Beam tail upgrades

[machasm]

Hi all,
I have been having a couple of issues with the BEAM tail recently.
Let me first state that these issues are probably caused by me running too high a head speed and is not a fault with the BEAM itself.

The problems started when I changed the tail blades from the standard blades to CY carbons.
On spool up within seconds of reaching max headspeed (running 15T pinion on 2221-8 scorpion 90% FL) the tail output shaft bent over 90 degrees and caught under the boom.
The belt then chewed through a few teeth and on closer inspection the tail pitch slider broke and the hub bent.

My questions are
1) Can I find a pitch lever made of ali instead of plastic (like the micro-heli ones)
2) Can I find a tail shaft which is hardened as these ones are too soft IMO.
3) The small elbow that the pitch slider crank screws into is easily damaged and is there an alternative.
4) Is it possible to fit the whole microheli tail case and rotor hub to the BEAM.
5) If so where can I get one from?

[rspblake]

Been having a read around and the only thing on this is around August last year..

http://www.runryder.com/helicopter/t443546p1/

Once the little shelf on the case is deformed from even a minor ding, it seems like the likely hood of movement is further enhanced.. I have bent 2 shafts 45 degrees when this happens..

My new Beam kit already shows to use a socket head 2x5mm screw..Looks like they have solved the issue

working out at 90%!

Voltage for this calculation (min):3,441/cell with a total of 10,323
Nominal voltage: Spool up RPM 100% throttle no governor (11,1v): 3990
Avg RPM you will see with 100% throttle and no governor: 3735

Max normal bogging applied you will see RPM at: 3340
(this number should be the minimum if your motor & battery is up for the challenge)

My thoughts are! With the carbon tails on, over the standard plastic one that seemed to be working OK! that the deflection load would increase and if so more force would be put though the pivot point of the L arm, could be this that turned.. although its been fine till the carbon blades and the extra efficacy, but then with the loads it could be just the shaft bent a little and at high speed will last a very short time.

I have asked the factory if they are willing to look at hardening the tail shaft, just for people who want to run say harden mains as well.. the only problem with that is you will never be able to bend straight the shaft to remove the tail case bearing, so every tail shaft replaced will need bearings as well.

Factory suggest speed set 2300 to 3000, So running high speeds any slight in balance, will be multiplied with the tail ratio..

1)Running a metal pitch lever will make something else take the load, and bend or break somewhere else..

2)Asked see what happens

3) No! Seems Not to have been a big problem state side, JB weld seems to be a fix to aid the higher head speed. might be worth adding to the preflight check, take a look at arm..

4) The boom dia is the same as the Rex so would think any after market tail will fit, if that the way you wanted to go! (many are using the beam one without a prob! and as a upgrade to the Rex one)

5) Depends on what you end up with!

Adrian, I just realise I said to tap the L arm hole to 3mm, its 2mm to start! Should of been 2.5mm, might of got away with that!

Rob

[richieclarkie]

Gotta be too high headspeed to bend it in flight, or it was already out. Or.... the small elbow came loose during the flight. I'm sure something came adrift or was slightly bent before you took off.

Still bet that just about finished off your week didn't it Ade

[machasm]

Thanks Rob for the very detailed explanation.
Would agree that the headspeed is prob too high for this configuration.
I am bringing the original tail blades along today so can put back to stock and also fitting the 14T back on.
Should be able to bring the TH curveback to 100%.
Personally I wouldn't mind a hardened tail shaft.
Perhaps the prob has been the small 2mm screw holding the elbow on had come adrift?
This might have given enough play for the tail to be out of whack?
Once off-center the forces then bent the shaft.
I did check the elbow prior to my last flight though as I was aware that it had come loose on my prior tail bend.
Couldn't the elbow become fixed to the tail case from manufacture?
What is the reason for it to be bolted on anyway?
Don't get me wrong, when the BEAM is performing it really is a trex beater and I love it.

[rspblake]

Couldn't the elbow become fixed to the tail case from manufacture?

Yes but if you bend it in a crash it would be a new gearbox, where at the mo, it a spare..

I would of thought the design with the ridge is to allow not only support but to make sure its square.. perhaps running the CHINESE WEIGHT MOD might help, any side deflection would be countered.

* Different ways of doing the mod
Version 1: Drill/Tap and use SS ball links as counter weights
Version 2: Use longer screws for blade grips and use Nuts/SS balls for counter weights.

Richie has a jig that works as well..

[ame]http://www.youtube.com/watch?v=XWkQGFaArzg[/ame]