700 My New T-Rex 700X Build

[Dennis H]

Here goes, lets start with a few and see how it goes

View attachment 16786 View attachment 16785

First job to load up a new battery and fit the pins to my digital calliper. Must make sure the tools are working ok.

More to come tomorrow..................

Bye now!

This is a great thread. First, thanks for taking the time to share your experiences with us.

Second, "Where did you get the PINS for your digital caliper"? This is the first time I have seen the pins. I would love to have a set.

Thanks for your time,
Dennis

 

[fran11784]

Hi Dennis, here's where I got my caliper pins...

FBL Turnbuckle Caliper Tool

 

[Dennis H]

Hi Dennis, here's where I got my caliper pins...

FBL Turnbuckle Caliper Tool

Thanks for the quick response, I have been following the thread, it's pretty interesting and informative.

Dennis

 

[Heliman450]

Hi Dennis, seems like fran11784 also bought himself some pins so if you want some , then that's the best place to go. I got mine from a dealer here in Switzerland. I find them extremely useful, especially for the swash links.

Latest update is that I've replaced the stripped front tail rotor gears today and am waiting for the weather to settle down before getting back to the field to continue with setting up my Bavarian Demon Axon gyro. I'm feeling optimistic and hope to have a video to publish afterwards.

Keep your fingers crossed.

 

[Smoggie]

Hope you get flying weather soon Phil. It's been awful hear today, the rain hasn't let up at all. I'm hopeful that tomorrow will be better and I can get out flying.

 

[fran11784]

Heliman450, did you say stripped tail gears? I have quite a few flights on my 700X and have heard of gears stripping on these models. I just ordered all the red gears for mine as a preventive measure. But I also heard Align has redesigned the tail rotor box as there was a issue with it. Ignore my post if you guys have already discussed this, this tread is quite long.
T

 

[Heliman450]

Hi fran11784, yes I've stripped gears twice now but it's been my own fault so I can't judge yet whether there's any inherent weakness. Align mention a strength improvement all over with the red gears but I doubt they'd have survived my BAD

I'm carrying on with my story here Tuning B.D. Axon Gyro on my T-Rex 700X as the build thread is getting very long but still seems to get a lot of views.

 

[Smoggie]

Hi Fran,

I've got one of those new tail cases fitted to my 700X.. to be honest i dont fly hard enough to need it but i was curious about whet they changed. The problem seemed to be with the new 202/23t gears, on those gears the slant direction is reversed, so torque on the slant tends to force the bevel gears apart. The original tail box was quite thin and flexible enough for the gears to loose mesh and strip. The new one is beefed up quite a bit but you cant use the old gears in it without a bit of modification because the thicker plastic rubs against the shoulder of the spur gear.

 

[Heliman450]

Hi all, I've opened a new thread.......

Final B.D. Axon Tuning??

It's been a long road but I can now call my build finished

I'll pick up any further feedback there.

 

[Smoggie]

Phil / All 700X owners

A heads up on a issue with the standard Super Combo servos binding on the 700X:

If you apply full positive pitch combined with back and left or right cyclic, the front swash servo arms hit the alloy heatsink. This causes the servos to stall which can potentially burn out the servos and cause the BEC to fail on over-current.

Here's a video of the issue (not mine):

The fix is to use a 1.5mm servo spacer to move the servo slightly rearward (SAB Goblin part # H0075-S works). You then need to trim down the length of thread on the swash ball so that it's just flush with the arm rather than protruding out. This should resolve the clash with the heatsink. If you have a large pitch range set then the arm may still hit the carbon frame at extreme travel, but for standard pitch ranges this shouldn't be an issue.

 

[Heliman450]

Hi Steve, thanks for this heads-up. I'm due to do some work on mine soon.

 

[Smoggie]

One thing i should have added.. ideally you would want to use slightly longer mounting screws for the servos (M2.5 x 12mm) because otherwise there isn't much thread engagement by the time you add the spacer.

 

[fran11784]

Good thing for me, I don't ever see my swash deflecting that much in flight....lol

 

[Smoggie]

Yeah, that's true, you would be have to be slamming the sticks around pretty hard to ever get the servos to move far enough for this to happen in flight.