Trex 250 build videos

[Heli-dood]

Another thank you to Jasmine and Finless for the videos. Helped me successfully build my new 250 SE. Had my maiden flight today (actually, just an indoor hover) and everything is almost perfect. The bird is definitely twitchier than my 450, but not as bad as I thought. Still need to fine tune....got a slight wagging tail and the cyclics feel a wee bit sluggish, but definitely a keeper!

Is there anyone else but me who thinks the factory recommended lengths for the servo to swash linkages did not result in a level swash plate? Had to level it myself...basically dropping the aileron and pitch linkage lengths by a few turns each. I was lucky enough to end up with a level swash plate at low, mid and high without messing with the swash mix tho.

Also found the pitch range to be quite extreme (I think I was getting +/-14 degrees) which I toned down in my pitch curves. Just some observations.

[whiskykid]

yes 2 thumbs up for Finnless,and Jazmin!

they

I built the EXI250 using there vids! and shure made the set-up strait forward, only had like 2 clicks of ail. trim ta be able ta hold it in a hover

as with the rods I tried aligns lenths and my swash was way wrong! I ended just twisting them together till they started bottoming out then leveled by eye

again tyvm FB and Jazzy

[Jasmine2501]

Originally Posted by whiskykid

yes 2 thumbs up for Finnless,and Jazmin!

they

I built the EXI250 using there vids! and shure made the set-up strait forward, only had like 2 clicks of ail. trim ta be able ta hold it in a hover

as with the rods I tried aligns lenths and my swash was way wrong! I ended just twisting them together till they started bottoming out then leveled by eye

again tyvm FB and Jazzy

In that photo, your servo isn't straight, and the swash isn't level. The servos aren't the stock ones, and even with those, the length of the three main swash plate rods is just a suggestion. The lengths of the other ones should be pretty close if not exact.

[whiskykid]

Originally Posted by Jasmine2501

In that photo, your servo isn't straight, and the swash isn't level. The servos aren't the stock ones, and even with those, the length of the three main swash plate rods is just a suggestion. The lengths of the other ones should be pretty close if not exact.

sry jazz! not best photo:o! if you look closer, you'd notice it only has 1 flybar wieght!

I think that was the pic I took before I readjusted the rods! couldnt find the other wheel coller, anded up buying some blade 400 flybar wieghts(that was stupid,at 5.50 a pair)

other then fine tuning my gyro! (gy48v) and I'm using a futaba 9cap radio! I can switch between HH, and rate, but as far as gain goes either way, I'm still clueless!

and the servo's are actualy eflites! that I took outa my 55mm DF that got painted red!

although its actualy my 3rd heli! its realy my first buld of a modern heli! my first being a kyosho nexus, which I built 10 yrs ago, and untill just recently had no idea if it was right, the secound heli was a venom nightranger, was finnaly able ta hover that befor the tail motor went out!

so thats why the begginer set-up on the 250,still a newb even though I hav succesfully flown my nexus, and could keep the nightranger in a tail in hover for a whole pack!

so with the help from you, Bob,and others here on the freak! I'm confident in my progress in this very exciting hobbie!

[whiskykid]

Ya baby!

found a sunny spot! in mother-inlaws back yard got 3 flights in this afternoon!

was even able ta outrun the wife with my heli!(my photographer) "ask WHAT ARE YOU DOING!" she said trying ta get a clooser shot! I'm like honey I'm not that good yet!

now thats trust!:o

all persons are safe! and heli is still in 1 piece!

[BaRoN30s]

Just on with building my 250 combo & was wondering why is it on the 450 & 500 size in the book the elevator is mounted on the right side of the heli, where's on the 250 its showing left side of the heli... how come with a heli so small both the rudder & elevator servos are on the same side.? would have thought this would have become a big weight issue.. especially when some also mount the esc on the same side..

can it be moved to the right hand side without any problems or is there a reason why its on the left of the heli..?

cheers.

[whiskykid]

thats an interesting question!

I have both the collective and rudder on the left side of heli(looking from the tail) and I needed some right side trim on the ail.

I have my esc under motor,and my reciever under tail,and my gyro on a home made pad over the tail! only thing not under center is the 2 formentioned servo's

you might have something there! I will stay tuned!

[Jasmine2501]

You can do it either way. It won't affect the balance very much.

[UKBananas]

Total noob here, just browsing and learning, planning to build a 250 sometime in the future.

Quick question, on the 450 Pro build video you undid the spindle screws to check locktite and pulled out the feathering shaft to grease the thrust bearings, but neither you or Jasmine checked the bearings for grease on the 250 vids, is it not necessary to grease the bearings on this one? Or were you just assuming they were greased at the factory?

If anyone is close to the Boston area let me know!

[Jasmine2501]

Originally Posted by UKBananas

Total noob here, just browsing and learning, planning to build a 250 sometime in the future.

Quick question, on the 450 Pro build video you undid the spindle screws to check locktite and pulled out the feathering shaft to grease the thrust bearings, but neither you or Jasmine checked the bearings for grease on the 250 vids, is it not necessary to grease the bearings on this one? Or were you just assuming they were greased at the factory?

If anyone is close to the Boston area let me know!

That is a good catch - on the 450 I would check this. On the 250, I had two issues - one is that it has no thrust bearings. The other issue is I couldn't get the thing apart. It finally came apart in a crash one day

[UKBananas]

Heh okay, told you I was a noob Thanks for all your hard work Jasmine!

[Peterovich]

Thanks for the guide.

[Badbird]

Has anybody had the pinion come off while flying? After 3 years of flying my Trex 450 and 600 I it was time to flip and roll one of these birds. I Do it all day on the sim. Never had the nurve to do it for real. I chose the 250. The first Flip and second flip no problem. Did a roll no problem. Try another flip, almost. It just died in mid flip and fell about 35' in the grass. Maybe I did something wrong? The good new is it only broke the fly bar. Thank you soft grass! During the inspection I found out the pinion came off. I read somewhere to put it on with red lock tight.

Any thoughs.

[Jasmine2501]

It can happen if your green stuff is old, or if your surfaces aren't clean, or you don't get the green stuff onto the shaft right. It's not a design flaw or anything - it works fine most of the time if you do it right. Some people have reported this with the 250 though it hasn't happened to me. If your heli is 3 years old though, it's not surprising - just normal wear probably. I wouldn't use red locktite, use the green stuff, as it's designed to hold bearings, and locktite is designed to hold threads.

[Badbird]

Its a new build, just finished this winter. I have about 15 packs on it. Maybe I did not get the shaft clean. Thanks Jasmine, i will try it again.

[Jasmine2501]

There might be some variability too - when I switched to the 16-teeth, I heated up the 15 and took it off, then cleaned everything real well, and I almost had to hammer the 16 on there, it was that tight. The 15 was not that tight when I put it on there, but it was tight. If it slips on really easily then maybe the hole is too big or the shaft has been spun down a little bit. Obviously one problem is easier to fix, so if it seems loose, try another pinion gear.

Then it's critical to get the right amount of green stuff - too much and it won't cure properly, too little and it won't be strong enough.

[schlehrbear]

Just wanted to say I am fairly new to the sport. I was a lil intimadated by kit helis and this 250 was my first. I deff second guessed myself alot about set up.
This video hit the nail on the head for me! I got the chance to check my work with what seems to be a HELI GOD!!!! Thank you sooooo very much.

Now if i could just get over the fear of flying this after I labored so hard. I Must say it looks great when its in one piece! and not busted all over the ground!!!!

[Peerlessrc]

Just getting around to building my 250 after purchasing it last year. Does anyone know of a link to a video showing step by step set up instructions for the Futaba 7C? I have a 550e sitting hear that I plan to build and set up once I have the 250 dialed in.

EDIT: found two by Finless Bob

thanks in advance,
John

[VD2021]

Video Link ->What's in the box!! (38 Megs)


[B][URL="http://video.helifreak.com/?subpath=/finless/trex250/&filename=head.wmv"]Video Link ->Head

Video Link ->KDE Direct's Trex250 Bottom Plate Review (16 Megs)

Video Link ->Frame Overview and Servo Install (24 Megs)

Video Link ->Servo Setup (48 Megs)

Video Link ->Head and Link Setup (94 Megs)

Video Link ->Tail Assembly (100 Megs)

Video Link ->Tail Setup and Align GP750 Gyro setup (97 Megs)

Video Link ->Motor Assembly (27 Megs)

Video Link -> Electronics Install and Final Build Parts / thoughts (56 Megs)



Video Link -> First Flight Evaluation (56 Megs)



Bob[/QUOTE]

[FranBarak]

Originally Posted by whiskykid

sry jazz! not best photo:o! if you look closer, you'd notice it only has 1 flybar wieght!

I think that was the pic I took before I readjusted the rods! couldnt find the other wheel coller, anded up buying some blade 400 flybar wieghts(that was stupid,at 5.50 a pair)

other then fine tuning my gyro! (gy48v) and I'm using a futaba 9cap radio! I can switch between bonusy, and rate, but as far as gain goes either way, I'm still clueless!

and the servo's are actualy eflites! that I took outa my 55mm DF that got painted red!

although its actualy my 3rd heli! its realy my first buld of a modern heli! my first being a kyosho nexus, which I built 10 yrs ago, and untill just recently had no idea if it was right, the secound heli was a venom nightranger, was finnaly able ta hover that befor the tail motor went out!

so thats why the begginer set-up on the 250,still a newb even though I hav succesfully flown my nexus, and could keep the nightranger in a tail in hover for a whole pack!

so with the help from you, Bob,and others here on the freak! I'm confident in my progress in this very exciting hobbie!

Totally agree with you. There is something to think about.