Tuesday 4 Dec 2012, 5pm
I’ve been a bit busy since my last blog.
Friday was a learning experience. I wanted to preform mounts
for the swingarm components, which are seen here after spraying with etch
primer. The tubes were later sheathed with a layer of
fibreglass and the smaller aluminium components were coated with epoxy, to
prevent contact of this metal with carbon fibre and consequent galvanic
reactions.
Which I realised was going to be inordinately complicated to
cast with the components in situ, and decided that night that it would be
rather easier to fit the components after casting the swingarm.
On the weekend I took a couple of days off and drove up into the forest at the end of our
road with Chris and David for the purpose of arting. Much fun was had by all.
Here’s the result (all pastel and Charcoal) –
Sylvester’s (Saturday)
Mt Walker (Sunday)
In the Creek (Sunday)
My first artistic efforts in three years. Not much to do
with engineering, but this is my blog after all.
Yesterday I got stated on the carbon fibre (that’s ‘fiber’
to any Americans reading this) components. I started by making two new cores
for the swingarms from surfboard foam.
Then I started wrapping them in carbon socks
This shows the materials used in the wrap. Unidirectional at
top and two diameters of sleeves below. The smaller sleeve (32mm) is stretched
and consequently the weave is more across the component than the 64mm tube, thereby
giving a couple of different directions of weave to combat twisting. The
unidirectional gives strength along the spar. Thirteen layers in all, giving
about 6mm walls to the tube. A bit over the top, really.
About ten layers at this stage.
This is the final tube assembly with the materials for the
layup, firstly peel ply (which I stitched in place), then breather fabric
(allows the resin to flow around the outside of the component) and finally the
transparent bagging plastic. All materials came from playwithcarbon.com
This is the part ‘in the bag’. Mastic used to seal the edges
and inlet and outlet ports fitted with extra breather under them (unnecessary,
as I discovered).
This is the vacuum pump and catch pot (for excess resin
drawn off the casting) in action
And this is the layup with vacuum applied (14 pounds per sq
inch, or one atmosphere), no resin introduced as yet
And here we go with the resin. The tube between the inlet and outlet is clamped during infusion, then opened to apply suction to both ends of the layup. Carbon nanotubes mixed in the
resin give it its black colour (Americans read 'color'). Fingers crossed.
Unwrapping at 9 last night –
Needs a bit more force –
Finally naked –
Today I put the second arm in the bag and proceeded to clean
up the first arm (has a note of cast iron when you bang it on the fireplace) and ready it for
it’s metal components. Apologies for the quality of the next few pics, didn’t
realise the camera was on the wrong setting until much later. Clamp the arm in
the jig –
Drill out a couple of holes and then bolt the arm through
these to drill the rest of the holes.
Preparing the jig, sealing with plasticene and bagging
plastic. It leaked. You can see the aluminium tube has a layer of
fibreglass on it.
Finally woke up to the camera setting -
Pouring resin mixed with nanotubes into the swingarm to anchor the metal components. That’s it for today, hope you’ve enjoyed my first foray into resin infusion. I’m nackered. Bottling elderflower champagne in the morning for a change.
This is a bit beyond me Mick, in fact, WAY beyond, but I'm sure all will be revealed in the fullness of time.
ReplyDeleteI like the progressive cubism in your art.
Ron
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ReplyDeletePS I like the detailed photos too. Have you done resin infusion before?
ReplyDeleteHi Ron, no I haven't, it's a steep learning curve. Done a fair bit of fibreglassing though.
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