multiblade help
 

Hey all..
I'm working up to a scale model on a Trex 450 and have a quick question.
I know adding blades increases the amp draw and torque involved, so I was thinking
either find a shorter chord blade (or modify stock ones) or put on a larger size tail blade.
This would help with the torque issue primarily, and I think address the amperage issue with a shorter chord blade.
The other thing I was thinking, would be to change my hover pitch to 3-4 degrees rather than 5-6.
This way I could increase my RPMs and hopefully gain back better tail authority.

Any thoughts from those who run more than 2 blades?
I would think it wouldn't matter what the power source is (gasser or electric), so any
input would be appreciated.

N3M3515

RE: multiblade help
 

The multiblade heads on the TRex 450 actually like a little lower headspeed. This of course causes tail authority issues for the reasons you mentioned. I put the older TRex autorotation and tail drive gears in mine which changes the tail ratio from 4.25:1 to ~ 5:1. An alternative that some are experimenting with is a Mini-Titan pully on the tail drive which also increases tail speed.

AFAIK, there are no narrow chord blades currently available for the little TRex. Maybe this will change with the number of fuselages showing up now. Find the heaviest blades you can, and lower the headspeed a little...

I've run 2200 with Align 325 woodies on a 4 blader with good tail authority at 4.25:1. Any lower and you're in trouble... I got down to around 1900 with a 3 blade head. I'm trying to figure out a failsafe way to add weight to the woodies, as I think that will help with stability. These things are very twitchy w/o the flybar... ;)

RE: multiblade help
 

The only way I could think to add more weight, would be at the tip.
It looks like there is a slot there already on the under side. Haven't look at a set of broken ones yet (or couldn't find that piece of the blade).
On the gassers, at least my old Kalt Enforcer, you had to install the tip weights, then cover the blades.
I'm thinking just route a slot (or cut carefully) in the under side tip area and epxoy in some lead solder, then either repaint or recover.

I'll have to go pick out an old beatup set of blades and dissect them.. :D

N3M3515