Quote from Hangar45 Admin on December 13, 2017, 7:55 am

(Original thread started on 10-08-09 by Shane Barnes)

What triggers the "stick shaker" in a joystick? I know when I first started FS a few years ago I used a joystick and it would react to stall situations. I know if you look in the cfg file there is something close to the end in the force feedback section and stall warning section. Just don't know how to interface to it. Would this not act like an input such as an LED if we wanted it to light when condition met? Anyone have any knowledge on how to make our stick shakers operate?

 

Here is a wiring diagram example of a set of stick shakers in a sim:

FOR ILLUSTRATION PURPOSES ONLY!

 

(Posted by Ron Rollo on 10-08-09)

Thanks Shane for starting this thread. The only thing that I am not 100% clear on is how do we interface with MSFS to tell the electric motors when the aircraft is approaching a stall condition and to start shaking.

 

Here is a picture of the copilot's stick shaker in the L45:

 

(Posted by Mark L. on 10-08-09)

By watching offset 036C which is the stall warning. Now the question is, is it to late when this offset goes from 0 to 1, or is that when the system alerts that you are about to stall? Testing I guess would prove the outcome.

 

(Posted by DonnyRay Jones on 10-09-09)

Monitor the AOA variable. When it crosses a certain threshold which signifies the onset of a stall, spin the stick shaker. This is easy to do externally if you are already driving a real AOA gauge. The real AOA gauge requires a small dc current, which you can monitor with a comparator IC. The comparator output will drive (through the proper circuitry) the motor in the stick shaker.

 

Be aware that this method is not *entirely* aerodynamically correct, but it is pretty easy to implement and is pretty good for the limited amount of modeling that MSFS performs. An AOA system cannot detect the onset of all kinds of stalls, particularly if the aircraft is performing some high-angle or unusual maneuver. But for our purposes here monitoring the AOA variable will cover most cases.

 

A source of motors which may be useful for stick shakers is at:

http://www.goldmine-elec-products.com/products.asp?dept=1107

 

Another source of cheap motors useful for making stick shakers:

http://www.allelectronics.com/make-a-store/item/DCM-344/VIBRATOR-MOTOR/1.html

 

These are tiny vibrator motors used in pagers and cell phones, but they are cheeeeeeeeep enough that you can use three of them in a bundle to get more "shaking". Not as powerful as the real deal, but remember, we don't have the same stick forces to contend with in our sims. I'm using three on each control column and they work well for me.

 

Another method of making a larger shaker is to use a simple Adel clamp on the shaft of whatever motor you choose. The Adel clamp has a hole in it which makes it very easy to fasten a weight of your choosing to the shaft. We're talking "Lazy Boy Vibrator Chair" here but if that's what you want that's the easy way to make it.

 

(Posted by Ron Rollo on 05-13-12)

I picked up a couple stick shakers on eBay a year ago. They are dated 1961 and came out of a helicopter. They are also 27volt which is common in most aircraft so the challenge will be getting them to work on a 12 volt system and to operate when the aircraft goes into or is approaching a stall condition:

 

(Posted by Eric Tomlin on 05-23-12)

Yes, you can get stick shakers to work in FS as there is a Stall Warning offset 036C. Remember, if there's an offset for an item, we can almost always get data out of the sim to activate hardware.

 

Thankfully, there's not a whole lot that we can not get to work in a sim. Some things are useless to some folks, but for the 'core' builder, things like this are great added items. However, don't go getting a call from the virtual FAA about doing unauthorized stall tests in the LJ45.

 

(Posted by Shane Barnes on 05-23-12)

I have tried the stick shakers that I have that call for 27vdc with 12v and they do not function with 12v. I plan on getting a 24vdc power supply and seeing if that will work . . according to DonnyRay they should work with 24vdc power supply. I will update once I get the power supply unless someone beats me to it!

 

(Posted by Ron Rollo on 05-23-12)

I tested mine and they [b]DO[/b] work with 12 volt power. However, I can tell that it is working with voltage lower than it would like. My stick shakers were built back in the early 60's. They are dated AUG 31 1961.  I plan to paint them black and build a bracket for them to attach to the columns.  Even with only 12 volts of power, the shack the mess out of themselves!

 

And remember the fact, a normal flight, flying within the envelope, will never trigger the stall system. So unless you wanna show it off to your friends, it is another nice to have but never used feature. But it is cool!

 

(Posted by Eric Tomlin on 05-24-12)

Another point- The System Test Panel has a position to test the STALL system and once a certain sequence has been completed, the Stick Shakers will be activated momentarily. So, it will be nice to "test" them and have them move even when not flying if you choose to install them.

 

(Posted by Alan Norris on 05-24-12)

Ron, that is interesting that you got yours to work but Shane couldn't.  Shane, do you think yours were faulty or maybe a different make?

 

(Posted by Shane Barnes on 05-24-12)

Hey Alan, they are not faulty . . they are a different style than Ron's. The ones that I have are out of a Lear 25 or 35. I have had the tops off and the motor moves the weight that is offset to produce the shaking but it is very slow . . 12v is not enough to produce the shake. If I remove the weight then the shaft will rotate at a higher speed . . so it comes down to not enough power to spin the weight. Most likely just a difference in design. I have ordered a 24v power supply so in a few days I should know whether that is the issue.

 

(Posted by Alan Norris on 05-24-12)

I've asked the guy selling the stick shakers on eBay to test them to see if they work on 12VDC. Will let you know what he says. Having said that, you can buy 12VDC motors with eccentric weights for about $10 that may do the same job.

 

Ron, any idea what model number yours are so I can ensure I order one that will work on 12v?

 

(Posted by Ron Rollo on 05-30-12)

Hey Alan, here is the information you were asking for:

 

Looks like model number 0-71602.  I wonder if the others that we have our hands on would work if full 28 volts was applied to them.....

 

(Posted by Shane Barnes on 06-28-12)

I have the 27v version and am powering them with 24v. If someone does buy a stick shaker and it does not work try removing the cap that covers the counterweight and try turning the counterweight. One of mine would not operate until I removed the cover and turned the counterweight a couple of times. My thoughts it that the stick shaker had sat for a period of time and some light corrosion had developed on the shaft . . just enough that it would not spin with power applied.