Re: 11112: cooling attempt to prevent warping
- Going to try another technique, of reducing the time of welding, and
shorten the welds considerably while using the LN2, so that the metal
will not heat much at all.
I was making welds sometimes, 3/4 to 1 inch long while using the LN2.
I was defeating the cooling process by keeping the weld time/length
Something that I had to learn through trial and error ;)
Other than that, the cone which was done, is under about 50/1000 for
the 11 inch (about 10.95 after hammering into circular shape).
It will have to be discarded, since it didn't achieve the diameter.
Aside from this, no focus has been made on the frame or rings. They
appear to be fine, as well as the osc table.
--- In firstname.lastname@example.org, "demondoppel" <mattihorn@i...>
> Okay, tried this new technique for welding the skins together.
> I used LN2 (liquid nitrogen) to cool the entire cone, prior to
> It worked, and the LN2 stayed in the cone, about 1 litre, for asome
> duration of at least 30 minutes. Enough time to weld the cone skins
> The warping factor was reduced dramatically, but still there was
> occurring. I did not have the LN2 all the way up to the lip. It wasthe
> sitting about 10 cm (4 inches below the lip). This is probably why
> warping occurred.vapour
> Estimate about 3 litres of LN2 would be required to fill the entire
> cone to top.
> It's about timing, since the boil off is steady. If a cloud of
> gathers above the LN2, it slows down.heating
> The entire cone becomes a big frosty.
> The welding discolourations appear to be narrower, since the
> is reduced. Of course, if the arc is applied too long, the warpingis
> factor increases. again it's about timing.
> The lip of the cone still tends not to uniform, there is some
> distortion which will have to be removed through hammering, which
> another problem for keeping the edge of the cone true. Careful workof
> THe biggest cone being the most difficult, and then getting easier
> the middle and then much easier for the smallest. In fact thesmallest
> reveal the least amount of warping.
> That's it for now.