messing around with flywheels

Marleysky wrote:Way to go! Very nice rrrrrrun!  I gotta make one of those throttles. Too Cool! Thanks !


PS: only video 1 opens and plays, #2 & #3 say they are unavailable.
SNL is on, see ya tomorrow.

I don't know why vids 2 & 3 won't play.. I experienced the same.. then the issue seemed to subside? Let me know if there's still trouble viewing them.

Thanks VERY MUCH for watching!!!

I am only getting the first video as well. The engine ran well though. Wish you would have let it run on peak a little longer!

Ron

Cool Run Man !! That is not what i would have thought it was going to do DUH but it is a boat /car motor now , Good to hear your voice

Man, that sounds like one very angry Bee Love the throttle response the light flywheel gives.

I just remembered, I have a couple of NOS Thimble Drome boat flywheels, cat#330:



The flywheel has knurled outer surface probably to help turning the engine by hand and also a groove for a starter belt. The nut has a stub axle where a plastic ”joint” can be slid on to provide a flexible connection to propeller shaft.



The plastic is obviously hard as rock after half a century of storage. The flywheel is white metal I think, and it weighs 1.2oz. The nut is aluminum.
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Roddie, that was pretty cool. Now, do you have boat plans? I have the shaft, the universal and the prop.I would need to fabricate the stuffing box for the hull. I'm not certain if Dumas offered that. I would love to put my parts into use.

Just an FYI.. the 2nd and 3rd vids are viewable now.

Ken Cook wrote:         Roddie, that was pretty cool. Now, do you have boat plans? I have the shaft, the universal and the prop.I would need to fabricate the stuffing box for the hull. I'm not certain if Dumas offered that. I would love to put my parts into use.

Thanks Ken, It was a fun little indoor project for a cold Winter's day.

CEF member halfAnut (Brad) is the man to ask about anything related to running a Cox engine in a model boat. He's given me lots of helpful tips.

Regarding Dumas running-hardware; they used to produce complete kits designed for Cox engines, for running in their 1/2A size boats.

I have the Dumas hardware kit #2306 which is designed for running a Cox .049 engine in their Atlas Van Lines hydroplane. I also have the AVL hydroplane kit.

shown below is Dumas kit #2306



not shown (in the sm. envelope) are prop-drive pins and a 5-40 fully-threaded stub-shaft which connects the engines' crankshaft to the kits' U-joint.

The AVL kit is long-since out of production.. and quite collectable.



I got mine through Tower Hobbies back in the early 1990's. I started building it.. but stopped when I had trouble understanding the instructions.

I did build the Dumas "Short Stuff" (aka DV-10 or Deep Vee 10) but powered it with a Graupner electric motor/hardware kit.






I don't know if those drawings will help.. but I'm sure that there's a myriad of model boat plans available for download.. or maybe "Brad" has some that he'd be willing to share. My AVL kit-box/plan is buried.. so I don't know (and can't remember) if it's a full-size plan. I doubt it though.

A few years ago I bought some small replacement model-boat props and drive-shaft set produced by "Aquacraft" for their little "Reef Racer" model. I figured that they might be adaptable for Cox engine power.

The Aquacraft props and hardware are metric.. but they utilize a "drive-dog" type prop-coupling.. which is superior to what Dumas offers/offered. The Aquacraft props are also suitable for a "surface-drive" application.. which is likely what you'd want to run in a high-performance hull.

Here's another configuration and test-vid for running an ultra-lightweight (.15oz./4gr. my lightest thus far) flywheel on the same engine.





Just to reiterate; the glow-fuel being used is a blend of Sig "Champion" brand 25 and 35, which is decades-old. Keep that in mind.. if you ever decide to throw-away your old/aged glow-fuel. It may still have some "kick" left in it...  

If you watch this video, please be patient... because it was a "cold-start" condition. It took me a few minutes to realize that the engine wasn't getting any fuel.. and the use of my muffler prevents priming the cylinder through an exhaust-port.

I found it interesting; how "little" fuel was required to support combustion this time. The mixture-needle was only open 1/2 to 3/4 of a turn. Any "richer" was too much "drag" on combustion with such a light-load. (at least that's my synopsis.. )

This one's for Ron Cribbs.. The same engine.. with the last tests' .15 oz./4gr. flywheel.. except an extended high-speed run to possibly obtain an audio-tach reading.

For those who don't know; Ron CD'd the 2017 CEF "Tach-Race".. which not only proves that he's a great guy.. but also a bona-fide "speed-junkie" (just kidding..)

Thanks Roddie, pretty cool, that’s as probably as light as you can go and still have it run. That testing couldn’t have come at a better time! Seeing as we are gearing up for a Tether event.

Hey Ron, It bummed me out that your tether-car's drive-wheel came-apart during testing.. and took the TD .020 with it..

Please accept my apologies if you already know the following information. The Cox .020 engines' crankshafts are threaded for a 3-48 UNC size machine-screw. This screw happens to fit nicely "snug" into the "I.D." of 1/8" standard-wall alloy tubing. Any wheel having a "hub" to accept a 1/8" (.125") axle could easily be fitted to your engine.

I have a supply of 1" length 3-48 black-oxide cap-screws.. and also some standard-wall 1/8" alloy tubing, in either aluminum, brass or copper. I also have 3-48 nylon-insert style lock-nuts.. and various assorted-diameter model-wheels having a 1/8" hub..

Let me know if you can use any of these items to make repairs to your tether-car. Can you use that engine-mount.. or is it for a Tee Dee .010?

I’ll send you a PM

That last run was cranking out some rpm's wish you could have got a tach reading , maybe Brad or Andras will chim in and ck. it . Good testing Roddie !!

getback wrote:That last run was cranking out some rpm's wish you could have got a tach reading , maybe Brad or Andras will chim in and ck. it . Good testing Roddie !!

Hey bro! Yea.. that little mill was screaming... Not sure if you caught-it in my dialogue.. but the mixture-needle ended-up being "leaned-out" to within one-turn open, to achieve combustion on every stroke.

These no-load/flywheel-tests weren't intended to prove much.. but let's examine a few variables..

The test-engine was configured using a crankcase and cylinder assembly that I had "on-hand". The crankshaft was not removed for de-varnishing. I concentrated more on the induction-side; making sure that fuel was reaching the venturi.

The .049 Bees' crankcase was fitted with an original copper/star reed-valve. Some modelers claim that the copper reed will "float" at higher-rpm's. .............  

I'd put "this test-engine" in any model..