On Tue, 26 Mar 2013 15:19:52 -0400, "Existential Angst"
wrote:

OK,

Apropos of my wiper Q, here's more info, with another Q.....

Since I don't think this wiper thing is going to be so easy to solve, and
since from a sliding/friction pov it don't get much worse than alum on/in
alum, I'm experimenting with making the slider ITSELF out of a
nylon-ish/UHMW material. Altho I would still like a wiper, a plastic slider
(and the lubricity thereof) should intrinsically help, from a
friction/galling pov.

So the Q is: what would be a good substitute for the alum slider? I'd like
a good combo of strength and lubricity, as stuff is attached to this slider,
via 10-24 screws, 3/16 pins, etc. The 10-24 screws will not be threaded
into the slider itself, but rather thru the slider and into another pc of
substantial alum.

I've always liked nylon, delrin, teflon. Nylon seems to be a kind of ref.
std, ito plastic strength, durability, and it seems that altho it doesn't
have the lubricity of delrin, it's OK. Would delrin be better? Anything
else?

fyi, the actual size of this particular slider is approx. 3/8 x 3/4, with a
1/8x1/8 rabbet on each side (so the captured sliding part is 1/4 x 3/4),
with a 4.5" L

Any class of materials I should specifically avoid?

Idears, opinions?

I suppose I could test various materials, by buying or making something of a
power hacksaw, and just let various materials reciprocate for a few days,
see what stuff looks like at the end. Hopefully I won't have to go that
route, tho.
For the best combination of slippery and mechanical strength Delrin AF
would be best. It is very slippery, more rigid than UHMW, machines
easily without making problematic chips, is easy to deburr without
making another burr. It's expensive but then you would only need to
make it once. It is about as slippery as UHMW.
Eric