Solved - How does the "rotators" jbeam section work? | BeamNG

Code:

    "rotators":[
        ["name","[group]:","node1:","node2:","nodeS","nodeArm:","wheelDir"],
        {"radius":1.05},
        {"brakeTorque":},
        {"parkingTorque":0},
        //{"propulsed":1},
        {"speedo" : true},
        ["FL", ["track_fl"], "trkfrmfl28", "trkfrmfl29", , "fhupl", -1],
    ],

So here is a section out of my tracks that I am currently making.

Essentially Rotators are set up kinda like wheels. I am running them in place of wheels, so thats why I have the Propulsed section commented out as the hubs kinda take care of that for me.

Essentially what your gonna do there though is set it up just like a wheel. So in your Powertrain code you should have somewhere where your specifying a connection to a wheel.

Code:

"powertrain" : [
        ["type", "name", "inputName", "inputIndex"],
        ["shaft", "wheelaxleFL", "gearHubFL", 1, {"connectedWheel":"FL", "breakTriggerBeam":"axle_FL", "uiName":"Front Left Axle", "friction":2}],
        ["shaft", "wheelaxleFR", "gearHubFR", 1, {"connectedWheel":"FR", "breakTriggerBeam":"axle_FR", "uiName":"Front Right Axle", "friction":2}],
    ],

For me this happens in the hubs... as you can see, for each side I have a "connectedWheel" and then I specify my wheel name. Naturally the FL and FR are generic wheel names, but you can name them anything you want as long as you have them named the same in the Rotators section and the Powertrain section so that it knows "what" exactly to power.

Code:

    "rotators":[
        ["name","[group]:","node1:","node2:","nodeS","nodeArm:","wheelDir"],
        {"radius":1.05},
        {"brakeTorque":},
        {"parkingTorque":0},
        //{"propulsed":1},
        {"speedo" : true},
        ["FL", ["track_fl"], "trkfrmfl28", "trkfrmfl29", , "fhupl", -1],
    ],

Coming back to this, the "Group" is exactly what it sounds like... the group of nodes you wish to send power too to actually cause the rotation. You set these up just like Flexbody node groups, and, in fact, on my tracks, they are one in the same. The nodes you are gonna want to send power to should "ideally" be the outer nodes of whatever your trying to rotate with as close to the same radius to 2 center nodes as possible. You don't have to do this, but for best results it is recommended.

Node 1 and Node 2 should NOT be part of that Group above. They are the nodes that whatever your trying to rotate should be centered around, and thus, where the torque is applied from (kinda).

NodeS... ehh... basically the same thing as a wheel... if your not running the rotator on a solid axle, don't worry about it. You might want to use it with a propeller though (unless you already made the beams manually). Essentially what it does is if you put a node number here, it will create a beam from every node in the Group you specified to that node for added strength automagically. I almost NEVER use this feature, but you can probably find it on solid axle cars. This not MUST be perfectly inline with your Node 1 and Node 2... if not you will end up with a mess. If you choose to skip it as I have here, then simply typing will turn it off.

NodeArm is basically where the torque from this thing will be applied to the vehicle. Usually this is like... where your brake torque is applied to... in your case it may be an outboard motor housing... ideally it is perpendicular to Node 1 and Node 2 rotational axis in space. This node may also need to be a bit weighty depending the kinds of torque you plan on running through your rotator, so keep that in mind. If something is spazzing out... its probably because this node isn't heavy enough.

Wheel direction.... I think you can figure this out but I'll explain it anyways. Set as a 1... load vehicle. If thing spins forwards then leave it alone. If thing spin backwards, set as -1. Job done.

Now I have a couple other bits in there as you can see.

Radius... this is mostly for getting your speedometer to read correctly (as you can see I have "speedo" set to "true"). For a boat of some sort... this probably really won't come in much use, so you probably don't even have to bother with it.

brakeTroque... for whatever reason my Rotators will not use the normal wheel brakes... I have no idea why, so I have it specified here. Same applies to the parkingTorque.

Propulsed... if you don't have it specified anywhere else in your powertrain, specify it here.

And that's pretty much it. Once you actually know what to do they are actually fairly easy to work with and very adaptable.