Maiden flight today: what tail blade length to match Rail 606mm main blades?

[jhamel]

Well, I am planning on performing the maiden flight today. I need to know what length tail blade I need to best match the Rail 606mm blades. I have 80mm, 72mm, and 70mm tail blades.

[RGorham]

I'm using 72mm but 80mm will work just fine with those blades.

Good luck on your maiden flight!

[flyul1]

Pre-spin the blades or make sure the tail is sitting in grass with the 72mm tails. Otherwise it will spin even with soft start.

[jhamel]

Thank you. I ended up using the 72mm Halo tail blades.

[flyul1]

I fly the 72 Zeals even with 611 mains. They are fine for speed. I found out the hard way they spin around. It is exciting. No crash but Exciting. Letus know how it went.

[jhamel]

Originally Posted by flyul1

Letus know how it went.

It went well for the first couple of seconds.

[Vinger]

What happened? Really sad and feel for you.

[jhamel]

I checked the Jeti radio logs (from the JLog 2.6 and the REX7 receiver), and there does not seem to be any issues with antenna signal loss, or loss of voltage. I am trying to rule out (1) servo failure, (2) Spirit Pro failure, or (3) mechanical failure. I found one blade grip link fractured (pic below) and I could not find the other blade grip link, but my guess is that the blade grips links got damaged from the impact, and were not the cause of loss of control.



My next step is to check the Spirit Pro log.

[john2kx]

Sorry to see that happen and hope you find the cause. I had a issue with mine right after the build that took days to figure out. Ended up being a servo wire squeezed between servo case and aluminum servo mount. In my case, everything worked while in throttle hold. When out of throttle hold servo had a mind of its own.

[flyul1]

I'm Dam sorry your maiden went so bad. It we saw the takeoff from the beginning. I looks like you pitch pumped it. with the short tail blades on a speed machine. You can never hit the throttle hard with out good forward speed. That would explain the piro during the climb. I don't know what happened after that but it all looks on the video to be tail. I hope you don't give up.

[jhamel]

Originally Posted by flyul1

I hope you don't give up.

Well, they build was not straight forward. It needed several modifications to include:

(1) Dremeling the canopy to avoid damage by the main blade bolts

(2) reinforcing the front canopy holes with fiber glass and epoxy

(3) need for after-market main blade shouldered bolts

(4) switching from the speed sub-optimal Halo 580 blades

(5) replacing the stock failure-prone micro servo for the retract landing gear

(6) elevator servo mount that rocks back and forth

Despite the best efforts, it will continue to be prone to tip-over from the short retracting landing gear, so high probability of blade damage. And no, I would not want to install a permanent landing gear.

The rebuild cost is around $500. I am not excited about rebuilding. I am going to give myself a week or two and decide whether I will rebuild or just sell the surviving parts for a super low price.

[flyul1]

I understand. Speed is not for the faint of heart. We call these types of models builder's models. After all the work to set up a thoroughbred racer. One thing can plant it and ruin all that work. If you rebuild put the crappy blades and training gear on the machine for the first flight. Take off very cautiously. Hover for at least 1 min befor you cautiously and slowly move in to forward flight. Then land and install the good speed blades. Now fly at least 2 packs making sure the tuning is good. Then and only then reinstall the retractable gear. Remember these are thoroughbred racers despite their size. I hope you do rebuild. and take it very slowly.

[john2kx]

John,

I know you are probably pissed right now and understand needing to take some time to decide on path forward. From the video, I'll have to agree with flyul1. It looks like you yanked it up before HS was stable and then lost orientation as it was right over your head. A difficult position to recover from, no matter what your skill level is, and with a new model.

Yep, the retractable gear is narrow. But, with 80+ flights on mine, I have only tipped it over once while at a new field with very tall grass and landing in a cross wind. (Note to self: bring a piece of plywood to unknown fields. On any flight (especially a maiden) I would recommend having machine pointing into the wind and you standing behind it.

I followed Robert Gorhams method during maiden and several flights after: leave fuselage off as well as retractable landing gear. I've been flying helis for 25 years or so and never ever do a maiden with fuse attached. This saved my ass and the R5 during those first few flights. Once it proved flight worthy in the bones, I slipped on the fuse and kept the fixed landing gear. A few more grimlins worked out (bad aileron servo id'd and replaced/ one bad solder joint on Kosmik , several weekends doing speed runs and tuning FBL unit, and then switching the fixed gear out to retract. The addition of retract was a major change but since all other systems were working properly, was not that hard to overcome.

There is no need to butcher top of canopy as long as the right blade bolts and nuts are installed. Yep, a PITA to source but plenty of posts on the topic.

I hope this does not rub you the wrong way. Just another old schooler sharing my experiences.

[jhamel]

I appreciate your sensitivity and words of wisdom. I am glad you guys were able to pinpoint the cause of this failure. I was not able to find anything on the Jeti/JLog/Spirit/Kontronik logs to help me determine the cause of failure and the electronics seem to be working properly and without a single scratch. So basically operator error. Honestly, I prefer operator error rather than mechanical or electronic failure. I can always improve my flying skills, but it sometimes takes a long time to figure out mechanical or electronic failure.

I am still tallying the damage parts. The frames and gears are intact. the fuse needs to be replaced. The canopy survived with just a few minor scuffs, but I don't think I can just purchase the bottom part of the fuse; I believe it is only sold as a top and bottom combo. The main and feathering shaft need to be replaced as well as the blade grip arms. I would also replace the upper main bearing even though it is not notchy. It also needs a boom, tail control rod, tail shaft, and a few other parts.

I am going to let it all digest over the next two weeks and decide whether I will rebuild it or just remove the electronics and move on. The decision to move on may be influenced by the fact that my 20/20 vision suffers from pretty bad astigmatism that cannot be easily corrected, so I have a hard time seeing the helicopter from far away which would be an unavoidable aspect of speed flying. So I am going to give myself another 2 weeks to think about it some more.

Thanks for all your help.

John