Tangent Joint Between Wheel and Rail

[Anonymous]

Is it possible to create a tangent joint between a rail and wheel as illustrated below - so that the wheel will roll along the rail? 

I probably should have chosen a simpler model to start my foray into Fusion 360, but what the heck - I am working on a railroad handcar that I based one of my older tutorials on.

http://www.textualcreations.ca/Flash_Gallery_V16/images/Railroad%20Handcar%20Tutorial_1000.jpg

http://www.textualcreations.ca/Flash_Gallery_V16/images/Railroad%20Handcar%20Tutorial%20Hardware_100...

[O.Tan]

Hi,

Currently Fusion doesn't have a tangent joint, but here's a workaround to achieve what you want (see the screencast link attached), though it's more clicks then one would want. The workflow might be slightly different if you're working in a timeline environment but you should be able to figure it out, keep us posted if you're having issues 😉

http://autode.sk/1KsPD1C

[Anonymous]

Hi, AFAIK the purpose of the coning on loco wheels is to centralise the two wheels on the track when running in a straight line but also to give a differential action to the wheels when they are going round a bend.
When the two wheels are going round a bend the centrifugal force pushes the carriage and the wheels outwards so that the outer wheel is riding against the flange and on a larger diam, and the inner wheel is riding on a smaller diam......the two wheels do not fit exactly in the track spacing or gauge specifically for this purpose.
The purpose of the flange is to prevent the wheels from riding off the rail.
I learned this in 1958 when I served my apprenticeship and worked on loco equipment.....correct me if I'm wrong.
Ian.

[O.Tan]

yeah, the method I provide will not work if you're dealing with sweeps/curves and Fusion at this moment doesn't have constraint along path movement.

It's possible to do some hacks to make it work, but it'll probably take awhile to get it to work.

[Anonymous]

Thanks Omar,

I had seen that video but it didn't look like it would work on this model. Maybe I can add a couple small flat faces on the parts to better simulate the plane and the cylinder in the video. It is not like it needs to be perfect for this exercise.

[Anonymous]

Hi Ian,

You could very well be right about how it works. I was not too concerned about that aspect during the initial modeling. It certainly make sense not to have them ride exactly as I have shown since the track would not have the kind of tolerance that would be needed to ride this tight.

[O.Tan]

Mine is a much simplified model but I'm certain it'll work.

If you don't mind, add me to your project (omartan90 at hotmail dot com) and I'll see if I can make it work for you.

The thought process is you would want your joint origin to match with wheel, so you'll want to offset your joint origin till it match the rotating wheel axis.

[Anonymous]

Thanks for the offer Omar. Let me give it a try this evening to see if I can figure it out. If not, I will be more than happy to take you up on your offer.