Monday, October 27, 2014

Kato E8A won't program

Not much new decoder installation material to report on lately but recently at a local show one of the guys in the Ntrak club was having trouble programming one of his Kato E8A's that he had just put a decoder in.  On our Digitrax system the throttle display indicated "NoPrG".

This photo shows the decoder installation. A visual inspection indicated that everything was done according to instructions.

What I found when I got this loco to my bench was that the motor contact strips were not making good contact with the board.  This is a common problem and I always solder the contact strips to the board.  What happens is that a current has to pass through the motor to complete programming.  That is why you may notice a loco move or feel a vibration when sending it a program.  On this type of mechanism the motor brush contact strips are held in place against the board by a plastic clip.  This clip by itself sometimes does not stay tightly in place.

This closeup shows how the motor contact strips are held against the board by the clips.  To solder the contacts in place, remove the clip and melt a small amount of solder to both the board and the bottom side of the contact at the end.  Then use a small screwdriver to hold the contact tight against the board while re-melting the solder making the bond. Care needs to be taken to avoid melting the kapton tape on the wheel pickup strips.

If soldering is not an option then I would suggest a thin piece of scotch tape be placed over the plastic clip and reaching the gray plastic motor saddle on both sides to help keep the clip from coming loose.

It is even possible that a loco could seem to run OK in DC or DCC and then show this same programming problem.   That is because the contact is not good enough to pass enough current to make the programming function work but enough current could flow to turn the motor.  I've also seen this happen a time or two on a wired decoder where the connection to one of the motor brush caps was just hanging by a few strands of the wire.

On this Kato E8 it is interesting to note that this particular mechanism was introduced by Kato in 1994 and was one of the first mechanisms designed to accept a board type decoder even though it would be a few years before such a decoder was available.  Since then several other models have be been introduced that use this same design on similar mechanisms.

Tuesday, June 10, 2014

TCS CN-GP in a Life Like C424

It's been awhile since I've had any new type installation to present on the blog but was recently asked to install the TCS CN-GP type decoder in a Life Like C424.  I had only done a very few installations on this type of locomotive and those were done using a wired decoder and having the frame milled.  Not finding much on the internet about installing this type of decoder in this model I thought this project would make a good subject.


The frame on this model looks almost the same at both ends.  The difference is that the front end of the frame is just a little lower than the rear end and has a small notch on each side for the light shield.

With the CN-GP decoder the board that is normally put on the front or short hood end is longer than the other board and I determined that it was not going to fit in that location.

This can be seen in this photo comparing the inside of the shell to the frame with the decoder board.

It was also determined in the same way that the shorter board would fit in this location.

In this photo comparing the rear of the frame with the long board and the rear of the shell with the dynamic brake section removed, it can be seen that the long decoder board will fit if the rear lens is shortened.

I have used this technique of reversing the position of the boards before to fit this type of decoder in the Atlas Classic RS1.

With the dynamic brake section removed and the shell on the frame it was also determined that there would be no clearance for the wires between the top of the frame and the shell so a groove on the top of the frame was going to be needed.

This is really important.   If wires are squeezed between the inside of the shell and the frame, the shell may not be seated properly on the frame causing body mounted couplers to be too high.  There is also the chance that the wires could become pinched and eventually short on the frame.

Now on to the installation

All of the filing is done on the right half of the frame.  There is a small tab that sticks out that I used as a guide.  Filing parallel to the length of the frame, I take my time to get a clean notch along the length of the top of the frame.  Slots like these take me about 20 to 30 minutes.  I don't have measurements but in two of the photos below the results can be seen.  The goal is to have enough space for up to 5 decoder wires so that they all lay below the top of the frame.

A slot is also filed with a jewelers file along the side of the motor in the location where the orange wire is in this photo.  The orange and gray wires were removed from the decoder and the brush holders are removed from the motor.  After the wires are soldered to the brush caps, the orange wire goes to the bottom and the gray wire goes to the top of the motor. There is a hole on the frame of the motor that indicates the bottom.

On the frame and using the motor assembly as a guide, make a notch at the point on the right frame half just above the top motor brush cap.  Any edges should be smoothed with a jewelers file.

The decoder boards may be thinner than the stock LED boards.  I added a bit of solder to the top side contacts as shown in this photo.  Some test fitting and file work may be necessary to get a snug fit on both boards.

At this point, the mechanism is re-assembled and wired.

Here is the completed mechanism in this photo.  The motor on this model will rotate a bit within the frame when moved by hand but not by the motor rotating. Once the shell is on, it will hold the motor in place.

Track testing at this point should have the loco running in normal direction in DC and reverse direction in DCC.

Before installing the shell back on the frame, the rear lens needs to be shortened.  I removed the dynamic brake section to access the lens.  I cut it with a plastic spue cutter then smoothed the end with a flat jewelers file.

In this photo the shell has been installed and the positions of the lens and the LED on the PC board can be seen.


Because of the reversed position of the boards, CV29 needs to be programmed for 07 if using 2 digit addressing or 27 if using 4 digit addressing.

Sunday, March 2, 2014

TCS M1 in an Atlas N Master Line GP7

Some time around 2006 Atlas released a decoder ready version of their GP7 and GP9 models called the "N Master Line".  The new model also had bright white LED's and the slower motor.

It was also designed to accept the shorter board type decoders like the  Digitrax DN163A4 or the Train Control Systems ASD4.  I recently picked up one of these and as most of my other Western Pacific locomotives already had decoders, this one moved to the top of my to do list.

I checked to see if the TCS CN or CN-GP decoders would work with this model.  They would work but as seen in this photo, the LED's would be some distance from the lenses.

As the locomotive already had the bright white LED's and room under the existing board for a small decoder, and I was not going to need the extra functions, I decided to use the less expensive TCS M1 wired decoder connected to the existing board.

After fully dis-assembling the locomotive, the PC board needs to be modified.

Most of the modifications to the PC board that are needed are on the bottom side and are shown here in this photo.

The top of the board just has one place where the circuit trace needs to be cut to isolate the frame contacts from one of the LED's.  I use a Dermal tool with a cut off wheel to do this.

I then attach the decoder to the TOP of the PC board after pushing all of the wires through the hole. This is because the board is going to be re-installed upside down.

Because the board is going to be turned upside down the old motor contact pads can be used to connect the decoder input to the frame.

I had mixed up the white and yellow wires and cut the white wire too short.  The bulge is 3/64 heat shrink to cover the splice I made.

At the front end of the board the longer scrap of blue wire is connected to the LED as shown in this photo.

The white wire is placed between the leads of the LED to reach the other side of the board.

Then the white wire is connected to the input side of resistor R2 as shown in this photo.

This photo shows how the motor wires from the decoder are connected to the motor.  I normally cut the orange & black wires to about 1-1/2 inches in length.  The gray wire is soldered to the brush cap with the brush cap removed from the motor.  Re-install brush cap after it has cooled.

Here is everything done execpt for replacing the shell. The wires should have enough room to fit between the frame sides on the top of the board. Secure the wires with scotch tape to prevent them from getting on the top of the frame.

This Atlas Master Line N scale GP7 locomotive seems to be a big improvement over the GP7's and GP9's that they released starting in 1996.  Besides the fact that either a board or wired decoder can be installed without any milling done to the frame, it also seems to be a more finely made mechanism.

This decoder install was the last one done in my old train room.  I had been using a spare bedroom in the house for my layouts and all of my model railroad work since 1997.  I have recently moved everything into a new room built especially for this purpose which is about twice a large.  There will be a new layout under construction and lots of new DCC decoder installations !

Tuesday, February 4, 2014

Lenz LE0511W in an Atlas MP15DC

This installation was first presented on my old web site in January 2006.

The Atlas MP15 had just come out and it was designed to be DCC ready but no decoder board was available for it yet so I decided to try to install a small wired decoder in it.  The Lenz LE0511W was one of the smallest available at that time.

After disassembling the engine, modify the LED board as shown.

Remove the LED from longer hood end of board and save it for later.

Decoder wire lengths:
7/8" inch - Red, Black
1 inch - Orange, Gray, Blue
1-1/4 inch - White
1-3/8 inch - Yellow

Scrape off the green coating from the circuit traces near the frame contacts on the LED
board to expose bare copper and solder the red and black wires, observe polarity.

Reverse the polarity of the LED by removing it, flipping it over, and then re-soldering it. Feed the yellow wire through the hole from the top side to the bottom side and solder as shown.

Place a 1/4 inch length of 3/32 inch heat shrink over the white wire and solder the white wire to the LED lead on side where the rim is flattened.  Place a 3/8 inch long length of 1/8 inch heat shrink over the blue wire and solder and 1K ohm 1/8 W resistor to the blue wire.  Then solder the other end of the resistor to the other LED lead. Slide heat shrink down and heat.

This motor design has a small PC board with two contacts sticking up. Cut these contacts to about half their original length. 

Cut two lengths of 3/32 inch heat shrink about 3/16 inch long and place these over the gray and orange decoder wires. 

Solder the orange and gray wires to the shortened motor contacts.  Use a low heat setting and be extra careful about the heat being so close to the motor housing.  Observe the correct polarity of the wires.

Slide the heat shrink down over the soldered connection and apply heat from a heat shrink gun.Again, be careful of damaging the motor housing. 

This is what the completed decoder assembly should look like with the PC board, motor, and front LED connected.

Notice the small red band over the wires near the decoder.  I've found that is helps protect the wires connections to the decoder while handling.  This can be cut with with small scissors and removed after the decoder is in place

When re-assembling the engine it is very important to get all 4 of the motor saddle tabs properly into the notches on the frame.

The Lenz decoder does not have any insulation over it the way a other brands do so we need to insulate the frame where the decoder is going to be.

Place a piece of 1/2 inch Kapton tape on the top
of the front section of frame.  Trim any excess from the sides. 

Here is the re-assembled mechanism with the decoder properly installed.  Lay out the wires in the channel at the top of the frame halves so they are as flat as possible.  Lay the wires to the front LED out so that the bulge from the resistor is where the gap in the frame is.  Put the decoder on top of the LED wires and angle the LED slightly upward.  Secure wires and decoder with scotch tape.

Re-install the shell onto the mechanism.  The shell should rest on the painted rails that are part of the frame.

If the shell will not go down all the way, the LED on the board may not be properly aligned.  There is a black plastic light shroud inside the shell at the hood end.  Fish it out and carve a notch in it as shown.  This should allow the shell to go down all the way.  Put it back into the shell as it was before.  Try installing the shell again.

Decoder boards made specifically for this model have been available for some time now but in case you ever want to try a wired decoder this is how it's done.

Friday, January 17, 2014

TCS M1 in an older ConCor E8A

The first new installation of 2014 is going to be on a very old model.  In the mid 1980's Con-Cor started to offer a model of the EMD E8A with the mechanism made by Kato.  This model has no flywheels and a more primitive motor that what we have become used to with more current releases.  Many of these models were sold up to the time that Kato introduced their own E8 models in 1994 with a great mechanism that is still in use on current releases of that model.

For this one the frame is going to have to be modified to fit the decoder.  I sent mine to Aztec Manufacturing for precision milling. The Aztec part number is TM3006 and the charge to get this done is only $10.00 plus shipping.  To send the frame to Aztec, fully disassemble the locomotive, put all the small parts in a small plastic and the motor by itself in another small plastic bag for storage until the modified frame comes back.

Decoder wire lengths:

Black  =  4-1/8 inches            Red = 3-3/8 inches             White = 3-3/8 inches              
Blue = 3-1/8 inches               Gray = 2-3/8 inches             Orange = 2-3/8 inches
Yellow = not used

 It's always been my practice to never solder the motor wires from the decoder to the motor brush caps while they were installed on the motor.  Normally with all other installs, I remove the brush, spring, and caps.  Then solder the wires to the caps and then re-install everything into the motor.  On all other loco's I've worked on this works out fine as the caps or brush holders snap into the motor body.  On these ConCor locos the motor brush mount screws into the motor.  With the wires already attached, the wires end up getting very twisted.

This upside down photo shows the correct orientation of the motor and how close the the motor brush caps are to the frame.  The white motor magnet is facing down.

The motor brush contacts point away from the top part of the frame.  When assembled, they made contact with the lower parts of the frame assembly.

So my method for the ConCor cab diesels is this:  I first fully unscrew the mounts and remove them.  Then place a small amount of solder on the surface of the mount.  After it has cooled, I re-install the brush, spring, and the fiber washer and screw the assembly back into the motor with contact part not used.  I don't fully tighten it but leave it loose about 1/2 turn.  Then I solder the tinned motor wire to the spot where the solder is.  The fact that the mount is a little loose, the fiber washer, and the solder already being on the mount seem to keep the mount from getting hot enough to melt the plastic of the motor.  The angle of the wire needs to be pointed upward as shown in the photo below.

When the soldering is done and the brush caps rotated clockwise to a snug fit things should look like this, with the wires pointed upward.

When the motor is re-installed into the milled top part of the frame, the motor wires go up through the slots that are milled.  This view is of the left side of the mechanism with the mechanism upside down.

I have found that the trucks can short on the frame so I add short lengths cut from .010 x .125 strip polystyrene to the areas of the trucks shown in this photo.  The polystyrene strip is held in place with Tap Plastics E6000 adhesive.

With the decoder wires laid out side by side they fit neatly into the milled groove on the top of the frame.  The yellow wire is not used but I keep some length on it in case it needs to be used later.

This photo shows how I connect the decoder input wires to the frame.

On the red wire I used a motor brush contact from a Kato motor to attach the red wire.

On the black wire because the screw is so close to the top part of the frame I did not use any ring.  Instead I just made a loop at the end of the black wire.

To upgrade the lighting to bright white LED first bend the leads so that they will fit around the rasied center part at the end of the top frame.

Place the heat shrink over the wires and solder the resistor to the lead with the smaller element.  Then attach the blue wire to the resistor and the white wires to the lead of the larger element.

This photo shows how the LED assembly fits into the area where the original light bulb was.  It may be necessary to flatten the ridges on the top and bottom of the LED.  The heat shrink will prevent anything from shorting on the frame.  This assembly can be secured with Walther Goo, Tap Plastics E6000 or other similar adhesive.

The model origionally came with black electrical tape over the headlight area to keep the light from shining unrealistically in the cab windows.

I did not see a better way to do it so I did the same thing.  The front edge of the tape should be even with the front edge of  the top frame and the LED.

The shell normally fits rather loosely on the frame so the electrical tape may make the fit more snug on the front end but it should fit.

The fuel tank clips into the shell at two spots on each side and that is what keeps the shell on.

The light should come out brightly on the top large headlight and more dimly on the bottom headlight and the number boards similar to this photo.