250 Tail Gear Heads
- Thread starter Matt
- Start date
Smoggie
Well-Known Member
Quite the opposite. If you lower the headspeed then you sometimes need a higher speed tail drive gearing ratio. When you lower the headspeed then the tail speed also decreases causing poor tail hold. It's a moot point on most 250 size helis anyway because very few have different tail drive ratios available, so you just have to make do with the standard ratio.
I’m going to bump up the headspeed. I was only running at 50% throttle which was causing the tail issues. I don’t want to be at 75% throttle so I’m going to try 60% or 65% to see if that is the sweet spot. I want a tame heli so I can try nose in hover and not have the heli all over the place too quickly because that’s what I’m seeing at a higher headspeed. The heli is harder to control at a higher headspeed and I want to tame the heli down but 50% may be too low.
murankar
Staff member
It can go 2 ways, 1) As smoggie suggested you could go the speed up gear route; or 2) if your frame design allows it bigger tail blades. Most airframes wont allow for super over sized tail blades. The 2 things to consider with blade size is cord and/or length. At the end of the day it's about surface area.
Manufactures like Align, S.A.B. and Oxy know that some pilots like lower head speeds. In return they designed the kits to operate at such an extreme. So do some homework on your kit. 3 if my 4 airframes have either a speedup gear (my gobby 570) or different tail size options (both oxy2 and oxy3). My gaui I dont think has any options for the tail.
Here are few other aspects to consider when lowering the head speed.
Headspeed correlates to inherant stability. It's the gyroscopic effect. The higher the headspeed the easier it is to tune. When you drop the headspeed you will be raising your gains to help compensate for the lack of gyroscopic effect.
Blade pitch will also have an effect on response with lower speeds. If you want to make a high headspeed more docile reduce your pitch by a half degree at a time. Once you hit a comfey spot your set.
Manufactures like Align, S.A.B. and Oxy know that some pilots like lower head speeds. In return they designed the kits to operate at such an extreme. So do some homework on your kit. 3 if my 4 airframes have either a speedup gear (my gobby 570) or different tail size options (both oxy2 and oxy3). My gaui I dont think has any options for the tail.
Here are few other aspects to consider when lowering the head speed.
Headspeed correlates to inherant stability. It's the gyroscopic effect. The higher the headspeed the easier it is to tune. When you drop the headspeed you will be raising your gains to help compensate for the lack of gyroscopic effect.
Blade pitch will also have an effect on response with lower speeds. If you want to make a high headspeed more docile reduce your pitch by a half degree at a time. Once you hit a comfey spot your set.
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Admiral
Well-Known Member
Hi Matt, I note that you want a Tame helicopter, I've owned two Align 250's an FB one and a FBL one neither of them could ever be described as Tame, exciting, wild but not tame. If you are using it for a learning tool I suggest that you go for a larger helicopter at least 450, it is true what they say the larger the helicopter the easier they are to fly.
I had mine both flying quite well but after I had learned on larger helicopters, but found them unforgiving if you made a mistake.
I had mine both flying quite well but after I had learned on larger helicopters, but found them unforgiving if you made a mistake.
No expert by far, but from what I have witnessed a larger bird and a faster head speed are more stable as said.
What about radio or servo arm adjustments? More expo and maybe a setting on the servo control arm for less travel? One or the other or both?
BTW I ended up with a 500 for my second heli after I thrashed a cheap smaller one.
What about radio or servo arm adjustments? More expo and maybe a setting on the servo control arm for less travel? One or the other or both?
BTW I ended up with a 500 for my second heli after I thrashed a cheap smaller one.
I never thought about changing the pitch to a softer pitch. Instead of having 50, 75, 100 I could set them with smaller interval between. I can try that. And also I can try the bigger tail blades. I guess it’s all just finding out what works for me. Btw, after I posted this I crashed my heli into a rock. I have to replace one of the servo arms. Crashes aren’t as drastic as they used to be which is a good thing. I remember flying my Blade 400 and I crashed that heli plenty of times. Each time the blades would shatter because they were made of wood.
I’m starting to see some drastic improvements in my flying and only wish I could fly more often. I’m basically following to rules now. Last time I was obsessed with doing flips without even knowing how to hover nose in. Now I’m following the rules and see drastic improvements.
I’m starting to see some drastic improvements in my flying and only wish I could fly more often. I’m basically following to rules now. Last time I was obsessed with doing flips without even knowing how to hover nose in. Now I’m following the rules and see drastic improvements.
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murankar
Staff member
If your that low your response should be a little sluggish. Now at higher head speeds that will work. If you drop the head speed you will need to increase that to 12 or so degrees. Again you'll have to play around and find what works. If you have telemetry and are able to monitor the current you can really dial in the pitch and headspeed.
I was thinking on the tail only. I have no expo on my head... Or cyclic and collective. Is head the correct jargon?
murankar
Staff member
What Expo is going to do is make center stick less responsive. Basically you will need to give bigger inputs around center stick. Most people run less expo on the tail when compared to the head.
Since you brought up expo on the tail i really want to know what your end state is? Are you looking to take the twitchiness out of the heli as a whole or are you wanting adjust the tail speed?
What are your unwanted characteristics?
Explain to us what it is you are looking for compared to what you have now? Once we know that we can then make educated suggestions to better help you.
OXY2 sized helis (basically any 250 class heli) is going to be twitchy. They are lightweight with high headspeed. That's just the nature of that size heli. Everyone that has ever been on here has the opinion about that size heli, they are not beginner friendly. you can't be afraid of the controls.
Oh and one thing I think got over looked in you OP. So if you drop the head speed you will loose tail authority. Which means the tail has greater potential to blow out or not hold. Once you start dropping your head speed you will want to fly it for a few batteries and adjust your tail gains as needed. Once you hit max gain and the tail is blowing out or you can't get the wag of death tuned out then you add the speed up gear. Its going to be trail and error as you drop your head speed.
Since you brought up expo on the tail i really want to know what your end state is? Are you looking to take the twitchiness out of the heli as a whole or are you wanting adjust the tail speed?
What are your unwanted characteristics?
Explain to us what it is you are looking for compared to what you have now? Once we know that we can then make educated suggestions to better help you.
OXY2 sized helis (basically any 250 class heli) is going to be twitchy. They are lightweight with high headspeed. That's just the nature of that size heli. Everyone that has ever been on here has the opinion about that size heli, they are not beginner friendly. you can't be afraid of the controls.
Oh and one thing I think got over looked in you OP. So if you drop the head speed you will loose tail authority. Which means the tail has greater potential to blow out or not hold. Once you start dropping your head speed you will want to fly it for a few batteries and adjust your tail gains as needed. Once you hit max gain and the tail is blowing out or you can't get the wag of death tuned out then you add the speed up gear. Its going to be trail and error as you drop your head speed.