Trex 600 tail

[Jungle Bob]

Last one from me, contemplating the Rex 600 boom and tail assembly on my Hurri, any advise, anyone happy/unhappy with the results. Thanks in advance

[istandalone]

i'm using just the tail blade grip and hub, so as to have thrust bearings.
this part http://www.readyheli.com/H60109_New_Tail_Rotor_Holder_p/h60109.htm
other then the fact that you need to be more careful, as the tail rotor disk is slightly bigger and tail strikes are easier now. i've never had a lock up since installing it.

[Jungle Bob]

Thanks, Istandalone, I have the Raptor skids on it which should give me the clearance. now I just need to find the bits and I will get it done. I have very little confidence in the Gaui tail (as a result of what I have read and a failing within my own bird in this area)

[worldofmaya]

Hi!
I also use the Trex600 New Tail Rotor grips and I've the Raptor skids... no problem at all. You get a little bit more bite into your tail :)
I also tried Trex600 Tail blades but these where too big. Way too much power and you have to really take care about your tail if you're flying low.
Have a look there -> http://www.helifreak.com/showpost.php?p=585099&postcount=10
-klaus

[Jungle Bob]

Thanks Worldo'. Did you find you needed to adjust your gyro sensitivity with the increase in power available at the tail (I am assuming that is what you meant by 'a bit more bite'). And the stock Gaui blades fit the Rex holders ok?
Thanks for your help buddy

[GatoVolador]

I completely replcaed the Gaui tail with a stock Trex 600 tail (see attached pictures). Works great! Only modifications are to drill a new locator hole for the tailcase and to shim-up the boom to provide for a tight fit for the ~0.5mm larger diameter Trex tailcase. You can whack-off a bit of an old aluminum Gaui boom and slip it over the boom, under the tailcase. As far as geometry is concerned I have my tail servo mounted on the boom and use the Gaui tail servo pushrod to get things lined-up. Note that I had to flip the bell crank and extend one ball to line things up. I also made-up a custom carbon fiber pushrod to connect to the tail servo as well as using Raptor 30 gear (tail rotor clearance is no problem). Overall I'm pretty happy with this setup and it cost all of $50 or so in parts.

[Jungle Bob]

Thanks Gato, a picture paints a thousand words, nice setup!

[ianjh123]

I did this to cure the tail vibrations and never looked back. See this thread:
http://www.helifreak.com/showthread.php?t=46910
Hope this helps.
I had to modify the tail pulley as the tail belt would skip teeth every now and then but others reported no problems without this mod.

[GatoVolador]

I didn't mod the Trex pulley although it is a snug fit. If I get excessive belt wear I'll probably try to chuck up the tail rotor output shaft in a drill (poor man's lathe!) and see if I can widen the pulley channel a bit. Yeah, it would be nice if we could find a slightly narrower Gaui belt. I wonder if you can custom order these from somewhere. I guess we'd just need to know the mod, the tooth count (522 I believe for the short boom) and the width (Trex 600 width in this case).

[GatoVolador]

I wonder if we can order a custom timing belt from here:

http://www.brecoflex.com/?CATID=1&SCATID=1&SMENID=1

[3sgte]

what do think about trying a trex 500 belt. it is a little longer but i think it could work.

[GatoVolador]

OK, did a little evening research. The Hurri 550 uses a standard trapezoidal timing belt with a pitch of 5.08mm/.200 inch (known in the industry as an XL or "extra light" timing belt), a width of 5mm, and a varrying pitch length depending on whether it's a short boom (52.20mm) or long boom (57.50mm). The problem is that it looks like the smallest standard width is 1/4" or 6mm. We need something about 4 to 4.5mm.