That’s the spirit!
Is the logic of the trim such that they find their desired position based on the opposite cam’s position or is there a force sensor for trimming?
Or am I misunderstanding all of this and is it simply a manual trim where you neutralize forces yourself?
Sorry for the confusion, yes, it’s just manual trimming to neutralize the forces myself. Having an auto trim using a pair of limit switches on each axis wouldn’t be difficult either, you could just use the hot switch as the signal to drive the trim motor till the limit switch was released.
Cheers! That is very cool! Trimming forces away in FBW aircraft really is a simple cam-lobe system in boeings which is kinda neat!
The gentleman who designed this stuff, Karl, is a helicopter engineer. I wouldn’t be surprised if the actual Bell 407 heavily inspired it all.
I have the plan and the parts for the power supply routing and layout. Covid, work, and weather have kept me from implementing it and finally getting everything together. I am hoping this coming weekend I can finally get it all together.
Well due to real life intervening this weekend, had to put off doing any work until this evening. The various power bits are now mounted and wired. It’s not as clean as I liked, because I am running out of 24awg wire. The 100m roll I had ordered 2 weeks ago, still on back order for 3 more weeks. Without that I can’t wire up the connector looms between the stick and the control box. I am debating ordering the same wire I got last time off Amazon, but if I do that I know my 100m roll will show up and I’d have a massive surplus of wire. I probably will regardless, as having different colored wire will be helpful compared to just a mass of white wire.
Hooked everything up, it all works as planned, nothing got above 80F (and we keep the house at 78F in the summer), and no magic smoke came out. So I’m calling it all good. One of these days I’ll actually get to do some flying with it!
I need to do a bit of modification of the covers that are included in the STL’s for the control box. They aren’t sized to really have the height for using dupont style connectors (honestly not sure what else you could use?). But other than that, this part is done.
That’s looking good!
I need to send you those switches… PM me your address.
That trim system has inspired me to see if I can figure out a way to retrofit something like this to the Thrustmaster Cougar!
Though at this point I don’t quite see how yet without designing a new gimbal and having it laser cut in some sort of metal to save space. Would be cool though.
I have pondered that very question for many years. I have never come up with a satisfactory answer that didn’t involve basically building a new joystick.
My giant spool of wire shipped so hopefully by next weekend it will all be done!
Wire got here Monday, finally had a chance to work on things tonight. I settled on a 2’ harness length for now. For what I’m doing at the moment that gives me enough to easily slide things around, without having just a mass of extra wire. Hooked it all up, and it works. Only had time for about 5 minutes of messing around in MSFS, but it definitely works. Now I need to get on designing some rudder pedals and figuring out good setup for a throttle/cyclic that I can mount to a chair.
Update time on this build.
So far we have a new B8 grip, that is a much better size. If the Bell 212 grip really is that big, I am apparently not nearly manly enough to fly it. Added a matrix board to the original Bodnar board, moved said Bodnar board to the stick base as well, and ran new cabling to make all that work. I can now add an Apache cyclic stick and still have about 6 button spots left over. Cleaned up the wiring some. Once I finally figure out how I’m going to use this I’ll finalize the wiring and make it look pretty.
I am in the process of updating my Arduino code. In short, I had wired the force trim button (which shuts off the motors to allow the stick to move freely) directly to the stepper controllers. This works great for the force trim part, but for something like the Apache, where using the force trim button sets/updates the SCAS it won’t work as there’s no connection to the sim. So the plan is to have the button read by the Arduino, have the steppers deactivate, and send the equivalent to an activate button to the Bodnar board. The last part is the one I’m not entirely sure about. I have to see what the Bodnar board uses for button voltage (I believe 5V), so logically if I send 5 volts to the Bodnar board I should get an activate button right? Testing will tell.
If that works, I’m thinking about adding a hardware switch to turn on/off the force trim feature, so I can use the button without turning off the trim. For example in the F-4 the button to the left of the hat is the pickle button, and I don’t need a trim disconnect button. Flip the switch and fly the Huey where the same button is force trim disconnect.
I’ll add pictures of everything this afternoon when I have natural light versus kitchen overheads.
As you can clearly see, I decided to go with a vertical orientation for the power supply and control box. This has the advantage of decreasing the overall footprint and making the stick and whatever other controls I come up with easy to hook up. Almost all that wire spaghetti is going away slowly as I have finalized where I’m putting the Bodnar board that handles the “game controller” part of the equation.
Here you can see how the two panels interface. Yes it is probably the least elegant option I could come up with, but hey it works.
And here you can see the Bodnar board being positioned for the base to be glued to the stick shaft. The board itself screws down, so it’s removeable if need be. With this positioning, only the 6 wires from the hat switch, and 2 additional from the force trim button need to pass through the wooden board to the Arduino. Everything else (up to 32 buttons, and 6 axes) goes to the Bodnar board. I am going to braze a hoop on top of the screw adjacent to the balance spring for the wires to feed back up gracefully from the rotation sensors.
Pardon the mess in the background, I’m in the process of rearranging a bunch of things to have a better workspace.
To do still:
Drill a set screw and insert a set screw in the stick mounting piece. This allows for customizable rotation for any stick body, rather than one fixed orientation for all of them.
Clean up that mess of wires. There’s no need to have breakout boards now that I’m going with everything in that close of proximity.
See if my idea for having an arudino operated “pseudo button” works.
I’m so looking forward to see this in action…
It works quiet well for MSFS, getting the button part figured out from DCS was the main slow down (well and life in general). Going to the new B8 grip was a big help, as it’s a much better design (2 stage trigger, uses the same buttons at all locations, the switch for the hat switch is much easier to work with). I am hoping to have a chance to work on the Arduino part this coming weekend (Mon-Weds for me), and if it works as I’m hoping it will be flown in anger over the weekend
The next major project is pedals, which unfortunately the current setup doens’t lend itself to very well. I need to figure out a good mount for my chair, but a simple collective will probable be forthcoming in a few weeks too.
Decided to take a look at the force trim issue before bed.
The stepper motor controller has an enable + and - connections. The + puts out ~5v and when the circuit completes to ground the motors disengage (ie the stick is free to flop about). The Bodnar board as a ~5v potential across the two pins on the matrix board, when that circuit completes to ground it says “button active”.
If I am thinking about this correctly, shouldn’t I be able to just:
It’s 0315 local, so I may well have this completely wrong, but it seems reasonable to me right now.
Update:
After a few fits and starts, had a chance to sit down and really look at the problem. I decided to take advantage of having the Arduino, and use it to “pseudo button” inputs to the Bodnar board as I had discussed above.
In short two pins on the Arduino are hooked up to the Bodnar board in place of the two wires coming off a switch. The pins default to high, and when it detects the hat switch being pushed a particular direction it sets one of the pins to low generating a button activation on the Bodnar board. This allows for the hat switch to control the trim stepper motors as well as send an in-sim button press for things that have some kind of AP/SCAS (looking at you Mi-24). The same principle applies to the trim motor release, I wired the button to the Arduino so that when it reads the force trim release button it deactivates the stepper motor.
Yes I could probably do this with one wire, per button but preliminary testing was giving me one button erroneously on all the time. I’ll sort that out later.
Now to just wire it all up.