Community
Inventor Forum
Welcome to Autodesk’s Inventor Forums. Share your knowledge, ask questions, and explore popular Inventor topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Help making a train go around a track

38 REPLIES 38
Reply
Message 1 of 39
brandonherrer14
9221 Views, 38 Replies

Help making a train go around a track

I have been trying to achieve this for weeks and i really need help. I am in an engineering class and i need assistance in trying to make my train move. I have been trying to make a train that i made roll on a track. I have seen youtube videos of people who have made their train go around a track (I have the same dimensions as the people in the video through project lead the way). I have the train constrained to the track with a tangent constraint. I just need someone to instruct me (specifically) on how to make the wheels turn on the track (i know how to make the wheels turn, i just do not know how to make all the wheels turn in unison/together and how to make them actually move along the track instead of make the wheels turn in place. 

Thank You so much!

Here is a picturetrain on track

 

38 REPLIES 38
Message 21 of 39
JDMather
in reply to: JDMather

In many of your parts you have this extra geometry that serves no purpose that I can think of.

Then you create a new sketch and feature to remove it.

Why not simply delete?

 

I don't understand the logic?

 

Extra Geometry.png


-----------------------------------------------------------------------------------------
Autodesk Inventor 2019 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional


The CADWhisperer YouTube Channel


EESignature

Message 22 of 39
JDMather
in reply to: JDMather

On many of your parts you have done too much work and have duplicated dimensions.

If you use symmetry about the origin (as described in the document I linked), construction lines, equal, colinear and other constraints you can dramatically reduce the number of dimensions.

You should never have duplicated dimensions for symmetrical geometry.

 

If you want me to walk you through how I might create one of these parts I can do that - but you will have to take the trip with me.

 

duplication.PNG

 

(this should have been covered by your instructor)


-----------------------------------------------------------------------------------------
Autodesk Inventor 2019 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional


The CADWhisperer YouTube Channel


EESignature

Message 23 of 39

Oh yah, i did this before i learned about the beauty of planes. So, i can fix it.

 

Message 24 of 39

What is my next step in making the train go around the track?

Message 25 of 39
JDMather
in reply to: brandonherrer14

Have you fixed all of the parts?


-----------------------------------------------------------------------------------------
Autodesk Inventor 2019 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional


The CADWhisperer YouTube Channel


EESignature

Message 26 of 39
brandonherrer14
in reply to: JDMather

Dear JDMathers

 

I thank you for helping me

 

I kind of got it to turn so i will try the rest by myself.

 

You have really helped me and i thank you for all the help you have given me.

 

If i have anymore questions, i will ask you.

 

Again, thank you so much for the help

 

-Brandon Herrera

Message 27 of 39
HarryP108
in reply to: JDMather

OK I give up. Right now I am a defeated man. I have been trying for days and days now to get this train to go around an oval track - but with no luck.

 

Anyone had any success over the years in completing this, and if so any further tips?

 

Dynamic simulation? What joints are necessary, constraints etc. I have made the oval track as 1 piece and placed a surface extrusion at centre for a path, but that's me done.

 

By the way - I am not a student attempting to a complete an assignment - just a middle aged man who doesn't watch much TV at night.

 

Regards.



Inventor Professional.
Windows 10.
Message 28 of 39
karthur1
in reply to: HarryP108

Paul,

Something like this?  http://screencast.com/t/bdD6qToC

 

Attached is a really simplified example of what I think you are trying to do (2013 files).  To get the car to move, drive the "Drive me to make the car move" constraint in the "Track Pusher Arm" file.  Havent quite fugured out how to make the car run at a constanst velocity (notice how it speeds up in the turns). Seems like I have saw an example of that somewhere.

 

The key is to use the translational constraint and something to drive the car around (the pusher arm).

 

Kirk

Message 29 of 39
karthur1
in reply to: karthur1

Here is a video on how to make it go around the track at a constant speed.  http://www.youtube.com/watch?feature=player_embedded&v=DiBGYdbBPHo

 

This video is for a chain, but the same principle should apply.

Message 30 of 39
dan_inv09
in reply to: JDMather

In the first one I had an arm push the "train" around the "track". I'm pretty sure I posted this before, are you sure you looked at ALL the other threads about this homework assignment?

 

#2 was my attempt at modulating the speed around the corners from (wow, almost exactly) two years ago. The "drive this" constraint gives me a "cannot solve at this point" but I replaced it with another and was able to drive that one okay. The funky curve on the arm helps adjust the speed, I don't know how well - you might be able to play with the shape to get better results.

Message 31 of 39
karthur1
in reply to: dan_inv09

I got the PLTW Train2 constraint to work.  I suppressed the Translational:3 constraint, then edit the "Drive This" constraint to start 1 deg.  Now unspress the translational:3 and drive the "Drive Me" constraint.

 

http://screencast.com/t/lMrMsPzaoy

 

Kirk

Message 32 of 39
dan_inv09
in reply to: karthur1

Where'd the other responses go? I was going to respond directly to the post about the chain video, but it seems to have disappeared. Anyway ...

 

I looked at the chain video and the problem with that is it only moves the length of the bottom straight segment, it doesn't go all the way around. Because the chain goes all the way around you don't notice that no link travels the entire circuit. I made a rubber slat conveyor that would animate the distance between two slats and then repeat - you couldn't tell that one slat moved (I don't remember, let's say: ) six inches and then reset to move the same six inches again - it looked like it was going all the way around because of all the identical bits. Trying to get the train around is more complicated, you actually have to move one thing the whole way around, with the chain you can push one link in a straight line and we won't realize that it just got to the start of the turn. JD did something with Dynamic Simulation - he had a pin on the train that rolled around and drove against a surface, or something, I don't know how Dynamic Simulation works so I don't know what's possible

 

Message 33 of 39
karthur1
in reply to: dan_inv09

My message with the link to the chain video is still there.... message 29, on page 3.

 

You are right about the chain not going all the way around.  Your solution is probably easiest/quickest.

 

You get the constraint to work?

Message 34 of 39
dan_inv09
in reply to: karthur1

For me message 29 is:

 

Dear JDMathers

 

I thank you for helping me

 

...

 

 

I had gotten it working earlier with a new constraint, I didn't try "suppress, edit, unsuppress" (it's weird how the order of the constraints can be so important every once in a while).

 

The big question is how does it work with more than just my idealized cowcatcher, does the actual homework assignment have any cars?

Oh, and then we have to turn the wheels somehow - maybe a function of the driven angle? (Then we can zoom in and watch the wheel to see how close the spline on the pusher gets to keeping it moving at a constant speed - do we go so far as trying to get the inner wheel to turn slower? A toy might have a rigid axle, but I haven't looked at what the real models are supposed to be.)

Message 35 of 39
karthur1
in reply to: dan_inv09

Wierd.. that message is message #26 here.

 

I dont think it is a matter of the order of the constraints.  The angle constraint needs to be nudged a little.  For some reason it could not solve it at "Zero". 

Message 36 of 39
HarryP108
in reply to: karthur1

Thanks for the responses folks. Sorry for the delay - I am in Australia so obvious time differences.

 

I'll study the posts and have another crack at it tonight.

 

 

Regards.



Inventor Professional.
Windows 10.
Message 37 of 39
sars0209
in reply to: brandonherrer14

I am currently working on what I believe is the same project in class. Attached are three of the four videos I used to do the straight forward motion of the train along straight tracks. Follow these instructions and it should work 🙂

Message 38 of 39
sars0209
in reply to: sars0209

Apparently the files didn't show up but basically what you have to do is make a plane go through the center of the wheel. When I made the wheel the front view was set as the back on the view block and the plane was offest from the XZ plane. Then in the train engine assembly you constrain the planes on the wheels of one side of the engine so that they are at a 0 degree directed angle and do the same for two wheels across from each other. Go to the assembly with the straight train track and train engine subassembly. Click on the constrain command and select the Motion tab. Click the rotation-translation type and selct the edge of the track and the side of the wheel. Set the rotation to pi*(radius of wheel) with the appropriate measurements. The train should be able to move if you click and hold on the train engine and move your mouse back and forth. If the linkage arm doesn't move, right click the train engine subassembly and select flexible. 

If you want to make an automatic motion, flush the back of the train to the back of the track. Right flick the feature in the browser then select drive. Next to the cancel button is a button with >>. Click on that and adjust the increment number to adjust the speed of the motion and select the forward button to make the train go forward.

 

NOTE: This only works for moving straight along a track. I'm still trying to figure out how to do more complex motions with the train and track

Message 39 of 39

Hi! Purely based on the image you attached here, I think there is a workflow using transitional constraint and offset surfaces which should work for you. Please attach the files here or send them to me directly (johnson.shiue@autodesk.com). I would like to take a look and provide you with the solution.

Thanks!



Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report