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

[bbussey]

June update:

Nothing to report on the physical pilot model.  Certain development aspects are still being debugged.  When the G32C gondola (which utilizes a similar design) goes into production, progress will resume on the LSG.

In the interim, all ACL lettering specifications for the K-7 have been secured from the ACL-SAL Historical society.  The MEC lettering specifications have yet to be secured.

Next update in early July.

[bbussey]

July update:

With all the back and forth on this model and the G32C, it's proving to be too much R&D to render the cars successfully on the ProJet 3000Plus and have the master easy to cast, even with the higher resolution.  So the strategy has changed to Plan B.  Mike Skibbe has had success with his Z scale models rendering them on the Perfactory, and the cost isn't much far off from repeatedly tweaking the ProJet.

The finish on large flat surfaces of Perfactory rendered models is smooth, so there no longer is any need for the etched brass insets.  The etching patterns were used to create the panels in the solid model, and they were added to the core.  This design is so the two halves of the rubber mold can be poured easily, without having to worry about the mold line separation.  It is designed as a two-part press-fit mold — but the parts may not fill entirely, even under pressure.  It may be necessary to inject the resin into a sealed mold in order to get all the parts to fill.  The extra runners extending from the perimeter are to allow for a number of potential entry ports from which to inject.

As you can see, all the surface detail is now part of the master.  This beta version has been submitted for quote to get a ballpark cost to render the Perfactory tool.  Small details that remain to be added are dimples for the grab iron holes and vertical brakeshaft mount.  The stirrups, brake platform, top chord corner reinforcement plates, and brakewheel platform still will be etched brass, while the floor will be brass sheet stock.





Next update in August.

Total hours invested to date:  33
Total material cost expended to date:  $257
Projected unit MSRP based on current material cost:  $6.85

[up1950s]

Wow , this has turned into a real PIA for you , sorry , and thanks for all this efforts so far .

[Chris333]

If you can do that much design work why not just CNC cut 2 pieces and have them injection molded? (not that I have any idea how hard that would be)

[bbussey]

Wow , this has turned into a real PIA for you , sorry , and thanks for all this efforts so far .

The cost remains manageable so far, and the MSRP is still below the threshhold.  Figure another $10 for OEM parts (trucks, couplers, brakewheels) and contracted parts (box, foam nest) added to the current number to have a rough idea of the final price.  Again, this is an example of what it takes to develop a new product.  So it's good for everyone to see what it takes.  This is not outside of the norm, especially for this type of specialty item.  Injection-molded products have their own set of issues, given that most of the work is sub-contracted out.  Best-case scenario to create an injection-molded freight car model from scratch and get it to market without any issues is a year to 15 months ... but there never is a situation where there are never any issues because you are dealing with outside contractors from different countries and different cultures.  I've never had perfect injection test first-shots, and I've never had perfect painted/printed sign-off models on the first attempt.

If you can do that much design work why not just CNC cut 2 pieces and have them injection molded? (not that I have any idea how hard that would be)

Design work doesn't cost me anything other than time.  The way the mold master currently is designed, injection-molding isn't possible.  This is designed for a two-part rubber mold.  It would take a lot of time/effort to CNC a brass mold, beyond this year.  Then, securing slots in the schedule of San Juan Car Shops, my contractor for that type of work, would be problematic most likely given that the American Limited core kits remain unavailable.  But that's an idea for down the line, as it would cost me less to CNC variant G26A and G26C side tooling from brass and have SJC run parts and ship them to China than to contract China to cut the new sides.

[wcfn100]

and the cost isn't much far off from repeatedly tweaking the ProJet.

I've been biting my tongue on this, but have been wondering where the crossover might be to just go with the Prefactory.  The success of this could really open some opportunities for small runs of cast cars or shells - for me at least.


Jason

[bbussey]

Taking cost out of the equation, Perfactory is always preferred.  But cost is an issue, as is finding a contractor that has some familiarity with our industry.  There is a Perfactory shop 15 minutes from me.  But they aren't nearly as versed in what we need as Mark 4 Design is and they are costly.  Finding a contractor outside of the States that isn't literally on the other side of the planet and is not cost-prohibitive (for these types of small projects) is a challenge, but not impossible.

However, the Perfactory option becomes the more sound solution with every failed ProJet attempt, as repeated failures there add up as well and the presence of the wax support structure becomes less of an advantage — particularly when the master can be designed to not require any support structure, as is the case with this lastest LSG master.

[wcfn100]

However, the Perfactory option becomes the more sound solution with every failed ProJet attempt, as repeated failures there add up as well and the presence of the wax support structure becomes less of an advantage — particularly when the master can be designed to not require any support structure, as is the case with this lastest LSG master.

Well you have my full attention from this point forward.  With your experience, I'm hoping you can set some rough guidelines in regards to the costs and quantities needed for someone like myself to make a small run of freight cars.

Mark says I have to rebuild my NE5 for his machine.  I could do it as two pieces, but with this thread,  maybe a flat kit is a better option.

Like I said, full attention.  Thanks for doing this.

Jason

[skm]

Like I said, full attention.  Thanks for doing this.  Jason

^^
This

[bbussey]

August update:  The gondola masters are now designed for output on a Perfactory machine.  Objects must be arranged on the tray so the number of layers is minimized in order to build them economically, as the rendering time has a far greater impact on the cost than the amount of resin used.   All of the contractors I've contacted have the machines with the small build tray, which has a footprint of only 3¼" x 2½".  A build tray with those dimensions limits the amount of N scale projects that can be built economically.  The gondola masters are 5" x 6¼" x ½" combined.  Building layers equal to 6¼" by standing the parts on-end instead of ½" laying flat clearly is not an option.  Perfactory does have a large tray option, which has a 7½" x 5" footprint.  The masters will fit on the large tray, but finding a contractor that uses a Perfactory with the large tray has been problematic.  I've contacted EnvisionTec, manufacturer of the Perfactory equipment, to see if they have any documentation on contractors having the large tray machine.  So the project is in a holding pattern until that information is known.

The rendering of the masters on the Perfactory will be a significant cost of this project.  Expect the expended cost to triple at least.  This will push the eventual MSRP into the $20s.  The projected kit yield remains at 50 pieces, unless there is an indication of heavy demand here which would push it higher.  A higher kit yield would lower the MSRP, but not to the point where it would offset the Perfactory cost.

Next update in mid September.

Stages remaining:
• Rendering of masters on Perfactory
• Rendering of rubber molds of Perfactory masters
• Rendering of polyurethane resin castings from rubber molds
• Procurement of OEM parts (trucks, couplers, body details, decals)
• Milling of brass floors
• Die-cutting of foam nests
• Printing of paper inserts
• Writing the online instructions

Total hours invested to date:  35
Total material cost expended to date:  $257
Projected unit MSRP based on current material cost:  $6.85

[skm]

Thanks for the update Brian,

I'm in the dark over half the processes that you are discussing, but that is what google is for! 
I'm learning s.l.o.w.l.y

[bbussey]

I forgot to mention – all the dimples have been added as drilling guides for the holes for the grab irons and the vertical brake staff mounts.  The push-pole pockets also were modified.  A few minor corrections remain to be done, but essentially the casting master is done.

[garethashenden]

Any updates on this project?

[bbussey]

Haven't been able to locate a Perfactory contractor with the larger build tray in North America or Europe, and it would be far too expensive to build the master on edge vertically.  DKS suggested an option for rendering on the ProJet which I will try, but that will take some modifications to the digital solid file.  The ProJet contractor I use also had their equipment out of commission in September for maintenance, and they had a backlog to work through.  I was notified yesterday of shipment of some parts that had been submitted in late August.  So there may be a progress update posted in November.

[bbussey]

January 2014 update:  It's been a while, but there have been some interesting developments in the interim.  My ProJet contractor has refurbished their equipment, and the results have been extraordinary.  Because of this development, it opened up another more viable path to rendering the LSG master.  The XHD rapid prototype arrived yesterday, and the detail is exceptional on both sides.  A heptane bath awaits, then it's off to casting sometime in February or March.



The runner is designed so that the resin can be injected with the two mold halves in place.  The multiple "injection" points are to find the best entry point for filling the mold.  In essence, this will be a resin model, but it will be created as if it is injection molded.  That is the theory anyway.  Click on the pic for a zoom-in view.  With a Perfactory master no longer required, the cost remains manageable.

Next update hopefully in late February / early March.

Stages remaining:
• Rendering of rubber molds of ProJet master
• Rendering of polyurethane resin castings from rubber molds
• Procurement of OEM parts (trucks, couplers, body details, decals)
• Milling of brass floors
• Die-cutting of foam nests
• Printing of paper inserts
• Writing the online instructions

Duration of project to date in actual time:  50 weeks
Total man-hours invested to date:  37
Total material cost expended to date:  $307
Projected unit MSRP based on current material cost:  $7.67