29 replies to this topic

[CP-ephY]

B&M's up-stop wheels are naturally touching the track when moving straight and level.

[coastergeekrtc]

Here is a video of the CoasterDynamix prototype coaster that I posted earlier. As you can see it is very efficient because the track is rigid and the trains use bearings. If someone could make a similar design for the SS train I think it would really help. But I would also use a harder rail, the current tubing is too soft.

[poizone]

How much more rigid? I'm thinking that maybe some industrial tubing might work. I'm looking at McMaster-Carr right now actually.

EDIT: Can someone with a pair of calipers measure the OD and ID along with the gap for the track connectors?

[coastergeekrtc]

I have some, but...

- I'm at work.
- My Knex are at my parent's house and I won't be over there anytime soon.

I would suggest something along the lines of the CoaterDynamix rails. I'm not sure what plastic they use for the rails though or how hard they are.

EDIT: I would find the dimension of the current tubing and find a matching dimension on McMaster-Carr. Then select the one with the largest bend radius. That way it will be less forgiving.

[poizone]

The thing is I don't have CD. If I did, I'd go off of them. If you could give me a rough estimate of (Very Soft, Soft, Firm, Hard, and Very Hard) with (Very Soft) being a rubberband, and (Very Hard) being a steel plate, that would help.

[coastergeekrtc]

The CD rails would rate at probably Firm or Hard, while the SS tubing is Soft.

[poizone]

I think I got the correct type. The thing is that it's clear. I would have prefered something colored. Oh well. Part number is: 5181K31

Bend radius of 3" and the OD is 3/8". That's 1/8" larger than SS tubing, and should help the cars along a little more. Also, the price is quite low. $0.26 per ft. for 1-99ft and $0.20 for 100+ft.

There is also part number: 9349T1
Bend radius of 2.5", black, but much pricier.

[MP thrill rides]

^That sounds cool where do you buy it from? Do you have any pictures?

[coastergeekrtc]

Would that OD work with the current trains, or are you assuming that custom built trains would be used? I would stick with the current OD and ID so that the proportions are correct...the track might look weird IMO. Also, you wouldn't be able to use the larger OD tubing in the center for extra strengthening.

As for the tubing it would have to be slit so that you could fit it on the tie. I think that might be challenging. It can't just be a slit, you have to remove some material so that bumps do not form at each tie.

[poizone]

I meant got as in I found it. The website is http://www.mcmaster.com/

You just put the part number in the search box. They only ship to the U.S.

CGRCT: there is at least a 1/8" gap on standard trains. I believe it is more. The tubing should work fine. I'll run up to my attic to grab an SS car right now though.

There is only one problem now. The tubing is a solid wall. You would have to cut your own slit in the side.

EDIT: SS cars have exactly 3/8" of gap when the wheels are pushed toward the center of the track on their axles.