What's New on the PRR Panhandle Division?

[G3750]

Updated 11/4/2014:

Just for your information, I thought I would relay some of the options I have pursued for the bridge piers:

• 1: Have made my own SketchUp 2014 drawing. I am stuck trying to get the major portion of the pier drawing to taper correctly. No progress. I have contacted an expert for assistance in correcting the diagram. He is looking at it and will get back to me.
• 2: I have attempted to hire a SketchUp designer to fix the diagram and to have the bridge piers 3D printed. This is extraordinarily cost prohibitive. "Shocked" is the best way to express the cost! Maybe "horrified" or "obscene" will work as well.
• 3: I approached two specialty lumberyards about CNC milling of the bridge piers. Neither was interested.
• 4: I have approached the bridge maker and there is some interest on their part, but they are just beginning their investigation into the 3D printing world. They are too far back in the decision process to be a factor in this. At least that's how I feel at this point in time. If the other options fail, that may change.
• 5: I have a tentative agreement with a local machine shop to make the piers out of wood. The price is pretty reasonable as well. I am cautiously optimistic that this will turn out well, but the jury is still out.

I had a sneaking suspicion that the bridge piers might be as troublesome to procure as the bridge. That suspicion seems to be coming true.

More when I know it.

George

[Roy]

George, You sure as shit don't need CNC or 3D printing to make up those piers. What you need is a table-type belt or disc sander, like this:

http://www.harborfreight.com/1-in-x-30-in-belt-sander-60543.html

That's just for illustration. The table tilts, so you can sand the taper all around.

[G3750]

George, You sure as shit don't need CNC or 3D printing to make up those piers. What you need is a table-type belt or disc sander, like this:

http://www.harborfreight.com/1-in-x-30-in-belt-sander-60543.html

That's just for illustration. The table tilts, so you can sand the taper all around.

Roy, I get it. And that technique (cutting and hand sanding) is what I used to make my ingot molds.

Ingot v2.jpg (60.11 KiB) Viewed 3788 times

Ingots and Car.jpg (94.45 KiB) Viewed 3790 times

Truthfully, I am not so sure of my abilities with such a large item and the use of something like a belt sander. I am more comfortable having someone make this. If it doesn't turn out well, then I may be forced to do it myself.

Time is also a factor in this. My father's health is not good, and I am starting a new job. So contracting this out makes sense to me right now.

But I appreciate your suggestion.

George

[Rufus T. Firefly]

I have attempted to hire a SketchUp designer to fix the diagram and to have the bridge piers 3D printed. This is extraordinarily cost prohibitive. "Shocked" is the best way to express the cost! Maybe "horrified" or "obscene" will work as well.

I have done resin casting of an item that was 1st 3D printed to obviate that cost factor for making many of the same item.

Can you see what it might cost to have 1 3D printed, making it hollow, and with maybe an 1/8" thickness so that it might be suitable for making a mold?

I could use that mold to cast these in hydrocal for you, or you could do that yourself.

[G3750]

I have attempted to hire a SketchUp designer to fix the diagram and to have the bridge piers 3D printed. This is extraordinarily cost prohibitive. "Shocked" is the best way to express the cost! Maybe "horrified" or "obscene" will work as well.

I have done resin casting of an item that was 1st 3D printed to obviate that cost factor for making many of the same item.

Can you see what it might cost to have 1 3D printed, making it hollow, and with maybe an 1/8" thickness so that it might be suitable for making a mold?

I could use that mold to cast these in hydrocal for you, or you could do that yourself.

Rufus, that is exactly one of the plans: get it 3D printed, make a rubber mold, and then cast it (probably out of resin). My friend (the one who helped me by casting the ingot molds) is prepared to help make a mold and cast multiple copies of piers.

I was just flat out shocked by the high cost of 3D printing. I never expected that type of number. The intention was to make the pier hollow to save material, but that point seemed to get lost in translation in my discussion with the designer. Casting multiple copies from the wooden "positive" is still an option. We'll have to see how this plays out.

Thank you for the offer.

George

[Rufus T. Firefly]

I have attempted to hire a SketchUp designer to fix the diagram and to have the bridge piers 3D printed. This is extraordinarily cost prohibitive. "Shocked" is the best way to express the cost! Maybe "horrified" or "obscene" will work as well.

I have done resin casting of an item that was 1st 3D printed to obviate that cost factor for making many of the same item.

Can you see what it might cost to have 1 3D printed, making it hollow, and with maybe an 1/8" thickness so that it might be suitable for making a mold?

I could use that mold to cast these in hydrocal for you, or you could do that yourself.

Rufus, that is exactly one of the plans: get it 3D printed, make a rubber mold, and then cast it (probably out of resin). My friend (the one who helped me by casting the ingot molds) is prepared to help make a mold and cast multiple copies of piers.

Ok, so you've got that covered. Do suggest still making it a hollow product using a "squish" mold -- resin isn't all that cheap! That's why I suggested hydrocal which you could cast as a solid pier and that takes paint, weathering, etc. nicely.

I was just flat out shocked by the high cost of 3D printing. I never expected that type of number. The intention was to make the pier hollow to save material, but that point seemed to get lost in translation in my discussion with the designer. Casting multiple copies from the wooden "positive" is still an option. We'll have to see how this plays out.

Yes, I was able to make ~12 of the item in solid resin that I made a mold from the 3D hollow printed master for the cost of the single master.

Thank you for the offer.

George

If you make it to Strasburg on the 15th, drop by my table!

[G3750]

Rufus,

The idea behind having a hollow, resin product was:

• Have a top floor for the pier using a 0.060 sheet of styrene. That would be strong enough to support the bridge feet and the bridge itself. Note that the bridge is rigid with internal aluminum stiffeners inside the bottom member. It will also be chiefly supported at its end points. Bridge piers 18" in from each end will provide stiffness.
• Save material. As you said resin isn't cheap and 3D printing "plastic" isn't either.
• Provide space for wiring. Each end of the pier will have an Evans Design slow red blinking LED.

Using the ingot mold, we were able to make 28 of them before it tore.

Assuming something doesn't come up at the last minute to disrupt my plans (like last time), I will definitely drop by your table at Strasburg.

Thanks!

George

[Rufus T. Firefly]

Rufus,

The idea behind having a hollow, resin product was:[LIST]
[*]Have a top floor for the pier using a 0.060 sheet of styrene. That would be strong enough to support the bridge feet and the bridge itself. Note that the bridge is rigid with internal aluminum stiffeners inside the bottom member. It will also be chiefly supported at its end points. Bridge piers 18" in from each end will provide stiffness.
[*]Save material. As you said resin isn't cheap and 3D printing "plastic" isn't either.
[*]Provide space for wiring. Each end of the pier will have an Evans Design slow red blinking LED.

Using the ingot mold, we were able to make 28 of them before it tore.

Assuming something doesn't come up at the last minute to disrupt my plans (like last time), I will definitely drop by your table at Strasburg.

Thanks!

George

Sounds like a good plan to me. Only 28 from one mold? Hmmmm........ Should get close to double that unless there's something odd going on.

See you on the 15th!!!

[G3750]

Updated 11/6/2014:

We have some progress to report.

I test-fitted the backdrop in place. More measurement and some cutting will be needed.

Backdrop_02_.JPG (39.19 KiB) Viewed 3741 times

I also removed some left-over supports from the old metal bridge. These were located at each of the river banks.

Backdrop_03_.JPG (37.97 KiB) Viewed 3741 times

Also heard from the guy with the machine shop. He is proceeding with making the piers. I should see something in a couple of weeks.

More when I know it.

George

[rogruth]

Good luck.

[Roy]

So George, I gather you're having a wood pier pattern made up. I like Rufus's Hydrocal suggestion. You might use that for your pier molds, to save on cost. (Of course, you would need to use a mold release agent, in any event.) Also, you may be able to insert seasoned lumber into the partially-filled pier molds to reinforce the finished Hydrocal piers, as well as reduce the cost. I don't know if there might be some expansion of the wood due to the moisture but, if so, it could be painted or varnished beforehand.

Another possibility is to cast your piers of polystone. This is resin mixed with aggregate - which, of course, reduces the resin cost. If you've seen those painted village pieces in gift shops, that's polystone. It's strong, and gives good detail, but would be more expensive than Hydrocal.

[G3750]

Good luck.

Thanks Roger. I am finally starting to see progress. Who knows? I might get this layout built.

George

[G3750]

So George, I gather you're having a wood pier pattern made up. I like Rufus's Hydrocal suggestion. You might use that for your pier molds, to save on cost. (Of course, you would need to use a mold release agent, in any event.) Also, you may be able to insert seasoned lumber into the partially-filled pier molds to reinforce the finished Hydrocal piers, as well as reduce the cost. I don't know if there might be some expansion of the wood due to the moisture but, if so, it could be painted or varnished beforehand.

Another possibility is to cast your piers of polystone. This is resin mixed with aggregate - which, of course, reduces the resin cost. If you've seen those painted village pieces in gift shops, that's polystone. It's strong, and gives good detail, but would be more expensive than Hydrocal.

Roy,

Rufus' hydrocal solution appeals to me as well providing I can create a slot or passage for wiring when I cast it the pier. It bears investigation and I will explore options with my friend. Hydrocal would certainly lend heft to the pier and I believe it would be strong enough to support the weight of the bridge and trains passing over it. We'll see.

Thanks,

George

[rogruth]

George,

Is it possible to drill the hydrocal?

[Rufus T. Firefly]

Is it possible to drill the hydrocal?

It can be drilled with care and patience, and an electric drill.