Kato M250 10-565 DCC Digitrax DZ125

[inobu]

I have edited the previous entries in order to provide a better flow of this install. I had a lot of issues and some rework that may leave the reader confused so I am updating this entry to give a clear picture.

 

Inobu

 

Kato M250 10-565 Super Rail, Digitrax DZ125 Decoder

 

Break down the 250 as seen here.

 

The light conversion: based on this http://www.katomodels.com/hobby/dcc/dcc_tips/light_kato.shtml

 

The hardest part of this mod is the de-soldering of the LED components. The PCB is thin and the leads will lift off. My first one took a beating and now is heat up because of poor connections. I'm going to have to rebuild it. So read up on unsoldering surface mount components in order to avoid this problem. Make sure you test the LED for heat. High heat could mean a poor connections somewhere.  

 

Added note: Have been monitoring the LED and they seem to run hot. I'm not sure why but I want to check into it. I have to re-evaluate the circuit components. I'm not sure if the 271 resistor is correct based on a input voltage of 13.9. I wonder if this setup (271ohm) is based on another input voltage. Ran temperature check and saw 104 degrees on the board. The original board runs at 80 to 90 degrees. I believe that resistor value is incorrect and may be causing the higher current draw.  .  

 

Lets start,

 

Remove the cab from the lead cars. You will see the light board 6018. It slides out with the brass pick ups. The first step is to remove them. You need a larger iron because the smaller tip cannot heat the solder fast enough. It just causes massive heat soak and will lift the copper traces off the PCB.  recommend to use a larger iron for the removal of the components but Not On Install.

 

Once you remove the pickups you need to lift the LED up so you can access the 561 resistor.

 

Heat up the solder and flake the resistor off. be quick about it or the heat soak will get you.

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Now that the 561 is off you have to install the 271 resistor in its place.

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In this step we are going to separate the LEDs into two circuits. Take an Exacto knife or something break or scratch a small section of the copper trace. This will divide the leads in two giving you connection points for the decoder. This is a little different from the instructions given but it seems a little easier this way.

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The last step is flipping the LED so the anode or + side is correct. The little side as you look into the LED is the anode this is the blue wire side. You have to flip the LED so it is in this configuration. Test it by connection the decoders red and black wire to the track and connect the blue, white and yellow to their location on the board and it should work.

 

Repeat these steps on the rear cab.

 

Inobu  

Edited December 30, 2017 by inobu

[inobu]

Modify the motor block

 

I have come up with an easier solution below

 

Terminate the DC power output from the decoder to the block is difficult. The problem is the DC motor block is made out of pot metal and we cannot solder to it. I tried other methods and could not get anything worth while to work.

 

I was back and forth on the up coming idea finally thought that I needed to do it the right way even if it was a longer process. So I tap the post into the front portion of the block. I used a mill a drill press will work also.  

Make sure that you don't get metal shaving into your motor. Tape up the sides and top. I used a 1 mm bit  about 5 or 6 mm deep. I tapped a DB pin into the drilled hole and cut the head off. It was a tight fit which is good and I (tinned the pin) let the solder soak into the pin to fill any voids. The pins are hollow so the flux will draw the solder into the pin and surrounding areas. I wanted the pin to become solid and secure.  

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Modify the track power pickup.

 

From the light board mod you should have 4 L shape pickup. We will modify 2 of them for the power routing to the top of the motor. The other two will also be used so don't think you have two chances to mess up.

 

Make sure that you cut them so they are flush with the outer edge of pickup. It not you will not be able to reinstall the motor. Make a template first in order to make that perfect fit. It has to be half way in the middle of the pickup. It going to look like this.

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You cannot have globs of solder as it will prevent you from installing the pickup. It has to be clean solders.

 

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Next we have to insulate the pickup so we can run track power without shorting the DC motor housing. This is where the Kapton tape comes in handy. Only wrap where it makes contact with the motor block. Leave the tip exposed so you can solder the power leads. Also cover the side of the block as shown. Make sure that you isolate the track pick up of you will blow something.

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Now install the track pick ups it should look like this and here is how we test for isolation. Volt meter to ohms. Look for short. If there are no shorts you have done well. Gotta short you need to find it. A short is 0.00 on your meter. Open is OL which is good.

You want to check the track pickup lead and the DC motor block.  Both sides.

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Man my volt meter is dirty.

 

Done with the motor for now.

 

Inobu

Edited December 31, 2017 by inobu

[inobu]

 

Now, the wire harness. I'm using magnet wire at 32 gauge. According to the specs this wire can support up to 90 mA. The LED are at 20mA. So we should be ok.

 

Magnet wire is stiff where it holds its position. This is good in that it stays out of the way. I use heat shrink to bind the wires together for easy management and access.

 

For the light we need three wires White, yellow and blue.  All the wire are the same color so I have to verify them before I solder them but this is how it should wire into the cab. Blue wire on left side of cab and white, yellow of the right. This is from the configuration of light modification earlier.

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Next we can mount the motor back into the chassis. Remember to watch for the trace leads that you solder they have the tendency to bind on the chassis.  

 

Notice how the magnet wire plays right.

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Now its time to load the decoder on. I un-soldered the three light wire because I'm going to use the magnet wire all the way to the decoder. This is tricky if you are not comfortable or do not have a low watt iron don't try to de-solder it solder wire to wire. IT will be hard. but better safe that sorry.

 

 

Now route the wires and bed the decoder. Heat shrink and binding makes things really easy. The extra time is worth it.  Helps in tracing and troubleshooting.

 

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Solder the main wires the red and black - Track power and orange and gray. DC motor. That this time test that it works. Pop on the trucks and tested. Make sure that the wire don't short anything out.  

 

I tested it ok.

 

Now finishing the light wiring. Using your volt meter to test for continunity and identify the matching wires. skin all the wires and search for the short and identify the wire and label it. Remember blue is on the left side of the cab with the one wire and yellow is on the right side front position and wire on the last position. Reference the  image in the light mod section.

 

With magnet wire you must scrape the insulation off. Use an Xacto knife. The insulation is hard to see and you need as much surface as possible.

Here is the final shots of the lead engine mod and decoder install.

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Lead cab Container mod

 

The last step is to modify the cargo container to fit over the wires that mount across the DC motor block. Do not try to force the container on it will just ruin your wires. Here are the dimensions of the template you will need to make and hone out a small portion of the cross member in the cargo container.

 

You will need to cut out 3mm down and 2.25 wide from center

 

 

 

 

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Rear engine install

 

You gained a lot of info on the lead engine install and you will use the same methods on the rear. The rear engine has to be broken down in the same manner as the front. Only difference is there is no motor to hassle with and the decoder will be mounted in the rear.

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The under carriage breaks apart and you want to run the wires from the back to the front. Same wire entry into cab. 1 wire (Blue) on left and  2 on the right (white yellow). This time you heed to reverse the white and yellow because the tail cab is backwards and will operate opposite of the lead cab.

 

You can see where the wires are ran. Tape them down and snap it in. You have to take care not to scratch the insulation off of the magnet wire especially around the track pick under the cab.

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The best way for access to the decoder is to drill a tiny hole for the wire to run up to the decoder.

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Because we are using the 2 function light feature there is no need for the orange and gray motor leads so they have been omitted.

 

Adding decoder power

 

This is where you use the other 2 L traces from the light mod. Solder the power lead from the decoder to these two leads and gently slid them into position.

 

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After the test you are done.

 

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The motor cap should be the only piece left out and the two tiny pieces of light pickup brass.

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This was really tough but really satisfying to resolve the issues.

 

Hope this can make for a secure install. If anything comes up, I'll post warning of what ever I find if I do.

 

Inobu

 

I have been improving this installation process. Take time to go over the complete thread as you will see faster and easier installation steps. 

 

Edited December 31, 2017 by inobu

[nik_n_dad]

Yeah- Our M250 is in a little box in pile of parts right now (and has been for months).  Once I get the new layout off to a good start I'll try to get back to it.  The biggest problem I had was getting the decoder wires up from the bottom of the motor.  I think I nicked it a bit and it all shorted, resulting in a bit of smoke.  (I've discovered that once you let the smoke out of the decoders, they don't work anymore) 

 

I wasn't planning on modifying the existing lightboard though.  Looked like alot of work and too many chances to make big mistakes.  I was planing on taking a piece of punchboard the same size as the lightboard and just making up a replacement board. 

[inobu]

Its convenient on paper but actually the mod is rough on the board, if you want to go back to DCC it would be even harder ware and tare. Punch board is the easiest way to do it, follow the basic LED circuit schematic and you are good to go.

After you do a few it get better and better.

 

Hopefully I can get this done soon.

 

 

Inobu

[inobu]

Finally got it. IT took some time to come up with a good setup for everything. I'm 80% sure it going to be ok. The 20% is with lights. I ended up using magnet wire. It is 32 gauge and is suppose to be good up to 90mA. So , I have to finish testing.

 

As for the engine this is the key to for the pick ups. You have to modify the existing track pickup and then insulate it. This allows you to wire up top without too much trouble.

 

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Here you can see how the track power is routed up top by the pick ups. It is isolated with the Kapton tape. The kapton tape really works good. A little difficult to apply but works good over all. I hate to alter or remove parts but I had too in regards to the black motor cap. I felt the the tape could hold the motor as good as the plastic cap and it allow me to route the wires toward the front. Forced trace off.

 

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The second problem was terminating the DC power/motor leads. The block is made out of pot metal and you cannot solder to it. I went round and round and finally found some silver epoxy. This allowed me to glue some copper tape to the block and solder the wire to the copper tape. You cannot use JB weld because it is non conductive. This stuff was expensive. $22 .35oz/14g. I guess it is real silver but it only took a half a drop. Its ok because I might start a business of installing and building so it will come in handy.

 

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While I was waiting for the silver epoxy to dry I jump ahead to the rear cab and started to used the magnet wire and its a really good install in that not much was modified. The decoder is in the rear and runs through the frame.

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Inobu

[inobu]

So, the drama continues..... but once again I'm learning..........

 

I got back to run the final test on the cab, flop, it does not work? I'm thinking it working last night, no one touched it??? Running lights are on no motor. Start running the gambit of test to isolate. Continuity test good, oh no the decoder is dead. Run decoder access and maps/CV are there, read write functions, ok just no DC output. Swap out new decoder the same thing. What? OK tear down the hole thing are start isolating step by step. Come to find out the $22 silver epoxy is not conduction on one side.

W@%. 

 

Start digging the trash can to pull out the leftover epoxy. I see that some areas conduct and some do not. Look at the container (syringe type) and it looks like it separated or settled. So it is impossible to premix part A or part B before hand. So you cannot get a good mix. It worked last night because it was still wet. 

 

After this fiasco I resorted to what I though was the better solution in the first place. The reason I did not go that route is I wanted a mod that everyone could perform easily.

 

Tap in posts. Drilled 1 mm hole and tapped in the pin as posts. Filled it with solder

 

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I would have been done day before yesterday has I done this. From now on I doing it the best way first.

 

I'm finishing up the cab as you read. I completed the rear cab last night and everything looks good. I will take picture of this last assembly to create a flow of steps. 

 

Inobu

 

 

 

 

 

           

[CaptOblivious]

With a Digitrax decoder, if the lights work, but the motor does not, this is how the decoder signals to you that there is a short somewhere. Of course, it could also mean, as it did in your case, that the connection to the motor is not right!

 

Could you say a little more about this new technique? I'm intrigued, but I don't know what you mean by, "tapping in a pin" then "filling it with solder".

[inobu]

Capt,

 

I am editing as we speak but it turned out that the silver epoxy that I used did not conduct very good (hard to mix equally). So my contact leads were not terminated to the motor block as well as  thought.

 

I'm updating the entry above so more information well post as I progress.

 

Inobu

[mrpig]

Great install Inobu, I just got the full M250 set so this will be real handy when I get round to DCCing it.

[inobu]

Great install Inobu, I just got the full M250 set so this will be real handy when I get round to DCCing it.

 

I really like the M250.

 

The only problem I ran into was the install of the lights. I did a temperature check on my wiring and found 110+ degrees on the lighting board at one of the trace leads. The heat dissipation should be at the resistor. I didn't like that so I'm going to do my own boards and see if it gets the temps down. So, watch the light modification

 

Inobu

[Martijn Meerts]

What's a "DB Pin" exactly? It looks like it's a much better solution, or at least faster one then what I did with my C57. In my case, I drilled 2 holes and tapped in some thread. I then soldered wires onto small screws, and put the screws in the threaded hole. It worked just fine, but the problem is that those tiny taps break real easy, and on top of that, they're terribly expensive.

 

Not having to tap a thread, but just being able to solder in a pin would be much more interesting, providing the pin stays in the frame..

 

 

As for soldering to the frame, it IS actually possible, but the bigger the frame parts, the more difficult it gets. Also, in the case of steam locomotives, you often don't want to have to remove the wheels and all the rods, because they're a nightmare to put back together. But if you don't remove them, they might melt due to the heat dissipation of the frame. I've seen an install of Tomix's Thomas train where they used an 80 watt iron to solder directly to the frame.

[inobu]

It is the male pin in a DB 9 serial connectors. I drilled one size below the pin and tapped/hammered it into the motor's block and  cut the connector off. The pin is hollow so I placed a little flux on it to draw the solder into the center of the pin to re-enforce it. 

 

 

The motor block is pot metal and it cannot be soldered. The temperature must be to a welding point which may warp the block unless you vice it. A 80 watt iron can reach 900F or 428C. too hot.  It may be done but I would not risk it. 

 

I tried the die and tap but its too small you will just break the tap sooner or later like you said.  I think the drill press and pin tap is the easiest solution.

 

Inobu

[Martijn Meerts]

Ah right.. Do you get them separately, or do you just take them out of the connectors?

 

Looks like the best solution for a problem which many locomotives have, or at least, many of the ones I have =)

[inobu]

You can buy them in packs of 100

 

http://www.marvic.com/shopexd.asp?id=381

 

This is just an example link I bought mine from a local electronic store. You want the male pins.

 

Inobu

[Martijn Meerts]

Great, thanks. I'm gonna go have a look for them. Probably end up having to order them online from abroad, I have a feeling the Dutch have some silly name for the pins which I won't be able to figure out =)

 

elfa.se seems to have plenty of them though.

[inobu]

I finally got back to installing a decoder on my other Mc250 and wanted to come up with a better motor wire solution and came up with this. In my last motor install process I removed the black cap and drilled/tap leads into the motor block. Although it worked it takes a lot of time and effort and a drill press.

 

This method takes about a minute and will cost you $1.50 + shipping. I order a lot of these and had the lying around not I can see they will come in handy.

 

Here is the part you will need. You can order them from http://www.katousa.com/parts-catalog/information.html

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Here is what you have to do.

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And you are done.

 

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You can solder the orange and gray wired to these two points and you are done.

 

Here is the decoder wired and soldered. Make sure that you place the pick up leads toward the head of the unit. That way the decoder has a short run to the cab and there is no need to modify anything. It will accommodate the wiring.  

 

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Funny how one moment you feel brilliant and a few months later you kinda feel stupid. Anyway here's a better way of installing motor lead taps.

 

Inobu

Junior Rocket Scientist

Edited December 30, 2017 by inobu

[bigford]

that seems alot easer then drilling,tapping soldering lugs

but how tight is this ground going to be? and what about

the wires you have taped in that spot?

[inobu]

that seems alot easer then drilling,tapping soldering lugs

but how tight is this ground going to be? and what about

the wires you have taped in that spot?

 

Actually the cap snaps on and clamps the flat brass springs onto the motor block. 

The contact points are about 2mm and black cap has no play.

 

After I get it wired up I will take heat readings to see how good the connection is. From the looks of it the contact is flush against the mount and the caps keep it secured. I will solder the orange and gray decoder wire to the brass clips and it should be ok.

 

We will see.

 

Inobu

 

   

[CaptOblivious]

Inobu, brilliant work.

[inobu]

Just tested it out and the taps are good they make good contact and no temp issues. This is one of the issues with the drop in decoders. They do not make good contact with the motor leads which creates resistance. Resistance = Heat.

 

I think this is the way to go on in regards to creating taps for the motor block on the MC250.

 

Inobu

"Posted by: CaptOblivious

 

Inobu, brilliant work" 

 

I hope this time.

[Bernard]

Inobu - what an innovating idea... and easy too!

[Martijn Meerts]

I just isolated the motor from the frame, and soldered the wires directly to the motor. For power pickup, I solder the wires to the copper pickups, as close as possible to the part of the frame that houses the motor. The wires will just fit through the plastic and the metal frame, and the container will cover them up. No need to modify anything, other than cut the copper tabs off the motor.

[CaptOblivious]

Reviewing this thread, in advance of giving Nik_N_Dad's M250 a go, I was struck by something: Inobu, why did you swap out the stock resistor for a smaller one? I can't find an explanation, and you admit that it seems to be causing heating problems (which you never came back to). Not attacking, just curious.

 

(Still in awe at the cleverness of your final solution re: pickup leads.)

[inobu]

Reviewing this thread, in advance of giving Nik_N_Dad's M250 a go, I was struck by something: Inobu, why did you swap out the stock resistor for a smaller one? I can't find an explanation, and you admit that it seems to be causing heating problems (which you never came back to). Not attacking, just curious.

 

(Still in awe at the cleverness of your final solution re: pickup leads.)

 

I would never take your comments as an attack. If something is in question it will only help us all to correct. I can go down the wrong path for sure.

 

This is what I found concerning the LED conversion.

 

On a dc track the maximum voltage that the LED can receives it 12v which is full throttle. The voltage varies from operation to operation on a dc track but on DCC it is continuous. As far as the LED is concerned (when attached to a decoder) you are running full throttle all the time. Which means the resistor is dissipating heat constantly. I'm not sure what the LED's board is engineered for which places a road block for me. 

 

As for the resistor I was following the diagram from

 

that appears that the 561 was replaced by a 271 so I followed it.

 

I found that wiring and reusing the LED are a crap shoot because you cannot identify the specs for the LED and the output voltage can be a number of values. Without the exact information it is hard to find the optimum resistor value to incorporate in the board. A built-in LED has 3 volts in the leads where as the function leads have 13 volts and is depending on the manufacture. I think the board was heating up because the resistor value was not the correct one for my Digitrax decoder.

 

Because of the heating question I stopped installing LED. Just have not had time to find a remedy yet. 

 

Sorry for the late response I just saw this a few minutes ago. Better late than never??

 

Inobu