Six Leg Robot / Walker Step – by – step (Installment
2)
The Build
I used two part epoxy resin glue to secure the pins and
legs. To help hide the joints between
the legs and body I used two part putty ("green stuff", more on that later) and
sculpted “fabric” dust covers around the joints. Using a toothpick, hobby knife, and other
small sculpting implements, I added wrinkles and folds to simulate a flexible
cover.
fig.4: "Green Stuff" putty sculpted into
flexible dust covers for the joints.
Another advantage of this kit is
that scale is entirely up to the modeler.
There are really no cast details that define a specific scale. I had played around with many back stories to
this build and tested the model against many differently scaled models. This kit looked great no matter what I had it
posed against. In the end, I settled on
1/100th scale. That little
human figure (“scale-guy”) in fig.3 above, is 1/100th scale. Determining scale will help during the
build-up and painting phase by informing us of the sizes of details we need to
keep to.
Adding Details
I knew that I wanted to add an extra level of detail to the
model. I added hydraulic actuators and
hoses, just to provide a little more visual interest and movement to the
piece. Before attaching the legs I pre-drilled holes that I would later fit telescoping aluminum tubing and wires into. These would give some purpose to the many
cylinders and shapes cast on the legs.
You can buy lengths of aluminum tubing in various sizes and I was
provided a few lengths to play with. If you want to do this, you'll need to drop by your friendly neighborhood hobby shop / train store (FNHS), and pick up some extruded metal tubes. You can usually find such items by K&S Precision Metals. Each tube fit nicely into the other so, by cutting off measured
lengths, I could create the hydraulic actuators at many of the leg joints. I also added lengths of wire to replicate
pneumatic or hydraulic hoses. These were
lengths of different diameter wire glued into more pre-drilled holes.
I used a small-ish diameter insulated electrical wire for
the thin hoses. The larger hoses were
cut from a roll of 16 awg Primary Electrical Wire that came in a 24ft roll from
Home Depot. 24ft will last you for a few
models! I found that this wire had a
multi-strand copper wire core which made it very "rubbery" so it wouldn’t hold its shape very well. To solve this problem, I pulled out the
multi-strand copper wire core which left me with the plastic insulation tube. I then threaded a single length of thinner wire (the same wire I used for thinner hoses) through. The thinner
wire had a single copper wire core and was much better at holding whatever
shape I bent it into. I used
cyanoacrylate glue (think Krazy glue) to secure all the wires into pre-drilled
holes. Once dry, I could bend and shape
the hoses into nicely draped forms.
fig.5: Pulling
out the multi-strand cores of the 16awg Primary Electrical Wire
fig.6: Replacing
the core with a thinner but stiffer single core wire
fig.7: Plugging
the hoses into my pre-drilled holes in the legs
Here’s some hints for applying cyanoacrylate glue. I first put a few drops of the glue on to wax
paper...the stuff you find in your well stocked kitchen. The glue will bead up on the wax paper and
stay viscous and usable for much longer.
I have an applicator that I made from a sewing needle. I cut the end off the needle’s eye leaving a
small “U” shape. I ground down sharp
edges and polished the “U”. Chuck the
needle into a pin vise and, by dipping the “U” into the CA glue bead, you can
transfer very precise drops of glue to your work. I use thin CA glue and it works great.
fig.8: CA glue
applicator made from the end of a standard sewing needle chucked into a pin
vise.
That's all for today. More to follow soon.
