5 Blade head woes

[RotorBlade]

Ok fellas - here's a project-stopper!

I have the Trex450 Pro that I am putting into an MD500 fuse, with a 5 blade head from ebay. The swash on the 5 blade is a different dimension to the 450 pro, which ends up with the anti-rotation arm being 4mm shorter than the stock version.

This then means that at anything like about 25deg of back cyclic, the arm will come free from the a-r bracket
If I dremmel out the frame to move the bracket forward, it fouls the elevator servo arm and the only way to avoid that, is to shorten the servo horn, which will mean moving the ball in, which will mean different geometry from the other 2 cyclic servos.

I've tried to buy a longer a-r arm, but they don't appear to exist

Has anyone had this problem? Any work-around?
At the moment, the project is stalled - the only alternative may be a different 5 blade head.
Thanks
Keith

[PilotPhil]

can you not just use the AR ball from the first pic?

[RotorBlade]

They are both identical Phil - it's the distance from the edge of the shaft to the edge of the swash that is different.
The 450 pro swash has an extended shape at the rear which puts the arm 4mm further back.

[sacko]

Can you not move the anti rotation bracket in on the frames?

[RotorBlade]

Nah - it fouls the elevator horn -see above

[Si Goodchild]

Dude, I'm still working on it for you!

[chris jones2.4]

are you going to need 25 degrees swash movement with a 5 blade head???

[RotorBlade]

are you going to need 25 degrees swash movement with a 5 blade head???

Almost certainly not, but I'm not happy to fly something with an inherent defect like this.....

[squeaky pete]

have u actually put all the servos on and set up your pitch and cyclics yet?? u may find it doesnt evne come close to coming out the guide, just a thought, it is a scale so you shouldnt need mass amounts of cyclic really

[RotorBlade]

have u actually put all the servos on and set up your pitch and cyclics yet?? u may find it doesnt evne come close to coming out the guide, just a thought, it is a scale so you shouldnt need mass amounts of cyclic really

Not with the 5 blade head - no. It has flown with the original fb head. The other issue is the wonky control rod angle that the 4mm loss causes.
Check this out!

[navzptc]

Depending on what thread your anti-rotation arm is, you could try one of these to achieve what you are after - Spacer Brass M3x5mm Male/Female Hex

They are M3 thread and available in various lengths - Screw it into your swash plate, and then screw the arm into the spacer.

Just a thought.

[Si Goodchild]

That's exactly what he needs, except the target thread is M2.

[dannyhough]

Out of interest, what make is the 5 blade head?? I Used the CopterX head on a 450 scale and the swash was fine.

[dannyhough]

Just looked at the pics more closley and it looks like the CX head. If you don't come up with another solution you could always drill and tap an extra hole in the original head for the swash follower dog leg to attach to.

Simple enough to do with the right tools.