[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PSUBS-MAILIST] alec smyth--mk 101 question

Alec,

Sub-conn? Ouch, as I remember, at least when the bill comes due. I'll contact them, however.

My K-boat has a real lash-up for penetrators. Being upgraded as it was from a 250 to a 350 at a flat rate, George went expedient, rather than expensive. The big 3 hp motor (which I am discarding) has a balanced pivot point top and bottom. The top one rides on O-rings and a delrin bushing, and is supported by the MBT frames, and a heavy pipe running through the hull. It seems to have worked well enough, but makes me shudder a little, looking at it today. And the side units were, as you talked about, using more delrin plugs, drilled for the wire size, and then RTV'd to a fair the well (as was the aft unit).

I am hoping the fixed 101s will give me enough umph to do without all the thru-hull rotating bits and pieces--not so much because I don't like them, but to keep things simpler for the pilot, who always has his hands full with motors and switches. My intention is to incorporate all four controllers, plus voltage and amperage meters, in a small, hand held consolette on a cable, so you can sit the thing in your lap and do something else from time to time, and not have to worry about steering. We'll see how that works out.

Thanks again for the input. I'll be testing the motors with and without oil, once I get the penetrators, both for pounds thrust and for amperage, so I'll keep you and the crew up to date as this progresses. It'll be fits and starts, I'm afraid, as I have a knee replacement scheduled for June 3, which will be annoying (to say the least) but not nearly as much as limping around.

Are you going to the Castine meet? I'm thinking about doing that again this year. It would be awfully nice to see George again, and, of course, psubs is a great bunch of maniacs to hang around with. Thanks again.

Vance


-----Original Message-----
From: Smyth, Alec <Alec.Smyth@compuware.com>
To: personal_submersibles@psubs.org
Sent: Mon, 28 Apr 2008 9:49 am
Subject: RE: [PSUBS-MAILIST] alec smyth--mk 101 question

Hi Vance,
 
Believe it or not, my setup in the K boat is so basic I haven't even got a current meter. I can tell you, though, that from the seat-of-the-pants perspective I cannot tell any difference. Each thruster has a distinctive sound, and that sound to my surprise didn't change a bit when I filled them. Nor of course did the thrust. It is entirely logical the motors should be pulling more current, since they appear to run at exactly the same speed. But I'm not sure how much. 
 
Sub-conn has a "high power series" that includes a 4-conductor penetrator good for 50 amps per conductor. That happens to be just right for most trolling motors, so long as you're running 24V or 36V. I run the K boat stern thruster on one of these, and have another installed on the project boat which is still far from getting wet.
 
This brings up something I'd like to ask you about. What did you do about penetrators when your K-250 was "standard"? The side thruster penetrators are the one thing I'm unhappy about with mine. The challenge is that those thrusters are shaft-mounted, and if you want to put the penetrator on the inboard end of the shaft, space is tight. I used some Seacon rubber molded series penetrators that I had lying around. By machining down the plastic body of the penetrators, they can be screwed into the thruster shaft and then pushed through the through-hull. It's not a legit installation, the penetrators are under reverse pressure and I sealed the threads, whereas they were designed to seal with a (now machined off) o-ring instead. They do seal fine, but the problem is they have low amp contacts, which heat up if I run the thrusters continually for too long. I'm very interested to hear what you or others came up with for this particular problem.  Kittredge, if I remember correctly, just had a drilled rubber stopper cable squeeze arrangement. If I weren't building a new sub, I'd be redoing these penetrators to try something else.
 
 
thanks,

Alec
 
 


The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it.

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of vbra676539@aol.com
Sent: Sunday, April 27, 2008 4:07 PM
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] alec smyth--mk 101 question

Alec,

What amperage difference did you see, if any, after filling the 101s with oil? The factory says 60 amp breakers, but my local guy is using 40s for the motors, plus the rest of a flats skiff's electrical system. Is that going to be enough? I'm about ready to plunk down for some penetrators, too. The motors use 10 gauge wire, and I'm going to contact Impulse to see what's what price wise. Any suggestions?

I'll be running four fixed thrusters, two aft on either side of the fairwater tank, vectored at 30 degrees toward each other, and two more just forward of the conning tower at forty-five degrees for vertical and lateral. It works for Phil, so I'm hoping it will for me, too. I'll let you know. Any suggestions on the penetrators? I've been out of that market for awhile, so having some idea of current pricing will help. If you did it cheaper, then count me in.

Thanks and Best Regards,
Vance