700 Boom Supports

[Steve]

I know this has been covered before.... sorry chaps, but I can't find the post I'm looking for, so maybe someone can help here.

I'm sure (but could be wrong) that it was richieclarkie who wrote a short and concise description in a thread a while back on how to firmly secure the TRex 700 boom supports so that they don't come lose.

Please can someone (a) explain the bestest way to do it, or (b) point me to richie's post, or both.

Thanks.

[Andy from Sandy]

Are referring to how to keep the ends on the rods or keep the M4 bolts from coming undo in the frame cross-member and horizontal fin holder?

[Steve]

Are referring to how to keep the ends on the rods or keep the M4 bolts from coming undo in the frame cross-member and horizontal fin holder?

Good call.

Both for now. I haven't actually looked at it yet (will do in a little while), but I suspect I might be suffering with one or the other, if not both.

[Andy from Sandy]

On my 700 I lost a bolt from the boom clamp. Even after cleaning thoroughly it still came loose. I know others are using red loctite and the vibration is still causing them to come undone. An option is to put a brace across the supports to try and alter their resonant frequency.

A guy at MK was telling me about the pins or set screws that hold the ends on to the rods. If they come out I guess CA shoiuld work to hold them in the plastic and carbon.

[3d_willz]

i have heat shrink tube over the ends of mine to cover the set screws and also have a bridge support just incase a bolt comes loose.
ive had one bolt come out at the frame end and hit a blade and damaged the blade.

[Steve]

Ok, had a look now.

All bolts are tight and fine. In fact, they've never come undone.

The plastic ends are lose on the carbon tubes. The securing pins are in place and well attached into the plastic, so it seems the holes through the carbon have become over sized.

I've tried drifting out the pins to re-glue etc, but it seems they don't want to come out very easily.

[barney]

The boom stay ends being plastic compress under the washer after a short time allowing movement leading to the bolts slackning off. You need to re-torque once the plastic has compressed and check from time to time. (you will see a circle where the washer was)

As for the tiny Allen screw in the boomstays ends its pretty pants TBH. Its dia being so small pulls through the tube, moves or even breaks.

Your best to remove the Allen screw and the plastic end if its loose, clean and roughen the parts. Assemble and Drill a larger hole through the boomstay/end and use epoxy. I used some old Raptor Frame screw self tappers.

As for the Boom clamp remember to put a wrap of tape on the boom to prevent point loading the boom. After a couple flight re-torque the boom clamp once the tape has moulded to the shape of the parts.

Brian

[Steve]

Thanks Barney

Drilled out the retaining screws, cleaned all with surgical spirit, roughed up, stuck back together with 30 minute epoxy and a new M2x20mm cap bolt through each end with two nuts also all gooed up with epoxy.

Will trim off the excess threads once it's all dry and refit.

[Tim Procter]

I have had the retaining screws come loose on more than one occasion Steve.

I glued them back in and put a thin tie wrap round them to stop them coming out again.

As for the boom stay clamp bolts plenty of loctite and purchase when tightening up.

[Steve]

Here you go - glue is drying. Will trim off the threads once dry, tomorrow.