[PSUBS-MAILIST] Viewport Question.

["James Frankland" <james@guernseysubmarine.com>]

Hello All.

Quick question regarding viewports tolerance.

Ive started machining and have done 2 at the moment.  Ive machined the depth of the bore to be exactly 1.25 inches as per the plans, and the inside diameter i have machined to 8 inches plus a clearance of 0.5 mm to allow the lense to drop in.  (sorry, the plans are imperial but we're metric here, so its a bit of both).

Im not making the acrylic lenses myself, i will buy them (probably from psubs store).  Assuming they come in exactly at 8 inches OD, as things are they should slot in nice and tight.

But Dan H mentioned to me that he got some slight distortion on the ports after welding.

So the question is, do you think 0.5 mm clearance is enough?  Obviously i cannot alter the ports once they are welded in, and don't want to have to start machining the lenses, they must fit.

You can have a look here as usual.  Some of the text titles are wrong.  I'll change them later.

http://www.guernseysubmarine.com/index_files/Page7497.htm

Any thoughts?

Thanks
James




----- Original Message -----
From: Jay K. Jeffries [mailto:bottomgun@mindspring.com]
To: personal_submersibles@psubs.org
Sent: Mon, 10 Dec 2007 20:16:42 -0500
Subject: [PSUBS-MAILIST] Digital Multi-Frequency Scanning Sonar

Here is what looks like a great scanning sonar for a PSUB.  If it is priced
like some of their other products, it should be a great deal.



http://www.imagenex.com/html/881l_imaging.html



R/Jay





Respectfully,

Jay K. Jeffries

Andros Is., Bahamas



A skimmer afloat is but a submarine, so poorly built it will not plunge.