Latest Twinn Rexx pics

[joe@tech-mp]

First, I would like to thank all who were involved in creating this forum and making it possible.

Here are some of the latest pics of our Twinn Rexx tandem which is currently under development.

This is the recently re-designed main frame with new sides. I beefed them up and changed to a thicker material. The frame is very solid now. The lighter frame allowed for flexing which was causing a resonance problem.

I have a new problem now though. There is a small vibration that is being picked up by the yaw gyro. The amplitude seems to increase with rpm which suggests it's coming from the rotor(s). I haven't been able to find the source yet. I ordered a sensitive accelerometer sensor that I will mount to the frame to allow me to measure the vibration amplitude and frequency. I am hoping to use is to dynamically balance each of the main rotors.

Otherwise, the heli flies like a dream and is rock solid. I am still using the stock Align 3550KV motor with a 3S 2100 battery. Flights are about 8 or 9 minutes with gentile flying. We have an AON 4S motor on order and are waiting for it to come in. It can handle 400 to 500 watts which should really get this bird moving.

For more information visit the Twinn Rexx webpage here http://www.techmodelproducts.com/twinn_rexx.htm

Joe

www.techmodelproducts.com

[woodturner]

Sweet.. Excelletn integration work.. Bet that baby has some serious lift potential..

[WillJames]

Very cool Joe, thanks for sharing!!

[joe@tech-mp]

The vibration problem has been solved :D It turns out that the front flybar paddles were slightly off center. This probably happened when I rebuilt the front rotor head (new 1071 & bearings) late at night and tired.

I am very pleased with how well this bird handles. I can't wait to begin flight testing with the AON 4S motor !

Joe

[TimG13096]

Joe,

Any projections on a release date for this???

Tim
Denver, CO

[joe@tech-mp]

It's going to be some time next year now. No target date yet.

Joe

www.techmodelproducts.com

[DebianDog]

Wow looking forward to seeing it fly!

Oh just found it http://www.techmodelproducts.com/Twinn_Rexx/TR%20041.avi

[johnson.mikep]

I can see your rotors will rotate in opposite directions which will counteract the torque, but how do you control yaw? I've just started with helis, flying a blade cx2 now, and I understand how the yaw works on that, allowing one motor to spin faster while slowing down the other turns the heli, but on your model wouldn't that also cause the heli to pitch forward? or is the pitch adjusted at the same time on the rotor that is slowed down to provide the extra lift to stay level?

[joe@tech-mp]

Yaw is done with differential cyclic on the roll axis. To yaw right, the front rotor tilts right and the rear rotor tilts left.


Joe

www.techmodelproducts.com

[johnson.mikep]

ahh very cool!

[slybynight]

I was asking myself the same question re yaw.. Feeling very pleased with myself, I worked it out myself after a bit of thinking. Is this how the full size ones do it also?

[joe@tech-mp]

Yes. The Twinn Rexx control system works the same way as on the full scale birds.


Joe

www.techmodelproducts.com

[WillJames]

I like it and hope to have one. Very cool and quite a bargain from what I have heard. SWEET project Joe!! When it is ready and in production, please make sure we all know, and make a bunch, I bet they will go fast!!

[cphtrex450]

Cant wait till this will b available, Put me down for one. will the kit include the canopy/fuse

[SB]

I want one!!
whats the grand total estimate for everything sept the radio?

[Skiddz]

I did a quick rundown on pricing to get a Twinn Rexx in the air. Using Joe's own website, I got a tally of right around $1700 for the kit, 2 meal heads, all the servos, gyros, mixers, motor esc etc...

I'm saving my pennies 'cuz I really want one, but I'd really like to see a CH-46 fuse for it. :)

[SB]

I did a quick rundown on pricing to get a Twinn Rexx in the air. Using Joe's own website, I got a tally of right around $1700 for the kit, 2 meal heads, all the servos, gyros, mixers, motor esc etc...

WOW! I could probably do that.
? = if i don't own a trex 450 how do i figure out parts i need for the head

I'm saving my pennies 'cuz I really want one, but I'd really like to see a CH-46 fuse for it. :)

this is the page for the Twin Rexx (i think)
http://www.techmodelproducts.com/twinn_rexx.htm
mid page is a video of a test flight, but what you want is all the way on the very bottom is pictures of the body (unpainted) on the bird. hope this helps

[Skiddz]

That body is a CH47. The 46 looks like a Frog and has tricycle landing gear. Jow said he's going to develp a '46 body, but the development cost is pretty high and he wants to wait and see how the Twinn sells.. Personally, I think it's going to work out well for him