Craig,
Is this the local company your referring to http://www.lbicorp.com/navsea.html
I've saved allot of data from Flotation Technologies in the past, but Engineered Syntactic Systems was new to me, so thanks for the link. I'm getting ready to test out my ideas for infusion molding my own syntactic foam, because most of the places I need syntactic foam are odd shapes that would waste allot of foam if I cut it out of existing block, and I should get a higher quality foam with less microsphere breakage then hand mixing it like Karl did. To keep the microspheres from being taken into the vacuum pump I'll be using some small inline filters. But there are some applications that I would like to acquire pre-made blocks of foam for.
Of course your right about there being a major difference between 3000 MSW and 2000 FSW, but 2000 FSW is still no picnic pressure wise. As most of us are aware, not all syntactic foam is created equal.
I've sprayed several gallons of a Rhino lining type product call Rattleguard, and I would expect that it or Rhino brand would work well if applied in a thick coat over a rough sanded syntactic foam surface. I would do a test are to make sure the solvent in the coating didn't eat the type of resin used in the foam. One advantage in using Rhino, is that Rhino cures much quicker then Rattleguard, being dry to the touch in about ten seconds. That wouldn't give it much time to eat away at the resin. One great thing about Rattleguard is that it can be smoothed out or removed by sanding with no real trouble. So if you make a mistake or need to remove it for any reason you can do it readily. Also you can brush or roll on in areas that you can't spray it on properly.
Yes I also have reason to believe that Schilling and Sub-Atlantic had a friendly split. I suspect they have an agreement of some sort to still work together on allot of projects, and since Sub-Atlantic sells thrusters as a very large part of there business, the ring thruster might of really hurt there business. Another reason might be that some of the parts of the ring thruster,like the special magnets from NASA as well as other parts make it a very expensive unit. Also since most commercial ROV's are tethered with unlimited power available to them, having very efficient electric ring thrusters is not really needed. So why not just use cheaper models. The older Quest WROV's that Canyon is still using, still have ring thrusters on them, so they must still be working ok. A Schilling rep I spoke to some time back, said they are not selling the ring thruster to new customers, but are still supplying parts for existing units.
Regards,
Brent Hartwig
From: cbussel@comcast.net
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Syntactic Foam used on Schilling Robotic's Quest WROV
Date: Sun, 30 Dec 2007 00:51:39 +0000
Brent,
There is a major difference in the density of material that is used in say a 3000 msw syntactic flotation to a 2000 ft rated syntactic such is on Karl's sub. A couple of good sources for info would be Flotation Technologies www.flotec.com and www.esyntactic.com. If you are interested, a company not for from me, LBI in Groton, CT sells the material to make your own or they can make it for you.
Another good source would be Nuytco, they use formed syntactic blocks on their Deepworker submersibles.
Another material that I have seen on work ROV flotation is Rhino lining, I am not sure what kind of success they have had though, if anyone out there knows be sure and share.
As for as the ring thruster, I believe that it was originally developed by Harbor Branch and Schilling bought the rights to it. They still sell the electric Quest, but they are using the Sub-Atlantic thrusters in the design. Even though the two companies split up, I could be wrong, but it was a friendly split.
--
Craig Bussel
1660 Center Groton Road
Ledyard, CT 06339
860.961.8023
-------------- Original message --------------
From: Brent Hartwig <brenthartwig@hotmail.com>
Greetings Mates,
A good friend of mine used to work for Schilling Robotics as lead designer and assembly manager of
the Quest WROV unit. I was asking him questions about it's systems and syntactic foam parts
and learn some important things. The early prototypes of the Quest WROV used fiberglass
covered syntactic foam that was rigidly bolted to the ROV's framework. This turned out to be
bad for very deep dives, since the syntactic foam, fiberglass, and frame expanded and
contracted at different!
rates
under great pressure and cold. Mostly resulting in the fiberglass
cracking and separating from the syntactic foam and stress on the bolted contact points. So for later models they no longer used fiberglass over the syntactic foam, but just a thick layer of gel coat or other more elastic coating. Then the syntactic foam was attached to the framework with urethane mounts, that are allot like motor mounts, to allow flexing between the different materials in the assembly.
Now keep in mind this was for a ROV rated for 3000 MSW and for some models 6500 MSW.
In the pictures in the link below you will also see that the Quest WROV has electric ring thrusters on it. My friend also was a large part of the ring thrusters design as well. An
interesting note is that there was a special ring thruster motor that served as the hydraulic
pump for the ROV's systems, like the manipulator arms, because of the great efficiency of that motors design.
Now that Schilling Robotics is no longer merged with Sub-Atlantic, perhaps they will now bring back the ring thruster as apart of there product line.
http://questrov.com/
I'm interested to know how well Karl Stanley's sub Idabel has held up in regards to it's
syntactic foam being covered in fiberglass and being attached directly to a steel hull that
regularly goes down to 2000 FSW.
Regards,
Brent Hartwig
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