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BioDoctor900's School Reunion K9

Started by BioDoctor900, Jan 22, 2013, 11:15 am

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May 05, 2018, 02:59 am #15 Last Edit: May 05, 2018, 03:00 am by galacticprobe
Quote from: BioDoctor900 on May 04, 2018, 01:24 pm
...most of the buttons had lights in, they run off 12v, so I would of had to have ordered as MOSFET to trick the bulbs into running at a lower voltage, but I couldn't be bothered with that as it would have made it even more complicated...

He's looking great, BioDoc! I love that interior you've created. And I think that was a good decision with the buttons and their lights. MOSFETs are touchy, and some can be oversensitive to static electricity. One static zap and "POP!", you've got a dead MOSFET. Of course you could always get lower-volt replacement bulbs for the buttons if you wanted, but then they might not light up as brightly.

Quote from: BioDoctor900 on May 04, 2018, 01:24 pm
His antenna probe turned up (12v car aerial) I did test it, it extended, but then refused to retract....so I dunno, I'll look at that more when I've sorted out getting a fibreglass head

I wish I could offer some help with his antenna (car aerial), but I haven't worked with them at much. You did say it's a 12v aerial. What's your main power supply voltage? I'm guessing by your comment about the buttons that it's less than 12 volts? Maybe the aerial motor needs a full 12 volts to pull the aerial back in once it's extended? (Sorry, but that's about all I can think of.)

"What's wrong with being childish?! I like being childish." -3rd Doctor, "Terror of the Autons"


Dino, I'd actually wired up the car aerial to the mains with a 12v power supply, so I'm not too sure why it didn't want to work. Hopefully I haven't shorted it or buggered up the electronics by doing so, but it shouldn't have done. Maybe it's just a faulty aerial unit, it did only cost me £12 from eBay



May 06, 2018, 02:32 am #17 Last Edit: May 06, 2018, 02:45 am by galacticprobe
You're right, BioDoc. The power supply would not have buggered up anything. Even if that 12-volt supply had 500 amps at its disposal (like a car battery has its 750 "cold cranking amps" available to turn the starter motor), if the aerial motor only draws .5 amps (which would be a lot; the number is for argument's sake), then only .5 amps would leave the supply. Just like in a car; if the full 750 amps available went into the aerial when the aerial's motor turned on, the aerial mast (rod) would shoot out of the car like a missile! And 12 volts is 12 volts, whether it comes from a power supply plugged into the mains, or from a battery; the aerial motor wouldn't know the difference.

In contrast, it's not like trying to drink from a firehose where your source gives you 250 gallons per minute at an available pressure of 125 psi, and that's how the water comes out of the nozzle (which would knock you across the room... and probably through the wall). So your power supply wouldn't have damaged the aerial motor. Bad ones do come out of stock - it happens - so I could just contact the seller you bought it from and tell him what's happening, and take it from there.

I know this isn't of much help, but at least it lets you know that you didn't do anything wrong with your hook-up.

"What's wrong with being childish?! I like being childish." -3rd Doctor, "Terror of the Autons"


May 12, 2018, 08:47 pm #18 Last Edit: May 12, 2018, 08:52 pm by BioDoctor900
Well a few more bits turned up, mainly the handles and his tag

I've been fiddling about getting the wires in the Arduino programming breadboard, reason for this is that the small circuit boards I have, the contacts on the boards pulled off when I tried soldering bits onto them

I've done a bit of sanding and filling, although there's still a way to go



Hopefully the servos will turn up soon and I think I need to invest in a better palm sander, the one I have has the spring clips to clamp the paper in rather than velcro backs, so the sandpaper either falls out or tears, but I've got the top rounded where it meets the sides, front and back, so that will do for now

I'm off to go swear at the Arduino and see if I can get it all sorted out  ;D

More soon



Well I fixed the issue with the Arduino, I resolved this by putting the Arduino and the breadboard on the control panel inside, this way, not only does it add to the fact of functionality, but if I ever need to fix it, I just have to open the side panel and not worry about tipping him on his side.

Today I spent the afternoon making his head. After posting on the Doctor Who Props page on Facebook, asking if anyone had a fibreglass mould of his head....no one did, they all just suggeted using Styrene, and one guy suggested foam!? That would be about as much use as a chocolate teapot!

So looking down my local model shop, they sold smaller than A4 sheets of styrene...so I decided to use what I had to hand, which also meant not spending anything. So I used 3mm MDF for the sides, some ply for internal support and thin hardboard for the shell. I managed to get it near perfect, I had to tweak it after Mr. Nagel sent me some pictures of his Fibreglass head, which I've been after  :P  ;D and I only had to adjust the width of his nose so it was narrower




This is the gun I've made for him using an old bathroom light pull, then School Reunion version only had a hollow tube, but I want it looking a bit better than that



I'm rather happy with how he's turning out


I've got to get some PVC pipe for his nose barrel and the nose plate, some red acrylic for his eye, and then it will come to filling, sanding and then paint and the rest of the electronics/remote control

More soon



looking very very sharp indeed.
I want notes, lists and answers by the time I finish this here Juicy-a-Box! WARNING: I am Thirst-ay! And it is Fruit Punch! And it is Delicious!"


So today I got some semi transparent red Perspex and some PVC tube for free from my local Perspex place, and so I set to work on making his eye cover and the bezel for his nose. Last night I also added in the two round flat LEDs for his eye lights.

For his eye I used a thin piece of clear acrylic which my partner gave a light sanding to try and diffuse the light, she was calling him Demon dog  ;D He's not a demon dog, he's a good boy. I then cut strips of the transparent Perspex and superglued them in place. I'm not too sure about the clear behind the slats, but at the same time it appears to work...

I also added in the old sensor rod, a telescopic magnetic pick up thing which was in the cardboard K9, just to make him look finished and I look into what the hell is wrong with the electronic car aerial, and how it's going to fit, as looking at the School Reunion Prop, the probe comes out more or less straight rather than at an angle... ???

I also added in the laser barrel, I'm not too sure if it looks too small or not....






Asthetically, apart from paint, he's done, but there's still electronic/remote control work to do. I tried wiring up one of the servos for his ears to the Arduino, but unfortunately it's not got enough power to do the lights for the control panel and the ears...

I'm still trying to remember what the hell the name of the paint they used on this version of K9, I have a feeling it was a Peugeot or Vauxhall colour greyish blue....if anyone can remember it would be a great help

More soon



May 20, 2018, 09:27 pm #22 Last Edit: Jun 13, 2018, 12:53 am by BioDoctor900
So I took the plunge and bought some paint. The paint I went for was Denim Drift, a greyish blue colour that Dulux make...


It's only in a Matt finish, but it looks quite close to how K9 looked at the end of School Reunion. It was difficult trying to find a paint that matched as in different pictures of the prop, the grey looks different. I attempted the rust effect to make him like the School Reunion Prop, but it wasn't showing up as well as it probably could have...



You can see in some lights, you can hardly see the silver


So I decided to just have him clean





I managed to make his computer screen using an old metal utensil pot I had my paintbrushes in, but it's gone to better use



There's still a few areas that need attention, like some filling at joins, and some of the screws have divets where I filled them with filler, but painting him has helped to show them better

Now he's more or less done looks wise, I can start talking to my friend about motorisation

More soon



Kind Regards,



Cardinal Hordriss

That looks amazing. I think making him clean was the right choice.
I speak to you from the final days of Gallifrey. I am the past you have forgotten. You are the future I will not live to see...


Thanks guys, I've gone over the paintwork with some clear varnish which has darkened the paint ever so slightly and made him look metallic without the need for spray paint, but will also help seal the MDF...


You can see the gloss on the left...


I also lightly spritzed him with silver spray to give him some texturing


You can just about see the gloss effect. With regards to motorisation, I've bought some parts, but it looks like I'm going to have to go it alone and wire him up myself



Over the past couple of days, when I've had a bit of time, I've filled in the gaps in K9's bodywork. Ive still got some sanding to do, but haven't been able to do a lot due to working just after lunch time till evening, neighbors wouldn't appreciate me using my electric sander after 9pm

I'm now waiting for the speed controllers to turn up, and then I can look at trying to to wire up all the bits to get him moving....how the hell it all connects together....god knows....




As you can see in the second picture, with the paint, the join is more or less gone, but Mr. Nagel pointed out there's a slight bow in the top panel where it meets the sides, and I realized this is where I didn't sand the top angles where they meet, causing the bow, so I'm probably going to have to take the top off, sand them down so that it sits flat


Excuse all the filler and crap on the rug, it's from sanding his body. These are the component parts to make him move, the gun and ears are wired up to servos, although the gun needs to be tweaked slightly and I need to sort his tail mechanism

He's coming together slowly.

More soon



Looking really good so far,  its coming together nicely
I want notes, lists and answers by the time I finish this here Juicy-a-Box! WARNING: I am Thirst-ay! And it is Fruit Punch! And it is Delicious!"