600e Pro Tail Blow Outs

[Smoggie]

Yes, 100mm is the longest tail blade that the DFC will take (without modification) and still avoid all possibility of blade strike. If 100mm is enough to prevent blowouts probably depends on your flying style.
The ultimate answer to fitting bigger tail (and main) blades is to do a slight stretch, it's not a difficult mod.

[ReadyToCrash]

Two mates told me they flew their 600pro with 105mm blades w/o any issues. It would be possible because the main and tail blades have different phasings and will never meet each other. I can’t confirm that because I never flew 105mm with 600mm blades. I flew my 600pro with 100mm blades, but it didn’t solve my low authority issues.
In which situation are you having tail issues? Sometimes it isn’t a low rpm problem, but just a matter of giving the right amount of pitch to the tail blades. Too much pitch will cause the tail blades to stall and you will a have a low authority issue caused only by a non-good setup.

[Gladius]

Unless the gear ratio is an integer ratio, the phasing will not keep the blades out of contact. Most gear trains are designed to not have integer ratios, in order to prevent a wear spot from developing (the wear will get distributed over the entire gear instead). So, I wouldn't rely on phasing to run longer tail blades.

[Smoggie]

With 105mm tail blades and stock 600mm mains you can physically get the blades to overlap by 3mm by hand just by manipulating the blades into the 'worst' postion' though not applying any force.

If you can get them to touch by hand there must be the potential for it to happen in flight, though it's probably unlikely in normal use.

[OnTheSnap]

Also note non-DFC vs DFC heads. Your friends running 105's probably did not run the DFC head setups. The old head had enough clearance.

3 years later and no legitimate gear ratio upgrade. Good job ignoring what your customers want Align.

And the 550L has the same disease. 3.88 tail ratio. Total fail in my mind. I thought about getting one as a beater, but I'm not interested in a model with last in class tail performance. No thanks.

[Heli.Maniac]

Originally Posted by OnTheSnap

Also note non-DFC vs DFC heads. Your friends running 105's probably did not run the DFC head setups. The old head had enough clearance.

3 years later and no legitimate gear ratio upgrade. Good job ignoring what your customers want Align.

And the 550L has the same disease. 3.88 tail ratio. Total fail in my mind. I thought about getting one as a beater, but I'm not interested in a model with last in class tail performance. No thanks.

I have the old non-DFC head and have to agree, I have never had the blades touch at over 1000 flights now with hard flying and tail performance is pretty good. I can get the blades to physically touch on the bench only using excessive force and creating a lot of deflection to the main blades.
But 105s clearly isn't the perfect solution as I have stripped quite some front TT umbrella gears with this setup. What Align needs to do is beef up the gears a little bit (the 750MX is way too much for the current gears) and increase the tail ratio or at least offer it as an option part. I am sure this is never going to happen though as in Align's eyes, our helis are supposed to have excessive RPM to be flown hard.

[OnTheSnap]

Originally Posted by anmatheextreme

I have the old non-DFC head and have to agree, I have never had the blades touch at over 1000 flights now with hard flying and tail performance is pretty good. I can get the blades to physically touch on the bench only using excessive force and creating a lot of deflection to the main blades.
But 105s clearly isn't the perfect solution as I have stripped quite some front TT umbrella gears with this setup. What Align needs to do is beef up the gears a little bit (the 750MX is way too much for the current gears) and increase the tail ratio or at least offer it as an option part. I am sure this is never going to happen though as in Align's eyes, our helis are supposed to have excessive RPM to be flown hard.

Total speculation -

I think Align probably built some high ratio gears to test but they kept stripping. So they left it alone.

The tail gears even with the handicapped tail gear ratio never held great for me and I stripped them often (albeit I'm not a kind pilot). I never tried the black though since I abandoned the model well before they were released.

But my general rule of thumb is - If a model only has a low tail gear ratio option, it's because they are masking tail gear strength issues. I have not been proven wrong yet. :-)

[jmtyndall]

Generally speaking, lower gear ratios transmit more torque. Were using gears to exchange torque for speed.

In other words the logic would say that as you went to higher speed tail ratios, there should be less torque transmitted. I would think that increasing the ratio would lead to less gears being stripped. Although in a helicopter more than that comes into play. Since the load on the tail blade increases exponentially with their speed, this load is then transmitted back through the gear train.

Or am I missing something

[ReadyToCrash]

Originally Posted by OnTheSnap

Total speculation -

I think Align probably built some high ratio gears to test but they kept stripping. So they left it alone.

The tail gears even with the handicapped tail gear ratio never held great for me and I stripped them often (albeit I'm not a kind pilot). I never tried the black though since I abandoned the model well before they were released.

But my general rule of thumb is - If a model only has a low tail gear ratio option, it's because they are masking tail gear strength issues. I have not been proven wrong yet. :-)

i also agree align isn't paying enough attention to their customers.

[OnTheSnap]

Originally Posted by jmtyndall

Generally speaking, lower gear ratios transmit more torque. Were using gears to exchange torque for speed.

In other words the logic would say that as you went to higher speed tail ratios, there should be less torque transmitted. I would think that increasing the ratio would lead to less gears being stripped. Although in a helicopter more than that comes into play. Since the load on the tail blade increases exponentially with their speed, this load is then transmitted back through the gear train.

Or am I missing something

You are missing the dynamics of the entire problem. As far as the tail power is concerned, you have unlimited power/torque directly connected to your power system.

The problem is the shock loads caused by fast tail of pitch changes. And at higher rpm the max continuous loading increases with rpm

So as tail ratios increase impulse loads and continuous loads increase proportionately.

[Smoggie]

Originally Posted by OnTheSnap

So as tail ratios increase impulse loads and continuous loads increase proportionately.

Worse than that, the continuous loading being an aerodynamic generated load actually increases by the square of the RPM... So increase RPM my 20% and assuming same pitch angle you add approaching 50% to the torque required to drive the blades (44% to be exact)... And FWIW a 73% increase in power absorbed by the blades..

[jmtyndall]

I thought about that. But if you increase the tail ratio, but decrease the headspeed, the net result is that the tail rotos still travels at the same speed.

[OnTheSnap]

Originally Posted by jmtyndall

I thought about that. But if you increase the tail ratio, but decrease the headspeed, the net result is that the tail rotos still travels at the same speed.

Typical full out 3D 600 setups use 2200 RPM. When Kyle Dahl won 3D Masters in 2010 with a Logo 600 he flew at 2200. It's plenty of cowbell.

Align tells you to run it up to 2500 RPM. So yes, you are getting the effective tail speed as if you were running 2200. Except now your 4m flight is 2m. Great. No one in reality wants this setup. Unless your flying sucks so bad that you need the "shock" of that headspeed to impress your buddies. ;-P

So then the question becomes how will the gears hold up at 2500 headspeed long term with a pilot capable of pushing the machine to it's limits. I doubt it'll do well at all.

In fact, don't you find it strange that when the 600e Pro was initially released, you saw a few Align Pro's show up and fun fly's and fly them. But shortly after they all seemed to get rid of them. Speculation again, but I don't feel like factory pilots are loving this thing.

Anyway, my 2c.

[jmtyndall]

I have noticed there very few vids of szabo and the like running the 600 pro

I agree that 2200 was more than enough. I smacked mine around as hard as I could at that headspeed with no tail issues. But I didnt do any fast hurricanes or funnels because of your warnings. I went to to 2450 before doing that


I would be happy running her at 2000/2200 if the tail would support it. Mine is a dfc model, so 105s are out, unless I stretch the tail. In which case the tail will hold but I'll probably kill tail gears

[OnTheSnap]

Originally Posted by jmtyndall

I have noticed there very few vids of szabo and the like running the 600 pro

I agree that 2200 was more than enough. I smacked mine around as hard as I could at that headspeed with no tail issues. But I didnt do any fast hurricanes or funnels because of your warnings. I went to to 2450 before doing that


I would be happy running her at 2000/2200 if the tail would support it. Mine is a dfc model, so 105s are out, unless I stretch the tail. In which case the tail will hold but I'll probably kill tail gears

And note - it's not about a pro pilot posting a video of them with an awesome flight. It's about the model sustaining 100 awesome flights without failing. So in other words, a single video tells you nothing in terms of robustness of the gears. (-:

[jmtyndall]

Understood.

I'm going to do a 35mm stretch. Mostly so I can run cyclone blades, but also to clear up the main/tail interference issue

Then I'll pray every night the tail gears hold up.

[OnTheSnap]

Originally Posted by jmtyndall

Understood.

I'm going to do a 35mm stretch. Mostly so I can run cyclone blades, but also to clear up the main/tail interference issue

Then I'll pray every night the tail gears hold up.

Just soften the stops as much as you can. And run gain low enough so that it never wags in overspeeds or high winds.

I ran a Fusion50 for a couple years. Gear strips every 30 flights. I loved that heli, and just got really good at gear strip saves instead of dumping it.

So there are options. :-P

[ReadyToCrash]

Originally Posted by OnTheSnap

And note - it's not about a pro pilot posting a video of them with an awesome flight. It's about the model sustaining 100 awesome flights without failing. So in other words, a single video tells you nothing in terms of robustness of the gears. (-:

It is interesting how they fly awesomely on those promotional videos. I wonder if they fly that well because they are great pilots, or because the heli is just perfect in every aspect or because the heli has been especially prepared for that flight. I always wanted to know the answer…
I find hard a heli to last 100 flights nowadays w/o having to change some parts that will surely wear out in the process. Pilots fly very aggressively today and motors are very powerful. It places a big load on the entire heli structure, I think.
The main issue to me is the extremely low tail ratio since flight one and the problems it causes during flight. I don’t think align will solve this problem any time soon. If it was to happen, they wouldn’t release 550l with the same ratio.
If the 105mm blades don’t fit you, why not to move the boom block a tad forward and change the front gears to mod 0.6? It will give you the 4.5 tail ratio. I did that on one of my models and it flies very well. Zero tail issues anymore. The only hassle is to make the frame holes 1mm longer so you can push the block forward.

[Smoggie]

Originally Posted by jmtyndall

Understood.

I'm going to do a 35mm stretch. Mostly so I can run cyclone blades, but also to clear up the main/tail interference issue

Then I'll pray every night the tail gears hold up.

Mine is holding up perfectly. I checked the gears on the weekend and there was no visible wear after dozens of flights.

But i'm not a hard flyer so others might have different results, I also shimmed the gears to get a good tight mesh.

[OnTheSnap]

Originally Posted by ReadyToCrash

It is interesting how they fly awesomely on those promotional videos. I wonder if they fly that well because they are great pilots, or because the heli is just perfect in every aspect or because the heli has been especially prepared for that flight. I always wanted to know the answer…
I find hard a heli to last 100 flights nowadays w/o having to change some parts that will surely wear out in the process. Pilots fly very aggressively today and motors are very powerful. It places a big load on the entire heli structure, I think.
The main issue to me is the extremely low tail ratio since flight one and the problems it causes during flight. I don’t think align will solve this problem any time soon. If it was to happen, they wouldn’t release 550l with the same ratio.
If the 105mm blades don’t fit you, why not to move the boom block a tad forward and change the front gears to mod 0.6? It will give you the 4.5 tail ratio. I did that on one of my models and it flies very well. Zero tail issues anymore. The only hassle is to make the frame holes 1mm longer so you can push the block forward.

Well I've owned 15 different types of airframes. I'm not kind to them. Not making 100 flights at least is a failure in my mind. Plenty do it fine.

The heli's don't need to be fluffed. Holding up a few flights is no big deal.