ProBroJoe

Hello, my name is Joe and I have a problem. I have been hoarding, er, collecting, ummm, acquiring Cox TD .049s for several years. I thought they were "cool", "desirable", and a "must have". So over time, I've been fishing The Bay, shopping flea markets and yard sales, etc, etc... I now have several in my possession. The problem is, I haven't flown a single one [X(]... until yesterday...

Getting increasingly frustrated with the lack-luster and inconsistent performance of a Cox Sure Start .049 on my 1/2A flying wing, I was looking to throw a Norvel .061 back on - I knew this was a sure thing and would give me trouble free performance - albeit a bit too much. As I opened my engine case to remove a Norvel from it's lair, there were these Silver, Black, and Gold jewels staring back at me. I figured, "Hey, why not?", grabbed a handful of TDs and off I went to try one out.

I bolted one of better feeling ones to the front of the Kombat Kid thinking that I would run a tank out on the ground so I could get a feel for their temperament. I fueled, primed, and within three flips I had her running... a tweak or two of the needle and she was steady as a rock, wailing away. "Wow, that was easy." I thought to myself as I pinched off the fuel line and readied for flight.

The hot restart was one flip and in flight performance was spectacular! Smooth and steady for the entire tank, great vertical, and pretty decent speed, but what impressed me the most was how consistent and predictable it was. I've head horror stories of how temperamental and high strung these TDs were and hence my reservations about flying one. Now I'm kicking myself for not enjoying these sooner and putting up with those darn reedies for so long![:'(]

Oh, for what it's worth, this particular TD has a KK fine thread needle and I was running a 22% nitro, 20% castor/synth fuel and a Cox 5 X 3....

Anybody have any TDs they wanna part with fer cheap?

Tee Bee

My experience is similar to yours, PBJ. I'm known around here for flying reedie .049s but have never operated a TD .049 until recently installing one on my Das Splat Jr. I initially had fuel delivery issues with it using a standard style tank and was about to give up on it when I finally found a setup that worked well(Thanks, Dickeybird!). I was very surprised at the performance just as you were. At first, I was so frustrated with my TDs that I was ready to get rid of them but now have a real appreciation for the little power houses. I still fly the reedies but even my hotter ones seem wimpier by comparison. I've been shuffling parts around having fun and experimenting. My latest flying TD setup uses an old red/gold .051 bottom end, a lightened SS piston fitted to a modified SS cylinder by Tim Wiltse, a Turbo glow plug conversion head, a Dickeybird venturi which has a smaller ID than stock(This increases air velocity thru the venturi, therefore pulling better vacuum for fuel draw.). With a Cox rubber ducky 5x3 prop, this engine has run great and made my Das Splat Jr flat out scoot. Using Sig 25% nitro 1/2A fuel with some added castor.

BTW, you still flying your .010 LaStick? When I saw your vids several years ago, I was inspired to build one. Have had lots of fun with it. I've built 2 more .010 planes since then.

ProBroJoe

Hey TeeBee... Yea, I'm still flying that little fella! It was down for a while as the nylon fuel line was hardened and was leaking at the tank - but I found a cheap source for fuel line that works just great. You know how people on oxygen have those nose pieces with the two little nylon tubes going back over the ears to a "Y" connector.... ya see where I'm going with this? Eh, ole granny won't miss one of 'em! Anyway... that tubing is the right size and works great!

This one TD I'm running here is pretty impressive, turning over 19,500 on 25% with the 5x3, but what I don't like is the fuel consumption rate - I'm only getting about 3 min 15 seconds out of that 1 ounce tank!

I tied one on this morning... a streamer that is, and wrung the 'Kid out some more. I can't say that the 20' of streamer slowed it down any, but it was a blast. 72 degrees, clear, and hardly breath of wind... I burned up the last of my 25% and tried some 15% Wildcat with added Benol. After a tweak of the needle, the ole TD ran just fine, and towed the streamer like it wasn't there. (Although it did sound a wee bit ragged.) Keep in mind, I didn't bother playing with shims or anything...

Now, if this ADHD afflicted kid I call a friend would ever build his kit, we could get down to business flying combat, eating BBQ, and drinking homebrews!

Remby

My Feedback: (3)

Hea, thats Kewl!

combatpigg

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Years ago, Larry Driskill wrote a 2 part article for Model Aviation about how to get going with 1/2A combat. It was a construction article for a foamie plane and also a tutorial about how to get the TDs screaming. IIRC, his plane was called the HalfLite. It would be worth doing some digging to find that article sometime......
The plane itself would be too small for RC, but all it would need is enlarging. The construction details and methods should be of interest, it's an old school C/L foamie design that was built in batches..
A well prepped TD will hit 22,000-23,000 with a 5x3 on 30%. It's real important to monitor the ball socket...you can unscrew the cylinder with the engine still mounted in the plane to do a quick check every few flights. Zero clearance in the socket is what you want, slight binds can be worked out to perfection with manipulation.
Keep your eye on the tightness of the venturi after every flight, too.

ProBroJoe

>Keep your eye on the tightness of the venturi after every flight, too.

Thanks CP... I found that out early on, especially since I'm hesitant to torque those down too much. The needle was wondering a bit too, but a hunk of fuel tubing fixed that worn-out friction clutch / needle seal.

I have no idea how much abuse this specimen has had - as it was dragged outta the bay quite some time ago, but it was the better feeling one of the bunch. I didn't touch it other than checking the ball socket before I fired it up... thought it was doing OK in the mid 19's with little "tuning".

IMHO, this is a much better engine for this plane than a POS SureStart...

combatpigg

My Feedback: (3)

Yeah, the extra power is significant for good dog fighting and makes the planes handle less than perfect weather better, tow more streamer, etc.
If you get some stainless wire from a fishing tackle shop, it comes in handy to tie the venturi to the cylinder. To be able to make a day of 1/2A combat with the fewest interuptions, little stuff like this can be trouble. Same goes for clunk tanks, for combat I like hard plastic tubing placed at the bottom of the tank. This way hard landings don't cause kinked fuel pick up tubes. If the pit stops can be limited to just "gas and go", it makes more time for all the other stuff to keep the action going. This is why I like 2 oz tanks.... after going to the trouble to do the pitting chores, it's nice to be able to sit back for a full 15 minute round before getting back up to do it all over again.

flyinrog

My Feedback: (1)

Well my favorite td story was a few years back, I built a .010 or .020 wee stick, it had a trans green wing and white fuse, and as I am getting it out to fly one of the local geniuses told me that they were the 2 colors that dissapeared fastest from view...well about 60 seconds into its 90 run time, it disappeared,,,a couple of guys said" I can hear it, where is it?"...well I didnt have a clue except the last time I saw it, it was about 9:00, so I kept lookin that way, like I was watching it,,well it poked outa the sky around 10:00 (position) and it had a fairly impressive hang time, gliding in...so it was lost about 1/2 the time it was up there...,,,I dont know if any of yall were around to see Raymonds 3 .010 engined stick fly...but that was the coolest thing ever....I think I might try that with 3 tanked reeedies,,but on what ...a Whizard maybe???......Rog

build light

Said Rog: "I think I might try that with 3 tanked reeedies,,but on what ...a Whizard maybe???......Rog"

Oh my what an image that presents! Wheels are a turnin'!

More coming in a seperate thread, Robert

flyinrog

My Feedback: (1)

Might be a couple of outer (not too far apart) tanked reedies and a norvel in the nose for a few extra minutes of flying would be good,,would need landing gear, in case the norvel .049 couldnt keep it in the air.....Rog