HotSpot Airbrake
02-15-2008, 12:32 AM
#2
RE: HotSpot Airbrake
Ron;
I did have one with the servo set-up but don't have it anymore and no pictures, but to avoid this, with the brake on full deflection, your travel and rod/horn set-up needs to have the servo horn and the pushrod on a straight line from the servo shaft all the way to the point where the rod/clevis attaches to the airbrake, this so that all forces are transfered to the servo shaft, any angle beyong straight and the force is transfered to the gears on the servo, this will cause the blowdown
I did have one with the servo set-up but don't have it anymore and no pictures, but to avoid this, with the brake on full deflection, your travel and rod/horn set-up needs to have the servo horn and the pushrod on a straight line from the servo shaft all the way to the point where the rod/clevis attaches to the airbrake, this so that all forces are transfered to the servo shaft, any angle beyong straight and the force is transfered to the gears on the servo, this will cause the blowdown
02-15-2008, 01:02 AM
#3
RE: HotSpot Airbrake
Ron
With a friend of mine we had the same problems on our Hotspots. The original ram seems to be a little underpowered, we replaced them with (I think) BVM types, anyways our 2nd goal was to increase the angle of the brake, as it normallly comes up to some 70 degrees, which is just not enough.
Now it really RAMS open, no matter what speed, straight to vertical and the difference in braking power is enormously. You have to mix in some UP elevator trim in order no keep the nose from being pushed down though.
I just some piccies for You in order to clarify the geometrics of the linkage positions
With a friend of mine we had the same problems on our Hotspots. The original ram seems to be a little underpowered, we replaced them with (I think) BVM types, anyways our 2nd goal was to increase the angle of the brake, as it normallly comes up to some 70 degrees, which is just not enough.
Now it really RAMS open, no matter what speed, straight to vertical and the difference in braking power is enormously. You have to mix in some UP elevator trim in order no keep the nose from being pushed down though.
I just some piccies for You in order to clarify the geometrics of the linkage positions
02-15-2008, 06:40 AM
#4
RE: HotSpot Airbrake
Heres mine.
The important thing is to get the airbrake pushrod in line with the servo like in the 5th picture. Then there is very little strain on the servo to hold the airbrake up. I used a 5,5kg JR digital servo.
The important thing is to get the airbrake pushrod in line with the servo like in the 5th picture. Then there is very little strain on the servo to hold the airbrake up. I used a 5,5kg JR digital servo.
02-15-2008, 10:16 AM
#5
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RE: HotSpot Airbrake
Hi Ron, using a servo in the speedbrake is a good idea.. at least two times I had bad landings because of a malfunction on the air piston.
The installation is simple, using a high torque servo. The pivot point is about a inch and half above the rotation axis of the airbrake, and unlike Sonnich pics, my control rod comes over the fuse and servo and not thru it.. it was a little tricky to set it because the servo arm can interfere with the door closing, but the problem was saned with the angle and size of the servo arm, keeping the all the pivot points aligned at the "open" position.
Enrique
The installation is simple, using a high torque servo. The pivot point is about a inch and half above the rotation axis of the airbrake, and unlike Sonnich pics, my control rod comes over the fuse and servo and not thru it.. it was a little tricky to set it because the servo arm can interfere with the door closing, but the problem was saned with the angle and size of the servo arm, keeping the all the pivot points aligned at the "open" position.
Enrique
