Hi,

Isolating the centre is the normal practice. This can be done using plastic isolators available from marklin, P/N 7522. Alternatively you can cut the small contacts between the track sections or make a cut through the metal on the base (although these are more permanent solutions).

Cheers.....

Mike

Yes, I will be using the computer to turn track sections on and off.

These are very old locomotives (some probably 50 years old), nothing with built in computer control. Nor does he want to go to the expense of trying to modify them for internal computer control. He's got to have at least 30 to 40 locomotives. Many antique. So no DCC or such. Just raw locomotives.

Therefore, I'm going to control movement, by powering track sections.

I'm going to order a bunch of the 7522's and will dremel cut the underside of tracks where needed.

This thing it pretty big, an entire room. Maybe 30 x 30? The section I'm currently starting with is about a 1/3 of the overall model, and it's got about a 1/2 dozen decouplers, more than a dozen track switches (left & right turnouts, Double Slip switches, 3 way turn out) a round house and a transfer table, with 5 sections with Catenary wires. But the other portions are more than 1 level of track with bridges and such. (A number of track segments with turnouts underneath for storage). So this is a long term project.

So I'm first starting with all of the switches (turnouts, decouplers, I gotta get my vernacular together) and such (on this portion of the model), and setting up track segments. I'm having to pull up and reset a bunch of track as a result. Later (with the size of this thing, probably the year 2020), add some sensors to automate locomotive movement, and then put in signaling. He hasn't had it running in years, and I just want to get a portion, where I can make a locomotive go.

I'm using the CTI stuff that he has. So the next big magic trick is to rig an Arduino with a stepper to computer control the old style transformer, so I can get some computer control on the pile of transformers he has. I also have a 3-D printer, and am pretty decent at CAD, so I can come up with some brackets. I already designed a set of mounting brackets for all of the CTI cards.

Does Marklin have a digitally controlled transformer? I know the CTI stuff supports DCC. Could I use the CTI software to control a Marklin digitally controlled transformer for speed?

Thanks.

Michael

I browsed through the 185 page CTI manual on https://www.cti-electronics.com/Users%20Guide.pdf . Interesting. It seems as if this system moves the intelligence from locomotive decoders, to controllers connected to blocks. As I understand, you can use any Märklin transformer for power supply here. You don´t have to digitally control the transformer. The computer controls the controllers located between the transformer and tracks.

What I would worry about is that a google of ”CTI” and ”Märklin” gives almost no hits, as PMPeter also notes. It will not be easy to get support e.g. in this forum. Also, I am not sure cost will be lower, using CTI. For occupancy feedback, CTI have e.g. the ”Dual 3-Rail Sensor” at USD 12, i.e. USD 6 per indicator. Using the feedback modules in the ”Märklin and DCC world”, the cost per indicator could be as low as USD 3. Finally, the software doesn´t look that user-friendly as CTI claims. Compared to e.g. TrainController and WinDigipet, coding strings seems to be required.

But what the heck, this is a hobby only, and maybe this project will break new grounds!

I understand that you want to use the CTI cards on hand and that this project will be a challenge. However, unless I am missing something I believe you will be limited by the number of trains you can run simultaneously by the number of individual transformers that you have. That is the beauty of digital that you can run numerous locomotives with one power supply, limited only by the power available and the electrical load of the simultaneous running locos.

Cheers
Peter

Michael,

The turnouts and their electrical solenoid actuators would require no change. What you would require is a K83 type decoder that would operate 4 double solenoid type devices such as a turnout or 8 single solenoid devices such as a decoupler. These K83 decoders are relatively inexpensive and quite readily available in excellent used condition on eBay. To operate the K83 decoders you would need a digital controller such as a Mobile Station 2, a CS1, CS2 or a new CS3 if you want to stay with Marklin. You could also go with a different manufacturer's digital control station and this would all depend on budget and ultimate control. Since you really want computer control and based on the size of your layout, a CS2 or CS3 would most likely be appropriate. For my layout which is approximately 18' x 16' I can run 5 trains simultaneously (so far) with a single CS2 and Rocrail computer software.

For the locomotives to be converted to digital you would need to upgrade the motors from a 3 pole armature to a 5 pole armature (3 different kits available for the 3 different motor styles in old M locos) and then remove the mechanical reversing unit and then wire in the appropriate decoder. Again there are numerous decoders available and cost really depends on whether you want sound or not. The non-sound decoders have become relatively inexpensive and for 50 locomotives this would also be a time consuming and not cheap exercise. Depending on the model number, sometimes it is better to sell the old analog version and buy a new digital version rather than going through the expense and time required to make the conversion. If you list the model numbers being considered I'm sure you will get numerous responses in this forum whether it is worth it for that model or not.

Don't get me wrong, I'm not trying to talk you out of what you are doing, but considering the layout has not been operating since 2011 and you anticipate a 2020 completion of the conversion, I feel you can have a digital computer controlled layout operating in a very limited time without removing track, turnouts, etc. and just buy a digital controller, K83s, and convert some locos to start off with. The end result would be that he can operate a large number of his 50 locomotives simultaneously with the appropriate software, compared to the number of power supply limitations you would currently have.

Cheers
Peter

Are you sure some of these are not already digital? I see the dual Swiss & German crocodile set which I believe only came out a few years ago as a digital set. Some of the other newer ones could also be digital.

What you really need is a list of the Marklin locomotive numbers. Then you can go to the Marklin website and for most you will be able to find the parts diagram which will show if the motor is either a LFCM, SFCM or DCM type. Once you know that you can pick out the appropriate motor conversion kit to get it to a 5 pole motor with permanent magnet. The decoder then becomes a personal choice depending on the functions you want.

Here is a link to a site that I have found very useful regarding motor conversions: Conversions

In a way, the thing you are trying to do is almost the same method that I use with my layout.
Instead of trying to control the knob of the trafo, I feed the max power through several links of antiparallel diodes. As each pair drops the voltage with about 0,7V, you can set up a multiplexed speed-controller with relays; With 5 relays you can get 16 different voltage supplies. (With heavy-metal analogue locomotives you can even get smooth running with just 8 or even 4 different supplies of tension)

If you only plan to stop and start the trains at pre-defined spots (like in front of a signal), only 1 relay is needed, as you can feed each section of the track with a gradual falling (approaching the signal) and rising (leaving the signal) voltage. (That is what I do; Another reley is used to bypass the first relay, in case of the signal being already green before the approach)

-But the multiplex idea is still good for controlling the points/switches; The multiplexer selects which switch is to be operated, and then anoither relay activates the solenoid.

Additionally I want to mention that I use 24Vdc for the relays/solenoids. The extra power assures that no switch/signal "hangs" in any position. The computer control assures that no activation pulse is given for too long a time which could cause the solenoids to burn.
In old-school Märklin this is really good, as the common "Ground" of the 24Vdc and the 16Vac can be united. Even isolated track-feedbacks can be used with 24Vdc, when used in series with a resistor...

I am glad that you thnik it helpful. Finally a kindred spirit after so many years here.
Yes, my trains are all AC-locomotives in analog mode.
I used to have a comprehensive documentacion on the net, but some years ago www.majhost.com died, and much was lost. I might still have some plans lying around on the harddrive, but will have to dig them out and find a place to upload them...

I dont know what CTI is. I use an industrial PLC from Schneider (a former Square-D product).
Electrically it is pretty simple, that was why I hoped that my description above would be clear enough.
Uniting the 0V / Ground of the AC trafos and the DC power supply is just that; A cable from one unit to the other(s), and a common 0/GND disitributed around the whole layout.
Currently I use 11 AC trafos (around 400W) and 1 DC supply (300W).

Also I want to mention again the antiparallel diodes; I use them everywhere; F.ex. on falling grades; A link there will reduce the trains speed.
Also INSIDE individual locos I have installed 0,1,2 links in series, to adjust the speed of that particular loco; As the track voltage is always the same, some trains would go too fast. (Obviosly the trafos speed-knob will have to be set at something the weakest/slowest loco can use. -So the fastest ones need to be adjusted...)

Hope this helps. Otherwise I will have to try to find the old plans. Some specific thing you need a plan of?