Free-moN Staging Yard - 16"x10'

[C855B]

We do something similar with our club's N-Trak yard. From that experience, I suggest some manner of "accident prevention panel" that clamps onto the open end of the module or otherwise exposed tracks, to create a physical barrier to cars... or worse... rolling off the end and onto the floor.

Just sayin'.   

[M.C. Fujiwara]

Thanks for the tip so things don't tip 
The detachable extension blocks the two tracks on either side, but yes, I got some masonite scraps that we'll clamp on to prevent any 666 scale-foot falls to the floor.
I had already clamped stops to the ends of the detachable extensions.

Yesterday I installed the last turnout that needed replacing with a handlaid #6:



And wired it up, so now the yard is 100% operational for shows.
Still need to install the tracks to the turntable and to the machine shop, but those are "extras" and not necessary for show ops.
But soon I'll be able to paint the track & surrounding area and get rid of the plywood prairie.

Cutting the hole for the turntable pit is going to be tricky, given the close proximity of Bullfrogs underneath, but I figure I'll jigsaw a smaller hole (about 6"dia) and then use the sanding barrel on the Dremel to work my way out to the 8" I need.
The turntable will be in that upper left area:



I was going to drill holes about 1" apart around the circle so it's just a matter of short cuts with the jigsaw.
But any suggestions on cutting the plywood without a jigsaw (worried about the massive vibrations) will be appreciated.

Thanks for looking.

[eric220]

You could use a router.  It would be slow going and create a lot of sawdust, but you could set the depth of the blade much more precisely then a jigsaw.  It would also go a lot faster than a Dremel with a sanding drum.

[C855B]

+1 on the router. Most modern routers have a fitting for a shop vac, so definitely use it that way. Make a template for the router base to cut the finished diameter on a single pass without worrying about following a cut line on an otherwise finished piece. You will probably have to use a 1/2" bit; 1/4" will dull pretty quickly due to the plywood glue resins.

[LKOrailroad]

Drill a 3/4" hole in a small piece of lauan. Mark and drill the 3 mounting holes for the router using 3/4" hole as center point. Measure and drill a forth hole 4-(dia of bit)" from 3/4" hole center in the lauan. Mount router to lauan. Drive nail through 4th hole into center point of turntable location. If not a plunge router then drill a router bit diameter hole in turntable rim mark with hole tangent to inside of turntable rim. Pull router in a circle around the nail.

Have done this countless times for perfectly round holes with a router. Good luck. 

[M.C. Fujiwara]

Thanks for all the suggestions: using the mounting board with a pivot is a nifty idea.
If I had planned ahead [what?!?], I should have done that nifty router trick BEFORE I laid down the cork and track 
As the turntable pit comes about an 1" close to the mainline roadbed, I'm thinking the edge of the router will smack into the track.
Though I guess I could build a form for the router to sit above the track and just lower the bit more.

Right now I'm leaning towards using the router freehand to get close to the circle and then Dremel for small adjustments.
I've been looking at Rich C's tutorial on turntables, and with his method, the pit walls actually come all the way up level to the top of the ply, and so the ply itself doesn't have to be 100% perfect circle (as the bridge rolls next to the masonite pit walls, not the ply.
Here's Rich C's tutorial: http://www.thewhistlepost.com/forums/craftsmans-bench/13223-build-rotary-turntable-scratch.html

Still wide open for ideas, though 

[LKOrailroad]

Glue a small block of wood (with same 3/4" hole in it) over the hole in the plate. Set the router depth down to clear bottom of wood block. This will elevate the plate and router above the track. The little wood block will be the only thing contacting the surface so be sure to hold router level as you make the cut. Don't allow it to rock on the piece of wood.

It is terribly challenging to get a perfectly followed freehand circular line with a router. In fact, I would challenge anyone that says they can do it. The pivoting plate assures you of a perfect cut the first time no muss no fuss.

[Philip H]

MC,
Having done a lot of woodworking - some semi professionally - I second both the pivot plate and Alan's wood block ideas.  Cutting circles any other way with a router is just nuts.

[M.C. Fujiwara]

Oh, I'm totally down with using the router on a pivot like Alan suggested.
Just not sure how to do it with the router I have:



Do I need to take the base plate off and use the 3 screw holes?

Dad got it 30+ years ago at Sears, and the throttle cable is stuck, so I operate it by turning on / off a power strip I clamp to the work bench.

Here's a close-up of the area I have to work with:



A bit close to the main, but so it goes.
Thanks for all your help & suggestions.

[LKOrailroad]

MC
I sent you a message offline with pics showing how to mount the pivot plate. It should be in your Inbox. Best of luck. (You won't need luck, it will work great)
-A

[LKOrailroad]

BTW... the blueing on the router bit tip in your photo indicates the bit is overheating. It will quickly lose its temper and edge. Router bits are funny things. They dissipate their heat into the wood they are cutting. Moving too slow doesn't expose the bit to enough fresh wood to keep it cool. Advance the router at the fastest speed possible without overloading the motor. The motor sound should tell you it is under load and working but not approaching stall. If the motor sounds like it is easily spinning the bit then you are not advancing the router fast enough and bit overheating will likely occur.

[LKOrailroad]

MC,

One very important detail I forgot to mention. When you are 3/4 ways around on your cut stop the router, put a bunch of 2" masking tape on top and bottom of your deck surface across the previous router cut. Then finish the cut being very careful as you reach the end. The masking tape will prevent the turnrable wood circle (and your router and plate) from falling through the hole or drifting off center as you finish the cut. To make it even better place a piece(s) of wood wider than the cut underneath the bench so module weight is resting on it (or clamped in place) to help prevent fall through. Masking tape still needed to prevent drift from center.

[M.C. Fujiwara]

MC,

One very important detail I forgot to mention. When you are 3/4 ways around on your cut stop the router, put a bunch of 2" masking tape on top and bottom of your deck surface across the previous router cut. Then finish the cut being very careful as you reach the end. The masking tape will prevent the turnrable wood circle (and your router and plate) from falling through the hole or drifting off center as you finish the cut.

Funny, I was JUST thinking about that as I was eating my cereal!
I was thinking the wood plate/block, as it is wider than the bit, would support the router on the outside of the hole.
But the tape is a good idea.

Given that there's not much space between the edge of the cut and the roadbed, I'm wondering if it'd work better I glue a short section of 1" PVC pipe under the plate to act as the spacer between ply & plate.

Or perhaps I should just build a simple elevated platform that spans across the whole area, then I wouldn't need the spacer and just have the luan plate on the platform.

[LKOrailroad]

Surface spanning the whole area is a good idea. Just keep everything as close as possible to the cutting surface. Increasing router bit depth makes router increasingly more difficult to control accurately. Slight deviations from straight up cause greater and greater bit angle as cutting depth increases. Triangle geometry you know. Is it possible to cut from underneath? Maybe there are no interfering obstacles on the underside.

[M.C. Fujiwara]

Busy week as we're getting ready to show/run some trains on Sunday.
 (And the Euro Cup started yesterday. Need to get a TV out in the garage: Wife's not happy I keep bring train stuff into the house to work on while watching)
 
Put off the turntable until I can do it proper, so started building the machine shop in the staging yard.
 First made a pit by cutting out the center & then turning that into the bottom with some pieces of scrape styrene:
 


Decided to install the machine shop at a slight angle to break up all the parallelism.
 Had to cut a channel in the ply for the pit.
 After installing replacement ties, I spray painted the track Grimy Black:
 


Installed "concrete" strips of scored styrene for the diesel service area, then painted the rest of the ply "mis-tint tan" [WHICH I SHOULD HAVE DONE BEFORE LAYING ANY TRACK AT ALL!!!] (more on that in a bit)
 Couldn't resist throwing down some dirt on the wet paint, which led to throwing down some cinders as well (haven't quite decided how I want the yard to look, but sparse dirt & cinders is an ok base ground cover):
 


BIG NOTES TO SELF:
 --Paint yr ply at the start: seals the wood and provides smooth surface for throwbars (painted every other layout first: didn't on this one as in too much a hurry to get things operational for a show)
 --Don't forget to douse your throwbars with LaBelle oil BEFORE wetting ground cover and soaking with diluted white glue. The oil creates a barrier and so prevents the diluted white glue from creeping under the throwbars.
Because I forgot both, I had 7-8 throwbars that I had to unstick and then scrape out with a thin-blade knife and file [D'oh!]
 
But all worked out okie dokie, and I finished building the machine shop, though I had to move the chimney a bit:
 


The chimney is CA'ed for now, but I might break it off and use a magnet / dowel if it becomes a nuisance during transport.
 
What's that blue light in the shop, you ask?
 Hmm.....
 
[cont.]