Can the rings be pieced together in two or three
pieces?
Brian
----- Original Message -----
Sent: Saturday, August 13, 2005 5:31
AM
Subject: Re: [PSUBS-MAILIST]
extendair
Dan,
I agree with you. Why use nine square feet
of plate for a three foot diameter ring, and pay for having it water jet cut,
when you can purchase a sheet of plate for the hull and have the strips
sheared from the drop then role it. The only thing to be cautious of
when using sheared strips is to be sure the strips are sheared the same width
from end to end. Apparently the back stop on the shear where mine was
cut was a bit farther back on one end then the other. I had to fool with
them to make exact circles.
If you find a shop with roles grooved for
the thickness of the material you need to role on the jack, of course have
them do it but I couldn't so I devised a simple rolling machine out of junk I
had around. It wasn't that difficult to do. The shop I had role
the hull had huge roles and did a very good job with it. They even
rolled the 3/4 thick collar I needed for the intersection of the conning tower
and the hull, but they couldn't role the flat strips on the jack. They
didn't have grooved roles, so I spent a few hours making the wheels and
gathering my junk.
The rings warp so much with the heat of
welding, water cut rings aren't going to be round within a thousandth of an
inch when your finished anyway. The welding jig I used, and stagger
welding, got my frames it within a 1/16 out or round. When your
welding the frames in the hull they move anyway and can be adjusted
by jacking the hull as your welding and by choosing where to weld
when.
There are many ways to do the same job
and get the same result for the same effort. A lot depends
on what you have available and what skills you poses, but then, Dave
does this for a living so he probably knows best.
Dan H.
----- Original Message -----
Sent: Friday, August 12, 2005 6:10
PM
Subject: Re: [PSUBS-MAILIST]
extendair
Dave, With the high cost of steel these days, especially
SA 516 GR 70 can you justify that much scrap ? You still have to shear the
strips for the flange part of the "T" and roll them. It doesn't take that
much more time to shear & roll 6 pcs the hard way ? DL
From: Dave Banks <noperiscope@yahoo.com> Reply-To:
personal_submersibles@psubs.org Date:
Fri, 12 Aug 2005 12:16:08 -0700 (PDT) To:
personal_submersibles@psubs.org Subject: Re: [PSUBS-MAILIST]
extendair
Cliff,,,
You really don't need to build a
rolling machine for 1.5 by .25 steel. I'm sure there are a few weld
shops near you that have one and just have them roll the flat bar for you.
Yes, you have it cut long and then trim the ends. But
you also need to understand that having them cut in a circular form and
welding them together will give you truer circles. This is very
important to the integrity of the pressure vessel. I do this for a
living and you don't need to have the web rolled on edge, the flange, yes,
but not the web. I would not roll them, I would have them water jet cut
and then weld them together. Then they would be within 5 or 6 thousands of
an inch true.
Also would appreciate anyone with pictures or dimensions and
specifications on the rolling fixtures. This sounds like something
that?s going to take a little time to put together and get used to working
with. Of course, it would have to be something that has to be done
early in the project and can?t wait till later. I do, however,
appreciate the fact that I will be doing it myself and learning
another aspect of metal-smithing in the process. Thanks as
Always and Kind Regards,
Cliff McDonald
Hello psubbers, Thanks everyone for the
replies. I?ll go with the rings one way or another. I have a
question about making them. When you start with the flat bar, how do
you get the ends to curl on the same radius as the rest of the band?
I?m thinking I will have to come up with rollers at least 6? OD.
That would mean both ends of the bar will have a couple of inches
that aren?t rolled. Do you cut the bar extra long, roll it to
desired radius and then trim it to length to get a fully rolled piece?
Daniel I sure would appreciate! any pictures you may have of the
rings, especially if you took any during the process of making them.
Also would appreciate anyone with pictures or dimensions and
specifications on the rolling fixtures. This sounds like something
that?s going to take a little time to put together and get used to working
with. Of course, it would have to be something that has to be done
early in the project and can?t wait till later. I do, however,
appreciate the fact that I will be doing it myself and learning
another aspect of metal-smithing in the process.
Thanks as
Always and Kind Regards,
Cliff
McDonald __________________________________________________ Do
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