BBY Micro Turbine Hydro for SSSH

[Manny]

Dr Jet,
Is the frame work part of the normal build or is it a Santee Lake special build ?

Manny

[Dr. Jet]

I've glued the framework together, and sanded a few spots and it looks like it is going to work. For some reason, I think I'm probably not going to do much more work tonight.

Tee many martoonies:
I'm not under the alcafluence of incohol, though thinkle peep I am. I'm not half as thunk as you drink, yet I fool so feelish........

[Dr. Jet]

Manny,

The framework is a "Dr. Jet - Super-Custom SSSH" build.

If it works out to my satisfaction, I may make them available to the masses.

[Manny]

I am thinking your mini builds will work well at the lake I run in up here in the L.A. area. Hansen Dam. We have some new Mini Rios running here now and I think the guys might be hooked on the small stuff now, plus the bigger faster boats run out of room real fast.

http://www.rcgroups.com/forums/showthread.php?t=501819&page=125

[Dr. Jet]

Manny,

I looked at Tom's (Kmot) Mini-Rio video. You and Tom need to come to Santee and race against our SSSO Geckos. You may be in for a surprise.

[J Solinger]

It looks like a winner. Very nice looking laser work.

[Dr. Jet]

Thanks Joe,

I know your work, and coming from you, that is quite a compliment.

I am making small changes here and there to the drawings to improve the fit. A couple of thousandths here and there kind of thing. The nature of vacuum-forming makes a perfect fit difficult. Randy's molds are hand-made, so they are not 100% symmetrical, If they were CNC machined, I would expect complete symmetry.

My plan is to get the framework close, and take up any gaps with the expanding PU glue.

Thinned epoxy has been applied to the framework. Once cured. I'll glue the tuffing tube to the assembly and be ready for installing the frame into the hull.

[Dr. Jet]

Bearings

I needed to find a way to secure the bearings in the CF stuffing tube, yet still allow removal. Additionally, I wanted to make certain any thrust loads at the prop would be transferred to the inner race only. I did not want the propeller boss rubbing against the face of the bearing. I discovered that a small bit of antenna tube was a snug fit on the 2 mm propshaft and would solve both problems. I can adjust the location of the coupler on the motor shaft so that it just contacts the tube spacer at the motor end of the propshaft. The way this is laid out, the 2 mm prop shaft ends just a few thousandths from the end of the motor shaft. I'll post a photo of this before I glue it all together.

[Basstronics]

Looking good.

How much affect with the large stuffing tube have compared to a smaller tube not utilizing ball bearings?

How big of an OD is that tube anyhow, it does look big...

Also I was wondering if you were going to toss the CAD files up for those of us adventurous enough to make these by hand :)

[Dr. Jet]

The stuffing tube is 1/4" diameter(give or take), and has the same diameter as the prop hub. No problem. It is no larger than your run-of-the-mill strut.

[Dr. Jet]

The framework has been glued in with the expanding PU glue. This stuff foams up quite a bit. you can knock down some of the unsightly bubbles while the glue is curing if you keep an eye on it throughout the process. If not, you will get a bunch of bubbles in the glue like I have here. The glue bubbles have no impact on the strength or performance of the hull, so I'm not concerned about them.

The second photo shows the fit of the prop shaft / motor shaft.

[Dr. Jet]

Time for floatation. I try to make mine structural as well and here is how I do that.

First, I cut the foam to the approximate shape, and chamfered the edges where the glue joint in the hull interfered with the foam. Remember, the fit does not have to be perfect, since the glue will fill in most gaps. When it was time to glue it up, I coated the foam side of the framework with epoxy. Next, I coated the inside bottom of the foam with a zig-zag bead of PU glue. Then, I inserted the foam, taped the framework tightly to the foam, set the sponson on a flat surface, and placed a heavy weight on the foam. A can full of lead shot works great. The idea is to keep the bottom of the sponson flat and not to puff out when the glue expands. I will not put glue in the sides of the sponson just yet, and that will give the glue a place to expand along the anti-trip portion (beveled outside edge) of the sponson.

[Dr. Jet]

I've trimmed the foam and test-fitted the deck. I marked the stringer locations on the deck where I will apply the PU glue. I will also add PU glue to the top of the foam, in the space between the foam and sponson sides (just a little here), and in the front of the sponsons (again, not too much).

Note I have a different beverage of choice this morning.

[Ctonez]

Note I have a different beverage of choice this morning.

Gotta get yer caffeine where ya can...coffee, red bull, Hershey's Chocolate syrup...whatever's around.

Looking good btw.

[Dr. Jet]

I applied glue to the hull halves and I'm about to join them.