There was an old lady who swallowed a fly...

[kitkarsons]

Actually, it wasn't an old lady, it was me and, I didn't swallow a fly, rather the fly flew into my eye! Subsequently, my chopper flew into a fence!!!

I had literally, just 5-minutes before, solved (with the help of Ombler, Ginger6 & Dedclam) a problem that has been bugging me for weeks and I was pretty chuffed... to put it mildly. I was doing one final test in the back yard before setting-off my local site.

Everything is going fine and (thanks to support of abovementioned members) my TRex 4509 Sport is flying sweeter than it has for ages, when this nasty, malicious, six-legged little &!$*@%! flies straight into my right eye which cost me about half a second's concentration and WHAM!

It's amazing how this hobby can run you through the whole emotional spectrum in just a few moments; elation to despair in no time flat!

As it goes, the damage could have been worse. I've lost a pair of no-name CF main blades and a hardened-steel main shaft both of which I can cover from my current stock of spares....


.... BUT ....


of course, this is the time when the main gear jesus bolt allen head decided to round out!!!! Useless Align screws! I do have an rcscrewz set but it never had a replacement for this particular screw so I'm still using the Align ones top & bottom. It went in this morning without even a hint of trouble but the moment I went to unscrew it fails!

I've tried the usual application of heat to unset the threadlock but it doesn't make much difference since I cant get enough purchase on it to turn it at all. And of course, being the main gear screw... both bloody ends are RECESSED! So I can't even get a pair of cutters on to the head and unscrew it that way.... ARRRRGGGGHHHH!

As it stands, it looks like my only options are

(1) to remove the side frame & bearing blocks with all of the resultant disruption this is going to cause. And this is assuming I can get the bent shaft (a hardened steel version!) through the bearings. GGGRRRRNNNNN!

or,

(2) try to cut-away the recess/flange from around the screw head so that I can get the cutters to it and unscrew it that way. Of course, this will cost me an auto-rotate gear.

Anyone know of another way?

In desperation,
Rich

[SimonV6]

unlucky, I would get some flying Glasses if I were you, so it won't happen again

[ddracer]

Try a torx bit sometimes thet will get a bite where a allen key won't. Or a ball of fine grinding paste on the allen key sometimes helps.

[pgkevet]

DON'T use an RCScwez s/s bolt for the jesus bolt or indeed any s/s jesus blt..they don't have the tensile stregth for those side forces and will sheer.

Invest in a proper fitting hex diver. I recommend the Fastrax 4 in 1 set (ebay)...It'll solve the rounding problem for you if you replace any current dodgy ones.

Slot the rounded one with a dremel and get it out with a good fitting flat screwdrive

[Voodoo]

I'm sorry, that's hard.
Two weeks ago I was on the field with my Acrobat SE and while flying I felt a pain in my right little finger.
After landing I looked at the finger and there was a barb of a bee in the skin.
I tried to remove it but had only success at home.
After this the finger was red and numb for three days.

To the screw I would say, try it with a puncture.
I don't know if this is the right word.
But the screws aren't hardened.

[kitkarsons]

Hi Simon, yeah, a pair of Do-It-All safety specs are definitely my next purchase... maybe even a bloody diving mask! lol! Who cares if I look like a knob?

Hi Adam, a torx bit? Haven't heard that name. I did buy a reverse-thread extractor set with sizes #1, #2, #3, #4 but even the smallest of these is way too big for this little M2 screw. Is torx the same thing?

PGK, I guess that must be why rcscrews sets don't contain this screw? I did wonder and I have heard someone else say one of their screws sheared. Cheers for the heads-up.

Walter. You are definitely hard (lol). If only I could have had your stoicism and ignored that evil insect (lol). You did really well to land safely after that. By punture, do you mean a drill bit ?

Thanks for all your suggestions anyway.

I have just had another look and I think that I can separate the top & bottom frames and (maybe) pull the main shaft through from below. At least then I wouldn't need to remove servos, wiring, etc.

Guess I'll give that a try first. I don't have a dremmel yet (currently selling a house so maybe soon!) so I cant slot the little devil. Fingers crossed I get the shaft out first, then see what I can do about rescueing the main gear.

All the best,
Rich

[ddracer]

Torx - Wikipedia, the free encyclopedia

[Voodoo]

Hi Rich,
no, I meant a bit of steel with the diameter of the screw and a hammer to push this bloody screw out of the hole.
Sometimes it works without to ruin the bearings.

[kitkarsons]

Hi again guys

Cheers Adam, I know what you mean now. Don't have any though.

Also, to Walter. I understand. It may come to that.

I have now managed to get the main shaft out of the bearing blocks and free from the rest of the fusilage so I can at least repair my heli. As for the A/R gear and the attached bush, I don't know yet? I've tried soaking the whole lot in hot water to try and loosen any threadlock, and starting with a slightly larger allen key, I've used my (full size) grinding wheel to try and make a new key but unfortunately, my machining skills are not up to the job... yet.

I will probably accept the loss and try to count myself lucky that the prang didn't do more damage. What a day! I don't know if it has to do with the drop in temperature these last few days, acting on the threadlock? But almost every single screw holding the boom-block was a nightmare to undo.

Ah well...

Thanks again for all your support,
All the best,
Rich.

[Vic.P]

Hi Rich,
Pesky bloomin flies!! Very bad luck to loose it like that I had the same myself and just had to ride out that nasty acid stinging until i was safely down and then i cursed, swore, cursed and swore again and cursed some more for the next 20 mins

As for the sbolt, you could try drilling off the head of the bolt, find a drill bit just slightly larger than the threaded section of the bolt. You wont have to drill far before the head parts company with the rest of the bolt but drill slowly with gentle pressure to avoid it coming through suddenly and damaging the recess. You should see the socket head start to turn free and then just use a piece of thinner bar to punch the rest of the bolt through

[Voodoo]

Hi Rich,
for this kind of work you need time and a relaxed mood.
In my first career I was a toolmaker and I know what I'm talking about.
I have a T-Rex 250 with these tiny small screws, some smaller than 1mm.
For gods sake I have a lathe and a milling mashine in my cellar.
So I made some screwdrivers with a cone shaped hex form.
I have hardened them which is important to loose screws.
After this I grinded them from the tip until they fit perfectly into the screw.
And then warm the srcew and the shaft and try to wind out the screw.
My hitrate is nearly 100%.
Try it, that brings experiance and save money.

[Kozmyk]

I've managed to remove rounded out hex headed screws before now by finding a flat blade screw driver that just fits the head with a bit of force or by tapping it in. Not exactly subtle but it has been effective.

[kitkarsons]

Hi Vic

They are little devils. I will be investing in eye protection very soon. Unfortunately, my tool kit is not what it might be and I still need to invest in a Dremmel or similar. Currently all I have is an old style hand drill; I guess it might do the job? Gonna get the birtd fixed first then see if I can rescue the gear and bush.

Hey Walter. That sounds like a good method. As you say... a relaxed mood is important. Today was probably the wrong day to try. I will give this a go over the next few days. How did you harden your tool? I noticed that when I was grinding the allen key I got that blue colour in the metal after it glowed red and I quenched it in cold water. Would this work? Should I quench in oil or something else?

Hey Koz. I have also had some success doing it your way in the past. This one seems very reluctant to move though. I will keep trying, but at least I am now in a position to get back into trhe air even if my pockets are a bit lighter.

Thanks guys,
Rich.

[Voodoo]

Hi Rich,
this depend on the steel you use.
For this purpose I use a common steel wich name is silver steel.
The name is programme, the colour is silver and it is blank.
I glow it to red and then drop it into cold water.
Then it is really hard an sensible against shock and so on.
To harden in oil is upper class, forget it.
When the steel get blue while grinding or is glowing, then forget it also.
After glowing the steel, it will be like chewing gum.
You could try to harden it, could work, try it with a rasp.
So far.
Walter

[kitkarsons]

All better now

In the end, not too bad in terms of downtime. Of course, I can't test-fly until tomorrow but my repairs are now complete. I've had to fit a pair of 310mm Ripmax woodies until I can get some new CF's delivered but they have been ok in the past.

It's been quite an expensive day with:

2 sets of no-name CF's,
half a main gear assembly,
a high-carbon main-shaft

...and not forgetting several tones of hair pigment.

On the other hand, I've learned quite a lot too:

I now know that I ought to use eye-protection to lower my risk of another expensive crash and before today I definitely would not have thought of this!

I've received a lot of good advice that will be useful in the future.

Plus, earlier today I was shown a new method for throttle/pitch control which I hadn't realized was open to me and this has completely cured an irritating problem that's been buggin' for some time (see thread http://www.rcheliaddict.co.uk/t-rex-...-decrease.html)

On balance then, could have been a lot worse. Although I do rather hope that tomorrow is a little less edifying!

Boomshanka,
Rich.