Another Kato contact question....

[eja]

This time the problem child is an N scale Kate P42 Genesis locomotive.

I chose the solder the contacts option, put the loco on the test track and it ran perfectly.   Then I put the shell back on it and it would not move at all.

Any suggestions regarding where to start debugging this issue will be greatly appreciated.

Ed

 

[peteski]

This time the problem child is an N scale Kate P42 Genesis locomotive.

I chose the solder the contacts option, put the loco on the test track and it ran perfectly.   Then I put the shell back on it and it would not move at all.

Any suggestions regarding where to start debugging this issue will be greatly appreciated.

Ed

Ed, expand on what exactly you mean.  More details! Do we assume you installed a DCC decoder?  You didn't say. 
Soldered what? Motor Leads?
How about the truck-to-chassis pickup strips?
Is the Decoder readable on test track (with the shell installed)?
If yes, can you control the headlights?
When you remove the shell does the loco behave correctly again?
Closeup photos of the install (with shell removed) would be helpful too.

[eja]

OK....

I installed a Digitrax decoder and soldered the motor contracts to the pads on the dcc board.  No other soldering was performed.

This has been sitting on my to do bench for almost a year, so I am not 100% certain whether the lights were responsive or not, but I believe they were as I usually test everything before I put the shell back on.

Yesterday, I un-solderd the board (inspired by a recent thread) and plan to reinstall the board this weekend.

I guess, I am mainly looking for things to check so that I don't end up in the same situation.

Hope this helps .......  thanks for your support.

Ed

[Mark W]

...How about the truck-to-chassis pickup strips?...

...soldered the motor contracts to the pads on the dcc board.  No other soldering was performed...

I'm not a fan of the pickup design on these.  Yet there's not really any way to improve them except for hard-wiring them.   If you do hard-wire the truck tabs to the decoder as well as the decoder to the motor, they'll run perfect (on clean track). 

[peteski]

I installed a Digitrax decoder and soldered the motor contracts to the pads on the dcc board.  No other soldering was performed.

This has been sitting on my to do bench for almost a year, so I am not 100% certain whether the lights were responsive or not, but I believe they were as I usually test everything before I put the shell back on.

Yesterday, I un-solderd the board (inspired by a recent thread) and plan to reinstall the board this weekend.

I guess, I am mainly looking for things to check so that I don't end up in the same situation.

Ed,
I'm nto trying to be  a smart-a$$ but I'm still confused.  If you soldered the motor leads (as mentioned in that recent thread), why did you unsolder and removed the decoder?  Did you remember it ont working when you put it away year ago?

To me it would have made sense just to leave it as-is, try to verify the decoder install on the programming track, then tried running it on the main line.  Who knows, it could have worked properly. If not, you could have started troubleshooting it in its current condition.  Now you have, so to speak, disturbed the evidence of the original problem. 

Unlike Mark, I don't think the design of that model is bad. Not worse than all the Kato models with the electric pickup strips low in the frame.

What do with these locos to make sure the electrical contact is good is to polish the the strips in the area where they contact the metal prongs coming from the motor.  I use metal polish and a buffing wheel in a Dremel tool.  Then I sand and polish the tips of the metal prongs. I use a mutli-grit fingernail polishing stick I buy at a beauty supply store. It is perfect for the job.



I'm not a fan of using Kapton tape on the pickup strips to insulate them from the motor leads. Kapton tape interferes with the pickup strips making good contact with the bottom of the decoder, and I just think it is a kludge. Instead, I notch the pickup strips at the area of the motor tabs, so they will not contact them. I need to take some photos and post that procedure here.

I also bend the pickup strip ends down a bit more than what is done at the factory to increase the pressure against the truck's pickup prongs.

Lastly, since I' ma belt & suspenders type of a guy, I also do solder short jumpers between the decoder and pickup strips. If I have some spare time this weekend, I'll document my procedure and post it in the DCC section.

[eja]

Peteski,

I know your are not being a smart - a$$ and that I disturbed the evidence of the original problem.

When I originally tried to trouble shoot this issue, I managed to pull one of the contact strips partially out  from under the DCC circuit board.  Since I could not get it properly re-positioned, I decided to remove the board and start over.

I like your idea of of notching the contact strip rather than using kapton tape.

I am having cataract surgery tomorrow ... hopefully I will be able to see more clearly and work on this later this weekend.

[trainforfun]

On all my KATO P42 and E8/9 I soldered the brass strips coming from the motor and get rid of the small plastic grey clip .
But sometimes without the cab everything is fine but as soon as I put back the cab I loose the power to the loco ....

I found that the front headlight have to be bent a little down because it's touching the cab and it lift the DCC board just enough to loose power from the rear truck .

[nickelplate759]

On all my KATO P42 and E8/9 I soldered the brass strips coming from the motor and get rid of the small plastic grey clip .
But sometimes without the cab everything is fine but as soon as I put back the cab I loose the power to the loco ....

I found that the front headlight have to be bent a little down because it's touching the cab and it lift the DCC board just enough to loose power from the rear truck .

I think you want to solder the brass strips AND keep the grey clip.   You are likely losing power from the trucks to the board without the clip to hold the board in place.

[peteski]

I think you want to solder the brass strips AND keep the grey clip.   You are likely losing power from the trucks to the board without the clip to hold the board in place.

Yes, but The problem is that many modelers who are not soldering experts will use so much solder, and leave the motor pickups so long, that the solder buildup will not allow for the clip to be installed. This entire design is not optimal when using DCC decoder, while it is ok with the stock light board (due to the way the motor leads are installed.  But you are right, that gray clip provides a more positive connection between the bottom of the decoder and the pickup strips. Without it, they could be intermittent. That is why I also solder jumpers between the pickup strips and the decoder.

I might be able to post a step-by-step procedure on Sunday of how I do this.

[MK]

I'm not so sure that the gray removeable clip is doing that.  I've seen many people install the decoder on a P42 get intermittent results because they did not push the decoder back far enough (push down while pushing back) so the rear stationary clip catches the board.  The rear stationary clip needs to catch the board to force the board down to touch the pickup strips.

Unfortunately you can solder the motor tabs to the pads reqardless of whether the rear clip is catching the board or not.  Many just place the board down, bend the clips and solder without observing the back end.

Here's a close up of the rear clip on the right, courtesy of TCS' website:


Their full picture install:
http://tcsdcc.com/installation/n-scale/kato-p42-all-phases/k0d8

[nickelplate759]

I'm not so sure that the gray removeable clip is doing that.  I've seen many people install the decoder on a P42 get intermittent results because they did not push the decoder back far enough (push down while pushing back) so the rear stationary clip catches the board.  The rear stationary clip needs to catch the board to force the board down to touch the pickup strips.

Unfortunately you can solder the motor tabs to the pads reqardless of whether the rear clip is catching the board or not.  Many just place the board down, bend the clips and solder without observing the back end.

On further thought, I think it's best to use the push-in clip, but probably not 100% necessary.  Note that the push-in clip engages the grey plastic slot betwen the two solder points.  That said, the paramount  thing is to ensure that the board is engaged in the rear clip BEFORE soldering.

Or - use Pete's method (jumpers from the truck contacts to the decoder, and then clips don't matter.

By the way, whoever did the soldering in the TCS example picture used WAY more solder than necessary.

[MK]

By the way, whoever did the soldering in the TCS example picture used WAY more solder than necessary.

Yep, that would be a little more of a soldering challenge if the tabs had to be opened up for whatever reason.  It's a tiny tab, you're not welding steel. 

[peteski]

On further thought, I think it's best to use the push-in clip, but probably not 100% necessary.  Note that the push-in clip engages the grey plastic slot betwen the two solder points.  That said, the paramount  thing is to ensure that the board is engaged in the rear clip BEFORE soldering.

Or - use Pete's method (jumpers from the truck contacts to the decoder, and then clips don't matter.

By the way, whoever did the soldering in the TCS example picture used WAY more solder than necessary.

If not using pickup strip jumpers it is important to the pinch the pickup strips as tightly as possible between the gray cradle and the decoder PC board. That will result in good contact of the pickup strip with the bottom metal pads of the decoder.  The gray clip is designed to hold the PC board tightly in the gray cradle.  But then the Kapton tape (by adding insulating thickness between the decoder and the pickup strip), so the electric connectivity between the contact strips and decoder could be iffy.

[NorsemanJack]

I'm not so sure that the gray removeable clip is doing that.  I've seen many people install the decoder on a P42 get intermittent results because they did not push the decoder back far enough (push down while pushing back) so the rear stationary clip catches the board.  The rear stationary clip needs to catch the board to force the board down to touch the pickup strips.

Unfortunately you can solder the motor tabs to the pads reqardless of whether the rear clip is catching the board or not.  Many just place the board down, bend the clips and solder without observing the back end.

Here's a close up of the rear clip on the right, courtesy of TCS' website:


Their full picture install:
http://tcsdcc.com/installation/n-scale/kato-p42-all-phases/k0d8

Yikes!!  Is that what we're calling "soldering" these days??

[MK]

More is better!    .