BBY Micro Turbine Hydro for SSSH

[Dr. Jet]

I've used that method as well. A wheel collar or a piece of fuel tubing will hols the prop on. I've found that the K&S 1/8" SS tube is actually a few thousandths bigger than 0.125".

Now this is a bummer. I went back and read this post and realized I made a typo. I wrote "hols" when I meant to write "hold". The "S" is right next to the "D" and it is a common error I make in typing (not one of my better skills). No biggie I thought, I would just go back and make it right.

But wait!! Now I can not go back and edit a post. I can edit the most recent one for an undetermined time period, but after that, I'm stuck looking at mis-spelled words, and you know how that chaps my arse.

Steve, I know you are working on the site, but how about allowing us to edit our posts?

[JimClark]

I found these to hold the prop on

http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000229619&I=LXFBG3&P=K

Not sure if it is oversize ot not but it fits the Octura .125 drive dog just fine

Jim

[peells]

The hobby store I frequent has similar collars in different sizes hanging on the rack in like 4 packs I was just there yesterday, getting some grub screws and quick couplers and happened to see them, I was scoping them out to buy for the grub screws to put in my quick coupler so I would not have to use the cap screw which came with quick connector (cleaner look)

[Dr. Jet]

I found these to hold the prop on

http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000229619&I=LXFBG3&P=K

Not sure if it is oversize ot not but it fits the Octura .125 drive dog just fine

Jim

Those are just the ticket.

[Dr. Jet]

I have been diligently working on this hull (in addition to widening the fiberglass fenders on my trailer - another major project) and have a short progress report.

I have finished rough-sanding the hull and have applied a first coat of primer to the hull. Remarkably, it looks better than I thought it would. There are a few low spots to fill, and some high spots to sand off, but in general, it looks pretty good. I thought I would find a lot more spots requiring attention, but they are actually minimal. The dark grey primer really shows off the sharp edges, so you get a better idea of what it is supposed to look like when a hull has been “blueprinted”. There is still a lot of sanding, filling, and priming in my future, photos will follow when I get time to take a few. The primer needs to dry for a few days before I start sanding.

While waiting for the primer to cook off, my next step was to build the fins and the wing. At first, I thought of doing them from vacuum-formed plastic, but I decided to make them from balsa and glass them afterwards. I think this will actually be less work in the long run. The fins are nearly complete, and after the fins are made, I will put the fin mounting tubes in the hull. I need to have the fins made first in order to use them as a guide to position and glue the mounting tubes accurately in the hull. Once the fins are installed, I can make the wing (which will be adjustable) and get everything ready for final sanding and painting.

[Dr. Jet]

Jeeze, I only have 30 minutes to edit a post. I was going to add this sketch to the last post, but my time was up.

This is how I made the fins. The wing construction will be similar.

[Sneasle]

Looks nice.

How do you plan on using that pin to adjust the wing, I don't quite see it.

[Dr. Jet]

Looks nice.

How do you plan on using that pin to adjust the wing, I don't quite see it.

It may be a bit difficult to describe before I make it and take photos, but here goes:

The front of the wing will have a 1/16” pin in a 3/32” tube that will be at the front of the wing. The wing will pivot about this pin within the tubes in the fin. In the back portion of the wing, there will be a 1/16” tube. A 0.030” wire will go into this tube in the wing, then, be bent 90º as it comes out of the tube. Next, an adjustable “V” bend will be made in the wire, such that the “V” is parallel to the fin. Finally, another 90º bend will make a “pin” at the end of the wire that will go into the small brass tube at the back of the fin.

Isn’t that perfectly clear?

[Dr. Jet]

Isn’t that perfectly clear?

They say a picture is worth a thousand words. Here is a lengthy essay:

[peells]

so is there a slot or something in the vertical fin so you can make adjustments to find the sweet spot?

[Dr. Jet]

so is there a slot or something in the vertical fin so you can make adjustments to find the sweet spot?

No, I'll just re-bend the "V" until I have it right.

[Sneasle]

I would worry that the V would allow the wing to deflect a little during a run. If that happens, you may find the wing acting much more like a wing then you would like.

Is there enough mass in the wing back there to put a threaded insert? I don't know how small they make them, but it you could find one for an M2 or M3 screw, it should work. Then you can cut an art into the uprights and just adjust the wing in that arc and tighten the screw down when you are ready to set it.

Another idea is to use a wing that bolts to the top of your vertical posts. You can then use a flat counter sunk screw that is held captive within the wing and then have a threaded insert in the vertical post and you can adjust the angle but tightening/loosening the bolt.

[Dr. Jet]

The 0.030" wire will be plenty stiff, especially as a pair. This is not a 200 mph boat; the 30 to 35 mph that these things see will not put that much load on the wires. Besides, it is light weight and simple.

[Sneasle]

fair enough :)


edit:

It would be funny as he11 to see one of these go 200mph. Not that it is physically possible, but can you imagine the blur it would make?

well.. more like what blur :)

[Dr. Jet]

Some status photos: