working in the garden, our next door neighbour wanted to start strimming. Our Rescue Rottie/Great Dane has issues with hissy whirly noises, so we shut him inside, whilst we continued in the garden. 

The strimming started and he jumped up at the door, unfortunately he also turned the key in the lock, locking the  door, from the inside with the keys still in the lock, although we had keys they wouldn’t work. Our front door, also had keys still in the lock. Our dog had locked us out of the house 🙁

All other Windows and means of entry were fully secured. Not versed in house breaking, I know a couple of local lock smiths Ill see if they could help. A few phone calls later proved that they were all on holiday 🙁

OK so you hear of people breaking in when keys are in the lock, how hard could it be… Well first obstacle, we had a “high security letter box” that took me less than 10 seconds to remove with a pair of pliers from the outside, I’m glad I spent the extra on that!

The letter hole that was left just allowed me to put my hand into the door, nothing else. Even borrowing a small local kid didn’t help, the hole was too small. Being locked out also gave me a few other issues, all my tools were inside, but finding garden wire etc I tried to make a hook to remove the key.

No, the key needed to turn and be upright to be removed.

I then realised that I was left with assess to the most versatile tool a laser cutter.

I made a key spanner, actually I made two as I dropped the first one through the letter box, the second one had a piece of string attached, just in case.  After a little fiddling I managed to turn the key and unlock the door from the inside.

I even made a temporary replacement letter box with the laser cutter afterwards.

So why have I posted how to break into a house.

Because I couldn’t believe how easy it was. OK, I had a laser cutter, but making a tool like the one above could be done in a couple of minutes with a fret saw, and I’m sure they (or something better) would exist available on the internet. So the take away message is if you want to secure your house


The other thing is, I live on a street with a door that opens onto the pavement, I was trying to break into my house for over 30 minutes.


Perpetual Motion

In the Royal institution’s museum there is a perpetual motion machine (used towards the end of this video  )

It occurred to me that this piece of equipment is over 100 years old and over that time it has regularly been used to demonstrate the futility of perpetual motion.

So it has been running, although intermittently, quite consistently for over 150 years, powered purely by presenters and demonstrators demonstrating that it doesn’t continue to run.

It’s therefore powered purely by the fact that it is a perpetual motion machine, and no doubt will continue to do so for hundreds more years.


Tales Of A Cheap Chinese Laser Cutter – Extraction, Improving air flow.

Continued from Tales of a cheap Chinese Laser Cutter – Bed replacement

The cutter runs fine, but cutting anything away from top left was getting more and more of an issue. One of the biggest problems was the lack of air flow at the other corner (bottom right). This was visible as smoke not being extracted. The smoke from cutting at this end also reduces the available laser light by bing in the unfocussed laser beam meaning that you get incomplete cuts. The other issue is the smoke condenses on the optics, making the cutting worse.

Although adding an air assist would help (I may still do this) the cutting it doesn’t solve the other problems.

The real issue here is the asthmatic extraction fan in the unit. The fan wasn’t designed for laser extraction use, it is a repurposed and not very good, bathroom air ventilation fan.

Luckily, I was at an amateur radio sale and found a 6″ mains cooling fan for £1, for that money its got to be worth a go.

i needed to make an enclosure that would take the  fan, fit it to the cutter and to the existing 100mm pipe. Looking at the existing fan I decided to just add in the new one to the large flange and make a new plate to fit to the laser.

Taking off the old fan and the inner plate it looked an easy task, just replace this plate with a new one with the new fan.

So I cut and measured the laser, the fan and the old extractor, found a peice if 6mm acrylic and drilled mounting holes, all I needed to do was to cut two 140mm holes in the two peices of acrylic. Easy I have a Laser cutter…. So I reassembled the laser cutter and cut the circular holes in the mounting peices and then re-disassembled it.

I then mounted the fan on to the old fan.

and a plate to fit the slot on the back of the laser cutter

Slotted it in to place

A quick clean of all of the optics and tried some test peices.

A huge improvement – no smoke to be seen at all.