Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Laser Etching a Stone Arch Bridge's Facade

4715 views
40 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2009
  • 1,983 posts
Laser Etching a Stone Arch Bridge's Facade
Posted by railandsail on Tuesday, April 21, 2020 3:22 PM

Laser Etching a Stone Arch Bridge's Facade

In the past I have spoken and posted a number ot things about building a Stone Arch Viaduct.
Some construction methods got pretty involved with molds and multiple plaster castings, etc, etc.

At this point of time I do not have the time, nor inclination to get that heavily involved with a true 3-d
replication. Rather I am considering a method somewhat similar to the mock-up method I utilized. I took a photo representation of a single arch, resized it for my needs, then made multiple paper copies that I glued onto heavier card stock paper, then trimmed with scissors, and joined together at preset seams.

I taped these temporarily to the cellular PVC frame roadbed/structure I had built to display the track's inclination.

As you can see I have MANY somewhat duplicate arches in the overall expanses of my

via-duct,..except in multiple heights from low to high on both sides.

This would involved a LOT of plaster castings !

 

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Tuesday, April 21, 2020 3:24 PM

Laser Etched Substitute

Next I took my scissors to those arch hollows to see what this might look like,...not bad.

 

My current thoughts are how might I substitute some sort of laser etched piece of plastic for those paper/cardstock pieces I used in the mock-up??

Lets just say that at the present moment I do not really need a total 3-d relief for those stone facades, just enough to represent stone faces, ….not the fully developed proud stone columns in between each arch.
 

This should be relatively easy, and quick for a laser etching of a thin (.040-.050”) piece of styrene plastic,...and just repetitious ?? The 'hollow' in the archway would be just left un-etched, then scissors used to cut out the hollow. The heights would also be adjusted by scissors. Perhaps the arches could be 'printed out' in groups of 2-3 rather than just singles?

 

That piece of thin styrene will easily bend to the curves of my roadbed. Perhaps some other plastic material might be suggested?....or thin sheet PVC to mate with the cellular PVC of my frame structure.
 

Can I find someone with a laser etching device willing to tackle this project ?? (correct me if I'm wrong, but it should be pretty simple as I have laid it out?)

 

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,024 posts
Posted by richhotrain on Tuesday, April 21, 2020 5:37 PM

railandsail
 

Can I find someone with a laser etching device willing to tackle this project ? 

Just Google 'custom laser-etching services'. There are a number of online firms that provide such services.

Rich

Alton Junction

  • Member since
    July 2007
  • From: Yorkton, Sk, Cnd
  • 441 posts
Posted by wvg_ca on Tuesday, April 21, 2020 5:47 PM

you should add a filler or liner to the arch inside, would look quite a bit more realistic

Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,200 posts
Posted by tstage on Tuesday, April 21, 2020 6:37 PM

And the more arches you have laser-cut; the cheaper each one will be per piece.  They might even have a forum you could join...

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    December 2008
  • From: Heart of Georgia
  • 5,397 posts
Posted by Doughless on Wednesday, April 22, 2020 7:14 AM

I think it looks pretty good as is, with maybe more honing of the color to look less gray.  Kinda looks like a simple black and white photo rather than a color image.  And I would think about adding some sort of liner on the inside.  Lots of dark shadows there, so you wouldn't see much detail at all beyond a few feet of the inside.

Many modelers are beginning to build structures in the same way.  Highly technical and crisp digital photos glued onto simple foam board.

If you listen to the mathemeticians in the room as it applies to scale, we probably would not see a lot of 3D texture from that real distance anyway.  So the cast type of arches probably have too much detail for what should be seen.  (Kinda like ballast, where modelers might want it more coarser than scale because it suits their eye) 

Edit: While the columns or pilasters in between the arches look good, you may want to try to add a bit of 3D texture to them.  Place a strip of styrene under the photos slightly narrower than the columns.  Then when you crease the photo around the column as you glue the whole thing, the column stands a bit proud of the remaining arch.  A little actual 3D texture if you want to go that extra step.

I think that if you cut the photo and then add somehting to it, it will show rather badly.  I'd want to photo to stay seemless by simply putting something under each column then wrapping the photo over it.

- Douglas

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, April 22, 2020 7:16 AM

I'd carve it all out of styrofoam.

Mike.

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Wednesday, April 22, 2020 8:27 AM

wvg_ca

you should add a filler or liner to the arch inside, would look quite a bit more realistic

 

I have been considering that arched liner, and perhaps that could be added later. That flat curved piece very likely would NOT have to be etched, etc,...just stock piece of plastic stone sheet

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Wednesday, April 22, 2020 8:31 AM

Plaster Castings vs Etched Taskboard

I've not worked with either so my questions might appear novice.
 

Wouldn't the plaster pieces have to be of a considerable thickness to be durable during trimming, handling, and mounting? Making the arch pieces curve compliant might also involve other problems with these rigid pieces? I assume it could also be a little messy and dusty?
 

I realize that it would take X amount of time for the laser etch machine to make each arch piece (or perhaps each 3-4 arch singular piece),...but isn't that just machine time? In other words it doesn't require a person standing by doing the process, nor reprogramming the machine for each piece? Thus the cost could be very reasonable?

Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,200 posts
Posted by tstage on Wednesday, April 22, 2020 9:15 AM

railandsail
I realize that it would take X amount of time for the laser etch machine to make each arch piece (or perhaps each 3-4 arch singular piece),...but isn't that just machine time? In other words it doesn't require a person standing by doing the process, nor reprogramming the machine for each piece? Thus the cost could be very reasonable?

There is machine time.  There is wear 'n tear on the [limited life] cathode and ruby, which would probably be reflected in the machine time.  There is the setup cost of the material with the machine, as well the drawing/programming of the CAD/CAM file.  All those combined can really add to the cost of a project.

Bottom line: It would probably be less expensive for you to purchase a decent 3D printer and print them up yourself.  You just have to determine if it's worth the investment.  You could also contact Shapeways and have them quote you on a 3D project to give you and idea of the cost.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    August 2005
  • From: Austin, TX
  • 1,752 posts
Posted by Don Z on Wednesday, April 22, 2020 10:22 AM

Not trying to be the wet blanket to this party, but do you think a railroad would really go to the expense of buidng all of those arches instead of using fill for the upslope until it reached the spot where the span is needed?

I know, I know...it's my railroad and I'll do it my way. Too many arches was the first thing that caught my eye.

Regards,

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,024 posts
Posted by richhotrain on Wednesday, April 22, 2020 10:37 AM

Don Z

Not trying to be the wet blanket to this party, but do you think a railroad would really go to the expense of buidng all of those arches instead of using fill for the upslope until it reached the spot where the span is needed?

I know, I know...it's my railroad and I'll do it my way. Too many arches was the first thing that caught my eye.

How about the Old Stone Arch Railroad Bridge in Minneapolis? 

There is a prototype for everything.

Rich

Old-Stone-Arch.jpg

Alton Junction

  • Member since
    August 2005
  • From: Austin, TX
  • 1,752 posts
Posted by Don Z on Wednesday, April 22, 2020 10:47 AM

I was talking about the APPROACH to the bridge.

 
Don Z

Not trying to be the wet blanket to this party, but do you think a railroad would really go to the expense of buidng all of those arches instead of using fill for the upslope until it reached the spot where the span is needed?

I know, I know...it's my railroad and I'll do it my way. Too many arches was the first thing that caught my eye.

 

 

How about the Old Stone Arch Railroad Bridge in Minneapolis? 

 

There is a prototype for everything.

Rich

Old-Stone-Arch.jpg

 

[/quote]

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, April 22, 2020 11:31 AM

I think it depends on what's on each side of the viaduct.  I think what Brian is doing is more like the approach to the St. Charles Air Line bridge, in Chicago.

 Air line bridge by WC4ever, on Flickr

From the very start of this viaduct, it's on a structure, and not fill.  This screen shot courtesy of RailStream's Chicago cam.

Mike.

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Friday, April 24, 2020 9:54 AM

Don Z

Not trying to be the wet blanket to this party, but do you think a railroad would really go to the expense of buidng all of those arches instead of using fill for the upslope until it reached the spot where the span is needed?

I know, I know...it's my railroad and I'll do it my way. Too many arches was the first thing that caught my eye.

Regards,

 

You have a point there Don, I just may have to take that into consideration.

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Friday, April 24, 2020 10:29 AM

Doughless

I think it looks pretty good as is, with maybe more honing of the color to look less gray.  Kinda looks like a simple black and white photo rather than a color image.  And I would think about adding some sort of liner on the inside.  Lots of dark shadows there, so you wouldn't see much detail at all beyond a few feet of the inside.

Many modelers are beginning to build structures in the same way.  Highly technical and crisp digital photos glued onto simple foam board.


You are correct there, I just mocked it out quickly with black and white printer. Perhaps a color printer would do a better job

 

 

While the columns or pilasters in between the arches look good, you may want to try to add a bit of 3D texture to them.  Place a strip of styrene under the photos slightly narrower than the columns.  Then when you crease the photo around the column as you glue the whole thing, the column stands a bit proud of the remaining arch.  A little actual 3D texture if you want to go that extra step.

I think that if you cut the photo and then add somehting to it, it will show rather badly.  I'd want to photo to stay seemless by simply putting something under each column then wrapping the photo over it.

I like that idea for making those columns 'proud'. And I would like to extend their height to form part of the 'hand-railing post'
 

 

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Saturday, April 25, 2020 11:50 AM

I have decided that I do not need that much detail on mine, and will likely go with just  good quality 'printed on paper stone work' with some sort of proud columns.

Wonder where I might find the best quality photo of that stone/arch facade to 'adjust/photoshop' to an image that can be repeatable reproduced like I did with my xerox copies for the mock-up?

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Saturday, April 25, 2020 12:05 PM

Not the same bridge as above, but I found this on a web site named Dreamstime , and I found these photos of the same bridge  which is in Janesville WI. used by the UP.

Like I mentioned earlier, I would carve them out of styrofoam.  It looks like only the side facing out would need to be detailed.

Mike.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,024 posts
Posted by richhotrain on Saturday, April 25, 2020 1:19 PM

Alton Junction

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Monday, May 11, 2020 10:38 AM

Downloadable Cardstock / Paper Patterns (help interpret)

Lets see if I have interpreted this website's info correctly?

https://www.modelbuildings.org/bridges-and-tunnels-pack-deal-c/
(there is a video presentation there also)

I believe it is saying that you pay a one time fee to download an image,...then you can make multiple copies of that image?

Is it saying you might print that image onto a variety of materials,...like for instance relatively thick cardstock?....or other material that you might get to operate in your printer?....or some material you might get to operate in a more modern type printer??

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Monday, May 11, 2020 12:54 PM

Just found this video/process,...I LIKE IT

Printable bridges & viaducts
https://youtu.be/5W4_n8HfSjc

no messy casting of plaster or plastics,...then no painting and weathering,...etc

I'm SOLD on this idea

  • Member since
    October 2006
  • 88 posts
Posted by trevorsmith3489 on Monday, May 11, 2020 12:55 PM

You might consider this company

https://scalescenes.com/product/r017-viaduct-arches/

Trevor

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Monday, May 11, 2020 11:51 PM

trevorsmith3489

You might consider this company

https://scalescenes.com/product/r017-viaduct-arches/

Trevor

 

I had some trouble naviagating their website, and I could not pull up a larger image of the stone face vs brick faces they offer?

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Tuesday, May 12, 2020 12:10 AM

I'm wondering if I can just use my own image to print out multiple copies I could mount to cardstock or slightly heavier styrene or PVC board.

I figure I could use this image (or a better one if available) modified to my required dimensions (6" inches from center of proud column-to-center of proud column).

Then perhaps make seperate images of those proud columns and wrap them around a circular piece of cardstock and paste them onto the flat faces such that they covered up the joints between adjacent arch sections.

Just have to find the best image to use as a master (if this one I have shown is not the best?)

  • Member since
    February 2009
  • 1,983 posts
Posted by railandsail on Wednesday, May 13, 2020 9:21 AM

I just received this photo in an email from a gentleman who maintains a large blog about the Thomas viaduct. I believe this may have to become my 'master' from which to make photocopies for my cardstock model.

I think the use of this image solves my 'color questions'.

Perhaps I should even trim the image so as to leave the inner portions of 'arch ceilings' in place even though they would not really been seen by a viewer from 'above'. ?? (they are just so representative of the real thing)

  • Member since
    September 2003
  • 21,326 posts
Posted by Overmod on Wednesday, May 13, 2020 10:36 AM

Late to this party.

One of the 'keys' to making this work is to use 'trompe l'oeil' techniques to give more "3D" illusion to casual viewing.  For that you will want to process the image a bit to get more contrast where the 'shadows' would be -- in general, the illusion that the surface is rough will be the 'best' thing, probably more than color fidelity.  Some one of many here who knows the ins and outs of image-processing software can guide you effectively.

In the black-and-white laser days I ginned up some things which I subsequently hand-tinted with watercolors.  (You can easily build up surface detail with appropriate acrylics or oils, but that wasn't in my 'skill set' then...)  Hand overpainting might still be an option in these inkjet-and-color-laser days if you want heavy black in the image.

If you glue the resulting laser-printed image on cardstock or foam you can tool the surface with a stylus for more 3D detail short of trying to carve everything on foam.  When I was young and more enthusiastic I briefly tried vacuum-forming a thin layer of printed film over a carved substrate ... didn't follow up, and of course 'hobby' vacuforming in general is now viewed with some safety horror ... wish that would change!

Don't try the forced-perspective 'leaving the inside arch detail' -- it only works from a viewing angle similar to the original, and is very obvious off-axis, in particular for typical model-railroad high angles.  What you could try is making a jig of some kind to use 'panorama' on a cell-phone camera to make a strip picture of the whole inside, then print that and use it on flexible material to form the arch.  Or just tile and do a little overpainting to hide the joints and repetition...

Yes, wrapping projecting detail with the paper stonework ought to work.  You will probably need a little touch-up 'filling' and painting, but that could probably be done with only 'weathering' or 'shadow' colors...

By the way, I haven't seen this in the discussion but it might be there: When you're done with part of the fabrication, spray well with a good damar/Kamar varnish.  You can overwork this with more detail, but it won't fray and pick up dirt and other crap to look dingy and fake with time.

Also incidentally: I like your use of 'scale detail' railing material; note that on the pictures, the 'lacy' railings draw the eye more than the strict stone detail.  This might be a place to invest in some etched railings, or even the technology to make them, as a little of the stuff on the 'right side' of the arch photo would dramatically show 'realism' even if your stone were substantially flat...

Incidentally, the whole issue of stone viaducts used for approaches might be technically interesting.  There would be a couple of time ranges (comparatively constrained) where a railroad would use this -- one period being the general age of Starrucca/Thomas where railroads 'built for the ages', ending somewhere between Bessemer steel and the era of the Phoenix Bridge Company, but having a resurgence on roads like PRR that didn't like the Lackawanna white concrete modernity style.  The thing is then that inclined stone-viaduct construction might not have the proportions and structure you are copying from other stone bridge types -- not that this is critically important, just that the design problems and material use for 'best' structure may be a bit different.

  • Member since
    December 2008
  • From: Heart of Georgia
  • 5,397 posts
Posted by Doughless on Wednesday, May 13, 2020 1:41 PM

railandsail

I just received this photo in an email from a gentleman who maintains a large blog about the Thomas viaduct. I believe this may have to become my 'master' from which to make photocopies for my cardstock model.

I think the use of this image solves my 'color questions'.

Perhaps I should even trim the image so as to leave the inner portions of 'arch ceilings' in place even though they would not really been seen by a viewer from 'above'. ?? (they are just so representative of the real thing)

 

Not sure exactly where you're going with this, but I would be careful to use a photo that has a 3D embedded angle of viewing into the image.  If you use the pic in its entirety, including the inner arch ceiling and walls, it will only look right on your model if you happen to be viewing the model at EXACTLY the same angle the photo was taken.  Which is straight on and below the peak.  On your layout, you will be looking at it from the top and sides most of the time (and the angle will change as you walk around the layout), so you should never see the ceiling of the arch, JMO. 

Therefore, any fixed 3D angle you paste onto the cardstock is going to detract from the model becauee you will never be looking at it from the same angle, yet the 3D imaged will always be fixed upon one viewing angle. JMO.

I would build a blank 3D model in cardstock or foam board, including arch ceilings and walls, then simply line them with a flat photo of the stones.  

For your front profile, I would keep it simple by trimming out the 3D innards and using the face on your face of the cardstock.

Short version:  Don't cheat by trying to get a 3D effect from a photo.  Build the viaduct in 3D and line it with photos accordingly.

Again, JMO.

 

- Douglas

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,277 posts
Posted by jjdamnit on Wednesday, May 13, 2020 4:42 PM

Hello All,

Check out this web site for patterns...

Textures.com.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,336 posts
Posted by MisterBeasley on Wednesday, May 13, 2020 4:46 PM

How many arches are you planning to need?

If you could either buy or craft one full 3D model, you could create a mold from liquid latex and cast more.  I did this because I needed thin tunnel portals.  I found it very easy to paint the castings with rattle can spray paint.  I find that Rustoleum's textured, speckled paint gives a very good appearance, and the painted Hydrocal castings can still be hand-painted with a wash of India Ink to deepen grooves, which lets you individualize each arch.

This can go quicker if you do one or two castings a day, and collect a bunch so you can paint a whole bunch at a time.

It takes an iron man to play with a toy iron horse. 

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Wednesday, May 13, 2020 6:09 PM

I've seen that bridge somewhere.  Actually I was stupid enough to walk across to see the monument on the other side.  1/2 way across, I realized I couldn't out run a train if one came along. 

Henry

COB Potomac & Northern

Shenandoah Valley

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!