It's not "if"... but 2400 head speed definitely helps

[madeye]

Crashed the bird for the first time today, after logging about 30 minutes on it.

In a really stupid way, too - made a minor mistake, was about to successfully recover (a bit low, though) - and at the most critical moment accidentally flipped DR from 50% to 100%, sending it straight into the dirt. Now that I think of it, this is not the first crash of this sort - the only difference is that previous ones were with mCPX BL and zero repair cost. DR is mapped to rudder DR, right next to TH, you *have* to have your fingers on TH, and I bet I'm not the only one having done this. Will be remapping DR right after I'm done with this message.

So far, the only damage that I see is -

- sacrificial main gear bolt sheared - expected;

- main shaft bent - I understand there's no hope of unbending it?

- canopy cracked in a couple of places - I like this one, and it's not damaged beyond loss of use, but is there anything that is a bit more visible as far as orientation is concerned? Not really easy to see which way it's looking until it starts showing its green belly (contributed a bit to this crash, too, the bird started rolling and I didn't see it until I saw the top of the rotor);

- shredded main blades - what blades would I want to use to have better lift and control at low head speed?

- vertical crack under right front motor plate mounting bolt (picture below) - would it make sense to try to save the frame plate with CA? Do I remember correctly that someone's selling CF washers specifically to reduce stress concentration around these bolts? Is there a way to buy just one side? Or, can I get a couple of 1.3x5x10mm CF strips and glue them over the crack, or one 1.3x20x10mm with the slot - hope it's sufficiently reinforced by the motor mounting plate from the other side?

I think there's nothing else, but since this my first MiniP casualty - what are other things that are usually missed after the crash on this specific helicopter?

[dr dremel]

Sorry for your crash, not a good feeling when you put it in the first time.

Originally Posted by madeye

...accidentally flipped DR from 50% to 100%, sending it straight into the dirt....

Quite the difference between 50 and 100%. Do you even fly @100%? Maybe remapping to 50-65-75?

- main shaft bent - I understand there's no hope of unbending it?

Nope and they are reasonably cheap to just get a new one. Hollow shafts save weight, nothing wrong with solid shafts either (cheaper and stronger). Check main shaft bearings for notchiness, shaft bending hit can sometimes indent the bearing races.

- canopy cracked in a couple of places - I like this one, and it's not damaged beyond loss of use, but is there anything that is a bit more visible as far as orientation is concerned? Not really easy to see which way it's looking until it starts showing its green belly (contributed a bit to this crash, too, the bird started rolling and I didn't see it until I saw the top of the rotor);

Check out the Lynx one JustplainChris desinged, it´s a wrap around canopy.
http://www.msh-direct.com/products/m...scheme-02.html

- shredded main blades - what blades would I want to use to have better lift and control at low head speed?

Better lift with wider chord, so Mavrikk G5 maybe an option. As I see you´re flying with 50% DR I´d also look at heavier blades like Radix FBL. I have no firsthand experience with these though.

- vertical crack under right front motor plate mounting bolt (picture below) - would it make sense to try to save the frame plate with CA? Do I remember correctly that someone's selling CF washers specifically to reduce stress concentration around these bolts? Is there a way to buy just one side? Or, can I get a couple of 1.3x5x10mm CF strips and glue them over the crack, or one 1.3x20x10mm with the slot - hope it's sufficiently reinforced by the motor mounting plate from the other side?

The CF washers are for the Protos plastic frame, so the slot length and bold hole dia do not match. Could be adapted with bigger washers though. I´d epoxy a strip of CF (even around the slot). Maybe use a longer screw.

I think there's nothing else, but since this my first MiniP casualty - what are other things that are usually missed after the crash on this specific helicopter?

If it went in under power check OWB if still engaging correctly. Other than that really nothing special to the MiniP when crashing. Typically it takes crashes quite good in my experience.

[Aryemis]

+1 on the new lynx canopies, I have this one : http://www.msh-direct.com/products/m...scheme-01.html
And it's super visible, helps alot in orientation.

I'm suprised you managed to crack the frame even a tiny bit, mine have been going strong through 4 pretty hard crashes at higher rpm's than you.

You're running a non-stretch setup right ? The KBDD CF blades have a really wide chord as well, and provide alot more lift than stock, they don't fit in the stock blade sponge holder (this :http://www.helidirect.com/msh41061-m...os-p-22801.hdx) though which is kinda annoying.

And +1 on checking the oneway and the counterbearing.

[madeye]

Originally Posted by Aryemis

+1 on the new lynx canopies, I have this one : http://www.msh-direct.com/products/m...scheme-01.html
And it's super visible, helps alot in orientation.

I was considering this one. I assume it doesn't interfere with Brain (or any other FBL) installed on top of the tail boom mount?

Originally Posted by Aryemis

I'm suprised you managed to crack the frame even a tiny bit, mine have been going strong through 4 pretty hard crashes at higher rpm's than you.

So am I. I think the reason for this is that I crashed before I had a chance to hit TH.

Originally Posted by Aryemis

You're running a non-stretch setup right ?

No, 6S stretch.

[JustPlaneChris]

Originally Posted by madeye

I was considering this one. I assume it doesn't interfere with Brain (or any other FBL) installed on top of the tail boom mount?

Correct! There is plenty clearance for the FBL unit. I made the prototype with a Mini VBar installed.

[madeye]

Originally Posted by dr dremel

Sorry for your crash, not a good feeling when you put it in the first time.

I wasn't clear enough - it wasn't the first flight. But still doesn't feel good. Still, a lesson learned

Originally Posted by dr dremel

Quite the difference between 50 and 100%. Do you even fly @100%?

Not unless it is reaction training in Heli-X, and I guess I need to change that. I've been trying to switch to 100% for a while, just didn't want to risk this helicopter yet - and well, that didn't work.

Originally Posted by dr dremel

Maybe remapping to 50-65-75?

Didn't quite understand. If you're talking about 3 DR settings, my transmitter is DX6i which just has two. If you're saying "increase 50 to 65, then 75" - yes, that's what I'm planning to do starting right now. The other problem is that my expo settings are quite different - 40% vs 20%, if I remember right. But this is all a matter of learning, I'll get to it.

Originally Posted by dr dremel

Better lift with wider chord, so Mavrikk G5 maybe an option.

It doesn't look like they make them in 350mm length.

Originally Posted by dr dremel

As I see you´re flying with 50% DR I´d also look at heavier blades like Radix FBL. I have no firsthand experience with these though.

I've heard quite a few good words about them. Anyone else having experience flying these on 100%?

[Aryemis]

Oh for stretch then I'd recommend the RJX Vector/Razor 360mm, they have a wider chord than most and loads of lift, and they fit in the stock sponge blade holders, unlike the KBDD.

[dr dremel]

Originally Posted by madeye

Didn't quite understand. If you're talking about 3 DR settings, my transmitter is DX6i which just has two. If you're saying "increase 50 to 65, then 75" - yes, that's what I'm planning to do starting right now. The other problem is that my expo settings are quite different - 40% vs 20%, if I remember right. But this is all a matter of learning, I'll get to it.

Sorry, yes I meant 3 D/R settings. If your tx has just 2 then maybe 50 and 65 until you´re comfortable, then moving up from there. -40 expo is very sensitive, most start with +15-30% (on Spectrum radios) to numb the reactions of the heli around mid stick. If I understand right you´re running @100% throttle? If the amount of D/R you´ve dialed in is an indicator then may I suggest dropping head speed a little, makes the heli quite less squirrelly, you get longer flight times and you can up the D/R to counter the slower reactions.

And I meant the first crash is not a good feeling, no matter how many flights. Of course crashing on maiden is especially nasty, ask me how I know lol

[madeye]

Originally Posted by dr dremel

Sorry, yes I meant 3 D/R settings. If your tx has just 2 then maybe 50 and 65 until you´re comfortable, then moving up from there. -40 expo is very sensitive,

Sorry, that was a dash and +40%, not -40% - that would indeed be nuts

Originally Posted by dr dremel

most start with +15-30% (on Spectrum radios) to numb the reactions of the heli around mid stick. If I understand right you´re running @100% throttle? If the amount of D/R you´ve dialed in is an indicator then may I suggest dropping head speed a little, makes the heli quite less squirrelly, you get longer flight times and you can up the D/R to counter the slower reactions.

That time, I've been flying it at 2400. Constantly resisting urge to flip it to 3100, though, it feels so much more alive

Running DR at 50% was a mistake - I've done that not because the heli was moving too fast for me (MSH Brain agility is set at "hard 3D", anything less seems too slow), but because it was moving too sharp (and even that may have been just an impression caused by lack of training, and even the heli was wrong - I cloned MiniP settings from mCPX BL). I've found lately that in order to get reaction that I want I have to mash sticks pretty hard (and accidentally trigger DR ) - another telltale sign. I'll see how fast I can get it back to 100%.

I wonder, are people using both (or three) DR settings on a regular basis, or just eventually settle where they're comfortable and leave it at that?

Speaking about flight times - I'm running about 7:30 with battery being discharged well above 20%.

Originally Posted by dr dremel

And I meant the first crash is not a good feeling, no matter how many flights. Of course crashing on maiden is especially nasty, ask me how I know lol

Yep, I can relate. The only maiden crash I had was with mCPX BL, but that one was nasty - the first RC helicopter ever, bought from Internet, defective out of the box (and I had no idea it was until much later).

[dr dremel]

I see, dialing in the heli between tx and FBL settings also took me a while. I was coming from an mcpx also and there was nothing to adjust electronically on the heli.

After fiddling around for 100 flights or so I now just use one setting DR/expo, so the 3-way switches on my DX8 are seldomly used except for flight modes. But this one I use regularly to switch between low/mid/high HS.

[stevebaker]

I used to keep my D/Rs quite close to each other when I had a DX8, so if I accidentally flicked a D/R switch it wouldn't go crazy.
There's no need to run different rates on a heli (except for experimenting) unlike a plane where you want to switch rates mid-flight to perform different manoeuvres.

With my Taranis I use the same rates in all flight modes but I have the ability to adjust the rates via my trim switches.

[madeye]

Originally Posted by dr dremel

The CF washers are for the Protos plastic frame, so the slot length and bold hole dia do not match. Could be adapted with bigger washers though. I´d epoxy a strip of CF (even around the slot).

Forgot to ask, what's a good source for raw CF pieces like this?

[madeye]

Prominently missing are references to LX6350-FBL 350mm Lynx blades - wonder if that's because they're not that widespread, or because they're not a good choice?

[dr dremel]

I source scrap CF pieces via ebay. It´s usually from (real) aircraft, medical equipment or similar.

[thanasi]

Originally Posted by madeye

Prominently missing are references to LX6350-FBL 350mm Lynx blades - wonder if that's because they're not that widespread, or because they're not a good choice?

I have a set and some bling on the way I after a hard hard dumb thumb on Friday
When I get it back in the air ill give my 2cents


Sent from my iPad using Tapatalk

[Aryemis]

Originally Posted by madeye

Prominently missing are references to LX6350-FBL 350mm Lynx blades - wonder if that's because they're not that widespread, or because they're not a good choice?

I didn't recommend them because I've never flown them. I've never gotten them because I can get good 360's (RJX) for 10€ less, and two pairs of align 360's for the price of one pair of Lynx 350's.
They are also not very available in Europe, wheras in the US everyone has them.
Trexwilly likes them alot though.

[madeye]

Been thinking and watching the flight video... The more I watch it, the more I think that the root cause was low head speed (2400, not 2600 as I originally wrote, checked settings today) and pilot's inability to cope with it (forgot to train myself at low head speed in the sim).

Sigh... back to sim at low head speed, and back to 3100 IRL, for now.

PS: Got new blades delivered today. Lynx blades look like twin siblings of MSH (everything's the same except the logo), and Radix 350mm are indeed 10g heavier (72g over stock and Lynx 62g), with a slightly wider chord (35mm over 33mm). Still fit the stock blade holder, though.

Oh, and for fellow weight weenies - solid main shaft is also 10g heavier than stock