Code 40 to Code 55 Transition Joiner

[C855B]

Since I've been having really good luck holding thin sections and fine tolerances with the Photon, I thought I'd try my hand at a C40-to-C55 rail joiner. I needed something quick since I'm getting into laying yard trackage on the layout. It worked. You might notice that its no taller than the C40 flex spikes, and running a variety of cars proved that anything already OK on C40 is good with this joiner:





Well, it sort of worked. Regular resins are entirely too brittle for this, breathe funny and it shatters. I went through all 15 of the print run before getting these two to behave. Nonetheless, it confirms the dimensions and concept in general. I have a bottle of the Siraya "ABS-like" resin on order (thank you @timwatson ), so we'll see how that goes.

A couple of minor tweaks in mind are a little more meat on the insulation divider and maybe 0.020" additional length on the C55 side. Once it's proven with the new resin I'll post the final STL file for those interested.

[ednadolski]

Does it work with both Atlas and ME C55 rail?

[C855B]

Yes.

[timwatson]

Happy to help Mike, good luck. After reading your post which Siraya Tech did you get? Was it "Fast"?

[wazzou]

Only curious, but why the gap?

[C855B]

Happy to help Mike, good luck. After reading your post which Siraya Tech did you get? Was it "Fast"?

Yes. Fingers crossed.

Only curious, but why the gap?

Not intentional, or, rather, not the plan. For this test I was reticent to jam the C55 side fully in because that was the point I was breaking the other joiners in the batch. I was on the last pair and wanted to confirm flange clearance. I'll know more when I get the "ABS-like" resin, and make any final adjustments then.

[narrowminded]

Yes. Fingers crossed.

Not intentional, or, rather, not the plan. For this test I was reticent to jam the C55 side fully in because that was the point I was breaking the other joiners in the batch. I was on the last pair and wanted to confirm flange clearance. I'll know more when I get the "ABS-like" resin, and make any final adjustments then.

Here is a link to the approach I used on my code 55 to code 40 adapter for tie strips.  It's easy and works really well.  It also builds in a smooth height transition from the code 55 to code 40 within the first few inches past the joint.  https://www.therailwire.net/forum/index.php?topic=48446.msg645365#msg645365

[C855B]

Your approach was certainly thorough and a high-quality modeling result.

In my build-out, the long-term plan calls for ~200 of these C55-C40 transitions. So my objectives are simplicity, process clarity and the ease-of-use of a basic joiner. It's got to be quick and brainless. If there's any added effort with this approach it's needing to throw a small slab of .010 plastic under the C40 for support near the joint. Done.

Which reminds me... it amuses me that ME "Code 40" is actually 0.044" tall. If I had assumed 0.040", there would be a perceptible bump at each joint.

[narrowminded]

Which reminds me... it amuses me that ME "Code 40" is actually 0.044" tall. If I had assumed 0.040", there would be a perceptible bump at each joint.

I have a fair amount of the code 40 rail and it all measures .043" high so your number is consistent with that.  I've also heard others mention both of these numbers so it's not an anomaly. 

[learmoia]

Would stability be improved by making it a tie insert? Vs individual rail joiners.

Take 2 ties out of your C55 and 2 ties out of the C40..

Then the design the transition as a 4 tie solid piece.

[C855B]

That's the essence of what Mark did, although he extended the "ramp" a couple of more inches on the C40 side.

Let's see where I get with the joiners alone. Aside from the brittleness issue I expect to solve, so far it seems to be an effective solution. If you are imagining something similar to Atlas' insulated joiners, I can understand why you'd think there'd be a good bit of slop. We're talking about harder plastics here.

[learmoia]

No, I wasn't thinking rubber stiff, I was thinking spread the joint forces and  transition over a larger contact area with more material under and around the joint to make the brittleness less of an issue.

(Though, I've never worked with ME track, I assume its stiff and holds a curved shape.. so once you have it formed, there shouldn't be many forces in the joint... vs Atlas flex having a tendency to want to be straight/kink at the joint if not laid carefully.

[C855B]

Nine (9) months later:



This one works. Same STL file as the last try in March, but new resin, Anycubic Flexible Tough; clear in this case. It didn't "bloom" nearly as much as the Siraya did in the Photon so the fit is slightly loose, which works well with the tolerance in handling. Not brittle at all. Again, it works. Finally.

The STL is on my server: http://www.everywherewest.com/C55-C40_Joiner_1.3.stl

[Erock482]

How does the anycubic flexible tough do on detail and cure times? messing with the sirya blu I always found the quality to be lacking and increased cure times needed

[C855B]

Can't really speak with any authority. Tonight was my first experience with it, and the batch came out perfect on the first try! The joiners were sharp and like I said, there wasn't any problem with bloom or overexposure or whatever the problem was with the Siraya. I post-processed in an Anycubic Wash and Cure 1.0, 4 minutes each cycle, and there was no noticeable residual stickiness.