Rayguns custom DDVP tail for my Trex 250

[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.

[Ozz58]

Just a question, as I've not heard anything about this mod.

Why would you go with a tail motor? Most that have a tail motor try to get mods to get rid of it.

Craig

[McKrackin1]

Slight mod to the tail fin...

[McKrackin1]

Originally Posted by Ozz58

Just a question, as I've not heard anything about this mod.

Why would you go with a tail motor? Most that have a tail motor try to get mods to get rid of it.

Craig

Most helis with tail motors work with variable speed and fixed pitch.
This has variable pitch and will run a very consistent speed for a very steady tail.
Without the belt,about 20% more power is going to the main rotor.
Also,no matter what I do to bog the main rotor,the tail rotor will not be effected in the slightest.

[dze]

awesome, cant wait to see how it works on the 250 .. i tested one out on a 450 and it looks like the system actually has potential. I wonder where this will go and if it will actually catch on?

[ame]http://www.youtube.com/watch?v=jXJKefAQeDY[/ame]

[J-S-Q]

There's a fairly high end heli I saw recently (was it a 90 size Minikopter???) that has a separate motor to drive the tail. I presume you'll still run it from the main flight battery right?

[Ultraviolet]

Originally Posted by dze

I wonder where this will go and if it will actually catch on?

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

Neat but impractical.

[Winfred]

All that's missing is the direct drive main rotor.
https://www.helifreak.com/showthread.php?t=18988

[McKrackin1]

Originally Posted by J-S-Q

There's a fairly high end heli I saw recently (was it a 90 size Minikopter???) that has a separate motor to drive the tail. I presume you'll still run it from the main flight battery right?

It runs on the main flight pack.Right.

It's pretty simple really and I think it's less work than taking care of a belt.

[sansone]

Originally Posted by McKrackin

It's pretty simple really and I think it's less work than taking care of a belt.

what do you mean by "taking care of the belt"? properly set up a belt needs only occasional tension check like a motorcycle drivebelt. Plus the belt puts no weight at the tail where you don't want any.

[McKrackin1]

Originally Posted by sansone

what do you mean by "taking care of the belt"? properly set up a belt needs only occasional tension check like a motorcycle drivebelt. Plus the belt puts no weight at the tail where you don't want any.

You die hard belt defenders have got to GTF over it
Nobody slammed a belt drive or said it was difficult.

I said the motor is easiER which implies the belt is EASY.

This is not meant as a debate as to which is better.
I'm simply showing you guys something I'm working on.

I'm sure you all can rest easy knowing the belt drive will be on the market for years to come

[Sonic_BOOMER_SOONER]

The guys on RCGroups that were doing this on 450s had tail pitch and throttle curves on their wish list for radio enhancements.

[McKrackin1]

My throttle curve on the tail is 0-50-100-100-100 so it spools up to full speed before the heli lifts off and runs wide open at a steady RPM throughout the flight.

You simply program the ESC with half throttle as 100%.
Since everything above half throttle is 100% idle up will have no effect on the tail speed.

[755 robert]

That is a cool idea, how did you calculate the motor size for the tail?

[Richard F.]

wow! And here I thought I was kind of inventive Thats a pretty cool idea!

[sansone]

Originally Posted by McKrackin

You die hard belt defenders have got to GTF over it.
Nobody slammed a belt drive or said it was difficult.

who pissed in your corn flakes?
I only asked because I was curious about your inventive modification. Obviously you are too defensive. I studied your pics and thought the work is neatly done.

[Ozz58]

Originally Posted by McKrackin

You die hard belt defenders have got to GTF over it.
Nobody slammed a belt drive or said it was difficult.

I said the motor is easiER which implies the belt is EASY.

This is not meant as a debate as to which is better.
I'm simply showing you guys something I'm working on.

I'm sure you all can rest easy knowing the belt drive will be on the market for years to come

Sorry about my first post as I didn't see the tail servo and thought you change it to a veriable speed tail motor, my bad.

After seeing what you are doing I'm very interested in the result.

Again sorry for the quick jump to "Why would you do that" statement.

Keep up the good work,

Craig

[McKrackin1]

Originally Posted by sansone

who pissed in your corn flakes?
I only asked because I was curious about your inventive modification. Obviously you are too defensive. I studied your pics and thought the work is neatly done.

lol...That's funny.You're the one that jumped bad in defense of tail belts

That's an old and tiresome argument which I want no part of is all I meant to say.
Not being defensive at all,just saying I'm not going to debate the merits.Gotta head it off early as a bunch here like to start off by calling me sad and stupid.

Thank you by the way.I think it's looking good so far.
I've had it fired up and I have some tweaking to do but it has a ton of thrust.
For some reason the tail motor runs in throttle hold.I'll try a big negative number in throttle hold later.

I ran it for 10 minutes and the little 6A ESC got barely warm.

[McKrackin1]

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.

[McKrackin1]

[ame]http://www.youtube.com/watch?v=7efiAIJoNso[/ame]