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Post by Deleted on Feb 12, 2017 18:30:13 GMT -5
Hello again.
I began with "trying to design" my new layout (with paper, pencil, compass and rubber, by "hand" without any software), and there will be no radius less than 400mm (only Märklin flex tracks : I made it the same way in the past with my N-layout). I plan to run 2 Amtrak California trains (each with 4 cars and one locomotive) in opposite directions and two freight trains with two GP38-2's (or one GP38-2 and one SD75M), each with 4 cars : 4 Gunderson High Cube for one and 4 coil cars for the other (I think cabooses are now almost obsolete ... ) ; no longer trains will ever run. Now the question : can these trains "climb" a slope of 1,5%, or not ? This slope is necessary because of the clearance (in height) when the track crosses with itself. I plan with following data : the layout would be about 2.90m x 1.45m (1.45m is less than the double of the distance I can reach without no risk from the edge, in case of a derailment ... which will not occur too often, I hope so ! ), 2 stations and 10 turnouts, single track for the whole layout.
Thanks for Your answers.
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Post by markm on Feb 12, 2017 19:25:42 GMT -5
Alberich, Welcome back. The standards say a 4% maximum grade and I think the locomotives and trains sizes you've described would do that. But in California the prototype standard and that used by most modelers is 2% maximum and 1.5% on curves. Unless you're modeling a short line, it just looks better. Yes, cabooses are almost obsolete. I'm am aware of a couple still in use on lines that require the train to back up for a long distance. They're basically used as a control cab. It will be interesting to see the layout you develop. Since you're using flex track, will you be using easement and elevation in your curves?
Mark
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Post by Deleted on Feb 13, 2017 1:51:25 GMT -5
Thank You Markm.
Some problems are not yet solved ... In France we have a proverb (by Jean de La Fontaine) : "Don't sell the bear's fur before You killed it". So my layout is in the state of a pre-pre-project. The first problem was in fact the slope ... now solved !
Now there are still several other problems remaining ; first the cutting of the supports for the curves : I will probably try to let a cabinetmaker make this, because he can cut all the curves (of 5mm plywood) at the same time by assembling all the layers together, in my design there are only curves with 400 mm and 500mm radius. The curves will be "flat", it does not make a significant difference for the appearance (I have read the topic about Rokuhan tracks) but a very big difference in precision of laying (including the "helicoïdal" transitions to straight portions of tracks ! )
Concerning the nails, I found some made of brass instead of steel, so no corrosion can occur, the same diameter as those by Märklin (0,5mm), the length is 10 instead of 8mm (no problem) ; they are made by Amati, Italy, for historical wooden ship models (together with the tool to set them) and seem to be strong enough, as I tried to bend one between my fingers. As I wrote, the noise of the trains is no problem for me.
And there are some other problems with the electronics (in my case, DIY) : some dealers continue selling the items they have in stock without any warnings, and if one looks to the datasheet on the net, he can see that some components were declared as obsolete at least 5 years ago ... No comment, perfect to get spare parts in the future ! But the electronics define the "cuttings" in the track, so I must know first what I will use. But definitely no DCC !
As You see, there is still a big amount of preliminary work to be done.
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Post by Hans Riddervold (AZL) on Feb 13, 2017 14:03:53 GMT -5
The steepest grade (slope) in the US (class 1 railroads) is 4.9% and it is only for a couple of 100 yards. As recommended by Mark, I would stick to 2% maximum.
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Post by Deleted on Feb 13, 2017 15:07:48 GMT -5
Thank You for Your answers. Concerning the problems with temperature changes, I have read on other forums that a gap of 0,75mm per meter is recommended for nickel-silver rails (when the layout is "cold" ) ; so I think 0,5mm per track section (660mm) would be ideal at every rail joiner, it should not cause any problems (each section with its own feeder, all connected in parallel). I think that block system is interesting on a section with 2 tracks, I built it into my former N-layout (4 block sections of 1,5m each per track) ; but with single track, it seems to be less interesting ; before starting any train in opposite direction one must wait for the whole track to be "empty" : so if block system is used, the main danger (with an automated and "optimizing" program) is to use immediately a free section to send a train from the station to the track, and so to create permanent trafic in the same direction ! For automation, I will try for the turnouts the so-called "capacitive discharge" with relays, they can switch the power to the corresponding track with the remaining contacts. I think I will run only one train at the same time. For the power, I will use PWM with a 1A transistor, polarity change via a relay. The PWM signal can be generated by the main microcontroller of the system. To run 2 trains at the same time, I found out that I would have to use 4 supplementary (small) microcontrolers, one for the PWM of each train (to perform it with 1 microcontroller, at least 2 interrupts would be necessary to manage the progressive acceleration-deceleration, which is not the same for all trains, one value for passenger trains and another for freight trains) and then there is the problem to switch the power to the different sections (preferably the PWM signal with a booster+relay per section, in my case 7 items) according to the position of the trains. And to allow simultaneous train movements in each station, the turnouts on each end must be independent ! So I calculated : - For one train only, one microcontroller, 6 relays with 4 circuits and one with 2 circuits (unfortunately 12v relays with 6 circuits are obsolete, one with 4 circuits and one with 2 circuits could be merged). - For two trains simultaneously, 1 main and 4 secundary microcontrollers, 7 boosters (amplifiers) with a 4-circuit relay each, and 6 relays with 2 circuits and 4 with 4 circuits for the turnouts. And a serious risk of short circuit in case of a "bug" or a crash of the main controller. For me it's what I call a "gaseous plant". I think seeing one or two trains running does not make a big difference in the appearance of the layout, but it would make for the complexity (and non-reliability) ; one version of Murphy's law says that if You are looking for trouble, eventually You will find it !
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Post by markm on Feb 13, 2017 15:12:16 GMT -5
Alberich, I guess in English we would say: Don't count your chickens before they hatch.
Regarding electronic components, I worked in Silicon Valley for many years and the typical life span for components is 36 months. From the "do not use for new designs" notice to end of production is another 12 months. So don't be too hard on your component suppliers, they have no control. You either do a "lifetime buy" or be prepared to upgrade the hardware every 2 years.
I've chosen to keep all my electronics underneath the layout with only LEDs on top. SO all I'm using is a simple hole topside for wiring.
Mark
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Post by markm on Feb 13, 2017 16:11:23 GMT -5
Alberich,
Since our last posts crossed, may I give you some thoughts using my automation project as an example. I'm using an Arduino with the power shield and DIY breadboard shield. The power shield will give me 2 independent power channels with direction control and if I want to use it, current monitoring. It seems that using PWM on most microcontrollers uses up all the interrupts. So my DIY part is to build status registers for the layout: edge-triggered latches to monitor track blocks and two registers to drive the layout, one for track control and one for scenery control. All input registers trigger a single interrupt. It's sort of an 8255.
I think you might to able to use a similar scheme for your layout. With the processing power in microcontroller these days, I find it difficult to justify multiple units. Another possibility to consider is something like the Parallax Propeller microprocessor which is essentially multiple controllers and a supervisor in one chip.
Finally, speaking of change, I just got a note about a new Arduino using the Intel Curie: 32MHZ plus Bluetooth.
Mark
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Post by Deleted on Feb 13, 2017 16:15:18 GMT -5
To Markm : I used four 8255's for my N-layout in conjunction with the C64 (2 Nand-Gates to convert the bus to Intel standard ! ). For train detection with conventional DC the combination of a diode, resistor and perhaps capacitor in parallel, in the "Gnd" line to the track, coupled with a simple comparator, was working fine ; I used the LM339 35 years ago, and it is still manufactured, the LM393 too. And look for example at the lifetime of the 555 or 567. So the 3 years period is perhaps true with hightech chips like microprocessors in workstations ; but the Atmel 8515 and 8535 are still manufactured for over 15 years with only minor improvements ; and they generate PWM directly via built-in registers. The problem is the VARIATION of the PWM rate via interrupts, for acceleration-deceleration. So my principle is : KISS, Keep It Simple and Stupid ! With one train, no multitasking is needed, and the variation of the PWM can be performed via a simple "delay" instruction. About Arduino : the platform is interesting from the hardware point of view, especially the "Mega" (with an ... Atmel 2560 controller ! ), nobody can solder a TQFP100 package without specialized (and expensive ! ) tools. I planned to use it for my "gaseous plant" version, it is the best way to get many I/O ports directly, and the new Seeduino Mega is even better, the 16 missing ports are brought out ; the only problem : the Seeduino board itself seems to have some availability problems, at least in Europe ... For the programming language, the Arduino software development environment causes "allergic reactions" to me : to say it simply, I HATE C ! (for Windows, I prefer Delphi-Lazarus) ; unfortunately the different versions of Pascal for the Atmel family are very (not to say too ! ) expensive ; so I think I will use the Bascom Compiler (only 1/3 the price of Mikroelektronika's compilers). In addition the Mikroelektronika languages are incompatible with the UAC in Windows 7, "they" recommend to set it to 0, in order to avoid the well known message for authorization at the start of the compiler. So, I will stop here, it is a model railroad and not electronics forum, I don't wanna start a "Troll" in electronics !
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Post by Deleted on Feb 13, 2017 18:25:06 GMT -5
Sto_o_o_o_ppp ! 1) No DCC please. 2) My old N-layout was sold for buildings and rolling stock a few months ago, after some years of inactivity. This was the example of what I should NOT do again : when it worked, it worked fine ; but if not ... much time to find and solve the problem. In 99,8% this was caused by an Arnold turnout (37 were installed) : either it was locked, the contacts didn't switch off, it became hot, and overheating destroyed it ; or the contact for the power supply to the tracks didn't work properly. Or some dirt on the tracks (a drop of sweat was enough) triggered the detection of a "ghost" train (too sensitive, but necessary to detect freight cars with graphite paint between the wheels). And measuring frequently voltages under the layout is no problem for a youngster of about 30, but todays I am almost 64. I think You understand the problem ... My new version for the detection system (lower value for "the" resistor) will detect the locomotive and nothing else ! 3) The system of "source transfer", switching the power to the correct section according to the position of the train, was a technique already described in some publications in the 80's, in conjunction with the block system ; the main difference was that it was performed via relays, and no amplifiers were needed because the output of the transformer was switched directly ; todays it would be possible to select the proper PWM signal for the final power stage via multiplexers at CMOS levels, under control of the main microprocessor. 4) I am not afraid by multitasking programming : One task is affected to each train, with a pointer to the present state (via a CASE instruction) ; when the corresponding condition occurs, the pointer is incremented, an exit from the task is performed, and the next phase is selected when the task is activated again ; the tasks are called cyclically and communicate via common variables (occupation state of the tracks in the stations, for example). I used this style of programming in the past (in Basic on the good old C64, R-I-P ! ), to manage the different phases when a freight train entered the station, then pushed back to the depot, a turnout was changed and another train came into the station and was started instead of the first one, the next time when it was possible (I don't know if my explanations are clear enough), so the freight trains were used alternatively "between" the passenger trains. 5) Perhaps the "gaseous plant" would work ; but I think the possibility of using 2 trains simultaneously instead of one alone is not worth the supplementary complications in hardware, wiring and programming. That's all Folks ...
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Post by markm on Feb 13, 2017 18:59:22 GMT -5
So, I will stop here, it is a model railroad and not electronics forum, I don't wanna start a "Troll" in electronics ! Actually I thought long and hard before submitting my last post. I could imagine the blank faces staring at the screen. But really model railroading is about electronics, and mechanics, and woodworking, and 3D printing, and operations and history. Like programming it's a matter of personal interests. Having been doing model railroading since before de Gaulle and Kennedy did the first transatlantic video conference, I've seen a lot of changes, most good in terms of equipment and accessories quality, detail and price. But in particular it seems that a lot of the DIY (or in 21st century terms: Maker) attitudes have been lost. Yes I know how to build a tank car out of a piece of brass tubing. Am I going to do it again? No, there are people that can do it much better than I. But it gives one an appreciation for what Hans and Rob do to produce AZL products. So if we got a couple of people interested in the electronics side, we did a good thing. Mark
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Post by Deleted on Feb 14, 2017 14:44:16 GMT -5
About the complexity of the control system for 2 trains simultaneously (without DCC), and the associated problems, I gave the details of a comparison in a former post in this topic. Because we are all speaking about our former "career", I can say that I began with an Univac 1110 system (and perforated cards, Fortran V) from 73 to 77 as a student, then I worked as a maths teacher for more than 15 years before I came back to computers again, network administator with Novell and then Windows servers, and worked for 17 years at the "academic school's administration" (in french "Rectorat") in Strasbourg as a software developper with Excel VBA (because it was available without any supplementary costs ! ) and Data Base requests developper with Business Objects (now owned by SAP). I retired in 2014. Before I got the C64 in 83 I used the Kim-1 and the Pet-2001 (with the "Datasette" ) too, and they allowed to develop some experimental sequencers for minimal railway layouts, to test if there were no risks of crashes due to electrical interferences ; I remember that I crashed the Kim once, because the line to the turnouts laid unfortunately ... over the processor ! I used the IEE-488 interface only for an Axiom "electrostatic" printer, this was the best a hobbyist could afford, a Centronics 7 pin printer was more expensive than two or three colour GDI laser printers today ...
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Post by markm on Feb 14, 2017 15:32:05 GMT -5
I'm afraid if we are comparing CVs (NOT DCC) I think I have you all beat. First computer was a Bendix G15 ( vacuum tubes [valves], 5 channel punch tape, 2K memory, 6.2 second integer multiply); Data General Nova, Nova 2, Eclipse; DEC PDP-8 & 11, VAX; CDC 6400, IBM 1620, 1130, 360, 370 4300, PC; Sun and several 24 bit HP machines I don't remember the model number. Programming: ALGOL, Basic, Fortran II, IV & 7, Pascal, C, C++, VB, C#, FACTOR and about 7 assembly languages. Also numerous microprocessors and microcontrollers. The truly ludicrous part of it all is that I've never been employed as a programmer and my only formal training was Basic and PDP-11 assembly. My actual job was product engineer for microprocessors and other programmable logic. It was all just stuff I needed to know to get my job done.
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Post by Deleted on Feb 14, 2017 15:34:53 GMT -5
I think that the main advantage of running only one train at a time is that there is only one traction current source (with stop sections simply switched off, unfortunately that system excludes multiple traction ... and a train with 2 Budd's ! ) for the whole layout, and that seems for me to be the safest way to avoid short-circuits by countiguous sections of opposite polarity ... due to a programming bug ! About multiple traction : I remember that in the 80's Atlas (and perhaps Lima) made in N-scale dummy versions of the locomotives and the B-units, without a motor. Why not in Z ? This would simplify some technical problems ... and at a lower cost for multiple units !
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Post by Deleted on Feb 14, 2017 16:42:00 GMT -5
And to my list, add Assembler (650x ! ), and Forth (on the C64) : : ? @ . ; I think we can stop here ...
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Post by markm on Feb 14, 2017 16:42:32 GMT -5
About multiple traction : I remember that in the 80's Atlas (and perhaps Lima) made in N-scale dummy versions of the locomotives and the B-units, without a motor. Why not in Z ? This would simplify some technical problems ... and at a lower cost for multiple units ! Actually Micro Trains made dummy F7A & B units. They were a bit of a load on the powered unit as the truck were still geared. The A units short lived just UP, PRR,SP & GN, the 12000 series. The B unit they produced until they retooled the F7 just a few years ago and added power to the B's. If you want to purchase a powered unit, I'd be happy to remove the motor for you.
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