Some pictures of the prototype trestle

First a picture or two of the prototype trestle:

Google maps overview:

And this is the benchwork status to date

And this is how far I've gotten with the module's bench work: the frame is built, the leg supports and roadbed supports are all glued in place. The last pieces of foam supports are being clamped as is the last piece of roadbed.

End plates are made of 3/4 inch birch plywood, all other woodwork is 1/2 inch birch plywood. I used #8 woodscrews to hold the outer frame together and Gorilla glue. All other pieces are just glued in place with Gorilla glue. Total weight so far is just about 10lbs.

Trestle definition

ybandell: Technically what you are building is a plate girder bridge, not a trestle. A trestle is a bridge with sloping bents supporting the road way. Many confuse the terms. A good job, none the less. Yours, Elvin Howland/E. St. Louis Rail Group Layout

scenery

what will you use for scenery base?

That's an interesting configuration.

I wonder why they didn't just put a fill there and make the other bridge to the left a bit longer if the flow needed more capacity at times? I guess it just runs over the road at high water? ...... .DaveB

Trestle vs Plate Girder Bridge

@Elvin: thanks for setting me straight on trestles versus bridges. I'll have to see now, how to update the Blog post name...

@Marty: the base of the scenery will be one or more layers of 1 inch (pink/green) foam. About half, if not more of the module will be relatively flat, the sloped areas will not be that high or low and I've got good experience with carving foam in general. I'm not much into building mountains, so the "plaster-cloth over cardboard" alternative method for the hill doesn't really appeal to me.

@DaveB: I wondered the same thing. If there is water in the field north of the line and goes under the bridge then it will be held back about a feet or two before it floods the roadway parallel to the tracks. So unless the area under this bridge is more swampy then it looks, I would have filled it in as well myself and widened the other bridge instead. Now it is just a nice interesting piece of scenery to building: first time I drove past this bridge I went: "Wait what, huh?"

Nice work

I am very interested in building my own Freemo module,  Would love to see more of how the module is put together and in all the ones I have seen,  never get to see how the foam is attached to the frame because everything gets painted and scenery is put in and I miss a detail.

Thanks and good luck

Putting foam on

@rekline: (real name, pls?)  I'll take some before and after close up pictures of how I attach the foam to the frame and post them. The basic plan is to have the foam glued to the 3/8" dowels I attached (see picture below) all around the sides at roughly 1" below the top of the frame. The foam would also be glued to the top of the inside support frame (the cross). Since this is my first time using foam without a whole piece of plywood underneath it, I'll have to hope my plan will work

2 bridges

If you look closely at the Google pictures there is a bridge under the highway that lines up with the short span.

It looks like there is need to accommodate additional run off and thus the longer span.  My guess is that the road is below the level of the track and rises up over the short bridge.  Since the bridge is fairly shallow its probably back water that doesn't have a strong flow, so it won't scour the road.  On the other hand if the water builds up against the roadbed and builds up too much pressure it could blow out the railroad fill or water flowing over the track would scour and washout the track.

If you put all the spans at the location of the long span the water under the road bridge would erode the tracks.  If you put all the spans at the short bridge it could increase the flow around the road bridge and scour the the road bridge.

The short bridge is for the watercourse and the long bridge is for situations when there's flooding.

Securing foam

rekline,

I've built modules with 1/4 plywood "ribs" sitting vertically and also with cleats along the sides (where Yaron has his 3/8 dowels). I've glued the foam down using Polyurethane glues. A common brand in the US for that is Gorilla glue. The foam, if cut correctly also eliminates racking and twisting in the module, it stiffins it right up.

Module progress up to 4/4/2014

This is the progress so far on 4/4/2014: The entire module frame has been glued together, including the roadbed.

A close up of the leg support, with a leg in it. Also the 3/8" dowels are visible that will support the foam top:

Close up of the side frame with dowel in place about 1 inch below the top of the frame, ready to accept the foam top:

And this is the module on its own 4 legs. Legs are made of 1x2's and will have another piece of 1x2 attached to them with a 4" leveler foot plus bracket to get to the various Free-mo (and hopefully even NMRA) desired heights. More on that later.

Start of bridge building

It has been a while since I made any updates to this blog. Life got in the way of building my module: buying a house was amongst those things that got in the way. Upside though: space to actually build modules and not have to use the kitchen floor as my workshop

Earlier this week I started with scratch building the first of several bridge segments needed. This is what the prototype bridge sections look like:

The prototype has a total of 7 of these sections. I might only do 5 or 6 due to space constraints on the nearly 4 foot long module. After about 2 hours struggling with 1/4 inch styrene I-beams and some rudimentary tools, it was done. It wasn't as neat as I wanted it to be: better tools and realizing I needed them while building it made me less patient and the result shows it:

So while being a bit disillusioned of my scratch building skills, it hit me: why not abuse the wife's Silhouette Cameo? We've had the thread on MRH about the Cricut Explore and people mentioning the Silhouette Cameo as less restricted from a "print" perspective. The Cameo can cut thin styrene sheet of up to 0.015 inches and makes scoring lines on 0.02 and 0.04 inch thick sheets. It would also allow me to make as many bridge sections as I'd like. Since I have no sheet styrene I could simply do some testing on 65 lbs cardstock. Well, an hour or so later in their designer software, I had a first drawing up and ready to print and my funk of disillusion was nowhere to be seen. This is what the design looks like in the Studio Designer software:

After hitting 'Send to Silhouette' it took about 10 minutes for the cutter to do its job on the cardstock. Cutter was set at '3', thickness at '33' and speed at '1'. This is what the cut out design looks in cardstock like before popping the parts from the tacky mat:

Yes, that cardstock was "borrowed" from the wife scrapbooking supplies At least this bridge section will be easy find when it somehow gets misplaced.

Depending on the settings on the cutter, the parts will pop right out or might need a little convincing to detach from the rest of the cardstock. If the parts were completely cut from the cardstock, parts may stay behind on the tacky mat when you pull the mat away from the cardstock. The various scraper and hook tools for the Cameo will help you remove those parts from the tacky mat, especially if your mat is new it is very tacky. We used a hand towel on the mat before using it for the very first time to make it less tacky: just dab the towel on it a vew times and you feel the tackiness get noticeably less. The tackiness of the mat is now such that it is possible to simply peel them off with a finger nail if needed.

Putting the prototype together with Elmers white school glue gave me the following result in just about 10 minutes of assembly time. Except for the top and bottom, all parts were tripled up to get some oompf to the bridge section. This is what it looks like compared to the styrene scratch build part earlier:

A different angle of the completed part:

And one more (final) angle of the part:

For a first try I think it was a very successful experiment. There will be some things that I will change when it is time to cut the parts from 0.01 inch styrene sheet though: the height and width of the tabs should be decreased to match the material thickness better. I also think I'll create some tabs on the cross members for more easily positioning them. The extra tabs should ensure they will be at a perfect 90 degree angle with the bridge sides. The length and width of the bridge section likely needs to be altered depending on the actual length of the Central Valley bridge ties I intend to use. The prototype has a total of 14 ties per bridge section and I'd like to keep to that number of ties per bridge section.

Now it's waiting for some 0.01 inch sheet styrene to arrive and do tests on that instead of cardstock.

Until then: Merry Christmas and a Happy New Year to all!

Great Work

Yaron, I think that's an excellent way to test out a design before committing to the final one.

Andrew

Great custom bridge!

Yaron,

This is looking great!  Using the cutter looks like it will work very well. I can't wait to see this module in person. 

That is very clever

Yaron,

Glad to see that you are progressing on your Free-mo module and using all your 'resources'.  Keep us posted on the expiriments!

When will this be at a show?

Yaron,

Will you bring this module to Timonium in a few weeks? I'd love to see it. I don't care if it's not complete yet. We can put it at the end of the layout with a section of flex track tacked down to serve as a tail track or you could work on it at the show. Can't hurt to show people what goes into the construction of one of these modules.

Silhouette Cameo Cutter

There are a number of modelers in the UK that are using the Silhouette Cameo Cutter to make some incredible models.  Not everything works out as intended, but there are lots of different projects and tips documented here.  Thirty-seven pages, so far:

http://www.rmweb.co.uk/community/index.php?/topic/79025-a-guide-to-using-the-silhouette-cameo-cutter/

Timonium show

Matt,

I don't think i will be able to make it to Timonium for the full weekend, if at all  Sunday is Super Bowl Sunday and if the boys play well tonight I'll be home watching the game with friends and family. Friday is a no-go since i have to save up all vacation days for at least 2 trips to the Netherlands this half of the year.

I guess you want to see it since your own schedule seems to conflict with the Timonium shows after this one, so i heard

To end this post on a positive note: my 50 styrene sheets came in this week (37¢ per 12x8" sheet, 0.010" thick) and i spent most of yesterday afternoon making test cuts using some of the settings as discussed on the rmweb discussion linked in dperry's post above. I've been following that thread for well over a year now and i still find new information in it every time i look. After breakfast i will run my redone bridge drawing through the cutter and hopefully everything will fit. If so, pictures later today or tomorrow.

My first die cut machined styrene bridge parts

After messing yesterday with various cut depths on the Silhouette Cameo on a piece of 0.010" styrene, I ran my updated design through the machine. I ended up running the same piece through the cutter several times with a blade depth of '10' but varying the material thickness for each cut:

• First run was done with a material thickness of '5', single cut.
• Second run was done with a material thickness of '12' , single cut.
• Third and final run was done at a thickness of '33', single cut.

I set the cutter to return to the origin after each cutting run and can simply submit all three runs in sequence this way. Submit and walk away, while it cuts the parts: awesome!

The main reason for using multiple cuts instead of just running at depth '10' and thickness '33' in 'double cut' mode was to try and avoid pushing up too much styrene along the cut edge. I think I should try and lower the thickness setting of the third run as the blade seems to have some difficulties at times making the corners nice and sharp at that thickness setting. Might also be that the blade is getting dull already

Anyways, after removing the parts from the sheet of styrene, and assembling it with some thin CA glue the following result was achieved:

And from a different angle:

My apologies for the bad lighting/photo quality: they were taken with my aging cell phone.

As you can see the latest design now includes notches for the cross members to hold everything a lot more straight. I still doubled up all the parts for strength purposes, so everything ends up being 0.020" thick. I will make a version of the design that doesn't double up the parts, just to see how strong that will end up being.

At 0.020" these beams are over engineered compared to the prototype. And the lazy bastard in me thinks that if I can get away with not having to glue identical parts together I will save time for other fun stuff. I do have to build a total of 7 of these guys, but these bridges have to support and carry the weight of model trains. The doubled up version will have no issue with this, that's for sure as it's extremely rigid.

On the current version the outside beams were spaced such that they are now directly positioned under the rails. This makes the bridge a lot less wide compared to the earlier cardboard version. I believe it should be this way based on what I can see in the (crude) pictures I took, and will cause the ties to overhang by about 0.180" inches on each side.

The ties on the prototype do seem to overhang quite a bit over the edge of the outer beams, even though they are standard length ties at 8'6". Since the ties are standard length, the cross beams laying parallel with the track on top of the ties, are scraped and ripped up in some places: I bet the snow plow on the NS dash-9's have caught/scraped the top of them if they were going to fast on the bumpy track.

Now my question is: what are these beams called that are attached on top of the ties running parallel with the track on the bridge? Are they attached to each tie or only every so many ties?

Doubling probably not needed

Material on edge is incredibly strong. I'm over a 100 kilograms and I can stand on an empty aluminum soda can without it buckling. I think you'll find that the nature of your structure replicating the web and other features of real life structural steel will be adequate for running some trains over. The only practical solution is to stress test one. I'm not sure what the weight of the heaviest locomotive that might run on it, but double that weight and if your span doesn't colapse you should be fine. Even heavy locomotives  are going to have their weight spread across more than one segment of your bridge. 

Leg advice from the "leg man"

Great work, can't wait to see the finished product!

I do have a bit of advice on your legs and their pockets: Rather than relying on the top of the pocket to stop the top of the leg, attach a scrap of 1x2 or plywood to the leg itself as a stop.  In the youth group that I advise, we had some similar type legs and pockets that would regularly bust through the top of the pocket, since there was nothing to stop them (irregardless of some other poor construction).  I also use a quarter as a spacer to leave a small space cushion on top of the leg when the module is resting on the stop.  Not sure if a quarter will fit in your 1x2 space, as I use it with 2x2s.

-Fuzzy
DM Rail Group
 

Single thickness bridge sections

"Leg Man" Fuzzy: thanks for the suggestion. I can see why that stop would help keep the top of the pocket from being destroyed. I'll have to check if I'll have enough space to do this once the second piece of the leg is attached. My intend is to use another piece of 1x2 to double up the current 1x2 and make these two pieces adjustable such that I can acomodate the full range of 49" to 62" floor-to-railhead height requirement. More on that in a later post.

Meanwhile, I've had some time this week to alter the drawing and create a version of the bridge section that isn't "doubled" up. I also decreased some intentional slop in the keying holes and slits so it all fits a little bit more tightly.

The result can be seen here, with the latest version in the middle and the first die-cut version on he left:

A side/top view:

A slightly lower angle view:

I really like the sleek and clean look of it not being doubled up. So after doing some simple stress/flex testing by hand, I concluded that a single thickness bridge section is indeed strong enough to hold HO locomotives or a schnabel car with an enormous heavy transformer...

Now that I've got 2 sections done there are only 5 more to go...

Thanks for the Cameo!

Thanks for sharing the use of the Cameo!  I've been wanting a Cricut for a while to try out with modeling, but this looks like a great alternative!  I'll be picking one up this spring.  

The module looks like a fun build!  

Tim

Improved bridge deck

An update, after a whole lot of delays due to family life and trying to figure out some technical difficulties with the off-brand cutter blades I got earlier in the year:

I decided that I wanted to see if I could punch rivets in the sides of the bridge deck as can be seen on the prototype pictures. I was thinking to use a thick needle to punch the rivets carefully. Of course I wanted to make sure the spacing was even and that I wouldn't punch too easily through the 0.01" thick styrene sheet.

I created a template from styrene in my design file that would allow me to cut two pieces of the same size and shape as the bridge deck sides. In the places where a rivet needed to be punched, I placed tiny holes. I could sandwich a deck side (middle) between the template top (T) and bottom (B):

After a few tries of punching rivets, the bridge deck had evenly spaced and sized rivets. In the past I had used ACC to glue the pieces together but at times I noticed that the smooth styrene would still inhibit the ACC to properly hold the pieces together under stress. The ACC would also leave behind noticeble glue traces when it would accidently run onto surfaces that didn't need glue. So without good hobby shops in the area I decided to get myself a cannister of MEK at my favorite home improvement store and create my own "plastic weld" by transferring some MEK into a smaller container and dissolving some of my scrap styrene. The result was great, chemically bonded bridge decks without any glue traces:

On to get my Cameo to cut another 5 bridge decks...