ianjh123
09-28-2007, 08:31 PM
After battling unsuccessfully with a tail vibration at 1800rpm, I decided to adapt a Trex 600 cnc tail. Here is what I found.
The Trex belt is the same pitch as the Hurricane belt, a bit longer and not as wide. I also used the Trex control arm and slider.
The Trex tail box will go on to the Hurricane tail boom with a thin (0.3mm) shim of aluminium wrapped around the boom (this material is used in Australia as flashing on tiled roofs). With the shim in place it clamps tightly onto the boom.
Now you have a choice. The Trex tail belt is not as wide as the Hurricane tail belt. So if you use the Hurricane tail belt it will ride up the sides of the Trex pulley and skip teeth. To solve this you can use the Trex belt and sit the tail back about 10mm more. This means a longer tail control rod is needed.
Alternately you can remove the side from the cnc pulley and machine some extra clearance on the side (as I did). I removed a bit less than 1mm and the belt now has enough clearance and behaves. The tail control rod will need to be shortened - I put a shorter Gaui link end on and it was the correct length.
I used the Trex tail blades, and this means the tail fin needs to be lowered by drilling new holes about 10mm above the old ones. Failing to do this will result in the tail blades contacting the ground - ask me how I know!
The tail works beautifully now and no hint of the old vibration. I can actually lower the head speed now without the tail going nuts! Tail response is impressive but I don't recommend this mod unless you have a tail problem as I did or just want to have a cnc tail.
This would have been easier if I knew where to get a Hurricane belt that was the same width as the Trex belt. The Trex belt has 592 teeth, The Hurricane has 572 teeth.
Hope this helps.
The Trex belt is the same pitch as the Hurricane belt, a bit longer and not as wide. I also used the Trex control arm and slider.
The Trex tail box will go on to the Hurricane tail boom with a thin (0.3mm) shim of aluminium wrapped around the boom (this material is used in Australia as flashing on tiled roofs). With the shim in place it clamps tightly onto the boom.
Now you have a choice. The Trex tail belt is not as wide as the Hurricane tail belt. So if you use the Hurricane tail belt it will ride up the sides of the Trex pulley and skip teeth. To solve this you can use the Trex belt and sit the tail back about 10mm more. This means a longer tail control rod is needed.
Alternately you can remove the side from the cnc pulley and machine some extra clearance on the side (as I did). I removed a bit less than 1mm and the belt now has enough clearance and behaves. The tail control rod will need to be shortened - I put a shorter Gaui link end on and it was the correct length.
I used the Trex tail blades, and this means the tail fin needs to be lowered by drilling new holes about 10mm above the old ones. Failing to do this will result in the tail blades contacting the ground - ask me how I know!
The tail works beautifully now and no hint of the old vibration. I can actually lower the head speed now without the tail going nuts! Tail response is impressive but I don't recommend this mod unless you have a tail problem as I did or just want to have a cnc tail.
This would have been easier if I knew where to get a Hurricane belt that was the same width as the Trex belt. The Trex belt has 592 teeth, The Hurricane has 572 teeth.
Hope this helps.