Turntable Motor

[jonathan]

I have the Atlas 9" turntable.  I also picked up the accompanying motor unit. 

The instructions suggest a DPDT switch to control the motor with the power pack.  I do not like this option.

I was thinking of this:

I have two wall warts: ones output is 9V at 150mA; the other is 9V at 300mA.  Can I set up a momentary switch to operate the motor with one of these power sources?  I believe it is a 12V motor.  Will this be enough juice to turn the table?  I understand I won't be able to control the speed. 

I've mentioned before I'm challenged in the electronics department.  It seems like a logical set up.  Just don't want to burn the house down.

Thanks.

Regards,

Jonathan

[pdlethbridge]

You are better off with the DPDT co switch as holding a button until the train is at the right spot will end up as a pain. With the DPDT switch, you can leave it on until its at its position and then shut it off. Because the way the turntable is geared it stops at every position and waits a couple of seconds, goes to the next spot, stops for a couple of seconds, etc, etc, etc. You could use the wall wort for power, but you'll need a way to stop and reverse the turntable, that's what the DPDT switch is for. 

[Doneldon]

jonathon-

The DPDT switch is the only way to go.  You can end up holding your momentary switch for a looonng time while you wait for the table to index at every stall. 

I'm not so sure your nine volt warts are up to the job, especially the 150ma one.  Even the larger one is likely to be taxed to its limit.  That's okay, I suppose, but you don't want a failure in the middle of an operating session.  After all, stopping everything while you search (possibly fruitlessly) for the crank which came with the table and install it would be a real bummer. 

          --D

[jonathan]

Thank you.

I was afraid someone would recommend keeping the DPDT switch.  I may swoon from the answer, but could someone rescue me and tell me how to wire the switch so it changes the direction of the motor?  I assume the answer will have a diagram like this:

       -      -     -   

       -      -     -

Thanks again.

Jonathan

[pdlethbridge]

Lets number each post. 1   2   3
                                    4   5   6   
To start, run wires from 4-3  and 1-6, That's for reversing the circuit
second, use 1 and 4 to power the turn table
third, use 2 and 5 to hook to your power source.
If the switch is thrown to the left, its contacts will touch 2,3  and 5, 6
If the switch is thrown to the right, its contacts will touch 1,2 and 4,5
If the switch is thrown to the center, no contacts are made.

[richg]

Got o the below Google search link I found. Scroll down to DC Power supples. The circuit is clearly shown.

http://www.trainweb.org/strrailroad/choirb08.html

Get a multimeter like the below one. I have three of those. Use the 200 ohms scale for continuity checks.
Sometimes this company has them on sale for $4.99.
Use the meter to check for motor current when installing DCC.
Check the layout  for wiring shorts when wiring the layout.

http://www.harborfreight.com/7-function-digital-multimeter-90899.html

There are plenty of Google links for using a multimeter. No model railroader should be without one and the knowledge to use it.

You can also buy them off of ebay for $10.00 or less including shipping. I have done that before. You just have to be a careful shopper. They alll come from China and I hope they are Melamine free. 

Rich

[Doneldon]

jonathon-

You can also use an Atlas Twin which will come with instructions.  It can also reverse the polarity on a turntable although the Atlas unit is designed to eliminate this issue if you are careful about wiring the stall tracks.  You can probably find a used one at your LHS or pick one up on ebay for a few dollars.  They aren't elegant but they work.  However, I'd pick up a switch at Radio Shack or a home store for much less.  Good luck with your project.  Just think of the satisfaction you'll enjoy when it's all hooked up and working like a charm.

          --D

[jonathan]

Thanks, all.

I now understand how to wire the DPDT switch, which should fit well on the little panel I made for turntable control.

I tested the 9V 300mA wall wart this morning.  It provides plenty of power for the motor.  So I secured the motor in place and ran a couple of temporary wires.  Lubed the motor assembly and tested the table operation.  Works great.  The motor is quite noisy, even with the structure covering it.  I may experiment with some kind of sound deadening insulation in the dead space around the motor.

I stored the crank in the motor kit box, for safe keeping.  I also discovered a spare drive belt in the motor kit box.  Bonus!

Off to Radio Shack for a DPDT switch...

Thanks, again.

Regards,

Jonathan

[jonathan]

Making progress on my turntable project, thanks to your help.


Here's the DPDT switch.  It's a little big, but it was also the least expensive one, so I'll live with it.  Plus, it works!  Thanks for the wiring tip, PD.


The Atlas prototype was a rare design.  It was engineered to share space with automobiles.  Thus it was totally flat to accomodate cars and trucks.  I'm building up the front to allow the same thing.  Still have 1/8" to go.  


I used every kind of scrap track I had for the stall tracks; steel, NS, brass, 83, 100, etc.  This piece of brass track reads 'Made in Austria' or 'Hungary', I can't remember which.  Notice the wood grain looks like finger prints.  It all works.


I made the wheel stops out of rail joiners from the really old brass track.  Just flatten, file, and install.  Thanks for the ideas on that, too.


Will build up around the structure, as well, to hide all the plastic pieces.


Here's the motor.  It's loud as all get out, but it works.


Regards,

Jonathan

[J3a-614]

Jonathan is turning out to be very old-school--Varney and Bowser engines and cars, ancient Athearn cars, brass track in some places--may not always be the closest to scale fidelity, but I think it looks cool and he has fun!  What more could you ask?

I recall reading in one of my ancient magazines, in a review of the Atlas turntable when it was new, that the turntable, with its deck, is inspired by the covered table in the roundhouse at the B&O Museum in Baltimore!

Now, for some more "homework:" check out "How to Wire Your Model Railroad," by the late Lynn Wescott.  Wescott was the editor of Model Railroader for many years, and in addition to a variety of articles and editorials, wrote a number of "how to" books.  This one dates from the late 1950's or early 1960's, and was still in print until relatively recently (like the last 20 years or so).  Given its age, it's about traditional block wiring, so for DCC users it's hopelessly out of date, but it also goes into the function of things like DPDT and SPST switches, motor construction, and a bit of electrical theory, all done in a sort of folksy style that is both easy to understand and, I think, enjoyable to read--and electricity is not one of my favorite subjects.

Enjoy.

[jonathan]

I'm more like cheap school.

Actually, I'm all about incorporating my inherited equipment as much as possible.  I like the connection across generations.  It also helps me afford the fancy engines (Spectrum, Genesis, Master Series, BLI, etc).

With DCC and a computer, one could set up a 'set it and forget it' layout.  You could conceivably, program an operating session, and stand back and watch it all run.  Instead, I have set up three operating stations, requiring me to operate throttles on/off switches, turnouts, and lighting eventually.  Makes me feel like I'm part of the action in my fantasy universe.

And, yes, I'm having a great deal of fun!  (except the homework)

Regards,

Jonathan

[ABC]

Jonathan, I think you may have some Rocco track on your hands.

[jonathan]

Man, more homework.  I had to look up Roco.  Just found a couple of wiki paragraphs.  It doesn't surprise me that my grandfather would have sought ought German/Austrian made equipment, since both sides of my family are either of German or Austrian heritage (going back a couple of centuries anyway).

This is why like playing with the old gear.  The history is great.

Perhaps, just perhaps, this is also why I like Bachmann stuff, too.  

Regards,

Jonathan

made in China

[pdlethbridge]

jonathan, were you made in china??/

[Doneldon]

Jonathon-

I'm impressed by the fine work you did with the Atlas turntable.  It looks great.  And your wheel stops are terrific, too.  There is one problem, however.  Pick up trucks almost always have wheels that turn in response to the driver's actions inside the vehicle.  So you don't need to use the turntable for them.

          --D