Bachmann Message Board

Discussion Boards => HO => Topic started by: Yampa Bob on June 12, 2008, 09:28:47 PM



Title: Turntable Information
Post by: Yampa Bob on June 12, 2008, 09:28:47 PM
Does anyone out there in forum land have the Atlas 9" turntable?  I am considering incorporating the escapement mechanism into my home made table.

Is it supplied pre-assembled, and not easily dismantled to keep snoopy people like me from seeing how it's made or bashing it?

I have searched the net, and all I can find are pictures by dealers.  No reviews, exploded drawings, or any details that might help me.

I can buy one for $18, but hoped to find some drawings or information first. I am also considering the motor drive, does the mechanical indexing also pause the motor or what?  Ideally it would have a momentary button with micro switches to "step" each index position. 

Last question: The thing is belt driven, so to increase the diameter means using a longer belt.  Is the belt grooved on the inside mated to gears, or just smooth? 


Title: Re: Turntable Information
Post by: Ten Wheeler on June 12, 2008, 10:05:37 PM
Bob...  I bashed an Atlas HO Scale turntable, and I like it's operation very much. The Atlas indexing is totally reliable, and it does pause at each and every indexed track position as it turns. The T/T doesn't have a belt.. it is strictly a geared operation.

The motor & indexing mechanism was a tad noisy for my liking, so I replaced the Atlas shed that covered the motor with an over-sized scratch built shed (so I could add sound-deadening material to all the inside walls).

I have seen applications where the modeler turned the motor unit upside down (inverted it)... and in doing that I think you could probably increase the size of the table platform/bridge as the motor would no longer be in the way.

I model the Montana Western (1950) when it only had two small engines, and a 2 stall engine shed... so their table was solely used to "turn" the lokeys.

I hope this info helps... I'm glad to help anyway I can.

Bob/Ten Wheeler

(http://i23.photobucket.com/albums/b371/IronGoat/IMG_4618SmallSmall.jpg)


Title: Re: Turntable Information
Post by: richG on June 12, 2008, 11:13:45 PM
I have a new one. Here are a few photos. Some railroads had some like this with the completely covered pit. The print is larger than 8 1/2 X 11. Two scans. There is some overlap.

A   link to an Atlas modification.
http://www.2guyzandsumtrains.com/Content/pa=showpage/pid=11.html

(http://i98.photobucket.com/albums/l267/richg1998/Turntable/AtlasTT1.jpg)
(http://i98.photobucket.com/albums/l267/richg1998/Turntable/AtlasTT2.jpg)
(http://i98.photobucket.com/albums/l267/richg1998/Turntable/AtlasTT3.jpg)
(http://i98.photobucket.com/albums/l267/richg1998/Turntable/AtlasTT4.jpg)

Rich


Title: Re: Turntable Information
Post by: Yampa Bob on June 13, 2008, 02:09:24 AM
Bob and Rich, you guys are super.  Thanks. 

On the web site there was mention of another article called "A TT for Drew", using an HO model, but I couldn't find the page.  I still find it odd that Atlas made such a small table for HO scale.
 
I notice on the larger ones, Walthers for example, the superstructure in the middle of the bridge.  What was that used for?

I've got an order on hold in Denver, will add a turntable tomorrow.

Caboose Hobbies has a Father's Day sale on, an extra 15% off for instock items only.  They had one 50' Overland set in stock with a loco, and several Overton sets. My office is starting to look like a hobby shop.  :D   


Title: Re: Turntable Information
Post by: Ten Wheeler on June 13, 2008, 02:55:22 AM
Bob... Try this one.

http://forum.zealot.com/t158415/

Bob/Ten Wheeler


Title: Re: Turntable Information
Post by: Yampa Bob on June 13, 2008, 04:14:19 AM
Informative thread, thanks again Bob.  It makes me feel better knowing I'm not the only "mad scientist" in railroading.

It was interesting to note that most of the posters were giving encouragement and good advice, but there is always one guy that starts screaming "But that isn't prototypical".  His advice was to either buy a bigger table or sell the longer locomotives, and that bashing the 9" wasn't worth the effort.  Whose effort?   

I seldom follow others, I prefer to build "Prototypes", something unique that's never been tried.  If we all wanted prototypical we would still be driving Model Ts.  My policy in life has been:  "Be an innovator, not an imitator".


Title: Re: Turntable Information
Post by: Woody Elmore on June 13, 2008, 08:41:06 AM
Yampa - the superstructure on the middle of some turntables is for an operator.


Title: Re: Turntable Information
Post by: richG on June 13, 2008, 11:20:28 AM
Here is a Atlas turntable project.

http://www.2guyzandsumtrains.com/Forums/viewtopic/t=3122/highlight=turntable.html

Rich


Title: Re: Turntable Information
Post by: Yampa Bob on June 13, 2008, 02:27:01 PM
Maybe I'm not describing it correctly.  Look at the Walthers 90 and 130. Just a small arch over the top.  I thought the operator is in the cab at the end of the bridge.

On the Atlas O it's just a piece of tubing, like a roll bar.

On the older types, guess they called it a bridge and had to brace it like a suspension type.  But with the truss bridge there is no need for bracing with the end bogies?

Anyway the Atlas is on the way, lots of ideas in the noggin.  I guess the belt drive thingie was about the motor unit.  I'm curious how the horizontal motor shaft belts to the manual crank shaft.  I imagine it will make sense once I take it all apart.


Title: Re: Turntable Information
Post by: Ten Wheeler on June 13, 2008, 02:43:57 PM
Bob, I'm not sure but just about all of the prototype photo's of that type of T/T show a "swivel" type connector atop that arch. There was a wire that was attached to the connector (that usually ran overhead from a util. pole near the table area). As the bridge would revolve, the electrical connection stayed constant, and simply pivoted. There usually was a blinking or flashing red light atop the arch, also.

Whether this was the power feed for the T/T motor, or not... I do not know.

The covered T/T I modeled was originally said to have been either "Steam powered"... supplied by the locomotive that was on the table, or was pneumatically operated. Finally I found a former employee who confirmed it had been "air operated".

Once again, I hope helps....   Bob / Ten Wheeler


Title: Re: Turntable Information
Post by: richG on June 13, 2008, 03:20:54 PM
Here is a little info on that structure at the center of the turntable. I supect some roads limited the rotation to 360 degrees or used a slip ring device for continus rotation.
http://www.walthers.com/instructions/0933/09330000002613.pdf

The Atlas is Not belt driven. There is a cam/gear assembly that stops the turntable every 15 degrees even if the motor is still running or the hand crank version is still being turned.
I had an older Atlas apart some time ago. The table is molded underneath for the cam so the TT stops every 10 degrees. Not easily modified. Some people do not like the TT stopping where there is no track. Below is one persons mod.

http://pages.sbcglobal.net/sgratke/sgrr/trains/matt/index.htm

Rich


Title: Re: Turntable Information
Post by: richG on June 13, 2008, 03:32:02 PM
I am mistaken on the belt drive. The newer Atlas TTs are belt driven I found out in a search. I was going by my "older" Atlas TT. Not even sure if the photos I posted are like the newer Atlas.

http://pages.sbcglobal.net/sgratke/sgrr/trains/matt/drive.htm

Rich


Title: Re: Turntable Information
Post by: Ten Wheeler on June 13, 2008, 04:18:25 PM
Rich...  I wonder if the belt drive will soften the noise a bit?  However. I think most of that is from the plastic gears....  I still don't find it that problematic.

         ::)
Bob/Ten Wheeler


Title: Re: Turntable Information
Post by: richG on June 13, 2008, 04:37:20 PM
In the link in my previous message, the writer does say the drive is quieter.

Rich


Title: Re: Turntable Information
Post by: Daylight4449 on June 13, 2008, 06:45:07 PM
will a spectrum 2-8-0 and 2-10-0 fit on that table?


Title: Re: Turntable Information
Post by: Pacific Northern on June 13, 2008, 07:29:13 PM
will a spectrum 2-8-0 and 2-10-0 fit on that table?

Not sure of your question.

Are you referring to the "new" Atlas turntable? It is the same size as the old turntable 9" in length.

No, neither turntable will hold a 2-8-0 or a 2-10-0.
 


Title: Re: Turntable Information
Post by: Ten Wheeler on June 13, 2008, 07:45:22 PM
Not on the (unmodified) Atlas HO scale T/T... it measures 65 scale feet in length.

Bob/Ten Wheeler 


Title: Re: Turntable Information
Post by: Yampa Bob on June 13, 2008, 08:11:22 PM
I won't mind the pause at each index, that's just the way an escapement works. That pause would give me time to turn off the switch or release a push button. 

Those gear mods shown are all done at the center, still requiring a pit.  From what I am able to see, there is no reason why the crank can't be removed, and spur gears added to the bottom of escapement box.  Then the table could extend out over the box. 

You guys can give me 21 lashes with a wet noodle, I searched the net for several days and got nowhere, should have asked you in the first place.


Title: Re: Turntable Information
Post by: SteamGene on June 14, 2008, 10:41:01 AM
If ieither does, just barely.
Gene


Title: Re: Turntable Information
Post by: japasha on June 14, 2008, 08:38:46 PM
I have used the Atlas turntable for a reliable drive unit for the Walthers kit. If anyone is interested, write me direct.

Jim Pasha
japasha@aol.com


Title: Re: Turntable Information
Post by: Yampa Bob on June 15, 2008, 11:24:49 PM
A friend in Germany is extending an Atlas table, sent me some great pictures. I'm sure once I get the table tomorrow all my questions will be answered.

The motor unit drives the table via a worm gear, so it can be turned around to give enough clearance for the extension.