A snapshot in time. A glimpse of the Plettenberger Kleinbahn in 1/22.5 scale.

[finescalerr]

I'm a perfectionist. So when somebody does something terrific, I want everybody to be able to examine every bit of it. Sorry if somehow that conflicts with "art" but it is nonetheless the ultimate compliment. -- Russ

[Hydrostat]

And now to something completely different with a quote from the 1985 "Runaway train" movie:

"I don't care about engines. I don't wanna loose the bridge!"

Phew, sometimes a good transition is hard to find. It's been more than 5 years since posting those pictures of the first parts for the bridge.








Some four weeks ago I got a shipment from Frithjof with the rest of all milled parts. It was fun to do some 'heavy metal' after all the housework (pun intended). One reason for that long hiatus was not knowing how to do all the rivets. We started successful attempts with pressing in different material thicknesses from 0.5, 0.8 and 1 mm, but this wouldn't work with the angle sections running alongside the bridge for some reasons: The idea was to mill grooved strips, press rivets and then kink them into angle sections on the leaf break, but this doesn't work without damaging the pressed rivets. Using brass rivets wasn't an option according to the sheer amount, too. Aside of the costs this would have meant to insert two milled rivets into each bore hole because they're all visible from both sides - to the risk of having them popping out when soldering the parts. In the end I decided for a simple, but a bit labor-intensive solution. 





And this is what it looks like at the moment. Length is nearly 75 cm.














Next step is sandblasting, burnishing and painting it.


Cheers,
Volker

[Ray Dunakin]

Very impressive!

[finescalerr]

I'm sure that took almost no time, effort, skill, or artistry to create. So why has it been so long since your last post? -- Russ

[Bill Gill]

I'm at a loss to come up with what to say. What an impressive build!
That's a lot of rivets and they look good.

[Hydrostat]

I'm sure that took almost no time, effort, skill, or artistry to create. So why has it been so long since your last post? -- Russ

Well, I took my time to prepare the reading matter for our esteemed wordless readership, trying to cater their every whim.

To be honest: my motivation to write comprehensive texts is not so very big due to the fact it developed more and more to a one way communication with a lot of readers and very few interaction and I don't really feel like presenting all the stuff for free to silent consumers. I have no need for self presentation, I'd rather have discussion and exchange of ideas and the less it becomes, the smaller my motivation gets.

Here we go:

I first planned to have those pressed rivets on folded angle section, as mentioned before. This meant to have separate vertical strips of same material thickness, carrying the short vertical angle sections at the bridge's sides. Since I decided to use another method Frithjof came up with the idea to mill the lateral parts as some kinds o ladders, which means a much less number of parts and assembling work. The following picture should explain how the longitudinal 'angle section' gets together in the end.





All inner edges of those 'ladders' have a radius remaining from the mill's cutter diameter:





This needed to be filed away. The later 'angle section's' visible outer edge should have a slight radius as prototypical angle section does. Since they are made from nickle silver it was hard to sand them down. The following picture is from this first attempt, but it gives an idea of what I wanted. Later on I used a file swaying it the 'wrong' direction and then sandpaper to smooth the edges a bit more.





All bore holes got the final rivet heads' diameter of 1.5 mm. Small segments of 1.5 mm brass rod are going to serve as rivet imitations. It takes some force to press them to position. This is very helpful for the later steps because it brings some stability and keeps the rods in position without need of clamps. Needing some twothousand rods Frithjof made a fenced jig for his mechanical jar to cut 5 rods at one time.





1.4 mm stainless steel screws helped to position all parts to be soldered as a 'sandwich' later on.





Cheers,
Volker

[5thwheel]

How do you round off the rivet heads?

Bill

[finescalerr]

One reason we have "wordless" readers is that not everyone qualifies to post a message here. -- Russ

[Les Tindall]

That is phenomenal!!!  Better than the real thing - I can barely imagine the amount of work that has gone into it.  The forum is definitely the place for inspiration

Les 

[Lawton Maner]

     The round rivet heads are the easy if not a terribly boring part of the job.  Once everything is soldered and cleaned there is a line of Swiss milling bits used by jewelers (and truly anal modelers myself included) which fit a Fordom or Dremel which will mill the dome shape for you, one rivet at a time.  A project like this will require several weeks of quiet rest in a sanatorium beside a lake in the country once completed. 
     A bit of planning must go into the assembly so that once everything is soldered you can still get to both ends of the rivet.  some rivets need to have one end finished prior to pressing into place so a spacer block needs to be prepared to see to it the rivet protrudes just so on the blind side.
     If need be the project can be broken down into smaller bites and assembled in stages starting with hard silver solder.  The rivets can be addressed with micro-bits of soldering paste and torch soldered on mass once ready.  Each sub assembly can then be added to others with lower temp silver solders working down the ladder to the specialty solders sold by Carr's in England.
    Applying the paste solder with a syringe means less is used and clean-up is easier.  Here in the US a drain cleaner called "Liquid Fire" which is an 18 molar sulfuric acid makes a cheap and available pickling solution.
    Just my way of doing it and by the end of this project I expect to learn others.

[5thwheel]

     The round rivet heads are the easy if not a terribly boring part of the job.  Once everything is soldered and cleaned there is a line of Swiss milling bits used by jewelers (and truly anal modelers myself included) which fit a Fordom or Dremel which will mill the dome shape for you, one rivet at a time.  A project like this will require several weeks of quiet rest in a sanatorium beside a lake in the country once completed. 
     A bit of planning must go into the assembly so that once everything is soldered you can still get to both ends of the rivet.  some rivets need to have one end finished prior to pressing into place so a spacer block needs to be prepared to see to it the rivet protrudes just so on the blind side.
     If need be the project can be broken down into smaller bites and assembled in stages starting with hard silver solder.  The rivets can be addressed with micro-bits of soldering paste and torch soldered on mass once ready.  Each sub assembly can then be added to others with lower temp silver solders working down the ladder to the specialty solders sold by Carr's in England.
    Applying the paste solder with a syringe means less is used and clean-up is easier.  Here in the US a drain cleaner called "Liquid Fire" which is an 18 molar sulfuric acid makes a cheap and available pickling solution.
Just my way of doing it and by the end of this project I expect to learn others.

Cup burs? Have a set of 12 from Rio Grande in USA.  Use them a lot but have problem with the bur bottoming out and leaving a mark on the base. I use a little hand held rotary tool like a Dremel.  Perhaps it I set up my little mill I can better control the depth but yes it is boring to do several dozen rivets at a setting. I am so amazed at this work shown on this thread. Bill Hudson

[finescalerr]

After studying the photos carefully all day, I think I found one rivet with a machining mark at its base! -- ssuR

[Hydrostat]

How do you round off the rivet heads?
Bill

Bill,
please see below.

One reason we have "wordless" readers is that not everyone qualifies to post a message here. -- Russ

Russ,
you're a mensch.

That is phenomenal!!!  Better than the real thing - I can barely imagine the amount of work that has gone into it.  The forum is definitely the place for inspiration
Les 

Les,
it was less than I was afraid of for years.

     The round rivet heads are the easy if not a terribly boring part of the job.  Once everything is soldered and cleaned there is a line of Swiss milling bits used by jewelers (and truly anal modelers myself included) which fit a Fordom or Dremel which will mill the dome shape for you, one rivet at a time.  A project like this will require several weeks of quiet rest in a sanatorium beside a lake in the country once completed. 
     A bit of planning must go into the assembly so that once everything is soldered you can still get to both ends of the rivet.  some rivets need to have one end finished prior to pressing into place so a spacer block needs to be prepared to see to it the rivet protrudes just so on the blind side.
     If need be the project can be broken down into smaller bites and assembled in stages starting with hard silver solder.  The rivets can be addressed with micro-bits of soldering paste and torch soldered on mass once ready.  Each sub assembly can then be added to others with lower temp silver solders working down the ladder to the specialty solders sold by Carr's in England.
    Applying the paste solder with a syringe means less is used and clean-up is easier.  Here in the US a drain cleaner called "Liquid Fire" which is an 18 molar sulfuric acid makes a cheap and available pickling solution.
    Just my way of doing it and by the end of this project I expect to learn others.

Lawton,
unfortunately I'm lacking a sanatorium as well as a lake. It took four weeks to build the bridge, but rounding the rivets (some 2.500) didn't take much more time than 5 or 6 hours. The annoying part was pressing the rods into the holes. I soldered all parts, no brazing involved. I took pictures of all steps and I'm going to show them bit by bit. It's funny, that doing iterative work is often associated with mental health problems. Indeed it's contemplative.

Cup burs? Have a set of 12 from Rio Grande in USA.  Use them a lot but have problem with the bur bottoming out and leaving a mark on the base. I use a little hand held rotary tool like a Dremel.  Perhaps it I set up my little mill I can better control the depth but yes it is boring to do several dozen rivets at a setting. I am so amazed at this work shown on this thread. Bill Hudson

Bill,
please see below. I think the twin cut tools are the best, much better than rasping ones. Which kind of tool do you use?

After studying the photos carefully all day, I think I found one rivet with a machining mark at its base! -- ssuR

Nitpicker.

This is the soldering set for the bridge's sides. I didn't have enough screws for the whole bridge and so the rear part isn't equipped with the brass rods. Aluminum angle section protects the brass and nickel silver parts in the vise. The protruding 0.8 mm nickelsilver strip tended to bend a bit away. A tweezer clamps it to the 1 mm brass plate.





The soldering fluid (Griffon S-39) creeps in between the screwed/clamped parts by capillary action. No need to get dirty fingers mounting wetted parts.





0.5 mm solder sections positioned on the upper edges at front and back; the sections at the six particular rods are much too big; a 2mm section for each rod is enough. Note the 0.8 mm aluminum strip between the brass angle sections. They are going to house another brass part of 0.8 mm and I didn't want to get into difficulties with a to small gap later on. If you watch careful you can see some embossed rivets at those angle sections, which I thought were not able to be done the way I did the other ones. Frithjof kindly pressed them after milling and annealing the parts.





Soldering was done with a flambé torch.





The stainless steel screws don't accept solder and are easy to remove and replace with brass rods, which again were soldered with the torch.








When the bridge's vertical lateral parts were done, next came the strips forming the longitudinal angle's other branch including a riveted reinforcement plate from 1 mm brass and a connecting Angle section from 0.8 mm nickle silver.





Soldering set for those parts.





Cutting down the rods with a 0.8 mm jig; I then found out that this is an unnecessary step to prepare the rivets' rounding. It takes much more time than cutting them down with the rounding tool. I bought some 10 of them, expecting a lot of wear. Completely unnecessary, unless you don't brake the cutting edge by negligence as I did at one of the last rivets.





Those parts needed to have the rivets rounded before soldering them to the vertical parts because they wouldn't be accessable later on.





And yes, I used a twin cut jeweler's tool at the cheapo drill, guiding the part with my hands to the fixed drill. It needs to run very slowly, maybe some 100-200 rpm. This gives control to cutting. It's important to stop as sson as the tool's edge touches the ground. I don't mind of  marks; on one hand you'd have to press very tight and on the other hand I've seen marks of riveting tools at prototypes, too.





Next post is about mounting the prepared parts.

Cheers,
Volker

[Lawton Maner]

Volker:

The sanitarium is where your significant other sends you after you finish the project.  Nice men in white coats will see to it that you will not get to excited during your stay.

I prefer to start with hard silver solder and work my way down because working in 1:48 scale projects is easier if I break them into sub-assemblies and I despise cleaning excess solder from things prior to painting.

I use the 0.9 mm cup drill most often as it represents a 1.5" rivet head which was common on most of the equipment built by the East Broad Top RR.

Some times, if I am doing just a dozen or so rivets, I use a pin vise to round them.    

Follow the link to the bits:https://www.riogrande.com/product/dentsply-maillefer-cup-burs/342368gp

[5thwheel]

Volker, thanks for the information on the twin cut tools.  My burrs are as you call them rasping ones. I will have t find a set to add to my tools.

Bill