Trex 250 SE Head assembly

[CaptReza]

Hi Dear Pro Bros
I just got a real deal a trex 250 SE, This is my first kit to build and I have a question regarding frame assembly and use of lock-tight. I know that I should use lock-tight on parts which are metals and not plastic, but there are so many self tapping screws which holds the main frame parts, plastic main blocks and other joints. should I apply CA on them or should I leave them without applying anything?

[Toocool4]

You answered your own question, only apply locktite on metal to metal surface.

[CaptReza]

Thanks for the advice. But what should I apply for self tapping screws on the frame?

[myxiplx]

Yup, doesn't need locktite on the plastic screws. And be gentle tightening them up, just use your fingertips and get them snug. Very easy to strip these if you use too much force.

[CaptReza]

Thank you very much. As this is my first heli kit I was wondering if I don't use anything on self tapping screws the frame structure would be strong or not.

[skunkworx]

They hold pretty well if you get them finger tight. But as mentioned previously, you want to be careful not to over tighten them since they're really microscopic compared to anything else you're probably used to. Even the metal on metal stuff just needs a little bit of torque to set them correctly or else they'll snap off and you have to buy a whole new piece/part. If you really wanted to you could put CA on the plastic screws to prevent them backing out but they rarely ever come out of mine. Make sure you don't get any in the hex head or else it might be a real core getting the screw out when you need to.

I try to keep locktite to an absolute minimum on the frame fasteners but some of the head parts I'll use the red locker since they tend to vibrate loose pretty often. Green works well too but it sets too quickly for my liking and it's pretty watery.

I learned that setting the main shaft screw to the right tension takes some fiddling with it to get right. Too tight and it locks up the one-way bearing and it won't autorotate. Too loose and it'll have up/down play in the shaft. I usually use red on the screw and won't fly it for at least 30 minutes to make sure it cures, but I prefer overnight if I can help it.

[CaptReza]

What a useful information. Thanks SKUNKWORX , I really appreciate it. Because of yours and others good advises I managed to assemble my 250 without stripping any screw.
Thanks all

[skunkworx]

Perfect! It's nice to help when we can