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Old Dec 23, 2012, 11:31 AM
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TH for FP? Why not?

A thought occurred to me today and I went searching on the various forums and could find no discussions of this type anywhere...

I am still relatively new at helicopters. I have been through a large 4 ch coax, a few micro FP helis and then a Blade SR (~200 to 300 size) CP along with a Genius CP micro.

One of the challenges moving from FP to CP was to train myself to use the TH switch instead of slamming the throttle stick down. I have learned this lesson and so, reflecting back on my progress through various heli's I now wonder...

For those who know they intend to move on to CP helis, and knowing ahead of time there will be this learning curve to resist slamming the throttle down and instead hit the throttle hold switch to kill throttle in an impending crash, why not program in a throttle hold switch to use in preparation while flying FP helis?

Even for the play station type controllers that come with something like the Xieda 9958 or the rtf versions of Blade helis like the msr and msrx, it doesn't seem that it would be difficult to mod the controller and add in a toggle switch that would simply cut the throttle. It doesn't actually require another channel, just a switch wired to simulate throttle all the way down.

I have seen mods for controllers for various purposes in the threads here but never saw one for adding in a throttle hold.

Just a thought, passing through my convoluted mind.

What do the masses here think? Bad Idea? Good Idea? Already done and I missed it idea?

Jim
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Old Dec 23, 2012, 12:19 PM
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It could be done. I could do it, and already thought of it.
All you need is a DPDT toggle to switch in and out the potentiometer,
and fixed resistors to match values at the potentiometer legs @ 0% Throttle.

*more thinking, might need a relay, but it could definitely be done.

Only issue I could see is the brief period where the radio has
no potentiometer signal while the contacts are between throws.

It would depend on the radio design.

This project is right up my alley, and I even have an empty spot to
mount another switch on my 9116 TX.

here is my modded TX:

Double Horse 9116 , 9117 Transmitter Backlight Mod (1 min 7 sec)


I figure just move the rate switch over, and put the hold where
the rate switch was.
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Old Dec 23, 2012, 12:21 PM
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It's only a matter of time before there are RX's with sensitive GPS
and accelerometers that will detect an impending crash, and cut throttle.

"Generally, altitude error is specified to be 1.5 x Horizontal error specification."
-Pulled from random site.

It would have to work FLAWLESS, though. Hehe.
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Old Dec 23, 2012, 12:28 PM
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In addition to the possible hardware mods to 4 ch tx's, I was also thinking of those who fly FP's (like the msr, msrx. 120sr with a Dx6i for example) with programmable radios. I have not seen a suggestion in the setups to add in a TH switch to the programming just for training purposes and to better prepare you for moving on to CP.

As a noob who has moved forward to CP helis, looking back it is relatively easy to see that this would have helped (now that I learned the hard way).

Jim
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Old Dec 23, 2012, 12:36 PM
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It is currently an issue for myself. I need to force myself to start
using Th-hold if I ever want to try idle-up.

My 9116 has ruined me.

Only reason I can fly my HK250GT is because I basically emulated the
the 9116 in the throttle and pitch curve o.0

[ Balr14 shakes head in disgust ]
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Old Dec 23, 2012, 12:53 PM
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Quote:
Originally Posted by jcmors View Post
In addition to the possible hardware mods to 4 ch tx's, I was also thinking of those who fly FP's (like the msr, msrx. 120sr with a Dx6i for example) with programmable radios. I have not seen a suggestion in the setups to add in a TH switch to the programming just for training purposes and to better prepare you for moving on to CP.

As a noob who has moved forward to CP helis, looking back it is relatively easy to see that this would have helped (now that I learned the hard way).

Jim
I don't have any radios with those options, but it seems possible
you could do this.

I know on the better Futabas, all the switches are able to be
programmed for whatever you want.
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Old Dec 23, 2012, 01:08 PM
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Quote:
Originally Posted by Steve_ View Post
It is currently an issue for myself. I need to force myself to start
using Th-hold if I ever want to try idle-up.

My 9116 has ruined me.

Only reason I can fly my HK250GT is because I basically emulated the
the 9116 in the throttle and pitch curve o.0

[ Balr14 shakes head in disgust ]
Lots of people do that. I'd rather see them use at least a few degrees of negative pitch to help with wind. The best trick I found was to use the throttle trim. Move it all the way up to soften landings, reduee it to stop the blades. But, it's not effective on all helis.

Many flight control boards have barometers that will sense how close you are to the ground, but they are only accurate to about 3 feet; which has some obvious disadvantages.
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Old Dec 23, 2012, 01:12 PM
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Quote:
Originally Posted by jcmors View Post
In addition to the possible hardware mods to 4 ch tx's, I was also thinking of those who fly FP's (like the msr, msrx. 120sr with a Dx6i for example) with programmable radios.
Jim
Interesting question.
I don't know how a Dx6 does it. I use a walkera 2801 8 channel, and keep in mind it only works with walkera stuff.

For each saved model I have, I have to select how many channels that model has, either 4, 6, or 8. It will only bind with a 4 channel rx in 4 channel mode, so I can't just change the transmitter to 6 channel and then bind it to an FP. And in 4 channel mode the TH doesn't do anything.
I can cheat on a few things. In 4 channel mode options like expo are not available. If I change it to 8 channel I can add in some expo, and then when I change it back to 4 channel the expo settings still work so I can add some expo to an FP (never had an FP that needed any, but the option is still there).
The only way I see to make it work on an FP with mine would be to change the rx to a 6 or 8 channel, and on most FPs that would mean adding an external speed controller and an external gyro.

You bring up a really good point - I've only had one semi-emergency with my CP, and I had just enough control to got it on the ground before I hit TH. But when I push myself in phoenix and get into trouble, I find that far too often I'll do zero throttle instead of TH - it's a hard habit to break.

Since walkera decided to discontinue the 2801 3 years after they released it (I can't get any more receivers for it) I plan on switching to spectrum in the near future. I don't plan on getting any more 4 channel stuff after the one I have dies, but I'm still kinda curious about how spectrum does it as well.
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Old Dec 23, 2012, 02:16 PM
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Quote:
Originally Posted by Steve_ View Post
It is currently an issue for myself. I need to force myself to start
using Th-hold if I ever want to try idle-up.

My 9116 has ruined me.

Only reason I can fly my HK250GT is because I basically emulated the
the 9116 in the throttle and pitch curve o.0

[ Balr14 shakes head in disgust ]
There was a post a while back where a guy who said he had been flying for a while (and so was kinda stubborn about how to do things) was asking how to set up his cp with no negative pitch. I got kinda upset 'cause most answers only told him it's wrong, and wouldn't tell him how to do it because it's wrong. My oppinion, tell him why it's not the ideal setup, then answer his question and let him decide what works best for him. Sometimes we have to make mistakes before we can learn.

You, on the other hand, haven't been flying heli long enough to really develope any of the bad FP habits that some of us are trying to break, so when I hear you've set up your CP to emulate the FP I do a wee bit of head shaking myself.

I don't do ay 3D stuff, I don't intend to ever intentionally go inverted, so I still only have 3 of negative pitch, and that's probably where it will stay. Fighting the wind is sooo much easier using pitch instead of throttle. Even landing is easier, and prettier, when the head speed stays relatively constant. Your 250 is much more advanced than that FP; take advantage of what it's capable of and it will make flying a whole lot easier.
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Old Dec 23, 2012, 02:54 PM
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I hope balr14 drops back in. I have a dx6i and so does he (I believe)
The dx6i has a two position switch where one is throttle hold. I set throttle hold active on all my models. Fixed pitch and CP. I am trying to use TH all the time. It works well on FP blade helis so I use it every time I power up.
As soon the heli powered up I set throttle hold. This way when I carry a model around it is locked. Ask me about moving the throttle when I was not watching. That lesson made me a TH believer.
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Old Dec 23, 2012, 02:56 PM
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I cannot adjust the rates on my TX for cyclic. When I fly it's
so sensitive, I still am not used to it.

Next step is to mount the balls closer to the shaft on the
servo horns, but have not got there yet.

I can barely fly the 9116, and get into trouble all the time
with it.

Still not ready, need more sim time, and been busy.
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Old Dec 23, 2012, 03:15 PM
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I looked at the curve and the way the servos were linked up,
and I actually do have slight negative pitch, but only just slight.

It will drop like a rock at zero pitch, even in low wind, so not sure what the big deal
is with -3 degrees.

Other than the fact that I'm making it harder and harder to transition, and have no
excuse because I'm new. 0.o
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Old Dec 23, 2012, 04:08 PM
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Even for scale flying and using just enough negative pitch to bring the heli down - or glue it to the ground if there is any wind - a small amount of negative pitch will yield the Aunt Jamima effect when the collective is slammed down. It is fairly easy to re-assign another switch for the throttle-hold function but it still doesn't change the reflex once you are programmed to slam instead of switch. The DX6i and DX7 are no help for the location of their throttle-hold switch - it is in the top-right corner and might as well be inside the battery compartment by the time your fingers find it. Latest try is to re-assign a switch and use a rubber band between the switch and index finger (dead-man switch idea) - so the throttle-hold switches on when the stick slams down. Still in evaluation.
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Old Dec 23, 2012, 04:14 PM
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CaptJac The trasmitters I have like the dx6i all have the TH on the right.
I am working with the deviationtx effort and am trying to use the right hand for throttle hold. While it is not standard if I program myself for the transmitters I have I will be satisfied.
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Old Dec 23, 2012, 04:20 PM
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Speaking of a dead man switch. How about a touch sensitive throttle stick.
release the stick and throttle hold is automaticaly on.
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