No more flying for me !!!!

[Lee]

440KV it won't be, 4400KV it could be. And that is a super high KV for a 450.
What about the pinion?

 

[Blackwarrior]

If you want a good quality kit and some spares at a good price look at my 450 DFC in the for sale section, see what you think,

I've looked at your 450 several times Kev, and seen the build thread, looks like an awesome bird, unfortunately cash flow restricts the purchase or I'd jump at it, and be driving to Wales now...lol

 

[Lee]

Ok I just checked that motor.
It is call the 440, but thats not the KV. The KV is 4200.
So if we know the KV of the motor, the tooth count of the Pinion and Main gear, we can work out the head speed for you.

 

[Lee]

You are looking for a head speed of around 2500/2700
With the motor and stock 11T pinion on the 140T main gear and a full battery,
your head speed is between 3500 and 4000!!!!
So to get the speed down you can reduce the TH curve to 65 or 60%, but in the long run a smaller pinion will help.
A 10 or even a 9T will be better.

 

[Blackwarrior]

Ok I just checked that motor.
It is call the 440, but thats not the KV. The KV is 4200.
So if we know the KV of the motor, the tooth count of the Pinion and Main gear, we can work out the head speed for you.

I think the pinion has 14 teeth, I would probably need to strip the motor out to get an accurate count, but I've triple counted...lol

The main gear is stock and I'm sure that's 140 teeth..

- - - Updated - - -

You are looking for a head speed of around 2500/2700
With the motor and stock 11T pinion on the 140T main gear and a full battery,
your head speed is between 3500 and 4000!!!!
So to get the speed down you can reduce the TH curve to 65 or 60%, but in the long run a smaller pinion will help.
A 10 or even a 9T will be better.

I've got a lot to learn, need to get my head around all that, although the maths sounds pretty simple...lol

Thanks Lee

 

[danhampson]

ive just had a look at the blade 450 3d manual and the stock motor is 420 @ 3800kv, the 440 @ 4200kv Lee mentioned is an upgrade for the 450 3d (stock in the 450x). The stock pinion is 10t (there are a 9t and 11t available) and the main gear is 140t

head speeds are working with 90% efficiency :

420 motor 3800*11.1*.9*10 /140=2783rpm

440 motor 4200*11.1*.9*10/140=2997rpm

neither seem to be crazy fast at 100% for a 450, i have seen a 450x flying that has the 440 motor and it did sound crazy fast but that was just the high pitch sound of the motor.

 

[Lee]

If its 14T then your head speed will be off the scale. No wonder it self destructed.
Easy way to count the teeth, mark each tooth with a marker pen as you count so as not to count twice

 

[Lee]

ive just had a look at the blade 450 3d manual and the stock motor is 420 @ 3800kv, the 440 @ 4200kv Lee mentioned is an upgrade for the 450 3d (stock in the 450x). The stock pinion is 10t (there are a 9t and 11t available) and the main gear is 140t

head speeds are working with 90% efficiency :

420 motor 3800*11.1*.9*10 /140=2783rpm

440 motor 4200*11.1*.9*10/140=2997rpm

neither seem to be crazy fast at 100% for a 450, i have seen a 450x flying that has the 440 motor and it did sound crazy fast but that was just the high pitch sound of the motor.

Your calculations are with an empty battery Dan 11.1
A full battery is 12.6, gives you a head speed of 3780

 

[danhampson]

thats whats scary with a 14t pinion and flat battery

speeds with a 14t pinion

head speeds are working with 90% efficiency :

420 motor 3800*11.1*.9*14 /140=3796rpm

440 motor 4200*11.1*.9*14/140=4195rpm

ive watched the video again and it does sound ultra fast.

 

[Blackwarrior]

I've removed the motor and it has 14 teeth on the pinion

 

[stokke]

To me it looked like you threw a link. When you take into account that you are using a different brand head with a mix of balls and links from the two brands, a link popping off doesn't sound far fetched?

Also, your head speed sounds crazy - just like the first time.

Sorry man

 

[Lee]

Are you trying to be a smack 3D pilot Tony
So your option are.
Lower TH curve (temporary)
Smaller Pinion 9T
Less KV motor (3500KV)

Edit:
Ok I see the motor now. What does it say on the side?

 

[danhampson]

who in the right mind would put a 14t pinion on that motor and then sell it on to a beginner.

Im not suprised you have been having problems with it.

 

[Lee]

I'm almost certain he threw a link with that head speed.

 

[danhampson]

maybe thats what happened the first time in the garden, just too high a head speed for the links to cope with.

 

[Slobberdog]

wow even with the math of 90% efficient at 70% throttle curve that will give you 3200rpm on a full battery,

 

[Derek]

It sounds, to me, that the culprit has been identified....and rightfully so. Sounds very possible and potentially probable.

I bought my 450 Pro from Tony (RCH Owner) as just a frame, head, and blades....no electronic. I made the "rookie" mistake of getting a 3600kv motor from Hobby King. I was using a 12 tooth pinion and the headspeed was just insane and slightly terrifying. I dropped to an 11 tooth pinion and I still only run 80% in Stunt 2. I'm actually wanting to get the 3S Dominator motor. It's a 3200kv motor. I think I'd appreciate the higher torque.

Anyway....Tony, I think you have plenty of "food for thought" from this thread and the guys helping out. I hope your next 450 helicopter goes smoothly for you. Granted, crashes are going to happen, but it sucks when the helicopter just goes crazy and destroys itself. I wish ya luck buddy!!!

 

[Blackwarrior]

Well guys at least the fault has been pretty well diagnosed by you guys, I would never have come up with that, too much of a novice.... I do still have the stock 420 motor with a 10 tooth pinion on it, so if I rebuild that's going back on..

I'm pretty sure both crashes are now pretty well diagnosed.

Your right Dan, the guy I bought it off new I was a novice but never mentioned the motor...

There's no markings on the motor Lee, all worn off..

I can definitely say the elevator link has gone AWOL. And the elev servo is shot...when you turn the horn you can hear it jumping the gears..

Thanks guys, I appreciate all your time and effort into finding the cause....

 

[danhampson]

its a pleasure Tony. Im just glad that you didnt get hurt or worse.

 

[Blackwarrior]

It sounds, to me, that the culprit has been identified....and rightfully so. Sounds very possible and potentially probable.

I bought my 450 Pro from Tony (RCH Owner) as just a frame, head, and blades....no electronic. I made the "rookie" mistake of getting a 3600kv motor from Hobby King. I was using a 12 tooth pinion and the headspeed was just insane and slightly terrifying. I dropped to an 11 tooth pinion and I still only run 80% in Stunt 2. I'm actually wanting to get the 3S Dominator motor. It's a 3200kv motor. I think I'd appreciate the higher torque.

Anyway....Tony, I think you have plenty of "food for thought" from this thread and the guys helping out. I hope your next 450 helicopter goes smoothly for you. Granted, crashes are going to happen, but it sucks when the helicopter just goes crazy and destroys itself. I wish ya luck buddy!!!

Thanks Derek...

I will rebuild I think, it's going to be the cheapest option for me.

I've gained so much knowledge from this conversion and so much help from you guys on RCH, I mustn't forget my old mate WC (Tom) on YouTube, there's nothing much he doesn't know about helis...

I got a few days of flying the blade, and it was an awesome bird. One thing for sure, I'll never go back to FB... Unless I get one free...lol

If I hadn't of tampered with the curves then I'd still be flying it, but I recon once I flicked that IU switch it would have self destructed for sure...I'm glad this all happened in a safe place and no one was hurt and no damaged caused to anything other that the heli and my confidence..... I'll get them both BACK...

Thanks guys..

Time to strip this heli down to bare bones and start again, so I'll still be needing advice along the way...