Scratch-Build 2021

Y have found way To build. M'y own kit using the .049 tee dee engine the cars is very fast and worth the price pay Not for sale right now very hard To Find correct parts to complet the kit y have some prototype redy for production just dont have the mony To start y love To build m'y own



New vidéo soon the truck fun mutch bether now sound run look scale now wit smoke from the two pipe it was fun To build

I'm definitely planning on a scratch-built Westland Wyvern some time this season. Already have plans printed out from Outerzone.

Cool! How do you plan on doing Contra-rotating propellers?

Sorry,  no
I wouldn't even know how to go about that.
The multi-bladed and contra-rotating props were a way to utilize the enormous torque of the turboprop engines. A Baby Bee hardly has "enormous torque" so the weight and complexity of a contra-rotating prop would have no technical justification.
Although I agree it would be super cool.

roddie wrote:Just what it says. Y not scratch-build something Cox-Powered? Y try to find a kit? Y not get creative?

roddie, ya gotta learn to write Shawingan.  Y is I not why.  

And Ron/Dirk when did Iran become connected with counter rotating propellers.  Reagan is turning over right now, and Oliver is not too happy.  

https://www.britannica.com/event/Iran-Contra-Affair

BTW, David since joining this forum has made great strides in his English composition.

Maybe it would be time to finally complete my ”Expendables Squadron”?





I bought a couple of sheets of 2.5mm balsa for wing ribs for some project that I’ve already forgotten... the sheets were very hard and heavy, not useful for the intended purpose. I figured they’d make good wings for a sheet wing model. Looking at other balsa and stuff I had on hand, I decided to build three identical models, equip them with identical Babe Bees and try to learn CL flying. With three identical planes, complete with dyneema lines and plywood handles already attached, I could crash three times before I need to start repairing. Makes sense, huh? Well, that was about 4 years ago. I think I have some piano wire and wheels somewhere, as well as the handles and a roll of dyneema, but the paints may have already dried in their cans

Darn, my reply vanished.
Bob: Contra-rotating props share a common axis while rotating in opposite direction, as in a single engine. Counter rotating means a twin engine with props turning opposite directions.

Rod.

Oldenginerod wrote:Darn, my reply vanished.
Bob:  Contra-rotating props share a common axis while rotating in opposite direction, as in a single engine.  Counter rotating means a twin engine with props turning opposite directions.

Rod.

Ya, but I just had (trying) to be funny...........

https://en.wikipedia.org/wiki/Contra-rotating_propellers

I got the joke Bob

Cribbs74 wrote:I got the joke Bob

Wasn't sure if you would Ron, what were you about 10. Your such a kid.

Bob

rsv1cox wrote:

Cribbs74 wrote:I got the joke Bob

Wasn't sure if you would Ron, what were you about 10.  Your such a kid.  

Bob

Zing!

11 when it came to light and 13 when the inquests concluded. Close enough. I was a kid in Canada at the time so I was oblivious to what was going on.

rsv1cox wrote:

Oldenginerod wrote:Darn, my reply vanished.
Bob:  Contra-rotating props share a common axis while rotating in opposite direction, as in a single engine.  Counter rotating means a twin engine with props turning opposite directions.

Rod.

Ya, but I just had (trying) to be funny...........

https://en.wikipedia.org/wiki/Contra-rotating_propellers

"Contra" and "counter" have the exact same etymology and semantics, they're basically two alternative spellings of the same word, so as far as I, a total language nerd, am concerned, calling one prop arrangement "contra-rotating" and another "counter-rotating" is completely arbitrary.

dirk gently wrote:Sorry,  no
I wouldn't even know how to go about that.
The multi-bladed and contra-rotating props were a way to utilize the enormous torque of the turboprop engines. A Baby Bee hardly has "enormous torque" so the weight and complexity of a contra-rotating prop would have no technical justification.
Although I agree it would be super cool.

Hey Dirk, Look at this picture



It's an experiment of me a few years back. You can make counterrotating props by fixing one to the engine as the drivinp prop and the second one, a LH prop mounted to turn freely. This second prop will turn in the other direction due to the airflow. The working RH prop must be fixed on the prop washer, so closest to the engine. The free turning prop must then be attached to the prop nut. I suppose you have to build a special prop nut for that with a shaft and bushing for the free rotating LH prop.

Below a link to the Macchi Castoldi plan. This scale CL model has the same setup.

https://outerzone.co.uk/plan_details.asp?ID=1551

My experiment didn't work because the free turning LH prop is the one nearest to the engine. When starting it by flipping the prop(s), the RH prop becomes loose.


Hope this helps. It would give an excellent scale touch to the model. Try it!!

Right, in this arrangement though, the freewheeling prop doesn't provide any thrust, as far as I understand.

I was thinking about fixing the second prop to the crankcase and mounting the entire engine so that it can rotate, like in the cox helicopters. But that's weight and a high-risk potential failure point, so I think I'm gonna pass. It's not like you can see how many props you have while in-flight anyway. If I was to go wild with scale accuracy on this model I would start with retracts and flaps, and leave the contra-rotating props for last

Side note, you can flip a reedie in any direction, it doesn't have to be in the direction you want it to run. I actually usually flip them "backwards" because of convenience (I'm right-handed) and it's about 50/50 between starting the correct way and the opposite way.

I like contra rotating props... I got a 3D printer... I got a few coxes...
HMMMMMMMMMMMMMMMM
Some contra rotating props on a cox sounds like a pretty darn cool idea to me!

Cool , Make it happen

Just check out this baby, arriving soon at a town near you.



Another interpretation, the P-38 counter rotating props to offset torque.



Not kidding, gives me chills just to look at the thing. Been in the P-38 closet for years.

I scratch-build pretty much exclusively.. as many of you know. I can't remember the last time I built from a kit. Truth be known; I've only built a handful of models in kit-form.. and those were decades ago. It's been a handicap on me.. because I've had to learn by making mistakes.. but I've never been discouraged for too long. At 64 years old; my patience gets tested more these days..   but I do understand the nature of that.. which helps.

I've done a good share of scratch-building since this thread was created 3+ years ago. Not all have come to fruition.. but what can I say? I love the hobby.. and.. I