Good Afternoon Cliff,
I've been planning on replying to this last post of yours for some time now. But I wanted to build a basic 3D CAD model first, to show you what I was thinking about. Thank you so much for taking the time to give use such detailed information. I for one will make good use of it.
I wasn't sure how you bonded the two main halves or your FRP (Fiberglass Reinforced Plastics) shells together, until I read the below quote of yours.
"The FRP shell had flanges that enclosed the hatch, this centralized the top of shell near the hatch. The bottom of the shell had a cutout and flange for the drop weight cavity. This centralized the bottom half of the shell. I bolted the split mold with the FRP shell parts layed up inside around the pressure hull after I broke off the plug mold. The flanges on the split mold gave the assembly enough rigidity to keep everything where it was supposed to be during the syntactic foam casting process."
So I'm assuming from the above data, that the syntactic foam is the main bonding agent to keep the two halves together, and that you just filling in the small gap on the outside seam of the two halves, with either polyester resin, epoxy, Bondo, or the like, and/or some of the resin poured into the annulus space seeped it's way through to fill the joint. For some time I thought you might of bonded them together from inside before you cast the syntactic foam, or layed down a cloth band of fiberglass in a indentation like the one on my CAD model. I couldn't think of a good way to work inside the two halves, when it was over the pressure hull.
http://www.frappr.com/?a=viewphoto&id=2628470&pid=7128523
When setting up part flanges I like to use clay damming like in the below pictures.
http://www.frappr.com/?a=viewphoto&id=2628470&pid=7161257
I see you used a different material for setting up the flanges. What is the material, and how did you attach it to the mold plug? I was thinking you might of used double sided sticky tape and foam filled sign board. Did you like the material you used compared to clay damming? With clay damming, we can wax a mold plug before we attach the clay and it sticks just fine. Were you able to do that before you attached your plug flanges the way you did?
Regards,
Brent Hartwig
From: Cliff Redus <cliffordredus@sbcglobal.net>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Cliffs - R300
Date: Mon, 16 Jul 2007 21:00:05 -0700 (PDT)
Brent,
There are some novel aspects of the design. After I have some flight time under my belt, I will be able to comment more on what has worked well and what has not. One of my earlier designs was a hybrid with same electric motor and drive train I am now using and a diesel for surface ops. For this first boat, I abandoned the diesel for space reasons and to simplify the design. If I ever scaled the boat up, I might reconsider as it would extend the range. I personally would not consider a two or four stroke gasoline engine for surface operations because of the safety issues associate with gasoline vapors in a confined space. As requested, I have added a few pics to the frappr site of the plug and split molds. Go to the frappr link and hit more Cliff Redus' photos and page down until you see the plug and split mold pics.
http://www.frappr.com/?a=viewphoto&id=2664457&pid=4280217&myphotos=1The FRP components I used for both the split molds and the actual boat shell were:
Resin, GP Polyester Laminating Resin, Aropol L65305-T27 Resin, North American Composites
Catalyst, Nor Norox MEKP-9 Catalyst, North American Composites
Poly vinyl alcohol (PVA), Rex #10 partall Green -5 gal PVA, North American Composites
White Gel coat, Hydroshield Lite White Gel Coat, 50# pail, North American Composites
This resign and catalyst worked well for my FRP layup work and I did not have any problems with the gel coat blistering. I think a low viscosity vinyl ester resin would work ok as well.
Do you think the epoxy resin you used to bind your micro and macrospheres together, bonded well with the the inside of the outer fiberglass hull? I
It bonded very well. I used a epoxy resin that had a slow exothermic reaction and low viscosity to prevent cracking and facilitated pouring the syntactic foam into the space between the steel pressure hull (coated with imron) and the inside of the FRP shell. You can now take a hammer and bang it against the side of the boat and it sound very solid. It needed to be solid as the two ton boat rest on the trailer at only 7 points where the rollers are located.
I didn't see any main seams on your outer hull. I would venture to guess that you made it in two halves, top and bottom respectively, and then bonded them together.
The split mold was in four parts (longitudinal quadrants) and the FRP shell was in two halves, top and bottom as you say and bonded together.
How did you center and attach the outer hull to the inner hull in preparation for filling the annulus space with syntactic foam? I didn't see much in the way of connection flanges on the steel inner pressure hull, to attach the outer fiberglass hull too.
The FRP shell had flanges that enclosed the hatch, this centralized the top of shell near the hatch. The bottom of the shell had a cutout and flange for the drop weight cavity. This centralized the bottom half of the shell. I bolted the split mold with the FRP shell parts layed up inside around the pressure hull after I broke off the plug mold. The flanges on the split mold gave the assembly enough rigidity to keep everything where it was supposed to be during the syntactic foam casting process.
You made a pretty boat, but you already knew that, didn't you.
With so many beautiful and elegant marine life shapes to to use as models ( orka, tuna, sharks...), my goal was to try and incorporate some of their clean curves into the shape . The process was however tedious.
Cliff
----- Original Message ----
From: Brent Hartwig <brenthartwig@hotmail.com>
To: personal_submersibles@psubs.org; brenthartwig@hotmail.com
Sent: Monday, July 16, 2007 8:27:37 PM
Subject: Re: [PSUBS-MAILIST] Cliffs - R300
************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 53 Weare, NH 03281 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************I second that,
I've read allot about using a jet ski type squirt drive in Pat Regan's now dead forum. But it's great to see one that is just about ready to fully test. As I recall Pat was using an older Kawasaki Jet Ski squirt drive powered by a Kawasaki two stroke motor, when on the surface for his mini Nautilus. The parts came out of a Kawasaki Jet Ski used in the movie Water World that was filmed mostly off the Big Island of Hawaii. Then for submerged running, a battery powered Minn Kota motor with it's own prop is used. I wouldn't want to be stuck in that small of a hull with a two stroke motor running for all the noise. The motor might be able to be walled off, and one of the good exhaust silencers that are now used on ATV's installed.
The articulating rear control surfaces on the R300 is also pretty rare to see on PSUBs from what I've seen. I last saw it being used on the Nessa Sub, but with the prop being attached to the end of the assembly, instead of the outlet of a squirt drive and control surfaces. I've been working on a couple of PSUB designs for a couple of years now that have some cross over with those two designs used on the R300. So I hope to learn from your trials and success if you don't mind Cliff.
http://www.frappr.com/?a=viewphoto&id=2628470&pid=6983195
Cliff do you have any more pics of the molds, and the lay-up of the molds you used to make the final fiberglass outer hull? What type of resin did you use for the molds and the final hull? I've been planning on using a low viscosity Vinyl Ester resin like, Hydrex 33253 and infusion molding the final parts. I want to use this type of Vinyl Ester resin so it will bond well will my Vinyl Ester based gel coat, to prevent blistering.
Do you think the epoxy resin you used to bind your micro and macrospheres together, bonded well with the the inside of the outer fiberglass hull? I didn't see any main seams on your outer hull. I would venture to guess that you made it in two halves, top and bottom respectively, and then bonded them together. How did you center and attach the outer hull to the inner hull in preparation for filling the annulus space with syntactic foam? I didn't see much in the way of connection flanges on the steel inner pressure hull, to attach the outer fiberglass hull too.
You made a pretty boat, but you already knew that, didn't you.
Best Regards,
Brent Hartwig
"If you don't have a vision, then your reality will always be determined by other's perceptions."
- Melanëe Addison
From: Brent Shaw <drydivenz@yahoo.com>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Cliffs - R300
Date: Mon, 16 Jul 2007 15:44:45 -0700 (PDT)
>
>Cliff
>
>Excellent to see someone thinking outside the square
>and taking on the challange of designing and building
>something that isn't or hasn't been proven in the
>past.
>
>Brent - nz
>
>
>
>
> ____________________________________________________________________________________
>Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel and lay it on us. http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7
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