Rayguns custom DDVP tail for my Trex 250

[dze]

Originally Posted by Ultraviolet

It probably will not catch on because of the increased complexity and failure modes.

Neat but impractical.

failure may not be such a problem, but as you pointed out my main gripe is its a pita to wire everything and honestly for the system to be flexible enough to tune to performance and to do it correctly would require an 8th channel (8ch radio to tune from there) to fine tune tail speed with a motor that is slightly more than adequate ..

[Mojappa]

Originally Posted by McKrackin

For anyone curious as to why....I am just looking for a bolt on mod for helis like the SR and other DD tail helis that have bad issues with tail motors.

That would make sense. The conventional tail has to change speeds to function since the prop is at a fixed pitch and that delay creates most of the DD normal downfalls. Since this runs at a constant speed and the prop pitch is changing. Speaking as someone who tried the belt mod for the SR this could be a good alternative, as would a TT setup.

I presume that throttle curve for normal only?

[McKrackin1]

Originally Posted by Mojappa

I presume that throttle curve for normal only?

I don't exactly know what you mean....
Since the tail ESC is programmed so everything above half throttle is 100%,it is locked into 100% in idle up.It's actually locked into 100% anytime it's airborne no matter what mode you're in.

[McKrackin1]

OK..I think I get the question now.lol...
My tail ESC does not have a separate throttle curve.
It is slaved off the main ESC.

But,the tail ESC is programmed to recognize half throttle as 100%.
This way,the tail rotor is turning at full speed before the heli lifts off and stays 100% at all times.

[DarkTherapy]

So you add a motor to the tail and keep the tail servo? Keep the tail variable pitch setup.. Add a second small ESC for the tail and program it accordingly, fit all the extra wiring inside what it already a cramped heli.. And thats EASIER than a belt??

I don't want to sound like I'm being offensive but I don't really see it catching on with a 250 size heli.. And you'll run into more issues than you would get from a belt setup.

Also, if you crash and the tail blades hit at full speed, you could damage the motor/bearings, or at least bend the motor shaft, is it easy to replace the shaft or motor bearings?

I am interested in how this works for you and what the ups and downs will be, do keep us posted.

[McKrackin1]

Originally Posted by DarkTherapy

So you add a motor to the tail and keep the tail servo? Keep the tail variable pitch setup.. Add a second small ESC for the tail and program it accordingly, fit all the extra wiring inside what it already a cramped heli.. And thats EASIER than a belt??

I don't want to sound like I'm being offensive but I don't really see it catching on with a 250 size heli.. And you'll run into more issues than you would get from a belt setup.

Also, if you crash and the tail blades hit at full speed, you could damage the motor/bearings, or at least bend the motor shaft, is it easy to replace the shaft or motor bearings?

I am interested in how this works for you and what the ups and downs will be, do keep us posted.

Originally Posted by McKrackin

For anyone curious as to why....I am just looking for a bolt on mod for helis like the SR and other DD tail helis that have bad issues with tail motors.

Nobody reads any more

lol...But yes,the motors pinion shaft is very easy to replace.It had to be replaced with this very long one to start with and the new longer pinion shafts are about half the cost of a regular tail shaft.
As far as bearings,I doubt they'd be damaged but I'm sure I can replace them.If not,I'll cough up ten bux for a new motor.

EDIT: The reason I doubt the bearing would be damaged in the motor is the fact that the shaft goes through three sets of bearings before it reaches the motor which is hard mounted on the other side.

[DarkTherapy]

Good luck to you then

[McKrackin1]

Once I get it flying right,I'll pick up a wrecked SR on ebay and put this tail on it.
Then I'm going to put a Microheli TT tail on the Trex 250.

[DarkTherapy]

Can you post a link to the TT tail for the 250 please.

[No_Gassers_Here]

McKrackin

once the wires are run ( i think throw the tail boom as there is no belt in it anymore) you could put a connector on it so you just unplug it and slide it down another tube without having to use a piece of wire. no I am just guessing but for a 20% gain in power I just wonder how much flight time if any you loss from the draw of the second motor and esc. I think it will work great for the 250. as for the belt drive set up. if the tt comes out I will bail from this crappy a$$ belt drive faster then you could debate. because there is no debate. belt drive is the second best drive set up IMO. this looks very interesting. McKrackin please keep at very least me informed on the outcome. I am mm's away from putting this micro heli FBL head on the 250 and trying a NOBAR 250. really like the idea but it does look/feel weird to add a motor. just doesn't seem right.lol

[McKrackin1]

Well screw it since they moved the thread off into obscurity.
That pisses me off.This mod is for any heli out there with tail motor issues but since it happens to be tested on a Trex 250 it's bundled in with the Align forums.

I'm finished with this thread.
Peace.Out.

[DarkTherapy]

I have to agree with you, i find this thread very interesting and applies to many heli's..

And why did they move it when stupid threads like "is an Rc heli a toy" and "if its not a toy, what is it then" are allowed to stay? after all, anyone serious about the hobby knows they are not "toys". And don't get me started on pointless polls taking up bandwidth and space...


EDIT: also add "where can I buy rockets for my heli" to that list..

[Vinger]

Minikopter in Germany are selling their Joker with an option for a motor driven tail rotor as well as Compass were experimenting with the same concept.



http://www.minicopter.de/en/index.html

[JesusFreak]

Very interesting. I had very bad luck with tail motor helis, but they were all fixed pitch tail blades (like the Blade CP Pro). I haven't seen one that uses the variable pitch and runs the motor at a constant RPM, but it sounds like it should work OK. Let us know how it goes for you. I would think the Gyro servo will work a bit more.

[Cirodi]

Originally Posted by McKrackin1

Just getting started on the installation.Just a couple super minor mods needed.

I'm waiting on a tail servo and gyro which are in the mail already.

The machine work is beautiful.

All I did was move my ESC from the rear center to the front and balance is perfect.

The motor added 10 grams but you have to remember,I'm losing the tail shaft,pulley and belt so weight is almost a push.
The second ESC is lighter than one of the wires.lol...Tiny.







Nice work Ray.I'll have it flying in no time.

Hello,
I'm very interested with this topic.
How did it end?
Successful?
Please let me know.
Best,

Sergio

[myxiplx]

Oh wow. You do realise this was a 5yr old thread?

[gimbleguy]

the tail motor design has way too much flaws, that is why these kinda threads don't last too long. I do like the Microheli tail though, but the soft metal is really off putting. Not much slop in them, cause I have one, but the price and soft metal is again a turn off.

Cmon lynx, where are those upgrades!

[alyon187]

Are they suppose to be making upgrades for the 250 or are you saying that because this is a 5yo thread?

[Maxus]

they are supposed to be making upgrades

[myxiplx]

They were considering it, but I honestly am not sure the market is big enough. Plus with the Oxy range I think they'll be more focused on that.