K9 Diaries - The Beginnings Of A Pattern

K9 Build in Progress 01-Jun-2016

There are a surprising number of chamfers required before the body can be glued together and some of the bits needed supporting structures, just to make sure they were secure whilst the glue was drying.

Smooth Operator11-Jun-2016

After much taping and gluing I had a body shell shape, which would still need a fair bit of filling and sanding to be good enough to make the mould from. Fortunately the sun was shining.

After what seemed like an age, probably because it was. It was time for the primer, I had to seal the surface and make it smooth as any imperfections in the pattern will be replicated in the finished part.

This didn't go so well as I'd bought a cheap compressor and spray gun off eBay and I'd no experience of spraying, so initially I couldn't get it to spray even water.

In desperation I decided I'd have to apply the primer by brush and sand it smooth.

Smoothish Primer 04-Apr-2017

I soon realised my mistake when I saw the results, and decided to  have another look at the spray gun, and discovered that the second spray gun that came with the compressor worked.

So I mixed up a fresh batch of primer and was away, until I threw it on the a slab. I quickly wiped up most of it with acetone and tried again.

This was more successful but unfortunately I didn't clean the spray gun out well enough so it wouldn't work again. This was unfortunate as I'd rubber through the primer in places trying to smooth the surface.
 
A couple of days later, Debs said "Have you seen my scrubbing brush Hon?" an image of me scrubbing feverishly at the primer, on the still discoloured slab swam before my eyes, "Ummmm, no dear" I replied. Unfortunately I'd forgotten to dispose of the ruined scrubbing brush, and the incriminating evidence was found the next day.

It was now that I asked for help from my Brother-in-law Matt, a talented sprayer who could help me with my predicament. So off to Manchester we went to drop off K9 for his rejuvenation.

Picture Archive

The latest is the acquisition of some mesh for the radar disc like ears, although I think it's a bit coarse.

And some potential handles.

I like the hexagonal mesh, but wouldn't be to K9 spec, so may try ordering some finer mesh.

I've also found the tail gaitor which I'd bough years ago

modelling K9 in preparation for making a mould for a fibreglass bodyshell

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 A 3D tracked platform to test bluetooth control as a possible K9 controller

Whilst watching some of the special features I did notice that K9 has a straight section tube coming out of his head to join the flexible neck tube too.

 

So I decided to stop prevaricating about the bush and get into the garage and make a start.

I have a rasp and I'm not afraid to use it

K9 Stash

here's the current state of play

 

A few more bits glued into place,the next bit on the list is the curved top. I think I may need to add a couple of supporting ribs.

 

Here's the latest state of play with my build, the bendy MDF has finally been glued on top. Featuring the return of the table lamp, it's just the right heigh

 

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I now have 4 different potential radar dish / ears meshes

 

Still sanding and filling, although rain stopped play for a while.

Filling and sanding proceeding

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Not much K9 progress today. we dropped off the Pangolin at the museum, sadly not as animated as I had hoped, but maybe for next year.

Just a little progress today, one intermediate shaft fitted along with the 3/8th chain.

The second wheel intermediate shaft fitted today, but I’ve had some issues with chain tension,

so I’ve had to modify the bearing carrier so that there is more range in adjustment.

I wired up the motors /controllers, and dug out some old NiCads, which used to power Chompalot, sadly they are well passed their best,
but good enough to hold a little charge to test out the motorised base.

I also borrowed the receiver from the practice bot, I built for Debs to practice driving fro the Iron Maidens tounament. These days it gets more use at the young roboteers.


During testing, all was going well, I even stood on it to see if would take a load, being in the kitchen it wasn’t a definitive test just a few feet, but seemed fine.
but I was in danger of falling off so I discontinued that line of testing.

Using the inbuilt mixer was odd as you couldn't steer without using the forward or reverse as well, so maybe I will use an alternative mixing method.

Then it died and there was a burning smell, it looks like the BEC circuit which supplies 5V to the motor control has died so not a problem.
It's more of a problem that I have to provide 5V for the motor controller and it doesn't do it for itself'

So, this is the preliminary idea for the ear mech. I was considering printing gears with angled faces to mesh but then though it might be fun to have independent ears.

Today I had a go at some ears, not very succesfully, but as a first attempt I guess there are not so bad. I bought some coat hangers and bent into shape,

then cut the mesh with tin snips. I then attemtped to silver solder the two together, with varying amount of success.

Now the sun has come out, I’ve managed to get back into the garage to do a bit more on the body shell.

I'm just adding some strips around the bottom to contain the base board depth. Once these are attached there will be another layer for the bottom of the fibreglass mould
and then after adding a few radii and a bit of filling and sanding, it will be primer coat time.

The supplies have arrived! Hopefully I've bought everything I need, if not it's tough, and I'll just have to make do.

After the debacle, I decided to mix some more primer and apply by brush

I realise that it's going to mean a lo more sanding, but progress needed to be made.

More 3D printing, this time a prototype nose laser extending mechanism

A little work on mounting the Raspberry Pi and associated boards and the screen, now all mounted in a 3D printed chassis ready to mount in the bodyshell.

and from the frontish

K9 Diaries - Build Reboot

As mentioned before there were a few abortive attempts to build K9, so when we were at the Silk Mill Museum in 2016, we were mixing with the Makers group and my wife Debs got to talking to Chris Symes who knew of the local Doctor Who group. Debs asked how you went about getting involved, - I think she was trying to find a way to motivate the build progress in hindsight. So Chris put me in touch with Steve Hatcher, who organises Whooverville in Derby, and I suggested that I could bring my K9 to the next Whooverville in 2017. This was perfect as there was plenty of time to complete the build and have time for commissioning and testing 😆

With this in mind I gathered all the K9 materials I'd collected over the years previous 9 years and began to mull over this cunning plan.

Whooverville 9, 2nd September 2017

I began by reviewing the model of the  body shell that I'd produced way back in 2007/8, so that I could produce drawings of the bits I'd need to cut out of MDF.


Back then I'd got as far as cutting bits of plywood for the body, but stalled when I realised that I would need to fill the grain in the wood, it seemed like a lot of hard work and I wasn't sure what to fill it with?

So it was one step backwards, but with lessons learnt, and this time I would use MDF to construct the pattern of the body.

So, with a new urgency the plans were turned into dimensioned drawings. Then the material was sourced from a local building supplies company and a few days in the garage with my trusty ruler, some pencils and a saw, K9's body pattern began to take shape.

For those that are keen to build a K9 of their own, there are friendly people online on forums such as Who Props, with knowledge and some plans that have been collected together, by those that have gone before. I had collected the plans I acquired years ago and made good use of them.

I couldn't resist taping together the MDF parts to get a sense of K9 coming together.

Whilst I was at the building supplies I had noticed a product called bendy MDF, which looked like it might be perfect for the top of the body.

I have seen other people glue in lot of strips of wood and then sand them to shape, but this would just form a nice contour with minimal effort


Of course this isn't going to be the final body of K9 as even with decent glue and fixing I don't believe it would hold up to the vibrations and occasional "Star Cruiser Crashed" moments, so it is the plug for the mould which I'm making, for the body which will be fibreglass.

K9's head was made a good few years ago and has been skulking around in various places from the loft to the garage to my projects room, (or as Debs calls it the junk room 😛 ) before the project was rebooted and I decided I'd better get on with it or I'd never finish it.

K9 Diaries - How It All Began

Manchester, Doctor Who Up Close Exhibition in the Museum of Science and Industry  21-Apr-2007

K9 is a project I’ve wanted to build since I was a young lad, ever since the first time I saw him appear on Doctor Who. I even wrote to the BBC asking them to send me plans so that I could make one of my own, but all I got back was a Doctor Who postcard, still at least they replied! Lack of plans didn’t stop me from making small models from balsa wood and even a head (about half scale)but not having the capability to see it through the projects got shelved along the way.

Looking back as I'm gathering pictures and info of my K9 adventures, I realise I started this build, and have been gathering parts since back in 2007! Where does the time go?

Blackpool 2007

I think picking the K9 project up again may have rekindled after we were winding down our Robot Wars activities in favour of doing something less destructive and more constructive.

Back then I had put together a basic CAD model, and made the head pattern ready to start making the fibreglass mould, but something halted my progress.

There were a few more abortive attempts to build K9, but there was something missing, I think it was the commitment to carry the project through, something that isn't my strong suit, I need to have a goal and a time-scale or a project flounders. 😝

Also there was going back to university to get first a foundation degree and then a degree in Mechanical Engineering, as well as other distractions.

I also got very enthusiastic about making an R2D2 and put a lot of effort into modelling the body and having the part CNC cut, as well as spending quite a lot of cash on a set of skins and a dome, a lot of resin bits and pieces, and some circuit boards for the flashing lights in the dome. However this project has also floundered., again there was no goal apart from the build, so if things get tough, it's easy to get distracted and there is no real consequence halting if there is no plan. Perhaps when K9 is up and running I should go back and finish this one next?