T-Rex 700T (like "T"urbine) Maiden Flight

[TheManFromMoon]

There she is :-)

But see yourself: :-)

http://www.rc-heli-fan.org/download/file.php?id=79712

This was the second half of the first fuel fill. :-)
The headspeed is a little bit too low up til know. That's why the heli wobbles a little bit.
It was the first flight out of the workshop, without any trimming and with perfect mainblade runout (what is the english word for "Blattspurlauf"?!?!)
Only the throttle curve has to be increase a little bit, and then its perfect :-)

Did I tell you that the simling doesn't disappears? :-)

Here are some pictures:




















best regards,
Chris :-)
www.heli-chris.de

[ualdrivr]

Chris, you are a sick puppy. It looks awesome.

What is the weight difference between the Nitro and the Turbine, have you weighted the heli before and after?

Does it balance nicely?

"Blattspurlauf" = Blade Tracking
Great work my friend

[Rotorholic]

OK dude, now thats cool!

[ualdrivr]

I was looking at your album pictures Chris, the only thing that I see and don't like is those Philips screws holding the flybarless conversion on the main blade grips. Don't you think that machined Hex (Allen) screws would work better?

This is what I am talking about:

[CTG1129]

very nice............now i want one

[ZzEther]

Awesome!!

[Justin Pucci]

Sweet bird! The setup looks really nice and clean too! Do you have any video of it?

[ualdrivr]

Originally Posted by Justin Pucci

Sweet bird! The setup looks really nice and clean too! Do you have any video of it?

Justin, look at the top of his post, the link is an AVI video file of the heli flying. The sound of the motor is amazing

[francowong7828]

sweet flying mob christ. it took you how long to get this monster out from the workshop?

[rafaelc9436]

Congrats buddy, nice heli , are you using the TURNIGY VBAR?? if true how does it fly any tail wag , bobbling etc??

POST A VIDEO PLEASEEEEEE

[Bob O]

That is just OTT...............wow!!!!!

[Justin Pucci]

Originally Posted by ualdrivr

Justin, look at the top of his post, the link is an AVI video file of the heli flying. The sound of the motor is amazing

Wow! I completely missed that...sorry! :o It was the pictures that got me...I saw images loading and just started drooling.

[TheManFromMoon]

@ualdrivr: I've never flown a 700Nitro. I first converted it to electro, and now converted it to turbine (not the same heli)
The weight is about 5,3kg without fuel.
The balcance is absolutely perfect. This is why all electronics are in the back. It works perfectly.
The Philips screws works perfectly and better than Hex screws, because you can transmit more torque with the Philips screws without damaging the screws. Specially on countersunk hex screws, there are very small hex sizes.

it took you how long to get this monster out from the workshop?

It takes nearly one year to do all the planning, manufacturing and building, because I have very very small time :-(

are you using the TURNIGY VBAR

No, it's a GyroBot900.

Some more pictures:

[kevinww]

If you can find one you can use 114t main gear and 15t pinion to give you a main gear ratio of 7.6:1, I got mine from FAD but alas they no longer seem to be trading, this will allow you to get the head speed up whilst keeping the turbine in its sweet spot. I run my headspeed around 1850-1900 and it really comes alive.

[mikmerl]

I am very, very, very, very impressed and also very, very, very, very, very jealous.
This project is something that I have dreamed of doing but could never pluck up the courage to begin.
Did you design and cut out the frames by yourself?

How many liters is the fuel tank and how long does the turbine run on a tank full?

[TheManFromMoon]

@Kevin: I was thinking about lowering the ratio. But a turbine has a very very small torque. So I guess that the headspeed will not be as constant with a lower ratio than with the stock ratio. What do you think about that?

@Mike: Yes, after designing one of the first and very popular electric conversion for the T-Rex700 2 years ago, I started last year the design for the turbine conversion.
Fuel capacity is right now 1000ml, but a hopper tank with ~250ml will be installed. I think the flight time will be good 10min.

best regards,
Chris

[ualdrivr]

Originally Posted by mikmerl

I am very, very, very, very impressed and also very, very, very, very, very jealous.
This project is something that I have dreamed of doing but could never pluck up the courage to begin.
Did you design and cut out the frames by yourself?

How many liters is the fuel tank and how long does the turbine run on a tank full?

Mike,

That has you written all over it. Chris has done wonders for the 700. If I'm not mistaken and Chris correct me if I'm wrong, his was the first Electro conversion kit on the market and then everyone else started doing it. Go to his online store to see all the goodies this guy is manufacturing.

The turbine kit looks awesome but very pricey , the motor alone is 4000 Euros.. However it looks neat, what a beast of a motor, love it.

[TheManFromMoon]

the motor alone is 4000 Euros.

Hmm, slightly, it's around 3400 Euros ;-)

[ualdrivr]

Originally Posted by TheManFromMoon

Hmm, slightly, it's around 3400 Euros ;-)

Ok Chris, not 4000 it's 3400, my mistake... It's still $4200 US.

[kevinww]

Chris

The general consensus of all those that have used the MW44 so far in the 700 is that the 7.6:1 ratio works better than the standard 8.2:1 especially if you want to run the higher head speed that the 700 likes.

As I said I run my head speed around 1850-1900 and it is very consistent in this range just on the curves using 7.6:1, if you look at the torque curve in the MW44 manual it puts the turbine just above maximum torque for the motor/gearbox combination.

I originally flew mine on the standard ratio and the difference was very noticable when I went to the lower ratio.

Kevin