Joystick Mod to Eliminate Trimming

I had this idea and started researching it... I found that a few other people have done it so here is a little description to help others. My original thread on this is here: Joystick Spring Removal and Modding

 

I removed the centering spring and added dampers on my Saitek ST290. This holds the stick in place where I leave it and eliminates the need to trim the cyclic. The ability is still there, but it is not necessary.

 

I simply cut the spring into small pieces with wire cutters (be careful, the pieces shoot off violently), then cut the centering disc into pieces to remove it.

 

I originally added electrical, then later duck tape to the ball of the joystick. This worked relatively well, but had areas of different resistance.

 

So I decided to add small hydraulic dampers to keep the stick in place... I simply ran a piece of electrical wire around the joystick and through the damper holes, then used a hose clamp to tighten the wire to the joystick. The other end of the dampers are held with regular wood screws.

 

I bought the dampers at a local hobby shop. They are meant for a small RC car suspension and come as a "shock replacement" kit. The cost was approximately $15. They are sold many places online. The trick is to not fill them completely full of oil, or they extend back out when compressed. (and do not use the springs of course...)

 

Click here for an article on filling the shocks with oil.

 

 

Here are some pics and videos:

 

 

Mine:

 

 

 

Unknown: (if this is yours, please let me know so I can give credit)

 

 

 

And the videos:

 

[YOUTUBE]

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name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

[/YOUTUBE]

 

[YOUTUBE]

<object width="425" height="344"><param name="movie" value="

name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

[/YOUTUBE]

 

[YOUTUBE]

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name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="560" height="340"></embed></object>

[/YOUTUBE]

 

This works very well and I highly encourage people to try it!! Thanks for looking!

Edited March 2, 2010 by walker450

Crazy idea. weldone!

very cool - how much are the hydraulic dampners? :)

 

 

I wonder why joystick manufacturers don't use this method - it adds style to the stick :)

remember though, to handle the aircraft properly you must still trim. Trimming tells the onboard Autopilot which heading to keep you on.

 

I myself have this mod (mostlu for the bell 206 tbh) But i still have to trim up the BS ion order to not fly sideways everywhere i go.

remember though, to handle the aircraft properly you must still trim. Trimming tells the onboard Autopilot which heading to keep you on.

 

When I was reading this thread I was just thinking about this. In both trimming modes the stick is supposed to be centered after trimming (whether forced after some time period, or when it's user-centered). So with the old implementation, one would accumulate input when not centering, with the new implementation, control input will not be accepted.

 

How do you cope with this? Is it possible in some configuration to just pretend having FF?

 

Bye, bfeld

I guess by turning on FD mode and ceasing to trim.

your contacts in the ball are going to ware out much faster inputting continues contact in other positions, when not using compared to trimming and releasing the points to rest in the joystick.

FD mode is all well and true - so long as you dont mind never being able to hover properly, because as you well know FD prevents autohover from working. As well as all of the other helpful autopilot controls.

 

I think the only way to combat this problem would be to trim once at takeoff and then never trim again, but you would need to frequently tap the HDG channel or the FD-AP in order to reset the current heading.

It can be fifficult handling the BS in an autohover without trimming as the aircraft will constantly want to turn to the last indentified heading.

 

I do have this mod as well. My cyclic is weight balanced so it is in fact a PITA for the shark. I now have a detent in the center point so i can feel it as a center the cyclic - otherwise i would be all over the place.

 

This kind of mod only really works for commercial aircraft, and most of the MIL helo's.

When I was reading this thread I was just thinking about this. In both trimming modes the stick is supposed to be centered after trimming (whether forced after some time period, or when it's user-centered). So with the old implementation, one would accumulate input when not centering, with the new implementation, control input will not be accepted.

 

How do you cope with this? Is it possible in some configuration to just pretend having FF?

 

Bye, bfeld

 

Could you not reset the trim before take off (obviously making sure the stick is centred) and then fly from there? Leaving the stick still will act as a trim anyway won't it?

 

The only thing that I see as a problem is the fact you won't be able to trim the rudder will you?

 

Looks damn cool though!

If you reset the trim on the ground - it will take the heading your on and use it as a desired heading - then when you turn - it will try to turn you back. Thus you end up fighting the autopilot. This is why we are taught "trim in - manouver - trim out" When you release the trim the heading your on is updated and the AP will follow that instead.

 

Basically - if you dont trim - your making like difficult for yourself.

 

Please dont misunderstand me - Im not knocking this mod at all. In fact i also did it. But now that i know more about the aircraft and its systems it has more of a detrimental affect than anything else.

So then, what's the difference, if you use a FF joystick? Does the joystick actually set its center to the trimmed position or is there a third trimmer implementation, that does not assume the stick to be centered in case it's a FF joystick?

 

That's why I asked about a configuration which pretends using FF. The best for this mod would be a trimmer implementation that does everything apart from the virtual centering. So feed the autopilots, but use the actual joystick position.

 

p.s.: As said before by others: great mod, just wondering about trimming.

As far as trimming goes, this is an area I am still experimenting with. I picked a bad title for this post, because it really doesn't eliminate trimming altogether.

 

How do I change the main subject line?

But now that i know more about the aircraft and its systems it has more of a detrimental affect than anything else.

 

I understand and agree. I am still learning how all the system interact. I haven't had a lot of stick time lately, but when I get some more time I'll update the post accordingly.

 

I have been flying without the heading hold engaged until I get to a target area. I'll then turn it on and let the auto turn/shkval do the work.

 

I know this is a crude description. I kind of jumped into this whole thing before doing my homework. :)

 

Thanks for all of the discussion guys!

I did that mods, and I got to admit it works great, be able to fly around smoothly without hitting trim button all of the time and re-center the joystick. glad that I had st290 joystick sitting around. :-)

I've been experimenting with it a little more... For regular flying, turning the flight director on (button lights up) makes it work better. The controls won't fight you back. However, the dampening is still in effect.

 

I am going to redo the base soon. The wood screws are starting to loosen up so it's not nearly as precise. Version 2 will use a metal base with metal bolts coming up to attach the dampers to.

Good idea let's probe it !

I did a similar thing with my X52 Pro but I went for 4 rubbers (for mounting something on the roof of your car) in 'X' shape. The results - awesome! Centering mechanism is the cause of 90% of imprecision around the center range (the most important part of the range!) it gets eliminated by this. Additionally you get a progressive force increase on the stick like in real planes.

 

I spent many hours disassembling my stick to the basic parts and I recommend you don't do that! Cut the wires instead! There's a hard pressed pin in the joystick handle lever (sleeve) that you won't be able to pull out safely anyway. Cut the wires and re-solder them.

 

Think good where to cut them. You need to cut them because the connector going to the main PCB will not go through the joystick handle sleeve. I would cut the wires near the connector and be over with it.

 

Important note:

Adding rather strong X-shaped springs or rubbers like that will introduce increased loads on the joystick gimbal mechanism.

Edited August 5, 2010 by Bucic