On Fri, 18 Nov 2011 00:41:46 -0800, Erik wrote:

In article ,
Tim Wescott wrote:

On Thu, 17 Nov 2011 14:58:34 -0800, Erik wrote:

In article ,
Tim Wescott wrote:

I'm building model airplanes. Nearly everyone bends up their
landing gear out of music wire (0.9% carbon, low alloy, hard drawn
wire), and either holds the wheels on with these really ugly
collars, or they epoxy on washers.

The washers won't come off when you want them to, and do come off
when you don't. I'm thinking up a few schemes to do a nicer job,
some of which would go a lot nicer if the steel were drawn a lot
more than it is. I don't want to go using my nice 5-44 die on hard
steel, nor do I want to try drilling .050" holes.

So: how to anneal, and how to just draw the temper a bit more? For
annealing I expect that I can just clamp the thing in my vise (both
to hold and to limit heat travel), get the end as hot as it'll get
with a propane torch, and let it cool. To just draw it, should I do
something like filing a spot shiny, then heating it to blue or
purple, then letting it cool? Or is there a better way to do this
by eyeball methods?

Comments appreciated. I know how to make it work with rocks and
sticks, I'd just like pointers on using hammers and screwdrivers for
the job...

Way back in my model airplane days (c. early/mid 60's)... seems like
we would find (or make) a brass washer that fit snug over the end of
the axel; put on the wheel, a thin 'shirtboard' type cardboard
'washer' to act as a spacer, then solder the on the washer with the
soldering gun. Once cool, the cardboard spacer was torn out. If one
were to mess with the axle length, find the right washer and really
get everything super clean before soldering, they'd look very
professional with the end of the axle not even visible. Last for eons
too. You could even R&R the wheel assy without much trouble.

These were large control line models, and the axle's were probably on
the order of at least .125"; maybe even a little larger in some
cases. Wheel hubs were aluminum. I recall never having any solder
other than 60/40, and a little white metal tub of that 'no-corrode'
(sp?) rosin flux (which I really haven't made a good dent in to this
day).

I recall neither collars or epoxy... well, some people might have
been using epoxy back then, but certainly not for wheel retention.
(Ambroid and white glue were the adhesives of the day, neither of
which bonded well to metals.)

IIRC, some axel/wheel assy's required both inboard, and outboard
washers.

Practice with some scrap first.

I should try it. Seems like I'd just succeed in melting my wheel hub.

With plastic wheels/hubs, I'd guess they'd melt for sure. You have to
pour some good heat into that music wire. All my wheel soldering
'experience' was with rubber tired Aluminum wheels.

An aluminum hub would be no problem. Modern wheels are mostly plastic
hubs (which is certainly nice and light), and most of those are probably
the highest-quality styrene that can be had when buying from the lowest
bidder.

--
www.wescottdesign.com