Weekend Update 6/10/18

[Bulbous]

First post with some models in it for me. I spent this weekend catching up on some Sn3.5 narrow gauge kits I had floating around, and got them halfway there. This is Western Australian prototype (cape gauge) and runs on HO gauge track. I am looking at moving into TTn3.5 which will be the same prototype but running on N gauge track. These kits have been fun, but the resin has been interesting to work with. I am starting the 3D modelling for the TTn3.5 wagons, and already have a few old DD40's and U50's to donate their three and four axle bogies for new chassis.

The four kits I was working on - (l to r) FD louvre van, KA open wagon, D van (New Zealand version) and GC open wagon:
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Working on some underfloor details, but nothing much there yet. Will be sorting out some more brake piping and brake shoes for the wheels:
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The DD40's will donate their four axle bogies to provide the centre four axles on a couple of models of the WAGR X class diesels:
https://2.bp.blogspot.com/-tdxbIK32GKA/Vwl7bfKI6yI/AAAAAAABZx4/Tz6vVOgSZkEdOhnOa_FNhdSO6AFjxfEVg/s1600/WAGR%2BX1001.jpg

The U50 will donate the three axle bogies to a model of a WAGR F class (or similar):
http://www.railheritagewa.org.au/archive_scans/albums/upload/print_P01001-P01200/P01169.jpg

I know the models are not N scale, but I will be working with TT scale on N gauge track soon!

Cheers,

Matt

[nkalanaga]

Vacuum brakes?  Do you know how they work?

One thing I've long wondered about vacuum brakes.  The ones used in the US were automatic brakes, the vacuum released the brakes, letting air into the lines applied them.  Hand brakes worked the same as always.  But how did one "bleed off" the brakes for switching?

With automatic air brakes, releasing all pressure from the cylinder and reservoir releases the brakes, and the car has only hand brakes, perfect for kicking it around the yard.  But I can't see any way to do that with a vacuum.  And if the hand brakes RELEASE the brakes when applied, and allow them to work when released, that would be a safety hazard, as someone could forget to enable the automatic braking in a train.

[Bulbous]

From Wikipedia:

"Release valves are provided on the brake cylinders; when operated, usually by manually pulling a cord near the cylinder, air is admitted to the upper part of the brake cylinder on that vehicle. This is necessary to release the brake on a vehicle that has been uncoupled from a train and now requires to be moved without having a brake connection to another locomotive, for example if it is to be shunted."

Brake diagram with the brakes released and the brake pipe "charged":


Brake diagram with the brakes applied via air accessing the brake pipe:


I would think that the release valve mentioned above may be the ball valve on the lower left side of the two images showing the brake operation.

Thanks for the question, it got me to have a proper look at the operation of the vacuum brake cylinders!

Cheers,

Matt.

[fcnrwy23]

It’s all good. You do realize by finishing the C39, you just guaranteed that ScaleTrains will announce that engine at the NSE convention next week...

YAAAAYYY!!!  That's ALL Right Than!

Though, I would like a "C32-8" FIRST!!!!

Jerry G.

[bbussey]

Finally finished three LSGs, one for me and two for the company display case.

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[nkalanaga]

Matt:  Ok, that makes sense.  Just like on air brakes, you can close the angle cocks on the ends of the brake pipe, trapping the vacuum inside, which would leave the brakes released, then open the release valve, which would allow air into the outer chamber, helping to keep the piston down.

Eventually, the air will leak into the brake line and inner chamber, equalizing the pressure, and the brakes will apply anyway, but that will take awhile.  In service, the vacuum in the outer chamber increases the effect of air entering the inner chamber, allowing the brakes to apply harder.

I don't think the ball valve is for the release.  It would be used if the car sat too long, and the vacuum "bled off", allowing air to leak into the inner cylinder.  When the car is next connected to a vacuum source, the ball would rise, allowing the air in the outer chamber to be sucked out, restoring the vacuum.  The release valve doesn't seem to be on the diagram.

Very interesting.  I always assumed vacuum brakes were more like straight-air brakes, with a simple, one-chamber cylinder.

[chuck geiger]

Like A Bridge Over Troubled Water!

[central.vermont]

Finally finished three LSGs, one for me and two for the company display case.

Those look great Bryan!!! Sure do wish I could put mine together. Had to pack everything away.

By the way did you sell all the kits? I have three but would like to get another.

Jon

[PAL_Houston]

Test fitting the load. 24.5” long.
(Attachment Link)

I really like the mile-marker on your fascia.
Please can you tell us more about how you made it?

[diezmon]

Working on a GN oddity.

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[chuck geiger]

[nkalanaga]

Diezmon:  The Hutch Caboose?

[craigolio1]

I am once again a seasonal modeler 

Been working on my VW pretty much everyday. Got the air ride all done. I drew some mounts up with CAD and had them cut in steel with a CNC plasma cutter    I got the body back on the frame and just minutes ago started it for the first time. The lighter green background color will be the body color... someday.

That's incredible!  I wish my '70 Ghia Convertible looks 1/10 as nice as that. Alas, she's going to get worse before she gets better. The body is about ready to come off. Needs the bottom 12" done, and more.

Craig

[jpwisc]

I really like the mile-marker on your fascia.
Please can you tell us more about how you made it?

I used Signomatic. It was a few bucks per sign, but worth t for me for the clean look. Now I have to go back and add my finish coat of black paint to the fascia.
https://www.signomatic.com

[wcfn100]

Peteski:  As far as I know, no, the draft gear is fixed.  I THINK, but an not certain, that the springs are to keep slack from running in/out too fast.  My AAR Interchange Rules book lists various types of draft gear, including "friction", "rubber", "rubber friction" and "transverse spring and rod", which this one seems to be. 

It does not say what the various devices are for, probably assuming that anyone inspecting or repairing the car would know that.  Unfortunately, I've never been. or known, a car inspector.

I forgot about this thread when I was out of town.

The draft gear is Cardwell.  It's a friction draft gear, the springs help apply the friction to the coupler to aid with slack.  This type of draft gear was good for heavier cars and were shorter than other draft gear styles.

Jason