Best Of ACL MEC low side gondola , interest ? ESM please read .

[bbussey]

Well, considering that the three BLMA truck styles are the only ones on the market that meet all five criteria of prototypical width, prototypical ride height, a centered bolster hole, having low-flange metal wheels and being readily available, it's academic.  I'll concede that ESM has access to all manufacturer truck-frames regardless of whether or not they are available to the general public.  But the BLMA products would be the truck-frames of choice regardless, and it makes little sense (for this type of resin kit model and for mass-market products) to design any model to accept a variety of truck bolsters when there is no N scale standard that they follow.

Regarding the coupler pocket, the same reasons apply.  It would make more sense to lobby Micro-Trains to introduce an N-scale coupler that features the Z-scale knuckle and thumb, as it would cost them less in development costs to bring such an item to market than it would for an all-new coupler design in either scale  - which is one reason they have standardized on the #1015/1016 and #2001/2004/1019 for their standard-length and extended-length coupler knuckle/thumb, and why other manufacturers have standardized on the #1015-style coupler box.

There are two end styles that were utilized on the gondola prototype.  The flat ends with the horizontal strengthening rib were on the prototype as-built, and were replaced with dreadnaught ends when the cars were rebuilt.

[skm]

Thanks for the reply Brian! 

I understand and agree with you regarding the BLMA trucks, the design with the lowered bolster will hopefully become the defacto standard in the future. I had forgotten about the offset bolster hole on the MT trucks. That is certainly a deal-breaker! I was suggesting a detachable cylinder/washer that fits between the underframe and the truck,
I was not aware that the prototype used ride control trucks, I can always grind down the underframe to suit different trucks if that is my bent. (and turn a blind eye to the incorrect truck placement)

The MT N couplers continue to be a problem, and until someone comes up with a better solution, I will use their Z couplers. I'm just a little sad to destroy the nice cast on coupler pockets to do so. Some of the latest releases (BLMA G31s, Atlas PS1s) make this almost impossible or, at least, too much work to be worthwhile.

Thanks also for the info on the ends, I have plenty of books on the PRR (and color guides on many others) , but find it difficult to find much prototype info (online) on many of the other local roads.

[bbussey]

The cars probably didn't use A-3 trucks.  But they currently are the best trucks out there, and they are the proper width in addition to height.  Most N scale truck frames are too wide, by a lot.

Washers cost extra money that can be utilized elsewhere in the project.  N scale MTL couplers may not be your preference, but they are not a problem by any means.  They remain the best couplers on the market, even with the oscillation issues.  You will be on your own regarding Z scale couplers because, as with all ESM rolling stock, the N scale coupler pocket based on the #1015 box will be integrated into the body component rather than as a separate attached coupler box.  This is especially helpful with flats and gons because it provides the means to secure the box lid without the screw protruding through the floor top.  You will have to drill/tap a 1/16" thick steel floor plate if you want to body-mount Z scale couplers on this model.
 

[skm]

Thanks again Brian,
I appeciate the dialogue!

I'm sorry I wasn't too clear on the MT couplers, they are not a problem per se, I just prefer a more to scale version. That's just me!
I've managed to convert most of my locos and freight to Z couplers, some easy, some not so 
The process of body mounting couplers with those products that have truck mounts usually means having to grind away part of the underframe and I have found that the Z couplers are then a perfec fit (without interfering with the axles)

I just learned something about trucks too... I've never measured the width of N scale trucks, and good to know that those from BLMA are to scale in more ways than one!

Would these gons have been found all over, or would they likely have remained in home territory?

I look forward to your continued progress on this project.

[wcfn100]

Would these gons have been found all over, or would they likely have remained in home territory?

You could probably work these into any region without too much of a stretch, but my take on these low side gons is that they were for large heavy non-uniform type loads like large rocks/boulders or tree stumps, things like that where the low sides made loading/unloading much easier.. With that said, I think some were converted to container service as well.

Rock from the SE was hauled everywhere, even if this wasn't the most common way to do it.

Maybe someone will have more specific information.

Jason

[up1950s]

ACL K7  O scale model with many views during and after build .
http://davejfr0.blogspot.com/2009/12/st-charles-model-works-acl-k-7-gondola.html

Another ACL K7
http://steamerafreightcars.com/images/modeling/models/golden/acl91776.jpg

[bbussey]

Second session.  Work done in between the snow shoveling.

The transformation of the Etrl model dimensions into digital form is complete.  The floor cross-members and bolster placement are incorrect on the physical model and were corrected on the digital model to align with the side ribs.  The flat ends were separated from the rest of the body in preparation for the design of the dreadnaught ends.



Time to reduce the scale of the digital model from HO to N.  Since it is a digital vector-based model, this doesn't affect additional extruding in any way other than measurements.





Adapting the model to N scale also begins now.  The walls were now only .17mm thick, which is roughly .007" and way too thin.  They were beefed up to .020", which is the maximum possible without interfering with the inside face of the dreadnaught ends.  A thickness of .030" is what I normally use for injection-molded models.



As it turns out, neither the corrugation pattern of the XIH nor the X58 were close to that used for this prototype, and I already knew the G26 was very different, so the dreadnaught ends had to be created from scratch.  Time-consuming yet necessary.  Because this is a gondola with visible insides, the profile for the inside face was needed as well.



Due to ESM projects in various stages of design that have required or will require one of the BLMA-designed trucks, the company graciously supplied a digital mock-up of one of the 75-ton trucks some time ago.  This digital model was imported temporarily into the gondola model to see the two components in juxtaposition.



The bolster profile had to be extended .015" to meet the truck frame (as shown above), and had to be widened at the center to have a large enough footprint to sit on the truck.  So that the visible areas of the bolster remained to prototypical scale, the bolsters were given a diamond-shaped profile.



The current digital model sitting on the virtual BLMA trucks.  The ASF Ride-Control was used as the guide, but the A-3 truck design shares the same specifications.



Total hours invested to date:  5
Total cost expended to date:  $0

Next step is creating the center sill housing and integrating the Micro-Trains #1015 coupler box, fishbelly center sill and hopefully one of the existing stirrup designs.  Currently I'm waiting for sample parts to arrive from Oregon in order to virtualize them and see if they can be incorporated into the model.

[wcfn100]

  The floor cross-members and bolster placement are incorrect on the physical model

Do you have a drawing for the MEC car that shows this?  Because the ACL and Seaboard gondolas are like the model where the cross members aren't on center with the ribs but line up with the rivets on one side or the other.


From what I've seen of similar gondolas, the model may be correct.


edit: N&W G-14 gondolas are the same way, off set to the side.

http://www.nwhs.org/archivesdb/detail.php?ID=2905


Jason

[bbussey]

That's easy enough to correct if that is the case.  I'll re-position them based on the ACL drawing.

[skm]

Awesome Brian!

Seeing this process is what makes modelling so challenging and interesting.

"Total hours invested to date:  5
Total cost expended to date:  $0"

You probably should talk to your accountant before deciding on such a low price for your time. 

[Ed Kapuscinski]

This is seriously one of the coolest things I've read online in a long while.

Thanks for doing this Bryan!

[bbussey]

Third session.  The sample parts arrived from Micro-Trains.  In checking the various assortment of stirrups with the calipers against the digital model, the 105000-series gondola version could be adapted the best.  Those stirrups and the diecast fishbelly centersill were then virtualized. 





While the 105000-series gondola stirrup was the best fit, it was too narrow.  So the kit directions will include cutting the part down the middle so it will be properly arranged.

With the fishbelly centersill digitized, the housing could be designed into the body.  The straight centersill will be a resin part designed to fit into the same cavity.  The Micro-Trains #1015 coupler pockets are in place at the proper height.



The housings and nubs to hold the stirrup halves are added, and the coupler pockets are integrated.  The .032" thick brass or steel weight will fit between the stirrups, and the etched faux floor will cover from end to end.



The coupler pocket with ample clearance for the back of the #1015 coupler parts.



The model assembly at its current stage ... with the body, flat ends, fishbelly centersill, stirrups and trucks in place.








UPDATE:  I changed the assembly to contain two configurations, to save time.  To simplify matters, the MEC configuration has the straight centersill and flat ends, while the ACL configuration has the fishbelly centersill and dreadnaught ends.  This will streamline assembling the remaining components for both variations so that efforts aren't duplicated.  The physical model will still be a mix/match of parts so that any era can be represented.  Digital MTL #1015 knuckles also have been added, to help with visualizing the final models.







Next update sometime this weekend.

Total hours invested to date:  10
Total material cost expended to date:  $0

[Philip H]

Brian,
That's well done.  I'm more inclined to get one or two then before - and I was already in for one no matter what!

[up1950s]

Love them Bryan , let me know when you want the money for my 10 cars .

[Chris333]

Love the step-by-step, and jealous of the 3D