The M1 Disaster

[Scott T]

Two thoughts of attaching it:
1. Drill some pilot holes through hull into keel; positioned below; then drill some stainles screws into the keel from inside the hull.
2. More work but ... Put in some rebars (while pouring Keel) that makes a hook shape on top of keel. Make slot in hull that accept hooks
and allows you to quickly attach or remove the keel by sliding the hooks forward or backward.

Right as usual probably use #1! (Keep It Simple Stupid = KISS)

Scott

[Kazzer]

I decided to epoxy the keel into the hull using my usual epoxy material (Gas Tank Sealer) but with a lot of Cabosil mixed in to thicken it to a gel. I died the resin black, just to show it up in these photos.



Even though the resin was a gel, I didn't want it to weep past the hull and keel, so I masked off each side of the keel.




I set the keel in my Workmate vice and discovered it wobbled. If I wasn't careful, I could easily have set the keel permanently at an angle. So once I set the keel in the vice, I checked it was horizontal using a spirit level.



I used a small spatula to work the gel in along each side of the keel, then smoothed it off with a small paint brush.



Next job is to place tabs alongside the edges of the upper and lower hull.

[Kazzer]

I must get the upper and lower hulls to fit together before I do much more. I still have nightmares from the Metcalfe/Darnell S Class I built many years ago, and want this part of the project behind me.



I started off making the material for the tabs to go along the upper and lower hulls. These will be staggered to make them interlock, and hopefully, align the two halves.

I'm not a fan of CA adhesive on styrene and fiberglass, (actually I'm not a fan of CA on styrene at all, it's too brittle and the bond doesn't do well when whacked). So, I'm using epoxy to make the tabs and to bond them onto the fiberglass hull.

In the above photo, I've laid out strips of fiberglass ribbon onto some plastic sheet and coated it with epoxy, then left it overnight to set.

Next morning the strips are peeled off the plastic, then cut into tabs with scissors. At this stage, because they are of thin cross section, the cure is quite retarded, so the strips are very pliable. I've tied a knot in them just to demonstrate this. I also placed some pieces in boiling hot water for 30 minutes, just to check they'll cure properly. (I must stop guesstimating resin ratios). They hardened up nicely when they cooled.

In the little can, (cleaned out cat food can) I mixed up more resin and added about 5 times the volume of Cabosil, to thicken it up. I didn't want the resin running all over the place, and the underside of the hull is rough, so this paste will fill all the voids.





You can see how the resin is gelled up. A dab on each location, then press the tab on, and clean up the spew, and, with luck, we have a winner. I think the thicker gel will set up quicker than the tabs, so I should have some flex when I put the together.

[oztruck]

Great work Mike, very interesting. This hobby is one big learning curve for me.

There is not too many sub builders that I have found here in South Australia, only me and another guy that scratch build a dynamic diving U boat 20 years ago.

So being able to watch your build (over your shoulder) on this forum, is like being there with you.

Keep up the good work and keep the photos coming.

Cheers Chris

[Kazzer]

While I had a batch of gelled resin mixed up to bond the tabs on the hull, I thought I'd deal with the rear dive planes and the rudder bushings.

On the dive planes, I cut a couple of of 1/4" lengths of brass tube and slid them over the planes shaft. I'd previously waxed the shaft, knowing fully well that being a messy bugger, I'd get this goop all over it and bond it in. Sliding the tubes into the walls, then I slathered them with epoxy and smoothed it out. Similarly, I bonded in the rudder bush, but this one was made from some 1/4" diameter brass rod, previously drilled out to fit the shaft.

I used a dummy shaft, that's the bent rod you can see, to locate the bush in the correct position.

I'm still not happy about these darned tabs and lining them all up to get upper and lower hulls to mate correctly. There has to be a better idea than this.

[Kazzer]

As I wend my way through the actual build of this model, I'm also preparing my molds for my first shot at getting some product off.


Here, I've already coated the mold with a brushing of wax, but as it dries, I can see the brush marks. To eliminate these, I've just warmed up the wax with a blow torch until it liquifies and flows out. Now the mold is super smooth and very slick.

[Albion]

What Sub driver are you planning on, the Gato one?

[Kazzer]

What Sub driver are you planning on, the Gato one?

Yes, the M1 uses the Gato Sub-driver.

[Albion]

Shall get one ordered then.

might even work for the T class too , i guess

[He Who Shall Not Be Named]

Yes, the M1 uses the Gato Sub-driver.

That's what I initially told Mike.

However, the SD for the M-1 is identical to the GATO with one difference: The M-1 SD employs a smaller ballast tank.

Should have shots of that SD installed in my M-1 tonight -- I'm also employing the 'semi-aspirated' ballast sub-system in the SD's I'm making for Mike and me; evaluation units. Film at Eleven!

David

[Albion]

'semi-aspirated'

Hmmmmmm. sounds scientific

[He Who Shall Not Be Named]

LOL.

Smart-Ass!

Think: Snorkeling submarine as the occasional wave washes over and shuts the snorkel induction valve -- where does the air for the diesels come from?

That's the semi-aspirated ballast sub-system in a nut shell: With the sail out of the water a float-valve at the snorkel permits air into the snorkel induction line and when the LPB is running, discharges atmospheric air into the ballast tank.

Underwater, the snorkel induction valve is closed, and the LPB takes a suction on the two dry-spaces within the SD to blow the ballast tank dry. The partial vacuum within the SD is broken when the sail breaks the surface.

End game is the elimination of the gas type of ballast sub-system (retained or retrofitted as an emergency back-up), simplification of the ballast sub-system mechanism by reducing part count and set-up/adjustment, and elimination of a consumable.

David

[vital.spark]

David,

Is this why you haven't answered me on the desiggn of the gas saver for my Gato? Will the semi-aspirated ballast sub-system be able to be retro-fitted if it works on your test model?

Regards,

Myron

[He Who Shall Not Be Named]

David,

Is this why you haven't answered me on the desiggn of the gas saver for my Gato? Will the semi-aspirated ballast sub-system be able to be retro-fitted if it works on your test model?

Regards,

Myron

No. First I saw of it, Myron

Yes.

David

[greenman407]

Great stuff guys. May I insert another picture here? Just came across it. In this picture it doesnt seem so big..