No.. could it be..?
05-29-2015, 01:54 PM
#501
That's a good question and I haven't been able to figure it out either. Years ago, there was an ARF available called the "Laser Arrow". It was about 36" span and built like a tank. It was too thick to be truly fast, but it was lots of fun with a .32-.46 on it. There were 5 or 6 at our field at one time or another, including 2 of my own. A guy in our club who has an RC website (VVRC) was selling them for around $80.00 IIRC. They became unavailable one day and that was it. I also had a couple of Outlaws, one of which still exists. That was another great delta, now also discontinued. For going fast and having fun, the Demon is the best I've encountered yet. I've seen a few of the BTE deltas over the years, but not many. For a piped .91, try a 12-10 or a 13-8.
05-29-2015, 02:59 PM
#502
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Thanks, that help a lot.
The Vortex is a fun build, manual and plans are nicely done, parts fit perfectly. I am looking forward to get this in the air.
What I'd like to have is a larger SD. Hanno Prettner had some interesting designs back in the day, but they are hard to find now.
The Vortex is a fun build, manual and plans are nicely done, parts fit perfectly. I am looking forward to get this in the air.
What I'd like to have is a larger SD. Hanno Prettner had some interesting designs back in the day, but they are hard to find now.
05-29-2015, 04:33 PM
#504
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Been working on it again tonight. Once I test-fitted the motor, I decided to do some watt-meter pulls with some different props. Started with 4S and an APC 8-6E. 104 amps. A bit much. I must have sorted through 50 or 60 props and couldn't find anything I wanted. So I cut an APC 8-7 sport prop down to 7" diameter. I got 79.4 amps out of that one, 1131 watts. That will be my starting point until I can find some more suitable props. The LHS didn't have any, either. Figures.
One interesting fact I found using a data logging esc is the static draw on the ground is much higher than it is when airborne. The draw drops about 10 to 15% on average from what I have found, and if your lucky enough to get it up to the prop pitch speed the amps drop even more.
05-29-2015, 08:06 PM
#506
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Your static amp draw is going to be much higher than when the prop is not stalled. You might want to try cutting down an 8X8 down to a 7X8 just for grins and giggles. Or if your really not in love with the results that 8X7 might just work as long as you don't stay pegged the entire time. I have a very similar motor I am going to try with my one remaining 8X8 tornado prop I have left.
If you don't have a lot of love for the motor why not go for the gusto.
Regards
Paul
If you don't have a lot of love for the motor why not go for the gusto.
Regards
Paul
05-30-2015, 10:08 AM
#510
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Good luck with the maiden.
Keep in mind when launching an electric delivers full torque from the start, so you may get a bit more of a left turn.
A test stand is not nearly as good as in-flight data, an in flight data logger will give you a lot more accurate results.
Keep in mind when launching an electric delivers full torque from the start, so you may get a bit more of a left turn.
A test stand is not nearly as good as in-flight data, an in flight data logger will give you a lot more accurate results.
05-30-2015, 03:42 PM
#511
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At 1500w input, your power to the prop is going to be more like .46 territory I think. That's 2hp input, at let's say 80% efficiency is equivalent to 1.6hp to the prop. It will boogie for sure.
05-31-2015, 06:52 AM
#512
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I flew my old Demon with the Evo .60NX / Jett muffler yesterday. APC 9-10 prop, 10% Omega. Effortless launch, and the top speed was pretty healthy. No tracking. I would say the Jett .50 and West .50 are noticably faster, but this combo was pretty darn quick. Bit of an overcast day with intermittent rain. The vertical climb to cloudbase didn't take long.
No rocket science was done, but was interesting to see how this engine combo would fare. On a nicer day I'll fit a 10-7 or 10-8 and try a vertical release launch.
No rocket science was done, but was interesting to see how this engine combo would fare. On a nicer day I'll fit a 10-7 or 10-8 and try a vertical release launch.
06-09-2015, 03:15 PM
#519
06-15-2015, 03:44 PM
#521
Finally I had time to go down to the shop and build.....and it felt GOOD.
The 7.5 K&Bs I have are pumped so the will sit farther forward in the engine mount but that should not be a problem. I also modified the cutout for the mini servos as I have metal gear micro servos for elevons that put out 56 in/oz of torque.
Taking a quick break then back down to rip some LE material.
The 7.5 K&Bs I have are pumped so the will sit farther forward in the engine mount but that should not be a problem. I also modified the cutout for the mini servos as I have metal gear micro servos for elevons that put out 56 in/oz of torque.
Taking a quick break then back down to rip some LE material.
06-15-2015, 04:56 PM
#524
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Mine's a ways out there, still a few projects to complete first. And after reading about all the unobtanium engines you guys have, I feel like mine is going to be slow. I've only got a Jett 428 Quickie with pipe and Red Jett throttle for my SD. 
But I think it'll be enough to harelip everybody on Bear Creek!
Dave
But I think it'll be enough to harelip everybody on Bear Creek!
Dave
Last edited by dbacque; 06-15-2015 at 05:07 PM.