Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Cox Bee ID
by NEW222 Yesterday at 10:30 pm

» The Cars are the Stars Contest.
by Cribbs74 Yesterday at 9:49 pm

» Aurora Tornado .049
by NEW222 Yesterday at 9:05 pm

» Open COX speed event with prizes out to 3rd place in 2 categories
by Marleysky Yesterday at 9:00 pm

» Tether car setup.
by Cribbs74 Yesterday at 6:41 pm

» Buick Riviera
by Ken Cook Yesterday at 5:29 pm

» TeeDee 051 carb sleeve replacement
by Ken Cook Yesterday at 5:27 pm

» Display stands
by rsv1cox Yesterday at 4:19 pm

» Large Cox Parts Lot
by jmcalata Yesterday at 1:50 pm

» What Cox engine is this?
by Jenuine Motor Yesterday at 12:29 pm

Cox Engine of The Month
December-2018
Dave P.'s

"RC Tee Dee 049"



PAST WINNERS
Speed Contest 2018
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


World of Aviation

Brodak 1/2A Flite Streak getting busy

Go down

Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Tue Nov 13, 2018 4:33 pm

I couldn't post this before but our Facebook page designer put the video on You Tube. I really would like to have more videos. My flying buddy Larry decided that he wanted to try flying 1/2A combat. I built Larry a Phil Cartier Lil Hacker on bladder with a .061. I had my son go up against him in a friendly match just to get Larry used to the speed. I used my Baby Flite Streak also .061 powered on a tank. It did rather well. This was Larry's first time flying 1/2A combat Larry is in blue https://www.youtube.com/watch?v=MLfjsA0M9bQ
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Marleysky on Tue Nov 13, 2018 4:46 pm

That was a cool video! First time combat or first time 1/2a combat? He looked like he knew was he was doing! Thanks for sharing.
avatar
Marleysky
Diamond Member
Diamond Member

I Support My Forum

Posts : 1929
Join date : 2014-09-28
Age : 66
Location : Grand Rapids, MI

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Tue Nov 13, 2018 5:28 pm

This was Larry's first time trying 1/2A. My son was following mostly keeping the maneuvers wide. If you notice, Larry's first maneuver was a outside which is typically what he does flying .25 combat. He almost hit the ground . He's hooked now. I've been trying to get the majority of us to fly 1/2A combat and no one wants to be bothered. That was the idea of me using a plane with a tank. Nothing fancy it's just a Perfect tank on suction. I think my prop was a APC 4.6x3.
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  944_Jim on Tue Nov 13, 2018 9:14 pm

Wow! How long are the lines, Ken?
Those guys are running suction only?
AP's or Norvel Big Migs?
Maybe I'm over-propping my P-40...or too chicken to try those moves! Yeah, too chicken!
avatar
944_Jim
Gold Member
Gold Member

Posts : 294
Join date : 2017-02-08

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Wed Nov 14, 2018 4:34 am

The line length is 42'. Larry flying the Hacker is flying with lines that make his center of plane 42' center of plane to center of handle, the 1/2A combat rules only allow a + or - of 3" from the length. My streak though has lines shorter and this is due to having leadouts, it just so happened that I had a set of lines that placed us both at perfect length. My Streak was just on suction while the Lil Hacker was using bladder. Larry is flying a older Norvel AME ( No venturi) while I was using a Big Mig Revlite in stock configuration aside from plug. Both of our planes use Nelson plug setups.I actually had Larry's plane on speed by just a little. This is because Larry was using a Cox black rubber ducky trimmed down to 4" Without checking, I'm pretty certain my engines was using a 4.6x3 APC. I used to do this using the AP Wasp but when I used it for a season at high rpm's it kept taking out plugs and then the crank bushing wore out. I ended up replacing the crank bushing and it just kept taking out plugs still regardless of how many head shims so I parked it.
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  944_Jim on Wed Nov 14, 2018 6:35 pm

Thanks Ken!

APs can be rebushed? Hmm. OK. That means I don't need to stock up in them.

How heavy are the planes? I just keep thinking my P-40 can't fly like those two planes. Or I can't (most likely). Laughing
avatar
944_Jim
Gold Member
Gold Member

Posts : 294
Join date : 2017-02-08

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Wed Nov 14, 2018 7:05 pm

Rebushing the case was a bit of work. Rusty K  flies with a fellow who used to live in my neck of the woods. He owns a Ferrari in which he rebuilt the engine a few years back. He gave us  all of the used valve guides. We made crank bushings for several engines with them.   My Streak in the picture weighs 7.62 oz's. Larry has the Lil Hacker so I can't weigh it.

I use both Big Migs and AME's. The problem with AME's are that they require more nitro and they also have a problem with the wrist pins. The wrist pins are staked to the piston and eventually due to the high rpm's we run them at, the staking is compromised. Generally what happens is that if it goes unchecked, the wrist pin can slide out and it jams in the port of the liner and can cause bad damage. I have had this happen numerous times. Big Mig's don't have a hole in the liner where the wrist pin crosses so this doesn't occur. AP engines use a circlip on one side of the piston.
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Wed Nov 14, 2018 7:34 pm

I did a check of some of the 1/2A's I could readily get to. I had to move them recently to service my heater. The Flite Streak appears to be the heaviest of all of them and I contribute that to the silkspan and dope finish. I don't recommend silkspan as it just rips too easy and always requires constant maintenance. I use Monokote of SLC covering from Phil Cartier which is clear. I have 3 coats of clear both sides of the wing prior to color and one additional clear coat over the entire model. I can easily see how this could've added some weight. The Perfect tank which is pictured has had it's feed pipe re routed and I didn't get a good pic of that but the stock feed came out on the far outboard corner which is directly behind the head. This is very poor as it will get damaged in a crash not to mention it makes the fuel line bend down and then back up to the spraybar. Anytime your fuel line does this, it will cause problematic runs when maneuvering. The fuel is going down and then back up. Even though the pipe is the same level, it does impact the engine run. I believe the fuel line flops offering slight pressure which richens the engine and then gives it a hiccup. I installed the line directly in the bottom of the tank which places it properly and also keeps the fuel line shorter. I left the stock pipe in the tank which I heated and pulled it forward cut it and crimped it over and soldered it blocking it off.




If you ever receive a Norvel, the needle comes with a wire sticking out of the top with a L bend, Do yourself a favor and lose it immediately, this wire is very strong and in a inverted landing it can break the case as it doesn't bend easily placing a lot of stress on the case which is thin. You can see in the center of the knob where I cut it off
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Ken's diet and excersize program for the P-40

Post  944_Jim on Wed Nov 14, 2018 9:55 pm

So my take-away is the P-40 is slightly over-propped, but that could actually save engine wear over time. It is most likely a pig. The fuel tank really needs to come up some, I probably drown the engine inverted. I should try no pressure to minimize the inverted flood. This one should be the one I'm willing to turn into toothpicks now, especially since I knocked the shine off it this past summer. If I get any good weather this fall/winter, use this one to work the beginner pattern...if successful, then work the OTS pattern.

Only then, make a new copy, side mount the engine. This puts the fuel tank right in line with the spray bar. Build it lighter, move the engine back 3/8"-preferably on bearers, not a plastic mount. Get rid of muffler pressure...get rid of the muffler to save weight. Run a slightly larger prop to slow the engine down just a smidge, but be prepared to trim it  1/4"-3/8".  Now the new, improved, revised P-40(b) should do a lot better than the (a) model, and has a decent chance of presenting the OTS pattern with respect.
I better get the building room ready...there is lots of dust to be made this winter!
Thanks Ken!
avatar
944_Jim
Gold Member
Gold Member

Posts : 294
Join date : 2017-02-08

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Thu Nov 15, 2018 4:27 am

In regards to propping, I use smaller than usual props because it helps when running bladder. If I don't use bladder, I typically stick to the 5" diam props.With engines like the Norvel and the AP,  one prop that I use for stunt it the APC 5.5x2.5. It has decent blade area and offers good pull. APC also makes a 5.5x2. The 5x3 APC is also a good choice. The 5x3 for some reason seems to cost twice as much as the others. I see no reason why you couldn't notch the leading edge to allow the tank to come up to correct height. The problem with the incorrect tank height is that even a loop can be problematic. It can cause a engine to go too lean and quit or just the opposite.  I don't fly the OTS pattern but the PAMPA pattern has more maneuvers which I prefer. The OTS pattern however is easier to do with planes that aren't as responsive.

A large prop on a smaller plane generates forces making the plane harder to turn. In addition, it robs needed rpm's to create the drive you need to get it through the maneuver without losing speed. In other words keep it in 2nd gear the entire flight rather than lug it up hills in 4th.
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  944_Jim on Sun Nov 18, 2018 1:56 pm

Hi Ken,

I understand what you mean by dropping pitch for pull. How does a three blade prop work (pluses vs minuses) compared to a two blade prop...all other aspects being the same (same pitch/diameter)?

WTR tank height, here is the P-40. The tank IS a smidge lower than the center of the spray bar. I like the bigger spinner on the three-blade. I will try without pressure today. The night of the  crash was"supposed to be" without  pressure.

Weather is beautiful, so I'm going to chuck this  plane around a bit. No more repairs for beauty...time to work the Beginner's pattern!
avatar
944_Jim
Gold Member
Gold Member

Posts : 294
Join date : 2017-02-08

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Ken Cook on Sun Nov 18, 2018 9:30 pm

Jim, I'm certain that this setups works as you've already flown it. The tank height would concern me a little. I suppose lowering the engine is not a option? The length of the fuel line is a bit concerning to me. If it works fine, no need to change it. I never ran my AP on suction so I'm not experienced with fuel draw with this engine. Just that from looking at the picture, the line length and the tank lower would seem to me that your automatically placing the engine in a lean condition.Again, if it's working, no need to change. I have seen many things that defy practices work just fine. If the engine runs better using muffler pressure then by all means install the pressure line back on.

I'm also unfamiliar to the throat diameter Jan chose to use for the venturi. I have only used 3 bladed props on roundy round planes like my C-47 twin. I wasn't too concerned how it flew just that it flies. Cox offered the 3 bladers in 5x3 configuration which probably places the load on the engine similar to a 6x3. If for instance I'm looking for a 3 blader on a larger engine, I go 1" smaller in diameter to the 2 bladed prop I was currently using.
avatar
Ken Cook
Top Poster
Top Poster

Posts : 3293
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Re: Brodak 1/2A Flite Streak getting busy

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum