O.S. FS 40 Marine

What rpm does that little Picco turn up to? I've always been concerned about over revving or overheating marine engines out of the water. That one was just singing at times.

50,000rpm without self destructing is impressive. Guessing that your little Pico does NOT use a ball and socket piston/conrod joint.

Reading a post n RC universe recently, I learned that it should be possible to marinize an OS FS30 due to the fact that the larger cylinder bore allows the piston to be removed (after removing the liner) without the wrist pin needing to be extracted. (The FS20 and 26 require this to be done which would mean the engine would be essentially unserviceable after the conversion).

So, I just have to decide if I should attempt this conversion to an FS30 that I presently have in a 1/6th GP Cub on floats.

If I end up doing this, the 30 would end up in a Dumas Ski Daddle 2 that I built in 1973.

And would keep this thread percolationg.

I enjoyed those vids immensely Brad! As you may remember, I have a rigger-build in the works.. and have a couple questions. Curious about the starter and belt. I will need to obtain these items. Do you use a pillow-block/bearing in the hull, for support while cranking?

I too was surprised at how long you ran the engine on shore. Does the pipe help to carry some heat away from the top-end?

My rigger is a lot smaller, and is planned for a Cox reed-valve engine installation. I bought some Aqua-Craft plastic props that are replacements for their "Reef-Racer" mono. They may be too much prop. Their pitch isn't stated.. but the diameter is 1.108". Their Reef-Racer (15" mono) is powered by a 380 brushed electric.  



They come two to a package. I also bought the Reef-Racer drive-shaft and stuffing-tube.. just in case it happens to work out.




Not sure how/if any of this will work with a Cox reedie.. but I hope it might. As for the engine.. I have options.. with the highest-performance being configured with a "Killer-Bee" style back-plate, Tee Dee-ported cylinder with high-compression head. I have Dumas 1/2A flywheels/U-joint.. that I hope to adapt to the Aqua-Craft running-gear. I think I'd need a 2.9mm to 1/8" coupler.. if I could find one. The Aqua-Craft driveshaft is .113" dia. I need to build or buy/modify a strut as well. Not sure what I'm going to do there. I'd prefer a simple "bolt-on" because of my lack of experience. If I can even get it to run.. I'll be happy!

Any thoughts on using those Aqua-Craft props as they are? I have absolutely no experience here.. but I figure they might be better than the standard 1" Dumas #3001. I "do" have some of those too.

Thanks for any advice Brad. I really love watching the vids of all your models!

Thanks Brad. I'll need to read-through that RCG-thread again. I think I'm in the ballpark as far as rigger-size for a Cox Reedie.. although it's not of a proven design. It's 16.5"L less the strut.. which I don't have yet. Width is 8.75" between the outboard-sides of the sponsons. I realize, none of that means too much at this point.




I made lots of parts on a CNC router. Mostly foam-board with a .030" Styrene hull-bottom that wraps up-over and around the bow. The transom is 6mil PVC and there is a cored 3mil PVC floor-reinforcement that supports PVC engine-mounts.

I made-up two different sponson-profiles. The ones shown have an angled-step. Not sure how that will work out.. but my feeling was, that it would help with stability?? The other sponson-profile is a square 90 degrees. Swapping is as easy as removing the four pins in the booms.

Is 65w about the most power that a Cox .049 reedie will produce on a good day? I'd likely be running Sig 35% fuel.

Thanks again Brad. I remember your previously mentioning the hole in the Dumas flywheel being slightly big. Maybe the same flywheel is used on the Cox Medallion/Tee Dee .09's which use a 6-32 machine-screw in the crank?

Have you ever tried "friction-wheel" starting? I figured that the knurling on the flywheel was meant for that option. I thought about possibly installing a pair of rollers (nylon?) in a bulkhead/cradle below the flywheel and straddling-it, to relieve some pressure on the crankcase when friction-wheel starting. It might even be effective "above" the flywheel for belt-starting.. as long as a slight gap can be maintained. These things add weight.. I know. I'm in the habit of working a drop or two of light-oil in behind the prop-driver before cranking my aero-engines electrically.

This rigger was originally meant to be experimental.. to test the building materials as well as the Cox-powered drive. I'd previously built (1992) a Dumas "Short-Stuff" (Mahogany/Birch) for a Graupner EP mono-drive and had a lot of fun with it. Around that time.. I also bought the Dumas 18" AVL hydro for 1/2A power. My goal is to power it as was intended.

My rigger uses sign-grade/open-cell polyurethane foam-core with .015" styrene facers. The hull sides are 3/16" and the sponsons are made from 1.5". The hull is assembled with film-tape.. and will be sealed on the inside with adhesive caulk. The sponsons are raw-foam top/bottom that will need a smooth skin applied. The vertical-surfaces have the styrene-faces. The boom-tube spacers and outside washers bear on the styrene skin. I could skin the sponsons' exposed-foam with 1/64" plywood, which I have on hand.. but I'd rather not use any wood if I can help it. I've thought about a few skinning-methods.. but am restricted by the raw-foam currently. I need to seal-it with something before proceeding. Whatever "that" is.. needs to be smooth or sanded-smooth.. and not attack polyurethane foam. Maybe applying thinned-epoxy with a spreader would be the way to go? It's not a submerged surface at speed.. so it needn't be like glass.

You asked about "paper" and how I'd seal it.. but there is no paper used in the construction. It's all foam-board, styrene and PVC parts thus far.

I do plan on throttling the engine. My PVC engine-mount's firewall piece is pre-drilled for a Bee tank backplate with a center-hole/guide and boss drilled-thru for a venturi-plunger-needle. I've done some tests with the Ace throttle.. using the marine engine-mount.

Perhaps you've seen this comical vid...

https://www.youtube.com/watch?v=Sy9o2WDzLqc



LOL.. I still laugh when I watch it. God Bless my wife. She's actually very tolerant of my model activities.

That venturi-throttle "concept" is an option. I tried non-conclusively to test a larger (.082" air-inlet) venturi and plunger.. but had issues getting my engine to even run that day. The muffler in the vid is my own design. I do have an exhaust throttle-sleeve and the cylinder for it. It's a single-bypass #7 cylinder.

I designed the modular PVC engine-mount and its floor-support to provide quite a bit of fore/aft adjustment.. and there's plenty of space up-front for the tank, radio and servos.

There's a reservoir down the street (walking-distance) for trials. I can't fly C/L without driving a few miles. That's the allure of model-boating for me. I just need to get it done. I have rescue-boats and would definitely outfit one with some sort of retrieval-device such as a buoyant "Y" frame attached to its bow.

Thanks once more, for the interest/hints/advice Brad. I hope I can have a report before too much time passes.

That's impressive and ingenious! Imagine being the creator(s).. I can't imagine what the sales #'s will be. Musicians who play acoustic, greatly outnumber electric-players.. and most electric players love playing acoustic.. and usually have one. It's a real nice effect for a solo-player.. whether performing.. or writing riffs while chillin'-out.

I have an acoustic.. but I'm a keyboard player. Guitar confuses the #$%& out of me. The guitar I "found" in its case.. up-against a dumpster where I lived years ago. It's a Yamaha FG-340T.



Martin and Takamine are beautiful instruments. A neighbor who recently moved to FL had several.. as well as a custom acoustic made somewhere in the Northwest US.

I didn't know that you were a Musician Brad! That's good to know, for when we have the CEF Summit...... .. . There's several of us who play! I'm the only keyboard player here that I know of. How cool it would be... if there was interest in a gathering of our international members for a weekend shoot-out/swap-meet.. jam-session.. at an undisclosed-location, somewhere on the globe? Summertime.. or Wintertime.. one weekend.. 2 full days/nights.. with on-site lodging...  

I digress... and have a few model-rigger questions..   I'd ask them in a PM..  but other Cox boaters might want to know. I'm wondering how far from the transom, my prop should be.. and whether the stern-tube exits' exactly at the step of the transom and parallel with the hull.. when applying a surface-drive?

Can I forego a strut for the stern-tube? It seems I've seen that applied. The rudder has it's own strut assembly centered behind the prop.

I know that you choose to water-cool your Cox marine-engines. The Cox surface-vehicle models with .049 reed-valve engines furnished a heat-sink/clamp around the glow-head to "help" cool their slow/geared-down operation. The question is; could it adequately cool an open-cowl reed-valve engine on the water? I'd like to think so. It would really simplify things. I feel that the heat-sink clamp dissipated most of the heat in those surface-drives.. which were partially; if not mostly enclosed.

I'd really just enjoy getting the model up on the step.. and planning-out at any speed.

I know all too well about the lack of vids on this model-boating class. Kudos to you.. for representing the US with your models.

Take a look at the "Previa" (Casio) digital pianos Brad. I'm on my 2nd.. and can say that they're dependable. I wouldn't hesitate to buy a 2nd-hand one. Mine get quite the work-out.. because I have a heavy playing-style. The piano new costs $600.. (PX 330/350 model ref.)

PX330.. (my 1st Previa)



and the 2nd.. a PX350..



The first (PX330-circa 2010) developed malfunctioning touch-sensitivity in an area of the keyboard where I lay-into some heavy rhythm-reinforcement when playing in the Southern Rock band. It held-up for 5 years of heavy gigging though.

Its replacement; the PX350, (circa 2015) is virtually the same instrument. Some buttons/switches are re-arranged. Both have amplifiers/speakers to naturally replicate the sound of an acoustic piano in the average small room of a home. Both have 1/4" ins/outs for audio.. with the inputs gain being controlled by the master volume. This is how you would output to an external-amplifier if desired.. as well as connecting an additional audio source. I connect a 1/2-rack size Kurzweil "Micro-Piano" piano module via MIDI interface/cable for layering-in its piano/organ/string samples for a fatter sound.

Do you know of the "Digitech" Vocalist Live 4 effects-pedal? I have one.. bought new about ten years ago. It's marketed toward the solo-guitar player/vocalist who wants to harmony-vocals.. without hiring singers. A pick-up would be required for an acoustic-guitar.. to provide an audio-signal. A processor in the unit converts/analyzes the signal to digital.. and assigns a tonal-value for harmonics.. depending on the chord-structure. For instance; it will "flat" the 3rd.. when it hears a minor chord being played on the instrument. "MusIQ" is Digitech's  patent on this effect.

Here's a demo of mine... using my old Technics PX-103 for a pitch-reference. The piano is muted for my rendition of this classic Eagles acappella  short-take..

https://www.youtube.com/watch?v=FrsoGQ2hM5s



just lost several marine-model related paragraphs.. I'll write again later..

Here's an Alesis 88-key digital-piano ad that I just received tonight via email..

https://www.amazon.com/Alesis-Recital-Beginner-Full-Size-Semi-Weighted/dp/B01DZXE9NC/ref=sr_1_2?ie=UTF8&qid=1482420161&sr=8-2&keywords=alesis+recital

Personally.. I'd spend another $400.. and buy the Privia for it's "fully-weighted" keys.. and proven reliability.

Your Tonewood amp sounded lovely. Seeing as this thread is somewhat derailed, here's one of mine. No fancy playing but (IMO) great guitar tone.
https://www.youtube.com/watch?v=LJrY_UoKzTM&feature=youtu.be