Roddie-Rigger.. a 2005 original design

excellent work Rodie and as always, very organized!...it's good that you restarted those pieces that were waiting for you friend!

Nice! I'm always impressed by your creative skills.

That little Cox .049 looks natural sitting in there, but what's the funnel behind/on the fuel tank?

rsv1cox wrote:Nice!   I'm always impressed by your creative skills.  

That little Cox .049 looks natural sitting in there, but what's the funnel behind/on the fuel tank?  

Thanks Robert! That's a velocity-stack that I fitted to the choke-tube.



There will be an external fuel-cell of approx. 10cc capacity.. but I'm not sure yet what type I'm going to use.

Ah......A Cox Sure-Start. I should have known.

rsv1cox wrote:Ah......A Cox Sure-Start.  I should have known.  

Yea.. that's what it looks like.. but I don't own any Sure Start engines Robert. I mix/match various engine parts to make custom configurations. That's what makes the Cox engines (especially the .049's) so much fun to work with.

The "Rigger" engine will undoubtedly morph into different configurations through both; bench-testing and "real-world" running on the water.

I'm working on a test-stand that will use a 2L. capacity bottle of water for the cooling coil around the cylinder-head.. to see how the engine behaves with a flywheel mounted "no-load" vs. a simulated working-load.

Here's some eye-candy..










The L-bracket on the back of the fixture is for a fuel-cell of some sort. Not sure yet; what that will be...

I searched and found a "rudder" on Amazon.. and for $10 (USD) got that plus turn-fins and trim-tabs in a replacement-kit for a small RC race boat that they stock. Amazon also offers through/below-the-hull rudder kits.. but those aren't what I would want to run on an outrigger hydro. Those below-the-hull rudders seem more appropriate for "scale-model" subjects.

This will work for the Roddie-Rigger..

getting back to the sponsons.. I knew that I needed to "skin" the exposed foam sections (the tops and bottoms..) but wasn't sure what to use.. and I'm unsure about this choice.. but when you're designing something.. you just have to go with it sometimes. The exposed foam depresses/crushes easily if even slightly impacted. I thought about trying a skin of plastic "sheet-protector" material.. but it's too thin and too flexible to protect the foam. I needed a "shell" of sorts.. but not at a big weight penalty.

The bare "tub" with booms/sponsons is pretty light..







The sponsons are made from 1.5" "Ultraboard" a sign-grade foamboard faced both sides with .015" Polystyrene. So they're 1.5" wide.. which is what the skins need to be. The "sides" have the .015" Polystyrene facers. The Top & Bottom are exposed-foam that needs to be skinned.

I'm "going with" another sign-shop material that I had on hand.. which is .018" phenolic sheet. The sponsons measure 8.0" long on the top.. which is flat. The bottom skin needs to be longer at 8.312" because of the upward-sweep running from the step... to the up-swept front tip. I laid out skins for both; 60 & 90 degree versions. Eight strips @ 1.5" wide.





It's been coiled tightly........   ... so I need to try to flatten it out. I'm going to try weighting-down flat with books overnight.. and will check to see how/if it relaxes...

It took steam to take the coil-temper out the .018" skin material.. but it worked.





I've got a plan for applying the skins.. but I'm using sacrificial sponsons in case it doesn't pan-out. I threw together a paint fixture which has rods that key into the two boom sockets.





I foam-brushed-on KILZ2





The weather here in Northern Rhode Island was superb today. I spent several mid-day hours at the markets. A husband's (retired) chores are never done...

getback wrote:Interesting , yes the weather was nice here to today going for hot thought at 88F ! Then a cool down . If can get caught up on old man chores may spray some dope to day ?! Glad you got sometime to work on the outrigger !

Thanks Brother. It was good to chat with you on the telephone. I find these days; that I'm more anxious to prove things. It must show here.. in my posts. Yea.. later on that..

So.. after scratching my head bloody; searching for info. on contact-adhesives that wouldn't degrade my polystyrene foam. There's so much contradictory info. out there.

I decided to go with a Gorilla Glue product.. but it's not a liquid.






That's a "scrap" (sacrificial) foam sponson that I used for this experiment. I've used double-sided tape before.. and it works quite well for certain applications. The Gorilla variety is 1.4 inches width. My sponsons are 1.5 inches wide. Adhering the tape-strips along the top and bottom "skins" worked out well. There's room for slight misalignment with the tape-strip without going over the edge.

The Kilz2 that I foam-brushed onto the bare foam sections of the sponson was dry when I checked it 12 hours later. I feel that this application gives the d/s tape more to stick to. I'll seal the edges/seams with an acrylic caulk prior to painting. The main issue was getting the skins to "stick" instantly.. and that's working.

So I had made-up X2 sets of foam sponson cores to experiment with; one set with 60 degree angled steps.. and the other with 90 degree angled steps.

I put together a painting fixture.. and prepared X2 sets of skins with the Gorilla D/S tape.








The sponsons are designed to easily and quickly slide on and off the booms and are held captive by little hitch-pins. The booms consist of X2 7/32" aluminum tubes of 9.5" length, which slide-through captive 1/4" aluminum tubes in the tub and sponsons. There are also 1/4" alum. spacer-tubes that "slide-on" between the tub and sponsons. I designed the system around the 1.5" width of the sponson material.. and made the tub 3.0" wide with a 1.5" (spacer-tubes) between the tub and sponsons.. for an overall width of 9.0". The booms are 9.5" long to accommodate a flat-washer/hitch-pin retention system.

It's a lightweight arrangement that can be completely disassembled if a part gets damaged.

I just read my last post.... and thought.... Jeeee... why would anyone else want to know that...

roddie wrote:I just read my last post.... and thought.... Jeeee... why would anyone else want to know that...

Lot's of numbers there roddie, but some here are number people.

Jeeee... why would anyone else want to know that...

I wonder that about all my threads roddie.

a lot of work there Roddie....great!

I like the details and the numbers Roddie… Plus replaceable/adjustable modular parts….Leaves plenty of wiggle room to make it do what you want

roddie wrote:

getback wrote:Interesting , yes the weather was nice here to today going for hot thought at 88F ! Then a cool down . If can get caught up on old man chores may spray some dope to day ?! Glad you got sometime to work on the outrigger !

Thanks Brother. It was good to chat with you on the telephone. I find these days; that I'm more anxious to prove things. It must show here.. in my posts. Yea.. later on that..

So.. after scratching my head bloody; searching for info. on contact-adhesives that wouldn't degrade my polystyrene foam. There's so much contradictory info. out there.

I decided to go with a Gorilla Glue

I have no doubt that the glue you use is good but for the foam I use this

Thanks Robert, Mauricio, Robert and David for your support. I've been stalled-out the last few days.. but hope to getback to it soon. I want to run this boat this Summer. (How many times have I said that about a model that I was working on.. and had it not happen..?   )

Little by little.. I'm getting things put together.. and/or sourcing what I need to get things put together..  

I drilled/tapped 5-40/UNC some 2mm couplers to accept a 5-40 stub-shaft on the input (engine) side... and the 2mm stainless steel bike spokes for a wire-drive on the couplers' output side. It's helpful to have 5-40 tap/die in your Cox toolbox.



I drilled a .063" cross-hole in one of the couplings to accept a piece of .062" music-wire as a "wrench" for tightening a 5-40 hex-nut.



Here's an alternate view of the rudder, from a kit that I sourced through Amazon. The white PVC block was something I had in my boat parts-box.. and will provide extra clearance behind the propeller. This will allow the rudder to be mounted on the center-line of the hull.

Hi gang.. WOW.. Where did the last 3 weeks go? As of late; there's been a little progress on this rigger.. (with emphasis on a little..)

I rattle-can painted some samples.. in the same colors as my last airplane model..



I like these colors. They remind me of "old time" days.. if you catch my drift..

So; over the last few days.. I've been trying to fit-up some drive-line hardware.. including "directional-control" (rudder )

The rudder I sourced through Amazon. It was part of a replacement "kit" for a FT012 RC model boat that they offer(ed). There was considerable "slop" where it pivots.. that couldn't be corrected without adding a shim. The assy. unscrews.. so I was able to squeeze a poly-carbonate flat-washer in between and reassemble. It's so easy to make your own flat-washers in the small sizes that we use. I drill then punch* them (*1/4" round) from sheet-plastic. Thin stuff; obviously for making a shim. I already had a shim on-hand, which firmed-up the joint. Being a plastic flat-washer.. it won't rust.



This rudder-blade runs DEEP. The transom on my rigger is only 1.5" above the tub. The rudder-mount was lengthened for more propeller-clearance.



The rudder descends 2.5" below the pivot-point.



There's no kick-back joint. If there's debris in the water.. something's gonna break.

We'll see.. I decided to mount a 1/8" brass water pick-up tube on the backside of the rudder-blade. The 1/8" brass tube was unused from a little Sullivan clunk-tank kit. I cut the 45 with my Dremel..







The brass pick-up tube is "taped-on" for test.

The transom set-up will determine whether this design will work. My drive's depth/angle will not be adjustable. It's not a "flex"-drive.. and there's no "U-joint". I figured that there's less chances of imbalance.

Here's another image of how I drill-through my coupling for inserting a .062" diameter "rod" (as a wrench) to allow tightening/loosening the 5-40 hex-nut.





The below image shows the unused parts from the FT012 rudder-kit. I'd like to think that I could utilize one of those for a turn fin on the inside sponson. (wishful thinking that I'll need one..)

Quality work roddie. I like those colors, I have used them together a lot.

I like those colors too….They work good at a distance as well….. Depending on the light, sometimes one is more visible than the other….

by rsv1cox on Tue Jul 02, 2024 3:51 pm
Quality work roddie. I like those colors, I have used them together a lot.

by rdw777 on Tue Jul 02, 2024 5:44 pm
I like those colors too….They work good at a distance as well….. Depending on the light, sometimes one is more visible than the other….

by getback on Thu Jul 04, 2024 7:32 am
Glad you got some time to get back to this project colors are a nice blend , looking forward to some test runs ..


Thanks all, for your comments. I'm struggling with these two boat projects. Too much "thinking"... and not enough "doing". There's no "step-by-step" instructions when you're designing from scratch. It's easy to mess something up if you're impatient.. or fail to "think it through". OTOH... procrastination can lead to complacency. Sometimes it's better to just walk away from a project for a while.. and "getback" to it later.. with a renewed sense of energy. You know what I mean.. I more concerned with the "radio" components; making them fit and making them work. I don't have much experience with some of the modern gear that I'll be using. More later on that..

The photo below shows engine mount components (Bee engine) that I may not use.. but I really should.. because I made a bunch of them.. as I did with all the other main parts of this rigger. Having access to the CNC router and CAD..  made it quick and easy to make parts in bulk.. and I didn't have to pay for any of the materials.





I had designed (CNC) a "modular" system of PVC and polycarbonate components to utilize the Cox .049 Babe Bee engine, with its 5cc tank-bowl modified for an external fuel-cell and the use of the "Ace" (Ralph Cooney designed) venturi plunger-needle throttle and my muffler design.

The engine-mount is a 3-pc. arrangement consisting of a 3" X 3" 13mm thickness PVC base, routered-out to receive a vertical engine plate which has the Bee's 4-hole mounting pattern and central "thru-bore" (guide) for the .062" dia. Ace needle to pass through and into the engine's air-intake. The 3rd piece is an offset PVC "post" for a polycarbonate throttle-horn/bellcrank. PVC cement is used to glue that assembly together. There's also a pair of optional PVC "wedges" to angle the entire mount assembly to allow exiting the transom deeper.. if need be.







Below; a couple of engine prototypes that would use the Ace throttle.





There's a LOT of foam components for building the hull and sponsons.



Craziness I know.. but I had thoughts of possibly kitting these, back when I made all the pieces.

Do it roddie. Roger Harris redux.