How can I animate an engine?

Hello, i am beginner here and trying to model 4 cylinder engine till now i have achieved bit of design and rotation of crankshaft and pistons, and I’ve added gears to crank for camshaft i have to animate my cameshaft and i have no idea how to animate pushrodes, rockers and valves with cam,

I have read all of the discussions but still not getting it and i am bad in english too.
Please help me.

Welcome to Blender Artists! Your question was unrelated to the topic where you posted it, so I moved it to it’s own place :slight_smile:

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Thank you.

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Hey, Welcome to BA !!
I have a bit of experience with this stuff - so much so I got tired of re creating these rigs so I built ‘Adjustable / Customizable’ ones, are you looking for something like this ? If you can post a file of what you have , that would be good.

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yes this is something i have been looking for, in my model i have tried to design 4 cylinder engine but i think i have stretched crank too much, i’ve made gears to connect crank to cam but haven’t connected them yet because i might have to change design of cam shaft according to firing order of engine, biggest problem is i don’t know how to make those valves open by camshaft without making animations to them and how to press spring of valves, i have tried to move pushing rode by cam using shrinkwrap constraint and it worked i have not included that in my main project i 've been trying it on my another file, i have just started learning blender from last 15 days i know that’s too early for me to make this kinds of projects but i love engines and mechanisms.

here’s my file,

sorry website didn’t allowed me to upload file directly saying i’m a new user.
i have tried to under stand mechanism i want in some conversations here but i really didn’t understood them because my english is weak.

thank you for your time i really appreciate your help.

That link will not work for me

Why, i checked link before it is working or is the any another way to send it to you.


I found this, it’s the exactly what i want.

Hey, sorry for the delay - website wanted me to register, done that too many times in the past. Maybe if you have posted enough by now , you can upload file directly here. I see you found something to possibly help you, hopefully it has a file. As far as the valvetrain animation goes - there is the mathematical approach and drivers which is the most accurate but the hardest to set-up, there is what I call the ‘Hybrid’ method which uses something to track the cam and copy that to a location object/bone that is keyframed, Then there is just keyframing, the thing most fail to do is use those ‘actions’ in an action constraint or they keyframe every object - engine parts of the same kind do the same thing, just at different / offset times, so one lifter location action could be used for all lifters and pushrods and even the valves with the proper rocker ratio added in.
As far as the springs animation goes, well that could be done several ways - my way was to create a shape key and painfully MOVE the verts to create a compressed state - it is very convincing at close-ups. Pic

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Yes i am new so i haven’t posted much stuff and i tried to understand the way it can be done by drivers it was way too hard for me there was some variable values wich i didn’t understood, but yeah i found another way it works same as that might not be accurate but it works and it’s prototype i haven’t modeled it yet i was just implementing constraints to know what happens and finally i got it i will see from my computer if i can post this directly.

Thank you.

rodecamrock.blend (815.3 KB)

i think i can upload now so here’s my both files one with crank pistons and one prototype of my came follower set please take a look and let me know, i know mesh is not neat and good but i am learning and i didn’t knew till last few days that cleaning mesh is that important

looks like engine 's file is too large to upload.
btw here’s google drive’s link if you can get it from there

Hey, The valvetrain file looks good - When ever your working with mesh objects it is best to ‘Apply’ scale and rotation before parenting or animating those items. The only thing I found was the shrinkwrap mod on ‘camdriverrode’ was set to ‘project’, I reset it to ‘Nearest Surface’ and I added a ‘Limit Location’ constraint to it (X & Y = 0 and 0 min/max), so it does not wobble around. You have this part figured out - but I will throw a wrench into your work, that has todo with Rocker Arm Ratio. Since that is never a 1 to 1 ratio, the use of ‘Copy Location’ constraint will no longer be the correct choice since it can only copy 100% or less and more is needed which it can not provide, that is where ‘drivers’ are a good choice.

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Hey, The constraint method is limited by a rotational handicap, so drivers are really the best choice - Ideally you want to use 1 transform to operate all the others.
I have put a file on Blend Swap under the Vehicle category > Engine Rigs is the file name. Since you are prob using Blender 2.8/2.9 you will have to ‘APPEND’ a ‘Group’ from the Group folder, please let me know if you have problems doing so.

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Thank you very much i will definitely check it out but i didn’t understood what you wanted to say in last yes I’m using blender 2.9 what does appends means and from where can i do this?

And as you mentioned above that youhave changed things can i get that file with you changes?
Thank you.

So in blender there is a backwards comparability, meaning you can not open 2.7 files in 2.9 version. To get access the the files content you open your version and under ‘File’ there is a menu with ‘APPEND’, you choose that option then navigate to the file location - click on it - open the ‘Group’ folder - select one or more (I would do just one) and hit the APPEND button

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Okay, And as you mentioned above that youhave changed things can i get that file with you changes?
Thank you.

Not sure which file you are referring to

My engine file which put link above from google drive.