Log in
Search
Latest topics
» A prototype Cox Reed-valve marine engineby roddie Yesterday at 11:51 pm
» My Cox .049 Marine inboard engine
by 1/2A Nut Yesterday at 11:41 pm
» Here we go again... another Lawn-Boy
by Cribbs74 Yesterday at 10:52 pm
» Jim Walker Firebaby
by rsv1cox Yesterday at 7:26 pm
» Roddie-Rigger.. a 2005 original design
by roddie Yesterday at 7:04 pm
» music vids.. some of your favorites
by HalfaDave Yesterday at 6:55 pm
» Norvel Needle Needed
by Greenman38633 Yesterday at 5:36 pm
» World's largest weathervane
by Cox International Yesterday at 3:38 pm
» Help Pee Wee tank cap .020
by rdw777 Yesterday at 1:30 pm
» **VOTE-ON-THE-NEXT-COX-ENGINE-OF-THE-MONTH** (May 2024)
by GallopingGhostler Yesterday at 11:34 am
» Revivng Some Childhood Classics
by getback Yesterday at 8:21 am
» Jim Walkers FireBee - This is going to be fun
by rsv1cox Tue May 07, 2024 7:29 am
Cox Engine of The Month
Scratch-Build 2021
Page 1 of 1
Scratch-Build 2021
Just what it says. Y not scratch-build something Cox-Powered? Y try to find a kit? Y not get creative?
Re: Scratch-Build 2021
*** SIGH ***
Ya just had to challenge me, didn't ya.
The "Bring It" Mark
Ya just had to challenge me, didn't ya.
The "Bring It" Mark
batjac- Diamond Member
-
Posts : 2337
Join date : 2013-05-22
Age : 61
Location : Broken Arrow, OK, USA
Re: 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
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
davidll1984- Diamond Member
- Posts : 2293
Join date : 2020-02-12
Age : 39
Location : shawinigan
Re: Scratch-Build 2021
I'm definitely planning on a scratch-built Westland Wyvern some time this season. Already have plans printed out from Outerzone.
dirk gently- Gold Member
- Posts : 429
Join date : 2012-02-03
Age : 41
Location : Poznań
Re: Scratch-Build 2021
Cool! How do you plan on doing Contra-rotating propellers?
Cribbs74- Moderator
-
Posts : 11897
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: Scratch-Build 2021
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.
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.
dirk gently- Gold Member
- Posts : 429
Join date : 2012-02-03
Age : 41
Location : Poznań
Re: Scratch-Build 2021
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.
rsv1cox- Top Poster
-
Posts : 10607
Join date : 2014-08-18
Location : West Virginia
Re: Scratch-Build 2021
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
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
KariFS- Diamond Member
- Posts : 2004
Join date : 2014-10-10
Age : 52
Re: Scratch-Build 2021
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.
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- Top Poster
- Posts : 3973
Join date : 2012-06-15
Age : 61
Location : Drouin, Victoria
Re: Scratch-Build 2021
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
rsv1cox- Top Poster
-
Posts : 10607
Join date : 2014-08-18
Location : West Virginia
Re: Scratch-Build 2021
I got the joke Bob
Cribbs74- Moderator
-
Posts : 11897
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: Scratch-Build 2021
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- Top Poster
-
Posts : 10607
Join date : 2014-08-18
Location : West Virginia
Re: Scratch-Build 2021
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.
Cribbs74- Moderator
-
Posts : 11897
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: Scratch-Build 2021
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- Gold Member
- Posts : 429
Join date : 2012-02-03
Age : 41
Location : Poznań
Re: Scratch-Build 2021
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!!
Last edited by OVERLORD on Fri Feb 19, 2021 2:00 am; edited 1 time in total (Reason for editing : spelling)
OVERLORD- Diamond Member
- Posts : 1790
Join date : 2013-03-19
Age : 57
Location : Normandy, France
Re: Scratch-Build 2021
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 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.
dirk gently- Gold Member
- Posts : 429
Join date : 2012-02-03
Age : 41
Location : Poznań
Re: Scratch-Build 2021
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!
Lukemiester- Gold Member
- Posts : 290
Join date : 2020-10-08
Age : 19
Location : currently Wickenburg, AZ
Re: Scratch-Build 2021
Cool , Make it happen
getback- Top Poster
-
Posts : 10141
Join date : 2013-01-18
Age : 66
Location : julian , NC
Similar topics
» Scratch build BRM - a first
» La Stick Scratch Build for Cox Pee Wee .020
» Qtee scratch build
» New P-38 profile scratch build log
» My Latest Scratch build Cox powered car
» La Stick Scratch Build for Cox Pee Wee .020
» Qtee scratch build
» New P-38 profile scratch build log
» My Latest Scratch build Cox powered car
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum