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Discussion Boards => General Discussion => Topic started by: aero_nautical on September 01, 2011, 03:48:56 PM

Title: foldable track
Post by: aero_nautical on September 01, 2011, 03:48:56 PM
I am thinking of building a folding HO layout that I could roll into a spare room when not in use. I want a layout that would require about 8' by 10' or so but don't have the space for a permanent setup. I was thinking about taking some thin plywood and sandwiching it around styrofoam sheets for strength and light weigth, making a tri-fold design with mayne a 12 inch to 2 feet center section to give clearance for scenery, and having two full 4' by 8' sections on each side. From the end it would resemble a taco. I would need a track that would fold at the joints. Any ideas?
Title: Re: foldable track
Post by: jward on September 01, 2011, 04:27:17 PM
4x8 is a bit big and awkward to be manoevering when trying to fold that layout up. it probably would be a two person job any time you wanted to take the layout down or set it up. in the end i think it will be frustrating as well. if you want ideas for layouts that come apart in sections look at ntrak and see what they've done in n scale.

perhaps you'd be better off finding the room for one 4x8 and settling for something smaller but less complicated.
Title: Re: foldable track
Post by: Jim Banner on September 01, 2011, 04:34:29 PM
Although I have used hinged pieces of track in large scale, I don't think you need it in H0.  Just hinge the ends of the tables, making sure the hinge pins are ABOVE the rail if the pieces fold upwards and below the rail if they fold downward.  Attach the rails firmly to the framework of the table, building the framework up to the required height using solid wood - no foam, no cork, nothing but wood between the frame and the bottoms of the ties.  For ties, use printed circuit board ties, glued and nailed to the wood below, and solder the rails to these ties.  This extra work will keep the rail end properly aligned every time you open up the table.  At least it has for us on our museum layout where we have two lift ups/lift outs hinged at both ends.  Each of these lift up/lift outs carry two tracks, giving a total of eight places where our tracks are aligned by this method.  Over the last twenty years, we have had more than a quarter million trains pass over each of these joints (by actual count.)  That works out to something over 8 million tests of this system without a single derailment.

Jim

P.S.  I agree with Jeffery about handling difficulties.  Our same group at the same museum also a a portable large scale layout, 13-1/2 feet by 42 feet.  We built that on 50 separate tables that all fit together.  Each table is small enough (about 2' x 4') that one personal can easily handle them.  We have about 150 places where tracks cross from table to table.  None of the tracks are hinged or even have joiners.  Closer to H0 scale, I have an 0n30 layout that runs on H0 gauge track and it too is in sections with no rail joiners between sections, just well aligned rails held in alignment by - you guessed it - printed circuit ties to fix the rails relative to the tables and a mechanical pin and socket arrangement to keep the tables aligned.  I did something similar for a local club using precision cut wooden cleats to align their tables both horizontally and vertically and again printed circuit board ties to keep the rails aligned with the tables.  They added plugs and sockets to the tables so that once the ends were shoved together, not only were the rails aligned, the tables were electrically connected as well.  This allowed them to set up their layout in the shortest possible time.

J.
Title: Re: foldable track
Post by: Jerrys HO on September 01, 2011, 06:40:27 PM
After reading this post I think my brain went into overload. What a great idea and what comes to mind is an old ping pong table. The one I had long ago folded like " a TACO". It is sturdy enough and probably would make a nice moveable layout. Now finding an old table is the key. Hope this helps get the ideas rolling around.
Jerry
Title: Re: foldable track
Post by: jonathan on September 01, 2011, 07:18:39 PM
Excelsior!

I often thought a folding ping pong table would make an excellent small layout.  Most of those tables are on wheels, too. 

If you check out enough yard sales, I bet you'd find one in less than a month.  Hurry! Winter is coming.

Regards,

Jonathan
Title: Re: foldable track
Post by: NarrowMinded on September 01, 2011, 07:21:25 PM
Some times you cant see the forest for the tree's.

Thanks Jim, I'm just getting started with this years Christmas Layout, it's going to be a little more permanent then years past,  I want to be able to fold it into a box shape for storage and the  track joints at the folds were on my mind, I was going to over complicate it with removable sections, now I will just shim the hinges up.

Jeff
Title: Re: foldable track
Post by: Doneldon on September 01, 2011, 07:59:53 PM
jerry-

Years ago lots of people had layouts on folding ping-pong tables.
The best folded up in the middle so there weren't any problems
with having to remove scenery or buildings.
                                                                    -- D
Title: Re: foldable track
Post by: Jerrys HO on September 01, 2011, 10:36:22 PM
Doneldon,
   I knew it probably was not original but never heard nor seen one. The table you describe is the exact one I had and thought it would work great as it had lots of room between when folded. Plus the table folded perfectly for the tracks to align with little to no gap if track work is done well. Wish I still had my old table. Hopefully someone has one and post some pics.
Jerry
Title: Re: foldable track
Post by: jward on September 01, 2011, 11:07:39 PM
in order for the track to work it must be aligned perfectly. every time. if it's off by a fraction of an inch it will derail.

there is a reason that modular groups such as ntrak use short pieces of track to bridge the gap. it's much easier to align that way, lateral movement can be compensated for. but even so, the tables have to be levelled up exactly each time they are set up. otherwise, the filler section will be too long or too short. add to that the fact that you can't rely on the rail joiners to carry the electricity, so you must use a form of disconnect plugs to route power around the junction.

it's an idea that sounds great in theory. in practice i'd think long and hard about it. there are alot of pitfalls.
Title: Re: foldable track
Post by: Jim Banner on September 02, 2011, 01:05:58 AM
Jeffery,
Whether or not a train derails at a joint that is a fraction of an inch off depends a great deal on what fraction of an inch is involved.  Misalign the tracks by 1/8" and the train will surely derail.  It has to because the inside of one rail is outside the outside of its matching rail.  This begs the question "how much misalignment will an H0 train tolerate without derailing?"  If the wheels are gauged at 16.08 mm. from outside to outside of the flanges, as per NMRA standards, and the rails are gauged at 17.07 mm. inside to inside of the rail heads, the maximum spacing allowed by NMRA standards, then the center lines of the two tracks can be offset by .99 mm. without forcing a derailment.  This assumes the ends of the rails are chamfered to prevent the flanges from climbing on top of an offset rail.  In the Imperial system of measure, this is about 1/25 of an inch or .040".  It is generally accepted that most people can distinguish 1/64 of an inch or about .015 by eye which means that if the rail ends are aligned by eye, they are accurate enough.  By aligning the rail ends with a metal ruler laid against the insides of the rail heads, the rails can be easily aligned to better than .005".  This compares favorably with the alignment of rails using rail joiners, soldered or not.

The trick is not in aligning the rail ends but in keeping them aligned.  If you solder the rails to printed circuit board ties which are glued and nailed to substantial wood framing made of clear, seasoned wood, which in turn is screwed and glued together, and then use good quality 3-1/2 inch or 4 inch butt hinges mortised into the wood framing, you will have no trouble.  Start cutting corners such as nailing together some wet, knotty wood straight from the lumber yard and screwing on some old, worn out hinges from a door your neighbour threw out, then tacking down some track that is loose in its plastic ties will guarantee failure.  As I mentioned before, this is not theory - this is what has worked in practice, at least for the first 4 million tests.

If aero_nautical or anyone else wants to use a ping pong table, which is an excellent suggestion in my opinion, then may I suggest that he makes sure the top is at least 3/4" thick.   Next, he should remove the original hinges, if any, and replace them with 2" continuous hinge set in a 1/2" x 1/16" rabbet, leaving the hinge pin 1/2" above the table top.  It will probably be necessary to further support the continuous hinge with cleats of door stop molding, 3/8" by about 1-1/4" screwed and glued to the table tops on each side of the hinge.  Ideally, the continuous hinge would be held to the table tops with both screws and epoxy, but screws would likely do if the table were handled carefully.  This would assure continuous proper alignment  of the table tops both horizontally and vertically.  When the track is laid, either on 1/4" roadbed or with roadbed built in, the tops of the rails would be about 3/32" below the center of the hinge pin so the rail heads would move apart when the table was folded up.  The hinge would have to cut down to within 1/4" of table top level where the track was to cross the joint, but this would be relatively easy with a Dremel tool and still possible with a drill and a hacksaw.

Bottom line, yes hinged joints can and do work but to work well and stay working well, they must be made with a lot of care.  If the model railroader lacks the necessary carpentry skills, this is one place he could consider enlisting the aid of a professional or a friend who's hobby is carpentry.  There is no shame in seeking outside help - but a hinged joint that performed poorly and caused lots of problems, now that would be a shame.

Jim 
Title: Re: foldable track
Post by: aero_nautical on September 02, 2011, 03:21:00 AM
Let me try to be a bit more precise as to what I was planning. I envision it having three sections. Two 4 x 8 sheets of plywood, or something, as the foldable sections and joined in between by a center section that is maybe 1 x 8. The reason for the center section would be solely to create a space for the scenery components of the two 4 x 8 sections when they were folded vertically. That is why it would look like a taco from the end. When it was laid down it would be about 8 x 9 which is a good size for a complex layout. But fold the two 4 x 8 "wings" up and roll it away. I could build legs and wheels on it too.

There are two problems that I am trying to work out though:

First, for it to be stiff enough to keep everything aligned the plywood would have to be thick enough to be rigid. The larger the size of a sheet the more a given thickness will flex. So, I as thinking of using two thin plywood "skins" glued to sandwich a styrofoan "cores" so that the entire rig would be light enough to handle.

The other problem is how to hinge the track sections at the hinge points of the folds. Is there a way to do this?
Title: Re: foldable track
Post by: mhampton on September 02, 2011, 10:36:45 AM
I am a bit jealous of the space you have available, but how are you going to work on laying track and fixing derailments that may occur around the middle of the table?  Most people find that no track should be more than 30" to 34" from the edge of a layout.
Title: Re: foldable track
Post by: aero_nautical on September 02, 2011, 10:51:28 AM
Well, I will have to get a lot closer to the edge than 30". And derailments are one of the issues. I thought that there might be some clever track design out there that would allow the track to hinge. I did see an idea from a reponse up above that says cut the track so that they two pieces will form a butt joint when the wings are folded down for use, if I am interpretting him right.
Title: Re: foldable track
Post by: Jerrys HO on September 02, 2011, 12:33:28 PM
aero,

  Jim is correct and I have seen it work well as far as a hinged section goes. Most are used for access to the control room but if your table is built correctly and track is laid well it should work.                                                                                                                         

   (Most people find that no track should be more than 30" to 34" from the edge of a layout. I believe mhampton was referring that the track should be from the edge to no further than 34" to the center so it would be easier to work with scenery or any other issues.) If you brace under the table you could brace around a cutout big enough for you to stand in to do scenery and fix any problems that may occur.
   My opinion would be to use a track with roadbed already attached. You stated you would be using thin plywood sandwiching it around foam and the plastic roadbed would be added strength.
   As for derailments go, when setting up just make sure everything is aligned and maybe run a piece of rolling stock around to check.
  Jerry
Title: Re: foldable track
Post by: aero_nautical on September 02, 2011, 01:58:11 PM
Thanks to all of you for your input...what swell guys!

I will post a picture when I get around to building this setup.

Mike
Title: Re: foldable track
Post by: jward on September 02, 2011, 02:04:03 PM
i would agree with the 30" rule for switches, and yard tracks or industrial sidings.  with switches you have a potential derailment site, and with sidings and yards you are probably going to need to reach in there to couple or uncouple cars. a normal section of mainline track, however, can be further than an arm's reach from the edge as long as you provide a hatch of some sort to reach any derailed or stalled train.
Title: Re: foldable track
Post by: NarrowMinded on September 02, 2011, 04:52:04 PM
To keep my track aligned I plane on installing tapered brass indexing pins with receivers think of the extra leaf for a dining room table same theory/pratice this will align the base to the same location both vertically and horizontally every time.

NM
Title: Re: foldable track
Post by: railsider on September 05, 2011, 05:15:04 PM
Modular technique might be helpful (contact an HO, N or O scale module club to see what they do). In as much of a nutshell as I can, here's show it works: sections are standardized so that tracks meet, with about a 3" (sometimes 4.5" or more, but always standardized within the system) gap at the end of each section. You set the sections up on legs, then push them together. Use pegs or bolts in precise holes to line them up. Once they're all set up and leveled(with power connections plugged together underneath as well), you put in bridge tracks to span the gaps. A 9" standard HO section works with two 4.5" end gaps. Ordinary sectional track works just fine, but it may help to use re-raler track sections, just in case there's a tiny mismatch, usually in rail height. You just slide HO or N railjoiners back, put the track in place, and push the joiners into place.

As usual, do not rely on track to carry power long distances; connect eacah section to a 10 or 12 AWG power buss running under the system (with plugs, of course). Storage is easy: place two legless sections face-to-face (i.e., top-to-top) with enough clearance to prevent damages to scenery and structures, and lock them together with a set of bars from one to the other. HO moudkles at 4' long x 2' wide carry comfortably singly or in pairs, and the delicate scenery is protected by the facing pairs.

Standardization is your key. When it's done right, any module matches any other one at either end (kinda like playing dominoes with the same spots on every tile). Pegs and holes make line-up quick and easy. Adjustable-length legs compensate for wavy floors. Folding, I think, would be harder than pushing pieces together, because it's hard to adjust a hinge by 1mm. The bridge track, though, does let you put in a tiny side-shift correction that won't derail most cars.

O-scale modules actually don't need bridge tracks; careful alignment with precision hardwood ends and matching pins, is close enough (with maybe a 1mm gap) that the big wheels roll right along over the joint. HO and N, of course, have tighter tolerances, so bridges work best.

P.S. (Plug, Shameless): If you are in the Santa Fe, NM, area over the Columbus Day weekend, all this will be on display, free, at the XIV Santa Fe Model Train Show at 3229 Rodeo Road. You're welcome to come by and say "hi" Oct. 8-9-10.

Happy rails to you!

Railsider
Title: Re: foldable track
Post by: aero_nautical on September 05, 2011, 07:44:25 PM
Thanks again everyone, and Railsider, I think the bridge track solves my problem.