I’m having an incredibly hard time getting this mesh to rig properly, according to the diagram. I want the upper half (blue) of the pantograph to swing up, restricted by the bones that connect to the triangle plane (green) that is at the bottom (stationary), but I need the above triangle piece (red), to go up with the second half (blue) of the panto.
The problem is, that when the upper arm (blue) swings up, the end triangle piece (red) does not go with it. And when it does, it is supposed to maintain a position vertically upright. The attached diagram that has already been embedded and scaled for this rig’s purpose shows how the rods and linkages (which I’ve failed to model) are supposed hoist the red triangle upright, vertical. In the diagram, this is number 3.
Can anyone help?
Below is the file with diagram, to see it in action, slide the ‘PULLERMAIN’ bone along the y-axis. It should already be selected. To unhide all bones, press ALT-H in Object Mode.
First, the rig’s a mess. It needs to be consolidated into a single armature, and things need better names. Otherwise it’s just a hassle for someone else to figure out how it’s working. That said, here’s the quick and dirty fix…
The object arms2.001(the triangular piece) needs its origin set to its pivot point(3D cursor in screenshot). Then select armature.001 and go to pose mode. Select arms2.001, and shift select the “upright” bone of armature.001, then Ctrl-P and choose Bone Relative. Then add a limit rotation constraint to arms2.001, and turn on the X limit.
The only thing I am not sure about, because I cannot see it on the drawing, is how Item 3 is constrained on the left hand end, so I had to guess at it for now! Any more info could help here. :yes:
SkpFX, I tried joining the bones already; ended up up with a parent-looping error, I’ve parented some armatures to the pivot rods since I can’5 get them to rotate.
Clock, thanks for the rig, funny as I was going through my old Blender posts to find out how to rig this, and you’d helped me on a rig around 2 years ago! A quick question, how did you get the bones to appear as thin, non-obstructive structures?
Also, there is a small linkage that attaches to the rest at rod #5’s left pivot, and the rod #3 connects there. If you scroll out in the .blend you can see the top part. I also think I have top view diagram set up.
Okay Clock, here’s your homework, show me how to have the train rigged to follow a curve, and have the pantograph rigged to follow along on the curve overhead. If Hector had AC power, just imagine the flashing lights you could add.
Lots of IK chains and so forth - really quite straight forward (NOT).
Now the overhead wires - these are never a curve, but a series of straight lines around the curve, between the anchor points on the posts - this is why the pantograph head is quite wide, so it never comes off as the train is going around the curve and passing the straight sections of the wire - he said being a bloody-know-it-all :yes:.
The pantograph does go up and down in relation to the train as it is sprung onto the wire and the wire is not always the same height above the rail. So for this I would have the IK target in my rig tracking along the wire and constrain it not to move along the train longitudinal axis. That would obviate the need for the scalable “operator” bone and put control with the wire instead. Now, some “smart-arse” is going to say “How do you lower the pantograph if the IK target is tracking the wire?” (come on some “smart-arse” say that please). Well that is easy, you just set the tracking constraint influence to 0 and move the IK target downwards to the stowed position.
Would you like me to build a little rig to show this and a two bogie electric engine going around a curved track?
Cheers, Clock.
PS. Think I may have had too much “pop” today I appear to be getting a little frivolous…
I haven’t a single clue what your latest post is about, but I can safely say that your pantograph rig is absolutely fantastic! A true timesaver, even though I’d spent last night hours in front of the screen trying to process these odd mechanics.
And, indeed, the last time you’d helped me was the brake rigging. It wasn’t exactly 2 years ago, more like early summer 2015.
Thanks,
Ron
EDIT: Just a quick question? How long do rigs like these take you? You seem to be gliding through these with full ease, and do a great job while at it.
Thanks for the compliments! Your rig took me around 45 minutes to build - a lot of that is interpreting the drawing, which has inaccuracies in the various poses of the pantograph. You can see these as you move the rig over the drawing, the drawing wasn’t done with CAD so these things often occur and the rig is a compromise of the various positions. I do a lot of these mechanical rigs so am well practiced. I worked as a Mechanical Design Engineer at the UK Railway Technical Centre in the late 70’s - early 80’s before going into IT - so that helps.
The main point with rigging these things is to reverse what happens in real life, so I concentrate on what the head of the pantograph is doing and work backwards from that to get the pieces to flow correctly. I worked the main parts first then added the constraining/operating rods afterwards. It really is a case of breaking it all done to manageable small pieces.
A simple IK chain of two bones with a scaleable third side making a triangle is the basis for many mechanical setups and a good one to remember.
It’s very impressive that you’d worked for British Railways, no wonder you hit the nail on the head with these railway rigs!
Which branch did you work in, as in which component of the wagons/locos? I still have to rig the front window wipers, I could do it if I had a name/brand/make for the wipers that were used on most locomotives. I can’t find a closeup image/shot of wipers, but I’m yet to model them so I’ll cross that bridge when I get to it .
I worked in the research centre (RTC) at Derby - on Locos, Freight and Carriages - I even worked on the APT at one time. Which power unit are you modelling? I cannot remember which locos/powered carriages this particular pantograph was used on. I will try to find some wipers for you when I get back home after my week long holiday. :RocknRoll:
@SkpFX - Ref: My Homework - sorry I could not post this yesterday - I have been out all day and very busy yesterday also. :yes:
Here is the best I can do to get a two bogie railway vehicle rigged to go around a curved track with the pantograph tracking a realistic overhead wire setup - i.e. a series of straight lines as it is suspended above the track. I used to do these drawings for real to test the body/underframe was always “in gauge” - it involves a great deal of maths, especially if the two bogies are on different curve radii on the track. Blender is NOT able to do this automatically with ANY rig, but this setup gets close. Of course the caveat on my last statement is “unless you do some very complex maths with drivers and Python scripts to get it 100% accurate” I reckon I am well under a 1% error in my rig.
Here’s the blend file: train.blend (982 KB) As ever with my rigs - just press Play to see it working - I have set it up to run from the Camera so you can see what is happening as the carriage goes along the track.
Of course feel free to pull it apart, or make corrections/suggestions and ask any questions you like. I have not made the wheels go round :spin: on this rig as I have explained how to do this so many times here before…
Cheers, Clock.
EDIT:
I should also say that no rail track would ever use such tight radii as I have used here - but modelling realistic rail track does not show how the rig works very well, so I made the curves a lot tighter.
You amaze me Clock. I was proud of myself for using google to figure out what a pantograph was. I’d probably have to go to Seattle or Portland to find an electric train. I’m in Spokane. We tore out our last electric train in 1929, opting instead for the miracles of fossil fuel. The Great Northern Railway, that’s a Spokane invention. That’s diesel-electric. Diesel-electric is awesome. It’s electric, but it still smells like a real train.
Thanks for the compliments my friend - don’t “real” trains smell of coal, steam and hot oil though? Having said that the fastest train in the Uk for so long was Diesel-Electric - the HST, which manages 125mph. This was powered by two power cars, one at each end equipped with 2250Hp V16 diesel engines driving generators. I was standing behind one such engine doing some test when one of the con-rods came out the side of the engine - and the side of the loco. My colleague and I got splattered with oil, water and diesel fuel - all of which was quite hot!
So here in the UK we now have all electric trains that go faster, operating on the line from London to Paris via the English Channel Tunnel, but all the old gits still prefer steam engines, such as “Flying Scotsman”, anything else just isn’t right apparently…
I grew up in Dogtown. That’s “the other side of the tracks” in Hillyard. Spent a lot of time getting chased out of the railyard, by cranky men who were put off, seeing kids enjoy themselves. I can certainly see the romance of the old steam engines, but I have trouble trying to image them shaking the neighborhood, like a diesel in the switching yard can.
Used to ride Great Northern’s Empire Builder back and forth to Seattle and Portland. I love traveling on the train. But this is the U.S. It’s only me and four other people like riding the train. People want their cars. I like getting on youtube and checking out the narrow boats on the UK canals. You guys just do fun transportation better than we do.
You’re a true blessing to someone who has absolute zero roots in UK Railways that wishes to model UK locos.
I’m not modeling a ‘unit’, per se, as in a DMU or EMU. I’m modeling a locomotive, the BR Class 85, which shares identical profile with the BR Class 81, both of which operated on the West Coast until the late-80’s-early-90’s time period. These pantos were used, however, on BR Class 81-87, which I’m sure you’d not have seen, since Derby isn’t electrified.
I really do appreciate you helping me with the wipers, though! Thank you very much for your help.
The wiper basically is a parallelogram arrangement, that can be rigged by using an IK rig. If I get some time before I go away later today I can make a quick armature for you, otherwise it will be when I get home next weekend. Doing the washer pipe will be more advanced, I normally use a Bezier Curve with a Bevel Object and Hook Modifiers to bend the curve as the wiper operates, although in 2.78a Blender you could try Bendy Bones.
Just press Play to see the animation :eyebrowlift: Any questions, just ask here, but I may not be answering until next Saturday.
You just need to make the rest of the metalwork and “bone” parent them (Select Mesh, SHIFT Select Bone in Armature - key CTRL+P => “Bone”) to the appropriate bone in the rig.
Thanks again for that rig, but this is for a simulator, having to model the wire that connects the wiper would cause far too much lag and slow down operation.
Speaking of lag, do you know if modeling a spring that fully contracts/expands slows down an animation? These are the springs that connect to the initial bar that the shaft is balanced by (see item no. 6 on the diagram of the panto). There’s a tutorial on YouTube to model this, so I’ll have a go myself, in the case that it isn’t too resource-hungry.
Okay Clock, here’s your homework, show me how to have the train rigged to follow a curve, and have the pantograph rigged to follow along on the curve overhead. If Hector had AC power, just imagine the flashing lights you could add.
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