scottychaos wrote:I know DCC technology exists that will automatically handle the polarity changes..thats a no-brainer..but as for the rest..I dont know..
The polarity changes don't even have to be DCC related, a pair of wipers on the turntable pivot or will change the polarity on the turntable itself, 1950's era technology.
The hard point is slowing down the train on the turntable and acceleratign it off. With DC is fairly simple to vary the track voltage. With DCC you have to have something communicating with the command station and it has to know which engine its controlling. It has to know that engine 17 is pulling on the turntable since its only going to control the decoder in engine 17. That will probably require some software and a computer interface.
The simple way to go is to just cut the power Have a sensor that detects when the engine reaches the end of turntable and it just activates a relay, electronic or mechanical, that cuts the power to the turntable. The train just stops (depending on how much momentum any flywheel contributes). After the turntable rotates it trips another relay, that turns the power back on. The downside is the lurching to a stop and a start. Visually it won't be a problem since it will be off scene, the only concern would be mechanical.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com
dehusman wrote: The simple way to go is to just cut the power
The simple way to go is to just cut the power
I admit I know nothing about DCC but doesn't cutting the power cause problems when the power is turned back on?
However, it brings up a whole different question, if you are just planning on 1 train operation, do you really need DCC? I guess I don't remember if you stated if you are planning on DC or DCC.
Check out the Deming Sub by clicking on the pics:
el-capitan wrote: dehusman wrote: The simple way to go is to just cut the power I admit I know nothing about DCC but doesn't cutting the power cause problems when the power is turned back on?However, it brings up a whole different question, if you are just planning on 1 train operation, do you really need DCC? I guess I don't remember if you stated if you are planning on DC or DCC.
No, I dont think cutting the power would hurt at all..in fact, it could be very useful!
Drive train onto bridge, cut power (somehow) to stop the train.
Turn the table 180 degrees.
Turn power back on..train starts back up right where it left off and heads off trhe table..
I agree the sudden jerky starts and stops arent that great though..
Im running DCC because I think it will be much easier than DC..and my first engine came with DCC sound..and IMO it is a far superior way than DC to run a railroad..even a small one.
so basically im using DCC "because I can"! ;)
Scot
el-capitan wrote:However, it brings up a whole different question, if you are just planning on 1 train operation, do you really need DCC?
Three word answer:
Sound, special effects.
Plus he may have another train switching in the yard.
scottychaos wrote:I agree the sudden jerky starts and stops arent that great though..
In reality, even if you did ramp down the speed, it would still have to be fairly quick, so there may not be that much difference between a ramp down over a distance of 6 inches and a straight shut off. On the other hand, a ramp up could be longer and less jolting.
dehusman wrote: scottychaos wrote:I agree the sudden jerky starts and stops arent that great though..In reality, even if you did ramp down the speed, it would still have to be fairly quick, so there may not be that much difference between a ramp down over a distance of 6 inches and a straight shut off. On the other hand, a ramp up could be longer and less jolting.Dave H.
If the turntables are out of sight, it wouldn't really matter if the stops were kinda sudden, unless the speed/stop was so violent it caused a derailment. The starts wouldn't be a problem, since when power is reapplied the CV3 momentum settings could be set to gradually bring the engine up to full speed.
Actually DCC would make great sense in a small layout, not have to worry about blocks if you do want to run two engines at the same time.
One thing though...if you're going to build the layout with the two "full train" turntables, do you really need two regular turntables with roundhouses (and what appears to be an engine house)?? If you're going to have 10+ locomotives I guess you might, but otherwise removing one TT/RH would open up space for something else.
wjstix wrote: dehusman wrote: scottychaos wrote:I agree the sudden jerky starts and stops arent that great though..In reality, even if you did ramp down the speed, it would still have to be fairly quick, so there may not be that much difference between a ramp down over a distance of 6 inches and a straight shut off. On the other hand, a ramp up could be longer and less jolting.Dave H.If the turntables are out of sight, it wouldn't really matter if the stops were kinda sudden, unless the speed/stop was so violent it caused a derailment.
If the turntables are out of sight, it wouldn't really matter if the stops were kinda sudden, unless the speed/stop was so violent it caused a derailment.
Sudden starts and stops put alot of uneeded stress on the drives of your locos. Depending on how much you plan on running the trains, it could be a problem.
Just out of curiosity, are these "extra long" cars and locomotives actually available????. If so I must have missed them in the catalogs and web sites.
Bob
Don't Ever Give Up
superbe wrote: Just out of curiosity, are these "extra long" cars and locomotives actually available????. If so I must have missed them in the catalogs and web sites.Bob
wjstix wrote:One thing though...if you're going to build the layout with the two "full train" turntables, do you really need two regular turntables with roundhouses (and what appears to be an engine house)??
This created an idea. if you put the turntable near the corner of the layout room, you could use the same turntable for either end and when you turn the turntable it could "open up" the aisle for entry. Simplified idea, draw a loop and put a turntable in the loop, When you rotate the turntable 90 degrees you open up at least a 2 ft "aisle" in the loop. So by positioning it correctly you could have a continuous loop or a turntable at each "end" of a point to point layout, plus unrestricted access into the layout.
superbe wrote:Just out of curiosity, are these "extra long" cars and locomotives actually available????. If so I must have missed them in the catalogs and web sites.Bob
Not really available commercially, no...well, not through the normal hobby catalogs anyway.
Most On2 models up to recent times have only been available in wood "craftsman kit" form, or brass..
no plastic "ready to run" at all..
there is still no plastic R-T-R, although with the recent introduction of the Bachmann On30 forney, based on Maine 2-foot prototypes, the interest in Maine 2-footers is beginning to grow a bit..in both On30 and On2..(some model the Maine 2-footers in On30, which the track gauge being 6" too wide..just as many people model Colorado 3-foot gauge in On30, with the track gauge 6" too narrow..just because On30 is easy and available.)
There are now some laser-cut kits beginning to come out for maine prototypes though, passenger and freight cars..so more is becomming available..slowly.
As for length, here is a scale-length Maine coach I built from two Bachmann On30 coaches:
and a webpage with more detail on the build:
http://gold.mylargescale.com/Scottychaos/On2/index.html
The prototype Maine car was nearly 50 feet long (49' to be exact) while the Bachmann On30 coach scales out to only 36 feet long..Maine rolling stock is generally longer and narrower than most available On30 rolling stock..
And here are more thoughts on On2 vs. On30..if anyone is interested:
http://gold.mylargescale.com/Scottychaos/On2-SRRL9/index.html
dehusman wrote:...The hard point is slowing down the train on the turntable and acceleratign it off. With DC is fairly simple to vary the track voltage. With DCC you have to have something communicating with the command station and it has to know which engine its controlling. It has to know that engine 17 is pulling on the turntable since its only going to control the decoder in engine 17. That will probably require some software and a computer interface.The simple way to go is to just cut the power Have a sensor that detects when the engine reaches the end of turntable and it just activates a relay, electronic or mechanical, that cuts the power to the turntable. The train just stops (depending on how much momentum any flywheel contributes). After the turntable rotates it trips another relay, that turns the power back on. The downside is the lurching to a stop and a start. Visually it won't be a problem since it will be off scene, the only concern would be mechanical. Dave H.
Here is something you might want to consider. Instead of having a normal turntable, have it pivot around to where the turntable track is parallel to the approach track and have it line up with a spur off of the approach track. The advantage with this arangment is that it only protudes into the room a few inches except when it is actually rotating, so you do not have to move anything out of the way when you are not operating. I replaced one of the turntables in your drawing with what I am trying to describe here:
CSX Robert Here is something you might want to consider. Instead of having a normal turntable, have it pivot around to where the turntable track is parallel to the approach track and have it line up with a spur off of the approach track. The advantage with this arangment is that it only protudes into the room a few inches except when it is actually rotating, so you do not have to move anything out of the way when you are not operating. I replaced one of the turntables in your drawing with what I am trying to describe here:
Robert, great design. I like it.
Scot, I've read most of the other posts, including the last one showing the "turntable" that is really a long arm that folds back along the approach track and connects to a spur off the approach track. I thought about this idea before I got to that post and I liked it, too. One other variation to consider would be to make the "turntable" a section of curved track as there is nothing that requires it to be straight. this might fit into your track plan better than a straight one. This would allow you to curl the whole thing into a corner.
It wouldn't be too difficult to automate that kind of operation. If your locomotives and cars have all metal wheels it is pretty easy to use those as sensors to indicate when the locomotive gets to the end of the turntable. Moving the turntable slowly and smoothly isn't too difficult, either. You would have to be willing to put together the hardware yourself but you could do it using mostly off the shelf stuff. That's a lot easier and usually less expensive than constructing your own from scratch.
If, you're interested, let me know by e-mail and I would enjoy kicking around some ideas in a more substantial manner than is possible in this forum.
By the way, I really liked the modelling work on the Sandy River coach you built.
Alan
real railroads do not generally turn entire trains, with few exceptions. and they don't use turntables to turn them when they do. a wye would make a lot more sense, and create many more operating possibilities. but why do you want the entire train turned? why not cut the train off on the mainline, then take the engine(s) around a wye or to a turntable to be turned, then have the engines run around the cars in a passing siding to get to the other end. this is far more prototypical, and actually very common in both past and present railroading.
real railroads sometimes turn cars to meet the requirements of a customer, such as a boxcar that has to be unloaded from a certain side, or turning auto racks so they can be unloaded from the end the customer desires due to them having their ramps on a certain end of their facility. and in some cases a short local might actually turn the entire train using a wye, but most of the time it'd just be a few cars.
This would still require a 5' semicircle, not to mention space for the operator.
Another idea: I know you don't like around the walls but you could go around the walls between two reverse loops, stacked on top of one another (loop-to-loop). You woudn't need a lot of grade separation and it would allow you to save a bunch of real estate. The total usage would be less than a 5' turntable at each end, unless you stack these, too. However, you might need considerably more grade separation for access to the lower turntable.
Yet another idea: Run the trains all of the way around the room to a 5' run through turntable. This would permit continuous running around and around, or loop-to-loop (actually Ttable-to-Ttable) while requiring that you construct only one turntable.
Wow!
very good ideas all around!
thanks everyone!
I like the idea of the two overlapping reverse loops..both taking up the same space.. that could work! :) thanks for the idea..
CSX Robert Here is something you might want to consider. Instead of having a normal turntable, have it pivot around to where the turntable track is parallel to the approach track and have it line up with a spur off of the approach track. The advantage with this arangment is that it only protudes into the room a few inches except when it is actually rotating, so you do not have to move anything out of the way when you are not operating. I replaced one of the turntables in your drawing with what I am trying to describe here: http://www.trainboard.com/railimages/uploads/7570/6-foot-turntables.jpg
http://www.trainboard.com/railimages/uploads/7570/6-foot-turntables.jpg
thats different! interesting idea..wouldnt quite work in my case though, because it blocks the door..but I could maybe fit it in somewhere else..definately something to keep in mind!
based on all these great ideas, im working up a few new drawings..I will post some more of them soon..
thanks,
scottychaos...interesting idea..wouldnt quite work in my case though, because it blocks the door...