Trex 700 build problems

[Si_B]

Does anyone elses tail pushrod clash on the rear plastic frame. The ball link on mine rubs on the web under the tail boom holder. I've checked the instructions and I'm sure that ball link should be in top tail lever crank ??.

Also, what's the score with the carbon stiffening rod, there's no way the metal pushrod will fit down the carbon rod, the hole dia is much smaller ??.

Any preferences on motors for this machine. Midlands have sold out of the OS91 as there is a new model due in at some point. Is it worth waiting for this, or looking around for someone who has the current OS91 in stock ??.

Cheers,

Simon

[mattie-lodge]

The second batch of kits the ball link ends are drilled wrong. Not too sure about the carbon rod though. I have put a ys 91 sr in mine.

[raptorheli2]

if the rod your referring to is the short one from the rudder servo to the bellcrank then mine was a tight fit. i just used a drop of grease/oil and put the rod into a drill and wound it in slowly.

yes there is a new OS due out but you should still be able to pick up the older one somewhere. there is also YS91sr if your a YS fan. i'm not a YS fan so i have the 939 OS91SHZ combo.

cheers

[Si_B]

Yep, it was that one to the rudder bellcrank I was referring to, I will put some oil on and give it a go. It's the ball link on the other side of that bell crank which is rubbing on mine (the one inside the frame). Thought about putting it under the bell crank rather than on top, but wanted to make sure I'd not missed anything.

Cheers,

Simon

[Arwel]

I had problems wuth the main shaft shims All ok now.

[Si_B]

I didn't need any shims, so I guess I was lucky.

I've looked at a few pictures of other peoples 700's and the ball link on the tail bell crank is definitely on the top inside the frames. I can not work out why mine rubs on the plastic web on plastic bracket which holds the boom into the frames.

I guess I'll just have to trim it a bit.

Really enjoyed the build apart from the screws which are used to hols the elevator servo stand off box on the frame. One of the screws rounded off which I can't get out easily. I used some 2.6 cap heads instead for the other 3 fixings. These small hex screws are way to soft.

Cheers,

Simon

[barney]

Niggles

Cyclic servo holes in the frames when using DS8915/8717's are just a little to neat for length causing the servo grommets to ruck up if care not taken.

Ball links as above are drilled offline.

Tail carbon pushrod rod tube was definetly too small a dia on this one and started to split. (In the end I cut the push rod in the middle and heavily abraded it. I then filled the carbon tube with epoxy and smeared the rods and slid it in from each side.)

Pushrod lengths. When you set up the 3 Swash CCPM push rods with the elevator lever centered the Pitch is biased to the negative side as the washout tops out against the headblock at full positive if you set it all 90deg on all the arms. (The ball link height on the top of the A arm is to long)

Also the pushrods from swash to the long side of the upper mixers are on the shortside.

Tailboom clamp. The supplied screws are shanked and bottom out before the clamp is fully tight resulting in wagging etc when pushed hard...and yes I taped the boom first as instructed

Other things..watch the wiring from the gov sensor/cyclic servos so it cant rub on the clutchbell area. Better guidance in the manual on the radio wiring routing during install would be helpfull.

Canopy.. around the grommets holes could do with a little reinforcement... Especially on the front exhaust side (its gets HOT!) as its difficult to apply even pressure around the grommet when removing the canopy due to the exhaust proximity causing spliting of the gelcoat.

Thats about it..

[raptorheli2]

the front A arm i cut about 2mm off the the plastic link and edge of it so i could lower the swash a little. that has evened out my pitch travel range.

the main mast i had to buy a tamiya shim kit as the ones with the kit will never fit on mine.

i have had to replace the bearings in the main bearing blocks after 2 gallons, the dampers went at same time.

the canopy i have re-inforced that around all the mounting holes and the usual places using toilet paper and thin CA (works a treat and not messy)

the tail boom when fitted was at an angle so the tail was pointing upwards (both booms in kit were same).

barney, the servo that you put into a case (8915/8717), just be careful as the wire rubs on this, it needs relieved with a file to make room for the wire.

i have had probs since day one with my gov not working. i have played about and it seems the revlock 20 i have is VERY picky about the angle of the sensor relative to the magnet.

the canopy grommets are far too tight, i put a drill through them and turned it slowly, has worked nicely and i don't use the clips now either.

i did have a vibration issue and i noticed the clutch was not helping, i had to buy a new clutch and i'm still waiting on a fan hub to be released to fi it.

i had a tail problem when i finished it. turns out the tail grips were caked in loctite, i couldn't get them apart when i was building so i left them. also no grease on the thrust bearings i eventually discovered.

i also have a problem with the nose tucking in doing anything side on, i can't find what is causing it though, i have ordered a swash levelling kit for it as i'm stumped with it.

cheers

[jeznewsome]

Does anyone elses tail pushrod clash on the rear plastic frame. The ball link on mine rubs on the web under the tail boom holder. I've checked the instructions and I'm sure that ball link should be in top tail lever crank ??.

Check that you have the metal tail crank pivot correctly in the frame. I had the same problem then noted that I had incorrectly assembled the pivot into the frame. With the pivot correctly assembled there is no clash.

[Si_B]

Could you tell me what mistake you made ??. I will have another look at it tonight.

Cheers,

Simon

[jeznewsome]

I mounted the pivot block such that the pivot was too close to the centreline of the heli. turned the block 180 deg such that the pivot was further out from the centreline and the problem disappeared.

[robgt]

I've had two niggles with the heli.
The first was getting the metal tail gearbox onto the carbon coated boom as it was a hellishly tight fit on mine. Other's I've spoken to didn't have the same issue so I'm guessing it's not a regular issue?
The second one for me was down to me using the MP5 muffler - the bottom bolt on the header was contacting the baseplate. After having some bolts come loose up the left side of the heli (boom stay bolts) on one flight, and the muffler half hanging off on another, I filed a little gap into the baseplate so the header nut no longer touches it, and all is well now.

I thought the build went pretty smoothly overall - just followed along with the manual and took it steady over yet another crap weather weekend. Probably about 15 hours in total from box to sky for me.

I think my engine is now getting dialled in too, so the power is getting there
Cheers,
Rob