Jeff's Type VII project

[fwjeff]

Next Progress (2)

Next note, hit the five picture limit! I was having some air getting trapped forward of the air bottle so I lowered it about 1/16th inch. This reduced the width of the sealing area at the top. The last two are under way. I'm still learning to control it. Getting the hang of it fairly good, at least no power dives into the pool liner or breaches with the sub flipping upside down! So far I'm running without the ADF connected. Now that it's balanced pretty good & I'm figuring out how to use the dive planes I'll turn it on pretty soon. Did find one problem today, the equipment chamber is leaking quite a bit, I think it's one of the motor shaft seals.

[He Who Shall Not Be Named]

Pull the core out the tire valve, slip a hose over the body, blow into it (holding the forward and after caps by hand so they don't unseat) and stick the whole SD underwater as you look for leaks. It it's a seal, replace it. You need spares -- let me know.

dmeriman@aol.com

David,

[pjdog]

Looks good to me. I'll have to find out who you got the brass kit from. I really like it. Type VII's are my thing.

Jack

[fwjeff]

Hi,
Thanks Dave! I spent a good part of yesterday troubleshooting. On the good side it kept me out of the basement! I was trying to figure out where the water was getting in by sealing off different areas with RTV but that didn't work. My wife looked at it (she also figured out what was wrong with my car once too!) & while she was running through what I was checking it dawned on me to pressurize it & look for bubbles. It was the port engine shaft seal that was leaking. I ordered new seal a few days back, both to cover this leak and for spares. Does the seal from Caswell include the plastic bushing and the oilite bearing or will I need to dissassemble mine to replace the seal?

I also finally connected the ADF, wow does that work nice!

Hi Jack,
The brass I'm making up by hand. It actually is much easier than I thought. The one thing I did learn both for the wintergarten and deck rails is to do them on a piece of wood for a jig. I re-did the deck rails this weekend & they turned out really good. Layout the shapes on the wood. bend up the top rail (one piece) and leave some extra where it goes through the deck, tape it to the board. Do the soldering on the inside of each rail. Next cut the vertical posts longer than needed & solder them to the top rail. I'm just using electrical solder & it is adequate, silver would be better. Put in the horizontal rails the same way. Cut to fit as close as possible & make sure everything is square & flat. The last part is the tabs for the ropes between the fore & aft rails. I had some sheet brass tabs from a wooden ship model that I cut down but otherwise just cut these from sheet stock. Take the rail off of the board & file down excess solder, this will also find the week spots! Drill the deck & slide the rail ends through & ca them to the deck. Cut off & trim the excess. One other thing, I added some small tubes to the areas where the radio antenna wires goes past the wintergarten rail & the stern mounts, it is about 1/64 diameter that I got from Squadron Signal & it's listed as machine gun barrel tubes for aircraft models.

[He Who Shall Not Be Named]

Hi,
Thanks Dave! I spent a good part of yesterday troubleshooting. On the good side it kept me out of the basement! I was trying to figure out where the water was getting in by sealing off different areas with RTV but that didn't work. My wife looked at it (she also figured out what was wrong with my car once too!) & while she was running through what I was checking it dawned on me to pressurize it & look for bubbles. It was the port engine shaft seal that was leaking. I ordered new seal a few days back, both to cover this leak and for spares. Does the seal from Caswell include the plastic bushing and the oilite bearing or will I need to dissassemble mine to replace the seal?

I also finally connected the ADF, wow does that work nice!...

You'll receive a seal body containing a rubber cup-seal and an Oilite bearing. You pry the cone shapped seal foundation up and off the face of the motor bulkhead -- no need to remove the motor, leave it there. Push the old seal out of the seal foundation, not hard as its secured in place with RTV sealant. RTV the new seal body into the foundation, slather some RTV at the base of the foundation, and slide the whole affair down on the motor shaft to the point where the seal foundation adhesive makes contact with the face of the motor bulkhead. Let the RTV cure for 8 hours, then leak check and you're good to go.

Keep us informed on how it goes. And take pictures and post so the rest of the mob can see how to replace a shaft seal.

David,

[fwjeff]

Thanks Dave,
Sounds like it will be pretty quick to change. I'll take the pictures & post them. Yesterday I had added some RTV around the shaft & it stopped the leak so that was definitly where the problem was.

[He Who Shall Not Be Named]

Thanks Dave,
Sounds like it will be pretty quick to change. I'll take the pictures & post them. Yesterday I had added some RTV around the shaft & it stopped the leak so that was definitly where the problem was.

Something you might want to check:

Sometimes it's not water/air getting around the shaft/seal interface. Sometimes its water/air getting by a void in the RTV sealant between seal body and foundation. Do the leak check again with that in mind, Jeff. The fix is simply to goop on more RTV onto the face of the foundation at the circular seal body/foundation glue line.

David,

[fwjeff]

HI,
That's a good point! I had removed the spare pushrod seal from the center & filled the hole with RTV. There was a pinhole that I found there too.

I was working some more on final trimming the sub tonight. I have the surfaced & submerged conditions level & with the surfaced condition with a good waterline. The problem now is with the tank flooded it sits with the main deck about 1/4" below the surface with the air tank empty. Would it be better to remove foam or add ballast at this point?

[fwjeff]

First open water tryout

Finally took the VII out to the local boat ramp. The water is pretty shallow there so I could only dive a foot or so, but enough for the first try!

[He Who Shall Not Be Named]

Cat got your tongue, Jeff??!!! ... let's hear about it: what went right; what went wrong.

REPORT!

David,

[He Who Shall Not Be Named]

HI,
That's a good point! I had removed the spare pushrod seal from the center & filled the hole with RTV. There was a pinhole that I found there too.

I was working some more on final trimming the sub tonight. I have the surfaced & submerged conditions level & with the surfaced condition with a good waterline. The problem now is with the tank flooded it sits with the main deck about 1/4" below the surface with the air tank empty. Would it be better to remove foam or add ballast at this point?

Charge the on-board bottle with propellant -- that puts about an ounce of liquid in there which should put the waterline (in submerged trim) near the top of the sail, about level with the bridge deck.

David,

[fwjeff]

Ok, lets see how much I can remember!
What went good:
1) The plastic components in the kit are very well done, In particular having everything drilled for both the pivot and the cable guard pins.
2) The SD worked very good. Adjustments & seal replacement is pretty easy.
3) The rudder drive gears work very good. I added brass sleeves for the pivots to ride in & held the center gear in with a wheel collar which can be removed for repairs through the stern torpedo tube. Also cut down the width of the rudder gears a bit to get as much travel as possible.
4) the ADF & SNORT both work very good. Both are easy to set up.

What didn't go as good:
1) I didn't try to use the white metal bellcranks, the rear one broke & fell apart pretty easily - I made brass ones & soldered them to the pivots.
2) The electrical insulation for the radio antenna was weak. After installing the wires it shorted to the aluminum plate & fried the speed control - I added a tube along the top of the SD & ran the antanna through it & sealed with epoxy.
3) Instructions for locating the SD in the hull would be helpful, I just set mine where the dog bones & drive shafts ended up.
4) I used the Nautilus wood deck. Looks great but problems with warping, expansion & it's pretty delicate. It has the slots cut out but they are too narrow to really let air or water through anyway.

Wish list:
1) Different drive motors. Maybe a smaller single motor running a gear reduction. More precise low rpm control would really be nice.
2) Make the Raboesch props a kit option - I ordered a set recently, just waiting for them to come in.
3) Add a couple more deck magnets and deck support perches to the kit.

[He Who Shall Not Be Named]

Very good critique. Much appreciated.

Yes, the beast is way overpowered, and the single motor idea is good -- something I'll look into when the torpedo work is done.

The antenna shorting issue: I assume that when the internal antenna conductor made contact with the aluminum device foundation it glitched the receiver and all devices went 'crazy', including the ESC? If you disassembled the aluminum foundation and re-installed it forgetting the antenna lug Nylon insulator boot, that could have been the cause of the antenna short?

Sorry about the failed bell-crank. White metal is the best substrate I can employ here for their manufacture. I could increase the cross-section of them, would that help do you think?

Yeah, the SD and fittings kit don't have any instructions -- something I'll have to address. But you got it right as to SD location in the hull: position of the SD in the hull is dictated by dog-bone length.

As to your need for more magnets: Maybe the deck is too tight atop the hull, popping it up off the flange? Try shaving the edges of the removed deck so it makes a non-interference fit to the hull.

[fwjeff]

Hi,
The nylon bushing was a bit thin & it moved a bit allowing the stud to contact the aluminum plate. I turned it on & the servos responed ok but no motors, a few seconds later smoke & it actually sprayed some solder out of the speed control! Quite impressive reminder what even a smaller battery can do.

Not sure on the bellcranks. I lean towards brass (1/4 strip, .016 or .032). It holds up well with all the pushing, pulling, & bending I subject things to.

The fit is ok & I had enough magnets for the deck but not the conning tower. It was ok though since I wanted it attached to the deck to strengthen it. Of course I ended up with a few clic-ons extra. Oh yeah, I forgot to mention these in the "worked good" These are perfect for the pushrods!

I'm not sure how small a motor would work but there are some really nice coreless motors being used in planes now & they are really small so the motor & gears would fit well within the existing space. Of course the ultimate would be a three stick transmitter & running both props separatly!

[He Who Shall Not Be Named]

Hi,
The nylon bushing was a bit thin & it moved a bit allowing the stud to contact the aluminum plate. I turned it on & the servos responed ok but no motors, a few seconds later smoke & it actually sprayed some solder out of the speed control! Quite impressive reminder what even a smaller battery can do.

Not sure on the bellcranks. I lean towards brass (1/4 strip, .016 or .032). It holds up well with all the pushing, pulling, & bending I subject things to.

The fit is ok & I had enough magnets for the deck but not the conning tower. It was ok though since I wanted it attached to the deck to strengthen it. Of course I ended up with a few clic-ons extra. Oh yeah, I forgot to mention these in the "worked good" These are perfect for the pushrods!

I'm not sure how small a motor would work but there are some really nice coreless motors being used in planes now & they are really small so the motor & gears would fit well within the existing space. Of course the ultimate would be a three stick transmitter & running both props separatly!

Sorry you slicked the ESC -- not cheap and a ***** to swap out, not to mention the aggravation. I'll modify the motor bulkhead assembly procedures to pay more attention to the insulator installation with a check of continuity between the antenna stud and aluminum device foundation (as in, 'no' continuity).

The Kli-Con linkage magnetic connectors was an idea originating with Brian Stark -- he showed me his arrangements at the 2006 Carmel SubRegatta and I was sold! The rest, as they say, is history.

Yeah, some day we'll be compelled to go the brushless motor route. When we do we'll have a wide range of sizes, capabilities, etc. Not to mention the loss of what is now the most electrically 'noisy' element of the SD -- all that arcing and sparking between brushes and commutator. I'm getting tired of soldering noise-suppression capacitors to each and every motor I install!

As small as ESC's and other devices are getting, soon we'll have room to put two ESC's in there so you can have your precious differentially running shafts. Just a matter of time (I love the MTronics line of ESC's!).

David,