I’m mulling over mounting my 120’ turntable and roundhouse on a lift out plywood base. My engine terminal is in a largely inaccessible corner of the layout with no additional room for a lift out hatch.
It would seem that cutting the 1/2" ply out around the t.t. and r.h. and simply installing ledges on the bottom surface of the table top would be all that is needed. I’m concerned about being certain it would remain level/ vibration free, etc. over time. Anyone do a similar thing?
I’m also seeking ideas for making the track from the edge of the pit (yard/approach side) removable and easy to make/re-make electrical connections. Has anyone here a removable connector of choice? Pics?
I’m not sure what you’re trying to do. Are you going to be able to lift this out from the top and set it aside, or is it the plan that you will push it out from below, and be able to hand it out to someone?
As far as the construction goes, your idea of cutting out a piece and then supporting it on ledges attached below should work. However, you will end up with some slop in the fit because the piece you cut out will be smaller on all sides by the width of your saw cut. You might want to pack out the edges of the cut piece with some filler, or maybe cut a new piece a little larger than what you cut out to get a better fit.
You can keep the piece locked in from below if you install some of those sliding barn door latches.
So far as the alignment of the tracks at the edge of the pit goes, if you can manage to keep the cut piece in the same position all the time you don’t really need to have any mechanical joint between the track rails. You would just need to have some sort of disconnectable electrical connection to the tracks on the removable piece. And if the location is as inaccessible as you say, you won’t be able to easily get in there to remove any sort of mechanical connector.
Hi, thanks. Yes, preferably remove it from above so I can do repairs on the rear-most tracks should the need arise in the future. Pushing from the bottom and handing it over would amount to the same thing in this case. I mostly want to be sure I’m not missing/forgetting anything before I consider cutting a big hunk out of a hard to rebuild area.
I was mulling over things to fill the saw cut space, my main concern about slop. The latches are a good idea.
I would suggest using 2 or 3 dowels that are mounted on the flange or lip that supports the plywood base piece. Drill the holes thru the plywood and thru the lip/flange while the plywood is clamped or screwed in place. then glue the dowels into the lip/flange with just enough protruding upward to engage the holes in the plywood base. After this is done and you are satisfied with the fit, you can lay your track so it will line up when you remove the plywood base. Just take your time in getting good fits on the dowels. You could also use steel dowels with mating hole plates, but that is a lot of work. Just another way to skin a cat!
The one thing I forgot to mention concerned the weight and size of the proposed lift out piece. That turntable is going to take up a big chunk of space, and of course there will be some sort of mechanism sticking down through the bottom to operate it. And then you’ll have whatever the distance is from your pit rail to the roundhouse, plus the roundhouse itself. The roundhouse will take up a large space depending on the number of stalls. Plus your roundhouse will have to be constructed keeping handling in mind.
Exactly how large do you think this liftout will be? Any possibility that only half of the facility would need to be removed?
If you want my straight forward advice, forget it.
LOL
If you are still reading, let me explain why I say this.
I have a situation that sounds similar to yours. I have attached two photos of that portion of my layout. Like yours, my roundhouse and 130’ turntable are in a relatively inaccessible corner of my layout, sitting on a 1/2" plywood surface.
If you look closely at the first photo, you can see where I installed a small lift out section so that I can crawl under the layout and lift that section out so I can reach the track work behind the round house. I used to get derailments back there so I had to have access. The cause of the derailments was a crossover just out of sight on the right side of the photo. That became such a nuisance that I removed and relocated the crossover. I no longer need to access that portion of the layout, and that is a blessing.
If you look at the second photo, you can see an open area of access to the left of the roundhouse. That open area gives me access to the round house stalls and to the track work behind the round house.
That turntable is 18" in diameter, and the round house contains 9 stalls. Those two structures sit on approximately a 4’ x 4’ area. That means that a lift out section would be heavy and awkward. Without the open access area to the left, I couldn’t lift that section out if my life depended on it. Too big, too heavy, too awkward.
Regarding the removability of the track connections between the turntable and the round house, I was far less concerned about removing the connections than I was about securing the track to the lip of the turntable pit. So, early on, I used CA adhesive to secure the rails to the lip. There is no way that I would want a series of removable connections. Plus, if I only had frontal access, there is no way that I could reach those connections to remove th
You might want to consider designing it so that you can remove it from beneath the layout, rather than having to lift it off over the top. If it is indeed deep in the back, then lifting it over the foreground scenery might be awkward.
Another thought is weight. 2-inch foam would be as stiff as plywood and wouldn’t weigh nearly as much.
I had considered what you are planning but voted against it for the same reasons given by others, size and weight. I elected to provide an adjacent access hatch as can be seen in the attached photo. The hatch cover is 1/2" plywood and will have some buildings on it but no track. I have plans to make it lift and rotate 90 degrees from below using a 1-1/2" dia pipe in one corner,with additonal mechanism to lift and lock. BTW, I used CA cement to hold the approach track rails to the pit flange
