A lot have been said on the web about kitbashing the HO Atlas Turntable into a pit version. However, little is said how to assemble the different parts together (the false-bottom pit, the shaft and the bridge).
I made the shaft out of a 1/2" copper tube soldered on large washer. It's large enough to make is stable and on level. However, my method as a flaw, I'll have to put the false bottom before making the electric connections between the Atlas TT and the new bridge. Also, I think it will be a real pain to glue the shaft on the TT perfectly centered. The solution I came up with is to glue a pin on the turntable which will fit the 1/2" tubing.However, I'll have to drill holes in the tubing for the wires.
Before doing it I would like to get your opinion about that. How did you made it yourself. Maybe I should start over with a plain tubing (I've seen a lot of people doing it from plastic). However, I think without a large platform on it, it's hard to align the brige perfectly...
Matt
Proudly modelling the Quebec Railway Light & Power Co since 1997.
http://www.hedley-junction.blogspot.com
http://www.harlem-station.blogspot.com
I did a similar project with the Atlas turntable but without the false floor back in the 1960s based on a photo of one by modeler Hank Johnston. Worked OK, but I wish it wasn't limited by those fixed and mandatory track stops.
Mark
I did this one a couple of years ago.
http://www.trains.com/TRC/CS/forums/1162765/ShowPost.aspx
I spent a lot of time on this, and I'm still happy with the result. However, I never got the bridge track completely and perfectly aligned, so I have to "nudge" the position slightly off the index points in some orientations.
If I were to do this again, I would provide some way to align the bridge after assembly and installation. I used an Atlas deck bridge, cut down, for my turntable bridge. This gave me the ability to slide the rails a bit end-to-end, since they are clamped into the bridge structure, but not glued.
I'd certainly not install the stall tracks until the turntable is in place. That way, you can eliminate the "rotational" component of mounting error.
There remains the lateral, or "sideways" error. Ideally, I'd use a couple of set screws to hold the track in place sideways on the bridge, giving me a millimeter or two of motion on either end. This would also provide a bit more rotational alignment.
It takes an iron man to play with a toy iron horse.
Atlas Turntable kitbashing always interests me. The Atlas TT truely is a fantastic kitbash candidate. I did the project documented in the link below about 12 years ago using the old 30 degree model. The project simply used two gears with 3:1 gear ratios to get the 30 degree indexing reduced to 10 degrees. Things changed and I had to store the project away so I never got it built into a layout. However, the indexing and rotation speed modifications worked - it stopped at 10 degree indexes and I could get variable rotation speed. The Atlas TT continues to turn at 30 degree indexing but the bridge above the pit floor turns at 10 degree indexes. Also, I used a brush on the center axle and the wheels riding the ring on the stationary pit bottom to transfer power to the bridge track. Keep up the good work and enjoy your Atlas TT kitbash.
http://pages.sbcglobal.net/sgratke/sgrr/trains/matt/index.htm
Hi!
I've been intrigued by these since they came out (1960s???), but never bought one because I wanted one to handle larger locos or A/B consists. But what I figured was that you could put a longer deck on them (say 130 HO scale feet), somehow move out the motor housing, and raise the deck up to allow for a pit. You would be stuck with the stopping points programmed into it (mechanically), and they would be too far apart for a roundhouse. Butttt, given the price of the TT and motor, I'm surprised I haven't seen more of these kitbashes.
ENJOY,
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
Mobilman,
I think you got your answer about changing the indexes with Stevetx method. On the club layout, a member scratchbuilt a 120' TT (16") from scratches and videotape pieces. The indexing system is a little bit unsophisticated but somebody could make it looks better with a well detailled pit and bridge. I don't know the details, but this turntable turns completely on itself. You control the position with the AC switch and a auto-alignment device control the position.I've posted a few pictures of this TT, it only need to be detailled.
I bought the Atlas only because I'll use it on a branchline and won't use it often so I don't mind about the stopping points. However, their TT is very precise which makes it a great candidate for kitbash.
Stevetx,
I like the way you made bridge boogies. Looks better than car trucks often used for this.
First solution: I used a washer fitting precisely inside the copper tube. I'll glue it on the deck to align the main shaft precisely on the center. I'll notche the tube to make room for the wiring. Also, I will glue spacer on the shaft platform to align the bridge correctly. Then I'll connect wire and use screws instead of gluing the bridge. Using a bushing like your example would have made my life easier I think.
BTW, I remember seeing an article on RMM about small TT mounted on a stereo headphone plug. Anybody tried this unusual method for small TT?
ButlerhawkI have the Atlas turntable and would like to expand it to a 90' TT - this post gives me some encouragement for the task
From doing my own, there are a couple of problems with that idea. Not to say that it can't be done, but before you start, it's important to remember a couple of things.
First, there's the motor mechanism, and the way it's mounted:
It's not right on top of the table, but pretty close. A 90-foot is probably doable, but not much more than that without modifying the drive train.
The other issue is the 15-degree indexing. If you use a bigger bridge, you are still stuck with the indexing, and the stall tracks need to be even further apart at the end of the bridge. This is OK if you're using open stalls, but it makes it even harder to align this with a roundhouse.
The solution, though, may be that brilliant idea of using reduction gears. This would allow you to offset the center of the Atlas from the center of your larger turntable, and you could get the indexing tighter to get rid of the 15 degree issue. If you're not keeping the Atlas co-axial with your own bridge, though, you have the problem of electrical pickup. The Atlas takes care of the pickup and reversing circuitry for you, but you might instead have to do it yourself. If you're using DCC, I'd recommend just wiring the bridge straight through and using an auto-reverser.