Precise flight speed brake bench tester

[larryb]

 

So far speed brakes have worked fine. I created this bench tester for the day when I have trouble.

[larryb]

This video doesn’t seem to play on Tapatalk but it does play on the PC.

[CharlesHuddleston]

Gotta ask... do your speed brakes have an on/off selector in your airplane? I just have one button/switch. Push once to deploy, once more to retract. Guess they are always powered by the bus/breaker.

[larryb]

Push button switch on yoke.

[carusoam]

Nice work Larry!

Probably ensures that your brakes will work perfectly for 15 more years… 

Great video, thanks for sharing it…

Best regards,

-a-

 

[larryb]

The on/off switch mimics the master switch and circuit breaker in the plane. There is a clutch in the speed brake that is always activated when the master is on. If you turn off the master with the speed brakes deployed the clutch will release and the brakes will slam down due to the spring.
The deploy/retract switch mimics the control relay in the aircraft. The relay is activated by the push-button switch. For simplicity I just implemented what I needed to get the speed brake to activate. There was no need to replicate exactly what is in the airplane.

[PT20J]

It looks like mine that are series 100 and don't have the controller -- just a relay. Mine are S/N 3847 and 3848 and they are painted red. I wonder when PF started anodizing them? Here's the schematic:

100 SERIES SCHEMATIC WIRING.pdf

[redars]

Hi, does anyone know how to remove the clutch on the series 100 speed brakes. Is the schmatic still available.

[redars]

On 7/5/2021 at 9:04 PM, larryb said:

The on/off switch mimics the master switch and circuit breaker in the plane. There is a clutch in the speed brake that is always activated when the master is on. If you turn off the master with the speed brakes deployed the clutch will release and the brakes will slam down due to the spring.
The deploy/retract switch mimics the control relay in the aircraft. The relay is activated by the push-button switch. For simplicity I just implemented what I needed to get the speed brake to activate. There was no need to replicate exactly what is in the airplane.

Hi Larry, is it possible to still get a copy of the schematic.  

[larryb]

Sorry, I didn't see this post until recently. Here is the schematic of the bench tester I built a couple years ago. The wire colors are just what I used in the build.