Roddie-Rigger.. a 2005 original design

rdw777 wrote:Better to find those places and beef them up now before you light it up ….. Pretty, Lookin’ like a hot rod

Robert! geez.........  my bad. My house doesn't look like my forum threads.. (IE; neglected.. )

Did a little work on the engine.. in an attempt to prep it for the task at hand.. and of which it was not designed for. I'm experimenting with .031" thickness silicone-sheet rubber which is made into flat-washers for in between the engine's drive-plate and the flywheel assy.... and also in-between the flywheel assy. and the drive-shaft coupler.







There's also a remote possibility... of some harmonic-balancing properties to come from their use.

Looks great, Roddie, precise down to the smallest detail!!

Looking forward to the mer-maiden run! Any water surface near you where you will try her? Hopefully weather permitting..

Where is the water intake point for the engine jacket cooling circuit, is it pointing forward somewhere below the waterline, or behind and facing the prop, like on an outboard Mercury?

BTW Mercury, my first encounter with American engine technology dates back to the early '70-s when on lake Balaton in Hungary some folks had motor boats powered by beautiful American black Mercuries, white Evinrudes and white Johnsons..my father was a well-to-do doctor and fan of motorboating, towing my sister and me on waterskis behind his boat powered by a 50 HP outboard  Mercury and later,  a brand new Johnson 50 that I have no idea how he could get hold of behind the Iron Curtain where American engines - including COX - were absolute rarities..( he also got me a COX Super Sport Trainer in '75 and how, remains a mistery to me...) no IC engines are permitted on the lake anymore, but my memories of those summers still make me smile...

That is a beautiful piece of work roddie.  Were it mine, I would kit bash another to run and place that one on a shelf where everyone could see it.

Seriously.......



And Andras, I'm of two minds regarding enviromental protections.  Tourist Europe is such a beautiful place and I'm sure they want to keep it that way. (No IC engines on the lake.) Maybe half enviromental half noise polution but people want to have fun too. On lake Onway in New Hampshire we ran all those engines but the Johnson Sea Horses were the most popular.

Yes, Bob, I do not miss the jetskis and powerboats, this lake is about 600 square kilometers with an average depth of 3meters, so it would not easily heal itself if the powerboats of nowadays were allowed..it has enough challenges due to droughts and hot summers already...and despite the motorboats banned it still gets overloaded in the tourist season by local and foreign visitors..

She looks really Good Roddie ! hope ur parts get there soon ready for a test ride

balogh wrote:Looks great, Roddie, precise down to the smallest detail!!

Looking forward to the mer-maiden run! Any water surface near you where you will try her? Hopefully weather permitting..

Where is the water intake point for the engine jacket cooling circuit, is it pointing forward somewhere below the waterline, or behind and facing the prop, like on an outboard Mercury?

Thanks Andras, There are many places where I could run the boat that are local to me.. including a reservoir within a short stroll's distance. The spot that I plan for the maiden is a small pond within a park/recreation-area in nearby Woonsocket, Rhode Island. It has shore-access all the way around.. which will aid in retrieval.

The water-cooling inlet-tube is attached to the rudder.

rsv1cox wrote:That is a beautiful piece of work roddie.  Were it mine, I would kit bash another to run and place that one on a shelf where everyone could see it.

Seriously.......

 

Thank You Robert. Yea... a 2nd one would go together quicker.. but probably not before the weather would turn too cold. We'll see how it goes.. there's still some stuff that needs ironing-out.

getback wrote:She looks really Good Roddie ! hope ur parts get there soon ready for a test ride

Hey brother! Thanks man!! I'm awaiting a different (smaller) switch-harness and an adjustable link for the rudder. Then there's fitting a fuel-cell of some sort (balloon probably..) finish the plumbing for the engine-cooling line.. (through-the-transom.. same as the exhaust..) and water-proofing the rudder-servo.

The turn-fin depth is adjustable.. but I need to figure out a means to temporarily "lock it" in place.. until after the initial test-runs.

Turned out very nice Roddie!!….. I think a balloon tank would serve well for your boat…. You can make one up and practice filling an evacuating the air on the test bench…. They give clean runs for 1/2A engines….

rdw777 wrote:Turned out very nice Roddie!!….. I think a balloon tank would serve well for your boat…. You can make one up and practice filling an evacuating the air on the test bench…. They give clean runs for 1/2A engines….

Hi Robert, Thank You! Yes.. I would think that the balloon tank should be less susceptible to the formation of air bubbles than hard-tanks would be. I sourced some tiny Tee-fittings and plugs which I'm going to test. The Tee should allow the evacuation of air from the balloon.. with the down-stream line to the engine pinched-off with a clip. This way I can maintain my needle/mixture setting between runs.

This rigger is an "open-tub" design.. and will catch water-spray while running. Because of this; the rudder-servo will need to be water-proofed... but more importantly; I need to provide a means of bailing that water out.. before it can accumulate adding weight/drag. A pair of small ports down-low through the transom should suffice...





... but I have issues between the forward bulkheads that need attention..







If water gets in there.. it's going to puddle-up at least 3/16" before finally spilling-over into the aft-compartment which can evacuate it.

I'll need to make notes to revise the bulkhead and transom components on future builds, to provide drainage-ports where they meet the floor-pan BEFORE assembly..

I know I'm being OCD here... but these issues will arise during the maiden.. if I don't foresee them and take action now.

OCD translates to attention to detail roddie. Beautiful job and well thought out. Your aquatic companion to the Rare Bear.

rsv1cox wrote:OCD translates to attention to detail roddie.  Beautiful job and well thought out.  Your aquatic companion to the Rare Bear.  

Thank you Robert.. I know that you understand!

I seal up everything possible and bag the RX. Way too many holes in your project water weight will bog the
engine down. You will learn more by water runs if that ever happens. Too many things to point out best you
walk the path and learn what last / what works.

Best wishes rare to see anyone attempt 1/2A boats.

Behold the fastest 2 ch .8cc 1/2A rigger on Youtube aka my design with ply const.

.05

19,336 views Oct 9, 2016
1st Run - Picco P-Zero Outrigger Hydro Profi Tuned Pipe!
.85cc / .050 cu. in. / 1/2A car engine converted for boats.
Very stable, design with unique sponsons for it's time.
Will do another vid after the setup is tweaked out.
True 3 point Hydro riding on the prop hub- no assistance / rear ramp.
Stock Octura X427 / 20% castor 30% Nitro. Per Doppler analysis.
Best pass read thus far hit 62.25 Kph or 38.7 mph. / 27,290 rpm
The cooling head car type makes it look like a .12 engine.

Empty weight of the plywood hull & carbon tubes 180g
196g fuel proofed less all gear / hardware. Ply sheet covered balsa
core sponsons. All up weight will check: 534.9g / 18.86oz dry weight and
555.6g or 19.59 oz with 2oz fuel.
Water cooled head. 165 deg. timing Profi .8cc tuned pipe / .062 wire drive.

Tub: 20.5" L x 2.5"W / Inside Sponson Width: 16.5in
Total Length Transom to Sponson Tip 26.25" / Sponson Ride pad width .98" each



2,813 views Nov 22, 2016
Picco P-Zero .05 / .85cc engine 2nd Vid
Profi 1cc Tuned Pipe - Cut Octura to 1426 de-tongued 1.8" total pitch.
Static rpm on the field bench hit tad over 50,000 rpm.
RPM higher than the stock X427 prop, best pass 36,902 rpm
Med lift prop. 30% nitro / 20% castor. Best note pass 43 mph.
Suspect the drive shaft was slipping. Good size running area,
water buoy race layout for the big gas boats. Rare flat water.

.07



1,353 views Mar 16, 2017
SH-.07 / 1.14cc converted car engine. 38,680 rpm static / 30% nitro / 20% oil.
With only a few mins. at a rich idle I leaned it up just enough to stage the engine on the pipe for a brief rpm check should do about 44k + Needle valve set about 3/4th to 1 turn rich per this vid. Belt started with the plug a bit loose the smoke was from the fuel still burning off around the plug. Low end needle setting from the factory was good for a great idle, can go much lower need to adjust the carb barrel to close down more. Update- finished rigger with sponsons ready to run: 457g / 16.12oz less fuel.

Great 1/2A boat engine can recommend!
7CXP Side Exhaust Nitro Engine Factory Specs:
Brand: HSP
Item No.: PT0701A1
Capacity: 1.14CC
Bore: 11.50mm
Stroke: 11.0mm
R.P.M: 31000
Power: 0.65HP
Weight: 125g

1/2A Nut wrote:I seal up everything possible and bag the RX. Way too many holes in your project water weight will bog the
engine down. You will learn more by water runs if that ever happens. Too many things to point out best you
walk the path and learn what last / what works.

Best wishes rare to see anyone attempt 1/2A boats.

 

Hi Brad, Thanks for your interest. Being a novice; I'm not counting on setting any speed records with this boat. My hope is to prove that I can get it to "plane-out" using a COX reed-valve engine combined with a drive that I mocked-up from random items.