What does a TD 049 weigh???
12-05-2008, 12:42 AM
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RE: What does a TD 049 weigh???
No, I am building a Ulmer Rc Blink and was in the air between a electric set up or my TD 049. The 049 gear comes out about the same. I think I will use the TD at 7oz auw and no throttle should make for one hell of a flight.
12-05-2008, 02:25 PM
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RE: What does a TD 049 weigh???
ORIGINAL: Andrew
Take an extra pair of pants!!! 
Well said and also take extra nitro pills for your heart.[X(]
ORIGINAL: iflyg450
What kind of speed do you think it will pull?
What kind of speed do you think it will pull?
Well said and also take extra nitro pills for your heart.
[X(]
12-05-2008, 04:40 PM
#10
RE: What does a TD 049 weigh???
I asked Joe Klause [more than once] about the liner shims and he felt their main function was to get the top of the piston set to the "blueprint" deck height [dead even with the top of the bore], this corrects the liner timing, but really isn't a "hop up"....some engines don't need it.
I experimented with various combinations on 40% fuel with combat props and never saw the need for more than a thin liner shim and single head shim. Never broke any cranks, just had ball sockets crumble with stock weight pistons above 24,000 rpm. Lightening the piston changes the whole picture, the engines will tend to just wear out uniformly without catastrophic failures.
I experimented with various combinations on 40% fuel with combat props and never saw the need for more than a thin liner shim and single head shim. Never broke any cranks, just had ball sockets crumble with stock weight pistons above 24,000 rpm. Lightening the piston changes the whole picture, the engines will tend to just wear out uniformly without catastrophic failures.
12-05-2008, 05:40 PM
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RE: What does a TD 049 weigh???
ORIGINAL: combatpigg
I asked Joe Klause [more than once] about the liner shims and he felt their main function was to get the top of the piston set to the "blueprint" deck height [dead even with the top of the bore], this corrects the liner timing, but really isn't a "hop up"....some engines don't need it.
I experimented with various combinations on 40% fuel with combat props and never saw the need for more than a thin liner shim and single head shim. Never broke any cranks, just had ball sockets crumble with stock weight pistons above 24,000 rpm. Lightening the piston changes the whole picture, the engines will tend to just wear out uniformly without catastrophic failures.
I asked Joe Klause [more than once] about the liner shims and he felt their main function was to get the top of the piston set to the "blueprint" deck height [dead even with the top of the bore], this corrects the liner timing, but really isn't a "hop up"....some engines don't need it.
I experimented with various combinations on 40% fuel with combat props and never saw the need for more than a thin liner shim and single head shim. Never broke any cranks, just had ball sockets crumble with stock weight pistons above 24,000 rpm. Lightening the piston changes the whole picture, the engines will tend to just wear out uniformly without catastrophic failures.
12-05-2008, 07:34 PM
#14
RE: What does a TD 049 weigh???
Q450, that's a pretty ambitious project! Especially changing the scale....I would be tempted to increase the aspect ratio [span] of the wing slightly if you're looking for speed. I always get fooled looking at full size drawings, they make stuff look bigger than in real life. This plane was "kinda fast" with a strong 1/2A engine, but not real fast. Sometimes strange things happen when you scale up, usually for the better, so you might end up with a real screamer. The rear exhaust throws in some design challenges, you don't have to run a full pipe if it comes down to that, but a pipe really takes the harsh bite out of the engine sound.
The plane has such a skinny profile, what are you using for a tank? I would use the 4 oz Tettra or Jett bubbleless type.
Are you going with a skinned foam wing? Gotta keep it thin, 8% of the cord is considered about right.
Have fun and good luck!
The plane has such a skinny profile, what are you using for a tank? I would use the 4 oz Tettra or Jett bubbleless type.
Are you going with a skinned foam wing? Gotta keep it thin, 8% of the cord is considered about right.
Have fun and good luck!
12-05-2008, 10:48 PM
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RE: What does a TD 049 weigh???
ORIGINAL: combatpigg
Q450, that's a pretty ambitious project! Especially changing the scale....I would be tempted to increase the aspect ratio [span] of the wing slightly if you're looking for speed. I always get fooled looking at full size drawings, they make stuff look bigger than in real life. This plane was "kinda fast" with a strong 1/2A engine, but not real fast. Sometimes strange things happen when you scale up, usually for the better, so you might end up with a real screamer. The rear exhaust throws in some design challenges, you don't have to run a full pipe if it comes down to that, but a pipe really takes the harsh bite out of the engine sound.
The plane has such a skinny profile, what are you using for a tank? I would use the 4 oz Tettra or Jett bubbleless type.
Are you going with a skinned foam wing? Gotta keep it thin, 8% of the cord is considered about right.
Have fun and good luck!
Q450, that's a pretty ambitious project! Especially changing the scale....I would be tempted to increase the aspect ratio [span] of the wing slightly if you're looking for speed. I always get fooled looking at full size drawings, they make stuff look bigger than in real life. This plane was "kinda fast" with a strong 1/2A engine, but not real fast. Sometimes strange things happen when you scale up, usually for the better, so you might end up with a real screamer. The rear exhaust throws in some design challenges, you don't have to run a full pipe if it comes down to that, but a pipe really takes the harsh bite out of the engine sound.
The plane has such a skinny profile, what are you using for a tank? I would use the 4 oz Tettra or Jett bubbleless type.
Are you going with a skinned foam wing? Gotta keep it thin, 8% of the cord is considered about right.
Have fun and good luck!
12-05-2008, 11:29 PM
#17
RE: What does a TD 049 weigh???
You're very lucky to have a guy like him to "show you the ropes". Have you met Ptulmer yet?
I have never run a VRDF .25, but 19,000 with a 7x6 sounds like what some .15s can do. I don't have a clue what to expect from this engine, but it sounds kind of low. If the engine has a stack of head shims in it for running 60% nitro and you're running it on sport fuel, that might explain why the .25 is running like it's got a piano on it's back?
I have never run a VRDF .25, but 19,000 with a 7x6 sounds like what some .15s can do. I don't have a clue what to expect from this engine, but it sounds kind of low. If the engine has a stack of head shims in it for running 60% nitro and you're running it on sport fuel, that might explain why the .25 is running like it's got a piano on it's back?
12-06-2008, 01:15 AM
#18
RE: What does a TD 049 weigh???
From what I remember with the VRDF's, when mounted in a ducted fan with the shroud, I believe they where turning in the mid to upper 20's. I do remember the break in procedure was to use a prop on a test stand before mounting into the fan. The VRDF will get a good boost if you can set up a tuned pipe with it which is the way it was intended to be run with the fan.
Hogflyer
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12-06-2008, 10:22 AM
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RE: What does a TD 049 weigh???
it has the pipe. I am sure I can get more power out of it. I found a post were somone found the right prop and got it to turn 24K wich is were OS says it will make 1.2hp just can't find the post
12-06-2008, 11:44 AM
#20
RE: What does a TD 049 weigh???
24,000 sounds like a good target rpm. A 7x6 sounds like just about the right prop. Small tuned engines are very picky about load, so you might find that thinning the blades or shortening the blades just a little bit allows the engine to get on the pipe. There are most likely guys in the Speed Forum who are very familiar with this engine. If the header hasn't been already shortened too far for fan use...at it's original length, then you'll need to spend time with a tach, fine tooth hacksaw and target prop to find that explosive jump in rpm. If you shorten the header and the readings gets worse, then the system is already too short or the pipe is too small. Along the way, glow plug life will tell you when it's time to add head shims.
It wont do any good to tune the engine with an unrealistically small prop for the plane. There are free prop thrust calculators online to help you "keep it real". I wouldn't think that going very much below 7 inches is a good idea, the calculators will help predict those results. The pipe tune is pretty "prop specific", so 7x6 sounds pretty reasonable as a max load not to exceed during testing.
It wont do any good to tune the engine with an unrealistically small prop for the plane. There are free prop thrust calculators online to help you "keep it real". I wouldn't think that going very much below 7 inches is a good idea, the calculators will help predict those results. The pipe tune is pretty "prop specific", so 7x6 sounds pretty reasonable as a max load not to exceed during testing.
