Coaster Designing

[TheBannedKid]

I know that Inventor isn't an animation program, I'm saying you are using it as if it were one, because I don't see much engineering savvy in your designs.

 

I can start with the wheels and axles. I understand if you just made some mock wheels to show off the assembly, but coaster wheels are a much more complicated assembly than a block of metal with an outer coaster of urethane. The axle should be pinned in place to ensure it does not rotate. As the train traverses the track the wheels will spin very fast. With the tight tolerances between the axle and wheel assembly the axle will begin to rotate...and with the weight of the train the axles will wear at the points of contact with the frame. Also, the bolt through the axle is going to wear on the frame and greatly weakens the axle at that point.

 

Now I assume the wheel assembly pictured is a side-running wheel and/or upstop wheels. If so they will not run the length of the track as well as an independent spring loaded system for each wheel. Your current system does not seem to take in consideration forces perpendicular to the spring axle (See the first picture). The wheels won't always have the same forces pushing on them at the same time. As the train approaches a turn, one wheel will push in/out before the other. With the assembly only able to compress along the spring axles, one wheel will lift off the track as well as one axle will take a lot of force perpendicular to it's axis. This is assuming that the axles are fixed at their current angle. You can fix this by allowing the spring axles to rotate at the wheels, but then the alignment of the wheels could potentially be a large tolerance of a few inches. I don't see any way of keeping your current system.

 

As far as the track, the ties should be one piece and they are very flimsy and there are too many. I guess you would need that many to compensate for how flimsy the ties are.

 

I don't know, I just don't see anything great about this project yet. It seems to me that you are designing from an enthusiast's point of view and not an engineering point of view. That's not going to work.

[where'smyhotdog]

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[TheBannedKid]

0.5" is not going to cut it. That is sheet metal compared to a coaster. Most ties vary from 1-3" thick. The profile of the ties are flimsy too...you can't have them narrow down so much or else they would snap.

[coasterlover420]

^Absolutely. B&M's ties are even a little more than 1 inch, even though they look thin and flimsy. Half an inch will buckle way too easily. It's not enough to support thousands of pounds of train. Go to a theme park sometime and look at the track inside the station up close when you're in the front of the line. On Intamin tracks, the ties are 2 inches thick. And from the looks of the ties, you need to get them out of the way of the up-stop wheels (or whatever you're doing with the wheels...) and have them continuous between the two rails for stability. There should be one tie per two rails, if you get my drift. Look at a B&M coaster and you'll see what I mean.

 

Another thing, which isn't necessary, but adds to the stability and controlability (yes I know it's not a word, but I'm at a loss of words, sorry) of the train, you should round out the outside of the wheels to conform to the curvature of the rails so the wheel fits to the rail rather than sits on it. You'll see this primarily on Intamin trains but sometimes on B&M's, and it helps a lot with keeping the train on the track laterally. Also, the wheels look rather thick and heavy. Try lightening them up along with the rest of the wheel assembly. Look at Top Thrill Dragster's wheel assembly. It's stable and light-weight.

 

ALSO, I know this is going on and on, you should put a bit more space between the top track and the bottom track for supports, especially if you want them to come out the sides, because if there's only as much room as you've got, then I'm seeing a problem with clearance concerning the up-stop wheels and with the strength of the supports you can fit in there. They'll have to be quite strong.

 

Concerning the use of Inventor, I would not suggest it. AutoCAD is much more precise and simple, which is why you see engineers using CAD much more than Inventor. Inventor is pretty much only for making 3D models and for presentation. You probably don't have it, but it would most likely be better for designing roller coasters. But Inventor IS better than nothing, so keep it up!

 

Oh, and it's spelled A-X-L-E...an "axil" is part of a leaf

[where'smyhotdog]

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[coasterlover420]

I was talking about the thickness as well. Half an inch is NOT enough. It should be more like an inch+.