I am trying to make the landing gear of the Boeing 777. As I understand, on the -200 variant the trucks are able to rotate freely for about 10-15 degrees when the gear are extended. So, the back hangs down about 15° on approach and then it becomes perpendicular to the strut on touchdown. However, there is a little peculiarity when the landing gear retracts. The trucks begin at a 15° tilt, then an actuator moves them into their “normal” perpendicular position before they are retracted into the belly.
However, if you use a rotator to do this in SP, the gear will not be able to rotate freely when the aircraft is rotating on the runway. (The 777-300 is slightly different)
As far as I know, no one has yet rotated the trucks on retraction on a 777 in Simpleplanes. They mostly are completely free-rotating and are still rotated 15° or so while retracting into the belly. The first thing I tried was to put a selection operator into the “speed” attribute of the rotator but it only accepts numbers, not strings.
So, does anyone have a potential solution to this? I basically need a Mechanism/FT expression that uses/controls a rotator/piston to rotate the gear but can also be moved to a “passive” state which allows free rotation.
@NaziParty Er… I haven’t touched it in a few months. The main thing that held it back from being released last summer was the artificial horizon. If I find a way to solve those problems and people seem to want the plane, I would consider working on it in the first half of this year.
@GalacticaAsia thanks for the advice and sorry for taking so long to reply. I originally had a similar setup to your A330 where the back was weighted to cause the tilt. I have since added a spring and piston per the advice of PlaneFlightX and it works pretty nicely. I’ll definitely be looking out for your control base method when you post it though. Sounds interesting!
how is the Cessna 206 Stationair going
You can try using 2 rotators, one thats floppy and another to rotate the other rotator/landing gear. To achieve gear tilt in this setup you could add weight to the back or edit the 'centerofmass' on a part. Best example for this is on my a330/a340's; here is an example
It's also possible with control bases, setting it to 'wheel' then make variable with the landing gear code(If gear tilt starts flat be sure the code starts at +1/-1). Then enter the variables name as the input, the 'scale' will handle the gear tilt angle and you can leave the rest. Then go xml edit the control base's 'slepMaximumForce' as it handles how stiff/floppy this setup can be.
I will provide you an example for the control base setup when I post my reworked/updated a330/a340's
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@PlaneFlightX– Thanks, that works quite well! I should have known by now that your SWL-120 has a similar feature.
Below is the best way to do it
I don’t think the preset rotation variable can contain FT
I use a piston to push the spring downward, while keeping the hinge free spin at all times.