3D printed proton pack finale.

I've posted a few articles about the 3D printed proton pack I designed and published on Thingiverse:

Who ya gonna call
Who ya gonna call 2
Someone saw a cockroach up on twelve
Making parts look right
Seeing things running through my head
Proton pack build continued
More 3D printed proton pack
Proton pack lighting 101
Fully 3D printed proton pack complete
Proton pack thrower mount

I though nothing more of this, until I was contacted by a guy in Los Angeles asking how I wanted to be credited in the titles of his fan film. Apparently, it was cheaper for them to buy a 3D printer and print 4 proton packs than it was to buy off the shelf units of equivalent quality. And now I have an entry on IMDB!

May I present:

EMF Camp 2018

After my first visit to Electromagnetic Field Camp in 2016 I've been eagerly awaiting it's return in 2018. EMF Camp is a long weekend camping festival dedicated to technology and the arts, with workshops, talks, activities and demonstrations for the technically minded.
This year's event was held at one of the fields of Eastnor Castle. about 2 1/2 hours drive from where I am. This year I volunteered to run a laser tag events for 5, one hour sessions over the weekend using the 3D printed lasertag guns I've documented over the years on this blog.

To properly stage such an event I needed some inflatable barriers. These are readily available from China but I didn't want to spend any cash. Fortunately my good friend Steve Bull at Operation Lasertag was able to lend me about £2000 worth of them for the weekend. Thanks Steve!

We arrived at around 11am on the Friday.

And once through security (They were a professional event security company. They looked really bored. I asked them if this was the easiest gig they had ever done: "We've had more disruptive people at other events.....") we were in to set up the tent. Matthew had a great time bashing the tent pegs.

The event is laid out as a series of marquees in which talks, up to an hour in length, are regularly held. The marquees vary in size and an online system of talk interest registration allows the organisers to allocate the largest tents to the most popular talks.

EMF camp has been compared by some to the UK version of Burning Man. However this is a link they shy away from. EMF camp is a much more educational event with the majority of activities aimed at learning something, be it a workshop or a talk. Also, children are somewhat rare at BM, where at EMF camp they go from babes in arms upwards.

As a result of this demographic, the lasertag was most definitely busy. With English speaking parents turning up with their native Belgian or Dutch speaking kids to translate my safety briefings. It really was enjoyable, though somewhat tiring. Also, as a result of the set up and tear down times I did not get to attend as many talks as I would have liked. Nevertheless, it was great.

Andy brought along a 3D camera so we could record one of the games.



Visit Tagbits to see the full range of tagger products described in this blog.



I had some welcome help from Joshua, Keiran, Andy and Carter to run these events. It was agreed that whoever was running the event should wear the 'Stahlhelm' with goggles to indicate them as the administrator. Most of us were sensible enough to avoid being photographed, except Keiran.

There were many great activities and things to see over the weekend:

An introduction to blacksmithing. I did this last time in 2016 and it was great:

A homemade organ:

A free retro arcade. Josh and Carter do Dance, Dance Revolution. I took on Keiran. He is 17, I am 53. I more than doubled his score...


There were various bots wandering around. This one seemed to have problems with it's LCD face. Which made it somewhat creepy:

And there were some balloon battle bots being tested. These were really popular with the kids. Each robot has a pin and a balloon on it.

X Robots brought Mantis along.

By day, a circle of fans is not compelling:

But by night they produce a fire tornado:



One of the new attractions was the 'Null Sector'. A set of shipping containers arranged in a circle with various attractions in each one. From arcade machines for the kids to a rave and a bar for the adults.



The disco was combined with a pyrotechnic system so that punters could discharge propane (apparently they went through 200kg over the weekend) by pressing buttons on a panel.

An indie film was being recorded at the same time. They asked if they could use my 3D printed lasertag guns for this scene. You can see them staggering along from 00:09 to 00:012:



Overall, an amazing weekend. The next picture sums it up. A map is made of the field and attendees are encouraged to mark their presence with a tag on the end of a piece of string. And this is only one half of the field.

Melting Aluminium..near disaster

I've been following The King of Random and noted he had some success melting aluminium. This seemed attractive to me as a 3D print could be used to make a mould, and pouring in liquid aluminium resulting in a casted part.

I watched his video exploits here:

Starting off with a metal bucket and a smaller plastic bucket inside, I poured plaster of Paris into the gap in between the buckets until the plaster reached to about an inch below the rim of the outer bucket. I then used pliers to remove the plastic bucket, leaving a void.

Using a holesaw, I drilled through the bottom of the bucket to allow me to insert a steel pipe for the air inlet. I 3D printed an adaptor to allow me to connect my DeWalt vacuum which has an air outlet to the pipe.

The kiln needs a lid and this had to be made from scratch. This was to be made from plaster of Paris too. I cut a piece of cardboard so that it formed a circle that was the outer diameter of the lid. Then I covered it in packing tape to prevent water ingress.

This was hot melt glued to a sheet of cardboard to for the outer circumference of the lid.

A small cardboard cup was placed in the centre and hot melt glued to the cardboard base. This would form the hole in the kiln lid.

After spraying the exposed cardboard with varnish to seal it, I then poured the plaster of Paris, inserting two B&Q 8mm threaded rods that I had bent into a 'U' shape as handles.

I trial fired the system using barbecue charcoal with a crucible made from a Berzomatic tank with the top hack sawed off. With the blower on this took about half an hour to melt the aluminium, but the overall temperature was too low. And when I attempted to pour the aluminium started to set before it reached the end of the crucible.

"Ah ha!" says I. "There is insufficient energy going into the system". "How can I get more energy in?". This is when I decide to vist my local coal merchant who sells me some Welsh anthracite.

With this burning I get a fair flame going.



This looks really promising as the aluminium is much hotter...

However....the thermal energy of the coal was much greater than I expected, and 'The Incident' occurred.



The melting point of aluminium is around 660C. I clearly needed more than this to get where I wanted to be. The crucible I was using was made of steel, which has a melting point of 1500C. The bottom of the crucible melted, dropping the molten steel and aluminium onto the burning coal. The aluminium then burnt in the presence of so much oxygen from the air feed. I had the good sense to pull the air line from the kiln to minimise the damage.

Needless to say I almost shit my pants. The immediate aftermath was a pool of molten steel on the concrete patio.

The Bernzomatic tank was destroyed, as this pic taken a few days later shows.

And the missus was most unimpressed with the hole it blew in the concrete slabs...

The lesson learned here is it is OK to increase the energy capacity of the fuel, but there needs to be a corresponding reduction in the amount of air available. Next time I will:
1) Have a variable air flow feed.
2) Do it on a slab that is not part of the garden.
3) Wear more protection (this is the important bit. I cowered in the garage after pulling the air feed and thought "Oh shit! What do I do now!"

The main lesson I learned was: Blindly following potentially dangerous youtube videos without research is a recipe for disaster.