Union Pacific FEF-3 4-8-4 Northern type steam locomotive, by Smokebox

[BNSFdude]

Piston should move with how fast air gets sent into the BC. It should also be variable with the PSI in the BC.

[mrennie]

Piston should move with how fast air gets sent into the BC. It should also be variable with the PSI in the BC.

Yep, I have the animation attached to the engine brake psi, so it should move a corresponding distance, but I have to tweak the animation speed (a parameter in the LUA script). I've got the left-hand brake animation done now (it was pretty complicated, not just a matter of mirroring or flipping the right side ... I had to do the animation all over again). Now I'll tweak the parameters and post another video.

[BNSFdude]

Should be a slight delay between application of the brakes and the movement of the BC needle and air pressure increasing.

[mrennie]

Should be a slight delay between application of the brakes and the movement of the BC needle and air pressure increasing.

Yep, that's already done

[GLRX12]

I'll see if I can get you some video of the 1203's brake cylinders in operation tonight or over the next few days. While the cylinders are smaller and its a more modern brake system, its still the same idea, and you can see the movement on the side of the trucks.

I think your animation is a little on the fast side.

[bpetit]

Mike and I were talking about having a snowy version for winter routes such as Donner Pass. What do you guys think?

[mrennie]

I'll see if I can get you some video of the 1203's brake cylinders in operation tonight or over the next few days. While the cylinders are smaller and its a more modern brake system, its still the same idea, and you can see the movement on the side of the trucks.

I think your animation is a little on the fast side.

In my latest experiments, I've slowed it right down so that it moves at exactly the same rate as the change in engine brake air pressure, which does look much better. I'm interested to see your video, thanks!

[mrennie]

Mike and I were talking about having a snowy version for winter routes such as Donner Pass. What do you guys think?

I have a iist of novel things I'm going to try with the FEF-3, which I won't reveal until closer to when the loco is ready to be released, to keep them as a surprise

[slick204]

You realize, you're making it very difficult to be patient!

[mrennie]

You realize, you're making it very difficult to be patient!

How does the saying go? "Good things come to those who wait" or something like that

[mrennie]

Another work-in-progress shot of the trailing truck, now with its leaf springs and about half of the cabling ...

2013-05-30_00002s.jpg

[CSX2057]

Tell me about it!

[GLRX12]

You realize, you're making it very difficult to be patient!

That's not gonna make it get finished any faster....

The R&D part alone on the scripting is going to take a huge amount of time. Let alone actually finishing the scripting

Also, I'll try to get you a video of Shay 9's air brakes, which is an 6ET system (844 has an 8ET), and the cylinders are closer in terms of size.

Realistically speaking, the piston should fully extend with the first 10psi or so, any additional pressure on the brake cylinder only acts to increase pressure against the wheel. Remember, there is no braking without contact, so the contact should happen fast. The only thing that changes the piston travel is worn out brakes that either need new shoes, or a brake adjustment in the rigging.

Was not sure if you knew or not, but I figured I'd throw it out there for your, and everyone's benefit.

[slick204]

You realize, you're making it very difficult to be patient!

That's not gonna make it get finished any faster....

Sorry, I was just joking around. I hope Mike knows that. I have no problem waiting for it to be done.
I have his Consolidation and it's very entertaining to run.

[mrennie]

You realize, you're making it very difficult to be patient!

That's not gonna make it get finished any faster....

The R&D part alone on the scripting is going to take a huge amount of time. Let alone actually finishing the scripting

Also, I'll try to get you a video of Shay 9's air brakes, which is an 6ET system (844 has an 8ET), and the cylinders are closer in terms of size.

Realistically speaking, the piston should fully extend with the first 10psi or so, any additional pressure on the brake cylinder only acts to increase pressure against the wheel. Remember, there is no braking without contact, so the contact should happen fast. The only thing that changes the piston travel is worn out brakes that either need new shoes, or a brake adjustment in the rigging.

Was not sure if you knew or not, but I figured I'd throw it out there for your, and everyone's benefit.

I had a suspicion that the piston would have to move during the initial part of the brake application in order to start to push the brake shoes up against the tires, just like you said. Thanks for confirming that. I'll modify the script accordingly.

You're right about the length of time it takes to do the scripting. An advantage I have this time is that there's a lot in the Consolidation's script that I can use again.

Sounds take a long time to get right too.

Looking forward to seeing the video!

Cheers,

Mike