Seaview SD motor Froze

[Lance]

Help! I took the my Seaview to it's first fun run last weekend and it was terrific for the most part! She's fun to operate and gets a lot attention whether on display or in the water. I have had her in the water about 4 times (~20 minutes each run) when I noticed the speed diminish dramatically on the last run of the day. I took her out of the water and back to my bench for inspection and found that the starboard motor wasn't turning. I took out the SD and turned that motor by hand and noticed there is a lot of resistance in one spot of the rotation. The motors didn't feel excessivley hot, so I checked the impellar/shaft rotations for binding and they seem to turn freely. After a little more inspection I noticed the port motor turns but I feel a little bit of resistance similar to the starboard engine but not as severe. I brought her home and am not sure were to go from here. Does anyone have any suggestions?

Lance

p.s. I did get some pictures hopefully they come through!

[He Who Shall Not Be Named]

Lance,

Good job of trouble-shooting there: you went to the most likely and proceeded up the fault-tree to the less likely. You found the running gear (rotor and rotor drive-shaft) free, then checked the motor shaft extension and found a 'hard spot' in the rotation. That makes the culprit either the motor itself or the shaft seal Oilite bearing.

Sounds like the internal shaft seal Oilite bearing has come loose from the shaft seal body and slide towards the forward face of the motor.

Pop the port shaft seal foundation (that cone looking thingy surrounding the motor shaft extension) clear; look into the base of the thing and push the Oilite bearing 'aft'. If it moved then that was your problem, and apply some CA at the base of the Oilite and plastic shaft seal body (taking care not to get any glue into the bore of the Oilite!).

And while the foundation and shaft seal are clear of the motor-motor extension shaft -- turn the shaft to insure you don't feel that 'hard' spot ... If you do, you're ****ed! That means you have a bad motor and it will have to be replaced.

Reassemble and test for operation. Then leak check the SD before returning to service.

But, I put my money on the shifted shaft seal Oilite bearing being the bad-guy here. An easy fix.

So ... tell me: How did the boat operate? Where you able to establish a reasonable amount of depth control? You've probably discovered that with this boat you need some amount of throttle to get any pitch response to the boat. Give us the good and the bad.

Report!

David,

[Lance]

Thanks Dave,
I'll have a look at it as you suggest and let everyone know what I find.

The fun run was in San Francisco's Golden Gate Park and it's a great place to operate subs, unfortunately we only have it once a year because it is in the flycasting pond and there is a lot of red tape to get the pond for a weekend.
The Seaview was very smooth to operate, the turn radius surfaced was much smaller than when she was submerged. I guess that's no surprise with those fins... Since I am still getting a feel for operating her I tend to keep the speed down. At 1/3-1/2 forward speed I was able to control the depth fairly well, held periscope depth consistenly. If I went much faster she would tend to perform the seaview "crash dive" and head for the bottom. I would override the APC and crank the manta/aft dive planes up all the way with mixed results. I may need to adjust the planes a bit more for that issue.
Overall, I was very pleased with her performance! It was a lot of fun to run and I'll bet I had a boyish grin a mile wide while operating her. This vessel (along with the Disney Nautilus) were my favorite when I was a kid, so there is some degree of satisfying childhood dreams going on here!

Two big thumbs up from me!

Lance

[He Who Shall Not Be Named]

Very good, Lance. I too look like a slobbering idiot when operating my SEAVIEW.

Your experience is consistent with mine: Reduced turning radius submerged, and it gets sloppy in pitch with increased speed.

Did you install the fixed vanes in the nozzles? They help.

David,

[Lance]

Looks like I'm screwed...I pulled off the shaft seal foundation and found the oilite bearing is firmly in the plastic seal body. When pushed aft both moved against the outer rubber seal. When I turn the motor shaft it still has the "hard" spot. So what's the next step? Does Caswell sell motors with the extended shafts or do I come to you Dave?

Lance

P.S. I did install the fixed vanes in the nozzle, I'm thinking that I should set the aft dive planes at a greater angle so as to help force the bow up at faster speeds. Currently they are nominally set with a very slight upward angle (a couple of degrees).

[He Who Shall Not Be Named]

Looks like I'm screwed...I pulled off the shaft seal foundation and found the oilite bearing is firmly in the plastic seal body. When pushed aft both moved against the outer rubber seal. When I turn the motor shaft it still has the "hard" spot. So what's the next step? Does Caswell sell motors with the extended shafts or do I come to you Dave?

Lance

P.S. I did install the fixed vanes in the nozzle, I'm thinking that I should set the aft dive planes at a greater angle so as to help force the bow up at faster speeds. Currently they are nominally set with a very slight upward angle (a couple of degrees).

E-mail me your mailing address and I'll send you a replacement motor with extension shaft.

Yeah, set up bow and stern planes like this: With the bow-stern plane operating servo at neutral the bow planes are at zero deflection, and the stern planes are at about a five-degree 'rise' deflection. That will help keep the boat from 'digging in' when you advance the throttle in submerged trim.

David,
dmeriman@aol.com

[Lance]

Thanks Dave,
I've sent you the note with my address, let me know what the cost is and I can cover it.
Meantime I'll adjust the aft dive planes a little more.

Lance