what is the smallest radius of track made...not flex track...something solid that will keep shape
Quote from: Hunt on December 20, 2010, 09:59:44 PM
In HO gauge, that is easy to find -- 15" radius.
What does your question about curve radius have to do with a turntable?
I may have an idea how they relate......
Fullmax, are you planning on building your own turntable? I see it workin as you making a circle of 15" radius curves, and using let's say trucks from a frieght car for the ends of the deck. Am I right? Seems like it could work.
maxx-
Neither rail of 15" radius is 15" radius. That's the centerline radius, so you'll end up with something just a little longer or shorter than 15" Frankly, you may have a good idea percolating here if the other posters' hunches are accurate. However, I'd urge you to cut the rim track in half and just use either inside or outside curves. That will look much more prototypical. Also, don't neglect the common turntable solution of building one on top of an Atlas turntable. All of your indexing and electrical supply problems will be solved and you can have plenty of stalls with the new model which is indexed at 10o or 15o, I forget which. Good luck!
-- D
Blink you are correct...that is my intention...i have till March to get it done,however if 15 is the smallest then it would have to be out of sight ... dont need a 30 in bridge...biggest engine is close to 13 in total length...how does the atlas index system connect to the turntable as in how does it make it turn
Atlas uses something called a geneva movement to index their turntable. It is a mechanical device used to change constant rotary movement into intermittent rotary movement. That is to say that as rotary movent is input (you turn the crank or run the motor), intermittent movement results (the turntable starts and then stops at each stall in turn). You can find an annimated example here:
http://kmoddl.library.cornell.edu/tutorials/10/
The problem with using a geneva movement is that you can NOT skip a stop. The advantages are that it is inexpensive to produce and it will work reliably until it wears out--nothing to adjust or fiddle with.
OldTimer
so I take it if it wont skip stops then the stops are not adjustable as far as the distance between stops
Quote from: full maxx on December 21, 2010, 06:16:53 PM
so I take it if it wont skip stops then the stops are not adjustable as far as the distance between stops
That is correct. I would post some photos of the Atlas I have but Photo Bucket is just about at a standstill.
I posted some photos here sometime ago but I doubt a search would turn them up. The search engine is not very friendly.
You might try though. From what I recall, there are two different versions for indexing.
Obvious Man just told me to look at You Tube for a video about this turntable and below is what I found.
http://www.youtube.com/results?search_query=atlas+turntable&aq=f
Rich
hey richg in the link you posted the third vid down it says atlas o turntable demo....is that also the speed at which it will turn in ho scale as well or can you slow it down
Quote from: full maxx on December 21, 2010, 10:57:41 PM
hey richg in the link you posted the third vid down it says atlas o turntable demo....is that also the speed at which it will turn in ho scale as well or can you slow it down
You can operate the motor with a power pack like any locomotive. Vary the speed like any loco. Just don't try to run the turntable at 100 mph like a cheap loco.
Connect the orange and grey wires from a decoder and use a DCC controller to operate the motor.
Both will work. The motor is a common DC motor.
Rich
ok the turntable is more or less a rotating bridge right and this bridge has two ends right ok so we will call them A n B ...so will A and B both line up with the same engine stalls for parking so you can drive it in or back it in depending on whether you keep rotating it or not
FM,
The short answer is "Yes" you can. The Atlas turntable, automatically switches polarity at one point in the turn. In DC, you don't have to change direction on the throttle, whether you drive forward or turn around and back in. Not sure I explained that well enough.
Can't speak for the other brands, as all I have are Atlas turntables.
Regards,
Jonathan
the atlas turntable will rotate through 360 degrees.
here are some other specs you might find of interest.....
track spacing is 15 degrees (as opposed to bachmann turntable's 20 degrees. this gives a total of 21 track slots, with 3 other slots taken up by the geneva movement.
out of the box, it comes with a hand crank, with a motor concealed in a shed available as an add on.
length of the turntable "bridge" is 9" and due to the location of the geneva movement if you wish to build a pit type turntable using this as a base you probably won't be able to lengthen the bridge. bridge length is sufficient to turn small steamers with tenders, just about any tank type steamer, any 4 axle diesel, and 6 axle diesels up to and including a u30c or alco c630. sorry, you won't be able to turn a dda40x on this table.
the turntable has a slip ring inside which automatically reverses polarity as it turns. you don't need an autoreverse unit with this turntable. half the track slots are one polarity, the other half the opposite polarity. an a or b in the track slot tells you which way to wire that particular radial track.
last, the following link shows how to convert the atlas turntable into a pit type turntable.....
http://www.2guyzandsumtrains.com/Content/pid=11.html
Check out these articles on Carl Arendt's excellent website. I started to construct one of the 'CD Turntables'; but never finished the project ('sound familiar?).
http://www.carendt.com/articles/index.html (http://www.carendt.com/articles/index.html)
Carl's website is full of clever ideas, so check it out.
Regards,
Ray
instead of a cd how about a lp ... vinyl...anybody know the diameter of a standard record...after all it is a turntable right...
33 1/3 LP's were, as best as I can remember, about 12" diameter.
OldTimer
Using an old LP record...what a clever idea! Old LPs can be had at any Goodwill or Salvation Army for pennies (not to mention all those old LPs some of us have stored in the basement). A step further would be to procure an old turntable (inoperable of course). The LP could be glued to the turntable and hand rotated into position.
Another option is to purchase the Atlas turntable, raise (and enlarge) the deck and install a larger length piece of track. [The turntable deck needs to be raised in order to clear the motor housing.] The turntable could then be 'lowered' into the layout surface - allowing one to utilize the excellent Atlas indexing mechanism. I suppose the new sub deck could be an old LP.
'Just a thought to stimulate discussion,
Ray
Best turntable I've ever owned is the Walthers "Ready Built" 90 foot 'table.
Once you've figured out what the instructions really mean it works like a charm. Indexes perfectly every time, without fail.
Pricey, yes but well worth it.
The 90 foot 'table takes every size of GER steam locomotive from the 4-6-0s right up the to 2-10-2s. The 4-8-2s and 2-10-2s are a tight fit but as the roundhouse where the 'table will be located on the new GER won't be used for servicing and or turning "main line" steam it's perfect for branch line, way freight and commuter power that will operate out of the new station and yard. The roundhouse will service a collection of 4-6-0s, 2-8-0s, 2-8-2s and 4-6-2s and, of course, the yard engines.
What the 90 foot won't take is a two unit diesel locomotive but that's OK as many a steam era 'table had the same problem and as the GER doesn't own any 'B' units, diesels are always m.u.ed tail to tail so there is always a cab leading.
Quote from: CNE Runner on December 23, 2010, 11:50:25 AM
Using an old LP record...what a clever idea! Old LPs can be had at any Goodwill or Salvation Army for pennies (not to mention all those old LPs some of us have stored in the basement). A step further would be to procure an old turntable (inoperable of course). The LP could be glued to the turntable and hand rotated into position.
Another option is to purchase the Atlas turntable, raise (and enlarge) the deck and install a larger length piece of track. [The turntable deck needs to be raised in order to clear the motor housing.] The turntable could then be 'lowered' into the layout surface - allowing one to utilize the excellent Atlas indexing mechanism. I suppose the new sub deck could be an old LP.
'Just a thought to stimulate discussion,
Ray
you were reading my mind with the old record player....I need to make it a little bigger so any future engine will fit w/o complication...
rog .... you have my couriosity about the 90 footer that will fit a 2-10-2...will look into it
Maxx.
My 2-10-2s are not Spectrum models so I don't know if an unmodified Spectrum 2-10-2 will fit on the 90 foot Wathers "Build Ups" turntable.
My 2-10-2 were kitbashed from "President's Choice" (re-branded IHC 2-10-2) Christmas promotion "train sets" sold by a Canadian supermarket chain that trades under various names across Canada. I replaced the odd looking IHC tenders with Spectum Hicken tenders that I converted from oil to coal and also removed one water course ring which shortened the tender by about four scale feet. I also did some other kitbashing to the locomotives to get them to look unique to the GER. I also converted them into two subclasses by varying the details, something I frequently do with my GER motive power so as to obtain the effect of the larger steam fleet than I really have.
I've attached two photos. The top one is of a 2-10-2 so that you can see the changes I made. The second is of a Spectrum heavy 4-8-2, which is about the same length as my 2-10-2s showing how it just fits onto the 90 foot 'table. Note that the heavy 4-8-2 has had it's tender swapped and now sports a medium (I think) tender and not the long one it came with. I replace all the long tenders with shorter ones, usually swapping them with people on this board. Right Gene? :-)
GER No. 783 a GER 2-10-2 arriving in Granville Junction.
(http://i94.photobucket.com/albums/l99/rogertra/Great_Eastern/GERNo783atGranvilleJunction-1.jpg)
GER No. 732 a Heavy Mountain on the Granville Junction turntable: -
(http://i94.photobucket.com/albums/l99/rogertra/Great_Eastern/Turntable9.jpg)
you have really short drawbars....looks very good tho...not saying we will ever own one but would like to build a turntable big enough to handle the big boy....just incase
Dont really need it but building that CD turntable might be good for turning my switchers around May try it for fun.
Yet another possbility for your consideration
http://www.modeltrainstuff.com/Heljan-HO-804-Manual-Turntable-14-Diameter-Kit-p/hel-804.htm
Same product, different web page
http://www.walthers.com/exec/productinfo/322-804
some more info
http://yardlimit.com/Projects/turntable.htm
found this by accident, a 130 foot turntable,,looks SWEET!
http://cchobbies.com/hoscale/structures/walthersturntable.htm
more from Walthers website
http://www.walthers.com/exec/productinfo/933-2850
Quote from: full maxx on December 24, 2010, 01:27:05 AM
you have really short drawbars....looks very good tho...not saying we will ever own one but would like to build a turntable big enough to handle the big boy....just incase
Maxx
Yes, I close coupled all my tenders as I had handlaid track with a minimum 28" radius. The next GER will have a minimum 30" radius or greater curves. Even with the 28" curves I was having some problems with close coupled full length passenger cars equipped with diaphragms. A minimum30" radius should, hopefully, cure that problem but I will conduct some tests before I begin major construction on the new GER
Merry Christmas.
Finally found a photo of a GER 2-10-2 on the Walther's Build Up turntable. You can see it's a tight fit even with the tender shortened by one water tank course. About four scale feet: -
(http://i94.photobucket.com/albums/l99/rogertra/Great_Eastern/GERNo783OnGranvilleJunctionTT.jpg)
Roger,
Really enjoy your 'art work'. Thanks for sharing the shots, and your talent.
Regards,
Jonathan
Quote from: jbsmith on December 24, 2010, 01:17:03 PM
found this by accident, a 130 foot turntable,,looks SWEET!
http://cchobbies.com/hoscale/structures/walthersturntable.htm
more from Walthers website
http://www.walthers.com/exec/productinfo/933-2850
I have that turntable and it is fantastic. I happen to have a brand new bridge for the Walther's 130 turntable, if anyone is interested. It is complete with a drive. I don't see me kitbashing anything with it because I lack the talent.