Maiden flight of my T-Rex 250 SE "Tiny-T"

[elkmaster01]

Here it is,,,,the very first flight attempt on my T-Rex 250 SE. It took me a few seconds to get it under control. I got it out of ground effect quickly,,good thing. The motor sounds rough,,,that was simply the gear mesh,,,it is very touchy to get right. And,,,I REALLY needed some expo, it responds very quickly. As far as trims,,,,,it was very close,,,but I didn't take the time to play with it,,,this first flight was just to see what I had so I know what needs tweeking. But I can tell,,,this heli has all the power and response needed,,and then some! The tail was perfect!

I set my aileron and elevator expo at +40. I adjusted the gear mesh,,,which I won't know if it's alright until I fly it again. The gear mesh sounded fine when I spooled it up without blades the first time. BUT,,,it's snowing now so it will have to wait for anymore flying. I wanted to get the very first flight on video,,,here it is;




Randy

[19000rpm]

Happy landings

[rcdbutz]

fun little bugger, isn't it?

Might want to turn the gain down a little too.

Glad to have another 250 flyer on the forum, now we gotta see Nunya's video...

One great thing about the 250 is, it can handle a crash much better than those bigger suckers you got in your stable. It's nice when a crash doesn't cost $200+. For this, get some extra skids and head gear and you'll be set. The EXI 250 parts on X-heli are the exact same and cost half as much too.

[dditch66]

SWEET ELK!!!!!
250 is Serious backyard fun, maybe even indoor fun!

The trex/exi 250 does not have any flybar weights. I tried my EXI 250 with and without flybar weights. Without, it's really touchy and has a really fast roll rate for it's size. I tried 2 2mm nylon locknuts (2 on each flybar paddle) and it tamed it enough to fly like a 450. Still enough to flip it and still have time to get yourself out of trouble but more stable for hovering upright or inverted.

I'm using all EXI 250 or HK250GT (same thing) parts and they are DIRT CHEAP! but I'm using Align 250 tail belt cause the stock EXI 250 tail belt was faulty.

In this vid, the backyard flight was lower headspeed but w/o flybar weights.
WHen I went to the higher headspeed (13T) (3minute mark)I put the flybar weights on:

[elkmaster01]

David,,,,as usuall, I'm going to pick your brain again,,you always have the answers for me.

What KV motor you running on your 250? And do you know your actual headspeed?

I have a 15T pinion on the 3500kv motor. I'll get around to putting the tach on it when I get some good weather. Whats a good RPM for this tiny guy? I flew with the plastic blades and it felt a little 'spongey'. I've only got this one flight so far,,,I have a lot to learn yet. But from just this one flight,,I was VERY happy with how it flew,,it actually 'felt' like my 500,,,,just a bit touchy,,but I can expo that out!

Thx

whooaa,,,I just watched your video,,,SWEET? 4500 RPM?? I don't think I should fly with the plastic blades at that headspeed,,LOL. Doing the math,,,3500kv w/15T should get me around 4370 rpms,,,that should plenty yes?

[dditch66]

I have this motor
www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8143
13T pinion
I tached it at 4500 using an optical tach light on the skids.
Plastic blades are ok for maiden.
Get the CF or FG from hobbypartz I have the CF on them now. I had the FG originally but don't feel too much of a difference.

Anything above 4000 is what you want. It is just both more stable and agile and the tail holds better. I noticed some slight wiggle in your tail that means its not holding vs. too much gain. I think I have a 100,90,100 curve in idle up.

[elkmaster01]

David,,,the only 'wiggle' I had in the tail was when I blew the first landing attemp and clipped the tail on the styro board,,LOL,,you didn't notice that? I was really fighting to keep up with it,,,I didn't even think about expo for the first flight.

I'm going to switch to a 16T pinion,,,,,my motor is actually 3400kv not 3500,,,,so the math says,,,15T is 4245 rpm and the 16T would be 4528 rpm.

I have 4 sets of those CF 3D blades for it.

We are fighting a blizzard up here now,,,be a few days before I can fly again!

Thx!

Randy

[elkmaster01]

I got the gear mesh right and I set +40 on the ail and elev expo. Here's a quick flight in my garage. It is quite stable,,,I was jerking it a round a bit to get a feel for the expo. I love this heli!! It sounds great!!



Randy

[elkmaster01]

Here's another one! I decided to check blade tracking with the camcorder,,LOL!!