Hydro-bat by Vic Smeed: engine probs

Cool Build , had to google the image to get in my mind the outset ..
Bee sweet when done .

getback wrote:Cool Build , had to google the image to get in my mind the outset ..
Bee sweet when done .

Yes sir! Lieven finds and builds the most interesting models I've ever seen. I wish I had his snow-car here for running after a big storm that's due to hit this region early tomorrow morning.

This little boat looks like a lot of fun! I'll bet it skips-along like a hydro!

roddie wrote:

getback wrote:Cool Build , had to google the image to get in my mind the outset ..
Bee sweet when done .

Yes sir! Lieven finds and builds the most interesting models I've ever seen. I wish I had his snow-car here for running after a big storm that's due to hit this region early tomorrow morning.

This little boat looks like a lot of fun! I'll bet it skips-along like a hydro!

Tomorrow would be a good day for a snow car 3+ inches predicted tonight.

Phil

Oh, great! Just what I need. Another plans site to spend hours searching and downloading plans....

The Time-Crunched Mark

Nice I like 1/2A boats, 2 weeks ago I finished one with a .07 engine. Waiting on good
weather to test it. Has a small converted car engine in it a SH 07 with a Profi .8cc tuned pipe.
Air boats are fun you can wet cut grass and run them in the back yard.

Hope to hit 60 mph

1/2A Nut wrote:Nice I like 1/2A boats, 2 weeks ago I finished one with a .07 engine. Waiting on good weather to test it. Has a small converted car engine in it a SH 07 with a Profi .8cc tuned pipe. Air boats are fun you can wet cut grass and run them in the back yard. Hope to hit 60 mph

Wow! 1/2A Nut, that is really sweet, looks fast standing still and excellent workmanship!

OVERLORD wrote:THE PYLON The pylon was cut out from 3mm ply. The fire wall is 5,5mm thick. The tank fits in the rectangular hole. The fuel feed pipe sticks through the fire wall. The parts were epoxied together and epoxied in the frame. I dry mounted tank and engine and the prop should have enough clearance. Next is the bottom planking.

Overlord, that is a really neat looking airboat, build looking good, especially the hotter Cox engine reedie installation, streamlined versus the simpler rectangular Dumas 1/2-A swamp buggy I built in high school almost 50 years ago.

Looking great Lieven! Fitting those side-hull pieces is definitely tricky. I remember that from when I built my Dumas DV-10/Short-Stuff.. and that was a die-cut kit. I ended up using some auto-body filler in a few areas, and I too.. needed to even-out some areas with a surface-plane. I'm pretty sure that I applied several coats of auto-body primer; sanding between coats.. and used epoxy-paint for the finish. That model is electric-powered.. but the epoxy-paint would probably be fine with glow-fuel. The entire interior framework was brushed/sealed with epoxy glue. Is there anything in a construction-article regarding sealing the interior of the Hydro-Bat?

Have you considered adding a ballast-hold to the hull; where you've raised the height of the pylon slightly and will be carrying a heavier initial fuel payload, as compared to a Babe Bee? An automotive wheel-balancing weight-strip could fit snugly into a fore-aft channel in the center of the hull and be easily repositioned via a small hatch and needle-nose pliers.. for adjusting how the boat planes-out on the water as well.

Coming along very nicely. I have had the plans for quite a while myself, but have just not gotten to it. One day I might have the chance.

Dang that looks good. This is killing me!

Geez yes... looking great Lieven! Love the "pinning".. reminds me of how you formed the "Cauldron's" engine cowling.. and several other builds that you've meticulously mastered. I wasn't aware that that this model was radio-controlled. I thought that it was a "free-runner" or tethered-design.. I'll admit that I did have some RC ideas to pitch to you though.

Look into the newer-technology receiver-batteries. There's some LiFe packs that are tiny... and would be perfect for this application. Combined with a nano-servo for the rudder... you'd have a micro-weight radio. I'm sure you can locate a feather-weight receiver to do the job.

OVERLORD wrote:Thanks guys. Only the batteries have any weight. The small servo is very light and the 2.4 gHz receiver even lighter. Vic Smeed's model had a weight of 8 to 9 Oz. That's 230 to 250g. At this stage, it weights 81g.

For sealing, the article says to dope and cover in tissue the hull, then paint. I was thinking of doping the Inside and outside, then to coat with PU varnish all with sanding in between. I like to finish the model with Oracover.

You may remember I bought a Hobbico 200mAh 6.6V 1C LiFe receiver battery a few years ago. Its weight is 15gr. It may require a regulator to drop the voltage to a safer 6V though. It's a TINY battery-pack...

See the below photo for a size-reference on the battery..



That's 130gr........ along with a Babe Bee engine, x4 nano-servos and 6ch receiver. I'm sure that your model could finish-out at well-under 200gr. and maybe even close to 150gr.

Shaping up great Overlord, should be a real treat for you to run!

Yes the rudder and turn fin was cut out using metal shears
filed sharp and buffed up to a shine. All ply design / build project.
Will post a vid when the water is calm.

Very nice Lieven! You always engineer your models.. I love that! Did you cut a SS rudder horn too? It would be nice to able to braze it on.. but that might distort /melt the carbon tube? Apparently CF tube is resistant to water exposure? If it can be easily-detached from the transom.. and horn brazed, it would be a solid no-slip link. Install a brass flat-washer followed by the M2 nuts first, to establish a bearing. Double-nut the m2's then jig the assembly for brazing the horn on, near the top. A horn need only be a strip approx. 6mm x 25mm (tab) with holes drilled on opposing ends for the shaft and a clevis/pushrod.

If you want to retain the gluing integrity of a square tube to the transom, you could opt to go all brass.. with a round-tube sleeve running inside it.

I'm sure whatever you come up with, will be a functional work of art. It always is!

Very nice craftmanship, watching with interest.
I have also considered building this airboat, or the Swamp Buggy, but finding a place to navigate is not obvious due to the noise.