Atlas 24” Turntable vs Pan-M-Bob Mftg Turntable

No experience with it, but the picture looks like you have much more flexibility on laying out the whisker tracks than with the Atlas.  Unlike the Atlas, it looks like you can put the whisker tracks anywhere you want them, and closer together.

Ron,

(or anyone else) is the lack of “indexing”

a big factor? Thanks!

I have had 2.    I still have one.

There is no indexing, you align it by eye.    I think it would be difficult install indexing based on the style of the drive.    The drive has a small DC motor that moves the bridge through a large gearbox.     The final drive is a small gear through the base that interfaces with a large gear on the base of the bridge.    Mechanically it is pretty robust.   The weak point is probably the motor.    Mine appeared very cheaply made.    One is still running and I replaced one with a motor out of an old battery screw driver.

I also replaced the controller with power from a small DC transformer and a spring loaded DPDT switch.

The assembly is easy to install.    You just cut a hole slightly larger than 24 inch diameter in your benchwork.   I would say about 24 1/8 inches diameter.    The Pit is a a metal stamping with a lip at the top.   You simply set it in the hole, and then use a few small screws to keep the pit from moving around.

It is probably a little more noisy than the Atlas.

In the photo above you can see the bridge, the controller on the upper left, and the gearbox below the controller.    The gearbox installs with screws to the bottom/underside of pit.    There is a bearing in the top of the gearbox.    A Pin on the bottom of the bridge slides down into this bearing hole and that keeps it aligned. 

On mine electrical contact is through that pin.   The pin is actually a metal tube that has a small pin coming down the center that is insulated in epoxy.    The out of the tube is one contact and the small inner pin is the other.   There are contact wipers in the gearbox that contact the tube/pin.    Then there are typical screw on connections on the outside of the gearbox to connect track power.

I have the Atlas 24" model, it's worked fine for me.  Given how busy it is around the TT and the visibility to the track ends, I can't imagine having one without indexing, I'd be forever trying to get the tracks aligned.  I'd love to have a Millhouse, but then you have to temper your expectations.

Like GRJ, the Atlas works for me too.  I had thoughts about a bigger more scalelike turntable but just can't justify the cost and the real-estate needed.

I can't imagine not having the indexing.  It just makes it easy, no fuss no muss.  I made a slight modification so our GG-1's can pass under the tower with the pantograph's in the up position.

Have Fun!

Ron

@Gerhardt posted:

Ron,  (or anyone else) is the lack of “indexing” a big factor? Thanks!

IMO, yes.  I can't imagine trying to line the tracks up by eye!  I had very little room for the TT, and initially I had decided against one.  However, I got to measuring the empty space available and gave it another thought.  When I saw the Atlas 24" TT, I  decided to give it a try.  It was easy to install and actually works way better than I expected.  Here's an older shot of it filled up.  As you can see, trying to line up the tracks from my typical vantage point would be a nightmare, at least for me!  In order to get inside so I'd be next to the TT, I have to raise the lift-bridge.  Doing that while you're running really isn't all that desirable!

After fooling around with several turntables without indexing at other layouts, I'd never consider one without indexing for my layout.

Thanks Ron and John on your input on the Atlas turntables and indexing.  Prrjim, I'm glad to hear as well from your experiences.  Although it is tempting to look at the Pan-M Bob turntable, I'm going to stick with what I have as Atlas is still around and making these turntables if I need parts or have any issues.  Thanks again for your input and Happy New Year!

Subject to the obvious visual limitation of no real pit, the Atlas TT works quite well, and can be embellished to looks somewhat realistic.  It actually works way better than a chunk of plastic that size would be expected to, that's for sure!

I will say that a truly level spot is probably key to reliable operation.  My benchwork is topped with Baltic Birch multiply and then Homasote and it pretty much pool table flat.  The Atlas TT dropped right in and was no issue.  I have seen one that was on benchwork that was a bit "lumpy", and it didn't work nearly as well.

I have a 22 or 24 inch Bowser with Indexing Kit I am willing to sell. It is New in the box I picked it up years ago and never used it. Parts of the bridge kit are missing and it has the old Bowser drive system on it.

The Pan-M_Bob TT is a traditional 3-rail accessory.    It is probably 1950s vintage.    So if fits well visually with a PW 3-rail layout.

The lack of indexing is definitely a disadvantage.    You need to locate it close to the front of the layout so  you can see what is happening.   

I had a friend who passed away a few  years ago that had scratch built his TT and mechanism many years ago in HO.   It was about a 10 inch long table.    He also built a really great, reliable, indexing system using relays that worked flawlessly.       He used many relays, I think two per postion.    In its last location it had a 26 stall roundhouse and 3-4 auxiliiary tracks.    But the neat part was the mechanism and indexing beneath the table was about 2 feet deep and about 2 feet in diameter in a 2x4 frame.

Great info

@gunrunnerjohn posted:

Subject to the obvious visual limitation of no real pit, the Atlas TT works quite well, and can be embellished to looks somewhat realistic.  It actually works way better than a chunk of plastic that size would be expected to, that's for sure!

I will say that a truly level spot is probably key to reliable operation.  My benchwork is topped with Baltic Birch multiply and then Homasote and it pretty much pool table flat.  The Atlas TT dropped right in and was no issue.  I have seen one that was on benchwork that was a bit "lumpy", and it didn't work nearly as well.

The BNSF ex BN ex Frisco has a pit less turntable in Springfield MO just off the east side of the highway bridge on the North Kansas Expressway over the BNSF tracks.

I planted grass in the white/tan pit area of my Atlas turntable, hard to see in these old pictures below.

Made a better picture of the grass in the pit area.

That looks really good!

Grass, another good idea to dress it up.

Really interesting post.  I have only been in 3 rail for 13 years now.  I have never even heard of a Pan-M_Bob TT, which " is a traditional 3-rail accessory."

@John C. posted:

Really interesting post.  I have only been in 3 rail for 13 years now.  I have never even heard of a Pan-M_Bob TT, which " is a traditional 3-rail accessory."

20+ and I never heard of that one before either.

After retirement started going to auctions and see many things that I never knew existed. Have been into model trains my whole life. This turntable is new to me also

@CBS072 posted:

The BNSF ex BN ex Frisco has a pit less turntable in Springfield MO just off the east side of the highway bridge on the North Kansas Expressway over the BNSF tracks.

I planted grass in the white/tan pit area of my Atlas turntable, hard to see in these old pictures below.

Made a better picture of the grass in the pit area.

I took a much better picture of my Atlas turntable yesterday.

Turntable looks good with the grass. Does it interfere with operations?

No, the grass moves with the bridge, the bridge is mounted too the base that turns as one large lazy susan.

Good to know

I have seen the real turntable you spoke of as I used to live near Springfield mo. your grass idea looks almost real. no issuses with my atlas tt. it is the older one.

Have always been wanting to ask atlas if they would sell just the new motor and base assembly. that way I could get the new belt drive without buying a whole new turntable.

@Lionelzwl2012 posted:

I have seen the real turntable you spoke of as I used to live near Springfield mo. your grass idea looks almost real. no issuses with my atlas tt. it is the older one.

Have always been wanting to ask atlas if they would sell just the new motor and base assembly. that way I could get the new belt drive without buying a whole new turntable.

Yes, my turntable is one of the older models. It works OK but have not used it in a few years.  Check the search on the forum for Atlas turntable belts, I think years ago someone was using O rings as replacement belts, I do not remember the size that they used.

Great thread !!!

Thanks to all posters !!!

CB&Q Bill

I called Atlas about a year ago and inquired about updating my older Atlas TT to the newer cog-belt drive.  The parts guy said it won't mate with the older motor mount and gear drive.  I just have a small supply of drive belts on hand.  Just in case.