BBY Micro Turbine Hydro for SSSH

[Dr. Jet]

Sketches

Here is a preliminary sketch of the forward bulkhead based on the published dimensions of the MHZ propshaft. I'm thinking of running a "spine" down the centerline of the stuffing tube to keep it from flexing.

[Dr. Jet]

I have been doing some research on the seller’s store for the “Spec” motor supplier. He has some 9-gram servos in a six-pack for about $5 each. I may add a servo mount in that spine I am planning and size it for these servos. That way, if you get the motor from them, you can order a servo and possibly save on shipping costs.

I have more ideas on this topic that I will reveal when the time is right.

[RandyatBBY]

what you just said makes me feel alot better, i got my boat up for sale now, i have to sell my other boat in order to build one of two of these boats. i kind of like the mhz shovel nose, and the geko.

That is one thing I hate to do sell one project to fund another. That is a last resort to me. The BBY hull is real cheap.

[RandyatBBY]

What is the transom width and height on the bby hydro? I will do some chewing on it.

The way I build mine I measured 7/8 of a inch for the transom and my bracket is 3/4 of a inch. It would be nice to have a machined bracket, I will be watching to see what you do.

[Dr. Jet]

Randy,

My preliminary plans are to have the front edge of the prop hub (where a drive dog would normally be) ½” behind the transom and ½” below the bottom of the hull (even with the sponson bottoms). As you can see from the sketch, I will have about 6-1/4º of “down” angle at the prop. The Graupner props are very similar to an Octura “X” series with some tongue removed, so I gather they are low-lifting like the Octuras

[Darin Jordan]

Seems like a perfect application for a .047" Wire Drive...

[Dr. Jet]

Wire Drives

I have successfully used 0.030" wire drives in my other SSSH models. I wanted to do this one with a straight shaft to keep it simple and cheap.

[Dr. Jet]

MHZ Rudder

Here is an interesting tidbit. I just received an email from MHZ telling me the rudder assembly I have is no longer available. I sent a response with the part number I have, just to confirm. I’ll let everybody know what the response is.

Joe,

If you are reading this, then the need for a decent micro rudder has moved up the priority scale, and you may be just the person to “do it up right.”

[Dr. Jet]

Fast Response from MHZ

I just received a response from MHZ to the email I sent out a couple of hours ago. This email said the rudders are temporarily out of stock and should be back in stock very soon.

Still, I think Joe could come up with something way cool.

[J Solinger]

I am curious to see how the straight drive shaft works out. I have been designing around a wire drive but a straight shaft would simplify things a bunch, and reduce costs.

[JimClark]

With the motor so far forward isn't it going to mean the battery is going to be midships and the CG will not be in a good position?

Jim

[JimClark]

Being the scale geek that I am having the prop so far back of the transom just looks very wired to me. Does it really need to be back so far?
Jim

The way I build mine I measured 7/8 of a inch for the transom and my bracket is 3/4 of a inch. It would be nice to have a machined bracket, I will be watching to see what you do.

[Dr. Jet]

I am curious to see how the straight drive shaft works out. I have been designing around a wire drive but a straight shaft would simplify things a bunch, and reduce costs.

Bullseye Joe, that's the whole idea!

[Dr. Jet]

Progress

I've been working on the drawings, all that remains is the transom and the cross-pieces at the front.

I printed the drawings and ironed them onto some balsa for a test-fit. Here's what I have thus far.

[G Doggett]

Being the scale geek that I am having the prop so far back of the transom just looks very wired to me. Does it really need to be back so far?
Jim

I'm with Jim, I don't mean to be critical but why on earth is the prop so far behind the transom ?
This 'stinger' type strut is only used on DV hulls to get the prop in clear water, hydros work fine with the prop close to the transom.
Graham.