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Thread: Ritewing Mini Drak Build and Info

  1. #191
    Co-Pilot Håvard Støre's Avatar
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    Quote Originally Posted by Rctintin View Post
    Guys, about to order some 1.3 stuff. Do I need Low pass filters with 1.3 and Singularity aerials?
    No

  2. #192
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    how did you guys do with your prop testing? got 138mph out of mine today. not the 'stock' setup though:

  3. #193
    Flyer of the lands Hoss's Avatar
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    Pretty sweet. It was a 400' full throttle dive... Which I think I might be able to pull with a paper airplane as well but sick nonetheless. What's your setup and what top speeds are you seeing flat and level?

  4. #194
    Fly,crash,glue,repeat! Jake Bullit's Avatar
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    Managed 151.6 MPH today,out of a dive with a stiff tailwind Click image for larger version. 

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    "Roads? Where we're going, we don't need roads."

  5. #195
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    Quote Originally Posted by Hoss View Post
    Pretty sweet. It was a 400' full throttle dive... Which I think I might be able to pull with a paper airplane as well but sick nonetheless. What's your setup and what top speeds are you seeing flat and level?
    show me your paper plane, want one, too.
    If you look closely you'll see she's still accelerating when level, so the dive is not really adding, just helps shorten the run. I had 2 135mph level runs but had to turn and wanted to see 140 so bad. This is a 5s setup, the Cobra 2814 2100kv with a Graupner 6x6. On 4s the combo makes 123mph. The 4s was pulling 800W so I was guessing in order to make 140mph (+15%) I would need at least 1.15^3 as much, 1.52*800W so roughly 1200W. On 4s that's more than 80A. Too much. so I went with 5s and the OSD numbers actually match the calculation. While accelerating she's pulling up to 1300W.
    Jake, yours must have been out of hell of a dive, 150mph at 450W, your prop was probably braking....

  6. #196
    Flyer of the lands Hoss's Avatar
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    That's awesome. 5s must haul. I'm not going to take away from your accomplishment - I can't hit that, dive or not (yet at least), but it was a pretty significant loss - 500' to 130' in 7 or 8 seconds... If you don't have a pitot tube on it and are relying on gps, you will always see a significant bump in speed once you go level again. The gps is tracking your movement across the sky, so when losing a ton of altitude, you're not traveling as far horizontally because you're also traveling vertically, so the gps just calculates the distance you've traveled horizontally in a given amount of time, and once you pull level, you start covering much more distance horizontally, so you see that sudden increase in speed that makes you think you're still accelerating, but the gps is just able to read your true distance covered at that point. If you have a pitot installed, ignore everything I just said

  7. #197
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    afaik, GPS uses doppler shift to calculate speed (https://books.google.com/books?id=6P...page&q&f=false), but maybe not the cheap hobby stuff. I thought the delay would come from processing. but anyway, the way you explain it would make the speed inaccurate when diving but true when level. doesn't really matter.
    I'm not out for records or such; I just like if theoretical guesswork is proven to be correct when tested. In theory, 15% more speed needs 50% more power, no way around it when if you leave everything else unchanged. That I could prove myself.

  8. #198
    Flyer of the lands Hoss's Avatar
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    Yeah man, regardless, you've built yourself one nice machine. Any hd footage coming anytime soon? Do you have an HD cam on it or just flight cam? Would love to see some flying.

    I put the 7x9 on the mini tonight. I'm going to test the static wot amperage to be sure ecalc was correct in keeping it in the 60's, and test the static thrust to see if it's even possible to throw it. Hopefully the prop doesn't stall too too much and still maintains some level of thrust over 1:1. I also need to get a big fat ESC all the way in the back. Probably going to have to get surgical with the x-acto, which I hate doing, but hey, it needs to fit.

    My last 3 launch attempts, 1 with a 7x6 and 2 with 7x5's all went into the ground. The first cartwheeled and ripped the wing joiner, so it went back in the car for the session. The next 2 I only had 1 prop - the one that was on it and it broke it both times. I've broken more props on this plane than any other plane I've ever thrown. It's not the planes fault - most have been skimming the ground at 70mph and just catching it with a few too many blades of grass and slowing it enough that I couldn't pull up in time, but nailing the throttle in the process not only breaks the prop, but immediately twists the nut off and I lose it, lol. I've considered doing lock nuts as well as pusher props to spin the motor the other way, but figured that was a good way to break more than the prop. I'll gladly buy stock in apc over some serious damage to the motor, mount or anything else.

    Anyway, mothers day tomorrow so I'll be making breakfast and getting flowers and cards with the kids rather than flying, so maybe next weekend. I finally hired a guy for my department at my job so I could take a day off this week and go, but my old flying spot has a gate and lock now, and my regular one is an elementary school during the week, so that might not go over well. Maybe it would... It's a separate park that's kinda attached to it - and I go way in the back and wouldn't fly over or near the school... Hmmmm.... I need a new, always solid place to fly...

    If you're in or near Central Jersey and want to play hooky one day this week and do some ripping of the skies and prop / speed testing of the mini, hit me up!

    Happy flying -

    Scott
    Last edited by Hoss; 13th May 2017 at 11:53 PM.

  9. #199
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    Sorry, no HD cam yet in the Mini. didn't want to cut those deep holes in the nose. Maybe I put one one top of the nose cone when I'm not speeding...
    Try some goop on the thread; that should be sticky enough to keep the nut on the shaft (that kinda sounds ambiguous). Not everybody likes bungees, but it would help in these cases. Just drop-launch it with a bungee, no ramp needed and you're still mobile. I'm using the Cobra 80A ESC and was surprised it's not as big as I thought it would be. just a bit pricy. good luck with the launches!

  10. #200
    Flyer of the lands Hoss's Avatar
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    Quote Originally Posted by crashsalot View Post
    Sorry, no HD cam yet in the Mini. didn't want to cut those deep holes in the nose. Maybe I put one one top of the nose cone when I'm not speeding...
    Try some goop on the thread; that should be sticky enough to keep the nut on the shaft (that kinda sounds ambiguous). Not everybody likes bungees, but it would help in these cases. Just drop-launch it with a bungee, no ramp needed and you're still mobile. I'm using the Cobra 80A ESC and was surprised it's not as big as I thought it would be. just a bit pricy. good luck with the launches!
    Thanks. Yeah, I was looking at the Cobra 80 - it looks like it would have fit without much, if any mod. I have a bunch of esc's though so I couldn't in good conscience buy another. I just cut a relief on both sides, in between the saddle bay and the main bay. Fit right in. It was too tall though, so I cut a relief in the top of the lid as well. I probably would have anyway because it's a heat sink and I'm probably going to be pushing this thing pretty damn hard with these props

    I'll post a pic in a minute.

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