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lofiscifi's full size K9 build

Started by lofiscifi, Jul 17, 2016, 07:00 pm

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Hello everyone, still a bit of a newbie, but hopefully this is the right place to be posting.

I'm going to start with a bit of detail - the keys areas I'm finding difficult to replicate are:

Eye/sucker shape
Tried the rubber tip found on cheap bow and arrow toys, but nothing seems to look 'right'.

Side screen/bezel
Originally, the prop appeared to use some sort of wire conduit which was then pushed around the off-square hole backed by grey acrylic to form a 'screen'. Around the time of 'School Reunion', a molded, recessed bezel replaced the wire.

Ear plugs
Those little bumps at the base of the ear/radar dishes (sometimes red, sometimes grey) - according to Mat, these were literally just pieces of Milliput, shaped to fit!

So, my solution to these? 3D printing!! I've found a decent 3D printing company fairly local to me in the UK and despite my inability to work with 3D CAD software, they're happy enough to work to 2D visuals I've created through lots of measurements taken through screen captures (and some inevitable guesswork).

Hopefully they should arrive this week, and I can set about smoothing those out so I can make some silicone molds.



First run of 3D-printed parts for the screen, eye sucker and ear bases...

The suckers will need reprinting as they're far too rough, however I'm looking to use a product called XTC‑3D to get the surfaces as smooth as possible, then get sanding!



Jul 20, 2016, 09:30 pm #2 Last Edit: Jul 20, 2016, 09:34 pm by lofiscifi
First stab at making a K9 'ear' a couple of months ago, based on Mike Tucker's rusty 'School Reunion' prop - using stainless steel woven mesh, metal rods and rings, and wire insulation... and a soldering iron! (And Photoshop, for the ball on the end!)

I'm going to attempt to redo this using acrylic and man-made materials as much as possible, then spray it silver...



Jul 21, 2016, 05:26 pm #3 Last Edit: Jul 21, 2016, 05:28 pm by galacticprobe
That plastic mesh they have for making those stiff cross-stitch... thingies... that people turn out as Christmas ornaments might do well for the mesh on the ears. Then there are the various sizes of plastic (PVC?) rods and tunes that you can find in craft and hobby stores that you could use for the center rod, and also get a plastic bead from the same such store for the tip. You might even be able to find some plastic rings at those stores as well.

Not sure how to tackle the main ear loop. That's got a really odd shape and it's curved. Hopefully someone who's already build a K-9 will have an idea or two for you on that one.

By the way, that ear looks pretty fantastic! You did a great job. If you photoshopped the ball on the end of the rod, but the rest of the ear still looks the same, just get one of those plastic beads I mentioned and glue it on. Then you'll have a spare ear if you need one.

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


Thanks, Dino!

If I can get plastic mesh with a similar aperture, I'll definitely go with that - otherwise, I may just continue you use the metal stuff and bond it all together.

I've managed to get some acrylic rods, and some beads at the correct size - the rings are proving to be difficult, however (approx. 22mm outer diameter and 16mm inner). I'll keep on trying to find the right material.

For the ear loop shape (which can be best described as a 'sagging oval'), I've used a lot of screen grabs to extrapolate the following illustration which is a bit of a mish-mash of Mat Irvine's and Mike Tucker's props so, providing the mesh is robust enough to keep its shape, I should be good to cut that shape out of the material, then create the bend/curve wrapping it around a drinks can.



Jul 21, 2016, 06:47 pm #5 Last Edit: Jul 21, 2016, 06:47 pm by galacticprobe
Quote from: lofiscifi on Jul 21, 2016, 05:59 pm
- the rings are proving to be difficult, however (approx. 22mm outer diameter and 16mm inner). I'll keep on trying to find the right material.

Would some larger PVC tubing work - like a bit of 1-inch diameter plumbing piping? I know it would be slightly larger with the OD, but it would be close (just under .14 inch larger). Once you cut it to the right thickness, some careful sculpting with sandpaper and an X-acto knife (not necessarily in that order) would turn the "rings" of PVC into "loops".

Short of getting some perspex/plexiglass that's the right thickness and cutting "discs" out at the proper diameter, and then cutting out the center to make them into "rings", and then doing the sculpting to round the edges so you have "loops", the PVC approach might be less work.

Just a thought.

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


If I can't find something suitable - that may be an option! There are a lot of o-rings which are perfect in size, but made out rubber, so no good - unless there's a way or adding some kind of coating to 'harden' them?


Jul 23, 2016, 01:05 pm #7 Last Edit: Jul 23, 2016, 08:03 pm by lofiscifi
Next bit of research: the nose gun! As far as I can see, it had a silver tip for the first couple of stories ... I'll assume it was something like metallic sticky paper because it didn't stick for very long!



Based on those refs, I'm looking to recreate it using acrylic tubes and black/silver paint.



Jul 24, 2016, 04:28 pm #8 Last Edit: Jul 24, 2016, 05:02 pm by lofiscifi
Working on remodelling his head today. Starting with a plug which will later be used to create a fibreglass mold.

Next step - expanding foam!





Looking at those close-ups of the nose gun, it looks suspiciously like a gas burner nozzle. Note the holes on the side to admit oxygen to the flame.

- Peter.


Jul 24, 2016, 07:12 pm #10 Last Edit: Jul 24, 2016, 07:17 pm by lofiscifi
That's a really good call, actually - if I could find something suitable (approx. 20mm diameter) and connect one of those to an acrylic tube, it would save a lot of hassle! :)


So, foam is fun.  ;D

The plan is to let this set, then coat the top surface with Bondo/P38 and sand til smooth, then hollow out a channel for the nose gun ... after that, I'll start on the 'lid' which I plan to form from balsa (I'm informed it's quite easy to bend after soaking in water).



A few more updates for you...

The base of the tail is a steering rack gaiter, and the rest is 3 acrylic tubes (12mm, 10mm and 8mm OD) and a curtain ring (40mm OD) all primed and painted matt black.


The K9 decal for the side panel is laser cut acrylic, it's primed and ready to be painted silver here...


Lastly, the eye panel - again, laser cut acrylic in two shades of red (the background piece is Perspex Chilli Red 4T50 which is frosted and gives off a diffused effect when backlit, and the 5 x 'sticks' are Perspex Red 440).



Jul 29, 2016, 09:36 am #13 Last Edit: Jul 29, 2016, 09:38 am by lofiscifi
One more thing!

K9's neck seems to be a bit of an annoyance for many - most people opting for ventilation hoses, or tumble dryer hoses, or something that looks right but is too wide or two narrow. However, I think I may have found something that fits the bill!


The outer diameter of the tube is 125mm (a smidgen off 5", as most people have speculated)... it's made of PVC rather than rubber, however it's more durable and lighter, in my opinion.

This is how it looks in the flesh!



I used MG Midget heater duct hose for my K9 neck.

I was restoring my old car and the first thing I noticed was the heater duct was exactly the same size :)

I love this build. I first made mine a few years back and I keep meaning to go back and redo my K9 head in fibreglass, exactly like yours...

Unfortunately it's on my ever growing to-do list...  :-[