Cox .049's sweep top two spots in Open Vintage Speed in Santarem Portugal

I like the way that the hard-tank vent is poking through a cut-out in the Bee's tank.. Just for curiosity.. have you tried a bladder using the Babe Bee's backplate? The stock needle seems to be more of a precision-part (as long as it seals).. than the stock (horseshoe) needles are.

I'm just now guessing that you drilled the Bee's backplate for both the feed and vent lines? That's such a cool idea for a built-up fuse installation.

Hi Roger,

The "uniflow" tank vent you see poking out on the l/h side of the tank was me FINALLY getting over 10 yrs of laziness! The std. stock Babe Bee tank was always ~ 5 MPH slower than the Black Widow tank because it never really ran steady throughout the run. What good is 24K rpm on the ground when it the RPM varies all over the place during the timed clocking run.
My first attempt glued the vent on with 5 minute J-B Weld, but it came loose after a few runs. No good as that now became a tank leak. ( Arg!) So with the "proof of concept" validated in flight, I re-glued the vent in place with regular J-B Weld & took more time to abrade the glue area so that it was more likely to stick. While I was at it, I reamed the venturi & tank holes to .093". (Normally this size only works with a pressurized fuel system). Being the quintessential lazy modeller, I ended up J-B welding the inboard tank filler hole shut. The outboard hole is now the tank overflow during fueling. After fueling, the tank is sealed using a small piece of neoprene tubing plugged with a small screw. (told you I'm lazy).
The net result is now the Babe Bee's engine run is stable at high RPM & has more than enough fuel for the required 12 lap clocking, even with the big bore venturi.
I did however have one flight at the British nats go off tune for some reason. On landing, I noticed the tankback vent plug had fallen off. I quickly made up a replacement & carried on. Now I use a newly made plug for every contest.... You see laziness has its setbacks too!

I have successfully used a bladder on a Sure-Start type engine. You have given me a new idea. Why not hollow out the fuselage for a bladder tank?? Possibly the engine venturi can be bored out even larger yet... Plus the front end could be made to be more streamlined... HMmmm!! I will need to contact the Vintage Speed rules coordinator to see if such a mod is legal....

Cheers, Paul

roddie wrote:I like the way that the hard-tank vent is poking through a cut-out in the Bee's tank..  Just for curiosity.. have you tried a bladder using the Babe Bee's backplate?
I'm just now guessing that you drilled the Bee's backplate for both the feed and vent lines? That's such a cool idea for a built-up fuse installation.

Congratulation on the Win !! Paul , Hope to see some video if you can get that you tube acct. up and running , Good looking set of planes there too .The mini is very cool I was wondering about that hole in the tank Eric

roddie wrote:I like the way that the hard-tank vent is poking through a cut-out in the Bee's tank..  Just for curiosity.. have you tried a bladder using the Babe Bee's backplate?
I'm just now guessing that you drilled the Bee's backplate for both the feed and vent lines? That's such a cool idea for a built-up fuse installation.

Paulgibeault wrote:Hi Roger,

The "uniflow" tank vent you see poking out on the l/h side of the tank was me FINALLY getting over 10 yrs of laziness! The std. stock Babe Bee tank was always ~ 5 MPH slower than the Black Widow tank because it never really ran steady throughout the run. What good is 24K rpm on the ground when it the RPM varies all over the place during the timed clocking run.
My first attempt glued the vent on with 5 minute J-B Weld, but it came loose after a few runs. No good as that now became a tank leak. ( Arg!)  So with the "proof of concept" validated in flight, I re-glued the vent in place with regular J-B Weld & took more time to abrade the glue area so that it was more likely to stick. While I was at it, I reamed the venturi & tank holes to .093".  (Normally this size only works with a pressurized fuel system). Being the quintessential lazy modeller, I ended up J-B welding the inboard tank filler hole shut. The outboard hole is now the tank overflow during fueling. After fueling, the tank is sealed using a small piece of neoprene tubing plugged with a small screw. (told you I'm lazy).
The net result is now the Babe Bee's engine run is stable at high RPM & has more than enough fuel for the required 12 lap clocking, even with the big bore venturi.
I did however have one flight at the British nats go off tune for some reason.  On landing, I noticed the tankback vent plug had fallen off. I quickly made up a replacement & carried on. Now I use a newly made plug for every contest.... You see laziness has its setbacks too!

I have successfully used a bladder on a Sure-Start type engine. You have given me a new idea. Why not hollow out the fuselage for a bladder tank?? Possibly the engine venturi can be bored out even larger yet... Plus the front end could be made to be more streamlined... HMmmm!!  I will need to contact the Vintage Speed rules coordinator to see if such a mod is legal....

Cheers, Paul

I've noted significant variances in the diameter of the air intakes amongst my Bee-style (Mazac?) back-plates. I discovered this while testing that "Ace RC" venturi throttle with the plunger-needle.. which is merely a 1.5" long piece of .062" music-wire with a taper ground on one end. Some (most) of mine will allow the needle-shank to pass through the bore.. and others have a smaller hole. Is/was the standard venturi-bore .0625" on the Bee engines? I've never tried boring-out a venturi.. but whether stock or enlarged; have you tried radiussing (possibly using a suitable dremel-stone) the air-intake for increased velocity? I know there's not much meat to grind away on that back-plate.. but one could surely grind a slight "dimple".. and polish the edges; using rouge on a cotton-swab.. chucked in a power drill. That polishing method might work very well on a venturi bored larger.

I re-read your quoted post... and am still puzzled by the comment you made concerning the "tank-back vent-plug". Aren't they (both vents) non-functional on that engine? Sorry if I misinterpreted.

roddie wrote:

I re-read your quoted post... and am still puzzled by the comment you made concerning the "tank-back vent-plug". Aren't they (both vents) non-functional on that engine? Sorry if I misinterpreted.

Roddie,
If I'm not mistaken I believe the babe bee tank still functions as the tank but it has had a uniflow vent installed .

Jim

Hi Roger,

Yes the original 4cc Cox integral tank still functions normally. All I did was re-vent it. Only one original vent is functional & it's only purpose is to act as an overflow during fueling. Then it's capped off.
OH... & I did try an experiment to increase the venturi size to .101" I.D. using a nicely tapered reamer. Engine was not faster, & would not run steady, so I discounted that mod as being useful. HOWEVER, with the steady feeding uniflow tank vent system, (or a pressure system) I may have to re-visit the idea...

Cheers, Paul

JPvelo wrote:

roddie wrote:

I re-read your quoted post... and am still puzzled by the comment you made concerning the "tank-back vent-plug". Aren't they (both vents) non-functional on that engine? Sorry if I misinterpreted.

Paulgibeault wrote:Hi Roger,

Yes the original 4cc Cox integral tank still functions normally. All I did was re-vent it. Only one original vent is functional & it's only purpose is to act as an overflow during fueling. Then it's capped off.

Hmmm....  I think I'm going to have to try this.  I was planning on using a well heeled Babe Bee on my Reed Speed plane, if I ever get it painted.  Maybe I'll try this on the tank and see how she runs.

The Trying Mark

Sorry Jim!  
My earlier reply to you seems to have disappeared into cyberspace (that's twice now), much to my chagrin.
I used to have the plan on my computer until it died taking most of it's info with it.  ARG!
Anyways, plans are available by contacting Mr. Tom Wilk who has all the Vintage Plans & more!
Photos are Salvi Angeloni's rendition from Italy.

Cheers, Paul


Plans on CD

by Tom Wilk
tawilk636@live.com
http://www.cpinternet.com/~tawilk36/

JPvelo wrote:That mini speedster is to cool! Where can I get plans or dimensions for one?

Jim

sheesh.. I totally misunderstood the design.. (feeling really dumb) Understanding now; I had an idea to try for that set-up. It uses flexible silicone fuel tubing (ID size critical?) stretched through a small rubber grommet that gets installed near the top of the tank. If the grommet fits tightly in the tank.. it should seal enough for a uniflow to work. The inner-vent tube could be tucked behind a screw and away from the fuel pick-up during assembly.. and maybe "sleeve-it" with a short piece of hard tubing to keep it in position near the bottom of the tank.) On the outside, a bendable wire bracket with a loop provides for positioning, with regard to the airstream.

I threw an example together.. but can't seem to upload a pic.

Here's a video link to my Mini Speedsters 85 MPH flight taken at the Tournament of the Millenium in Santarem, Portugal.


https://youtu.be/Mf-VeymiBsw

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Paul,

That plane is so incredibly small or so fast that I couldn't even catch a glimpse of it in the video.

I could hear it though and I saw you spinning yourself into the ground. You're video's are making me want to get serious with speed planes!

Ron

Paul,
I hope I'm not hijacking your thread but here's a couple of uniflow Bee tanks from the Rocky Mountain Aero Modelers newsletter:

HI Jim,

NO,not at all! I really like where you're taking this thread. That tire valve is really cool. I use such valves on larger racers, but never thought to apply it to a mouse racer. BTW, that sure looks like a skookum mouser you have there with all the tricks. Is that landing gear removable?  Keep those ideas & photo's coming!

Cheers, Paul



[quote="JPvelo"]Paul,
I hope I'm not hijacking your thread but here's a couple of uniflow Bee tanks from the Rocky Mountain Aero Modelers newsletter: