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Some Questions About Converting LL Proto 2000 FA To DCC (UPDATED)

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Some Questions About Converting LL Proto 2000 FA To DCC (UPDATED)
Posted by peahrens on Friday, March 23, 2018 9:59 AM

I just acquired unused P2K FA & FB locos.  I will be converting to DCC by removing the curcuit board, adding a LokSound Select decoder,custom speaker enclosure and LEDs.  I have done a number of P2Ks before but this one appears to have at least one important difference so I am seeking some clarity in advance of diving in.  (I need to finish another project before the FA).  

I did remove the shell on the FA and it looks like the FA in this TCS WowSound installation:

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Life_Like/Proto%202000%20Alco%20FA1%20WK/Proto%202000%20Alco%20FA1%20WK.html

I've done some google searching and found several threads of interest, mostly on P2K S1, S3s where an important wiring issue is noted.  I'll add a quote from BMMECNYC (2nd to last thread comment).

http://cs.trains.com/mrr/f/744/t/252474.aspx?page=2

"Starting my second LL S-1 today.  Summary of what has been learned:  Nylon screws are not needed.  

Test locomotive on DC before starting tear down to check for correct L/R pick up wiring, orange/gray wire on correct side of motor. 

Remove motor from frame and flip over (corrects the incorrect LL wiring scheme), Solder orange wire to the newly exposed unwired clip (remove clip before soldering) CAUTION: small spring and motor brush under nut that holds clip, do not lose this. 

Apply kapton tape to area around gray wire, bottom motor contact. 

File out the notches that held the light bulbs in place, 3mm LEDs do not exactly fit in same location.  Use golden white LEDs for 1st Gen Diesel Switchers. 

TCS MC2 decoder fits well.  Remove the 8pin plug entirely and hardwire, saves critical space when re-installing shell. 

Replace couplers (plastic spring Kadee clones are what came on this)."

There is also this Digitrax item on the S1:

http://www.digitrax.com/tsd/KB992/life-like-proto-2000-s-1-may-damage-dcc

And here is a thread on the FA itself, but the above items seem to indicate a similar DCC wiring issue and there is more info in the S1 threads.

http://cs.trains.com/mrr/f/744/t/178220.aspx

Now to my questions (any help most appreciated, to keep me ahead of the curve):

1.  Am I correct that the wire screwed to the frame, right of the cab, is one motor brush lead?  Which means that I will need to isolate that brush cap / clip as described?

2.  The TCS WoWSound link does not address that, does it?  Or is it not an issue, on their FA?

3.  What will I encounter with the truck pickups and track wiring on this P2K?  On other P2Ks I am used to wires to each side of the trucks for the rail pickups, and I solder these at the trucks.  Since my FA has that wire screwed to the frame (by the cab) does that mean that one rail pickup goes to the (hot?) frame via the (metal?) truck body, and there is a wire from the other wheels?  And do I need to use plastic Kadees to prevent shorts between locos via metal couplers, because the frame will still be "hot" because of the pickup approach from the (right?) rail? 

Unfortunately, I can not look at the loco now, so thought I would ask for any insight I will need when I get to it.  Thanks! 

Paul

Modeling HO with a transition era UP bent

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Posted by richhotrain on Friday, March 23, 2018 10:21 AM

I was a participant in that MR thread, the second link that you provided.

As I said in that thread, the problem is that the orange wire is grounded on the lower brush, and a metal clip from the lower brush touched the metal frame.  That in itself does not cause a short.  But, in a derailment when the wheels make contact with both rails, the decoder will blow.  I had it happen on both S3 switchers before I got educated the hard way.  

The solution is to insulate the clip so that it does not make direct contact with the frame. Another solution is to relocate the orange wire to prevent this short from occurring in the event of a derailment.  Look for the metal clip on your Life Like S1 or S3. Some releases do not have the metal clip?

That said, are you sure that you have that particular problem with the Proto 2000 FA? I thought the orange wire problem was limited to the P2K S1 and S3.

Rich

Alton Junction

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Posted by rrinker on Friday, March 23, 2018 10:48 AM

 Looking at that TCS page, it sure does look liek they just grounded the bottom motor pickup, and then screwed the red wire to the chassis. That would be the same problem as the S1, if a wheel should be forced into contact with the underside of the frame, you have provided a path for track power to get to the decoder output - smoke time. Unless the underside aroudn the trucks is covered in plastic so there is no way for a wheel to touch the metal frame. 

 My FAs are different than that, I guess because mine are from the non-Mars light run. I haven't put decoders in them yet. I also have a much older one, sort of - after MDC stopped using an AThearn chassis in their RS3 kits, they used a P2K FA chassis, it's the original run that had a belt drive between the rear flywheel and the radiator fan, except without the fan mechanism - the flywheel has a groove for the belt, ut that's it. Those are pure AThearn BB clones, right down to the towers on the trucks, but they use a wire soldered to the top motor clip instead of the Athearn metal bar. Bottom side pickup is through the bolsters and chassis just like a BB loco, so adding a decoder to those will be the same as doing a BB loco.

 I suspect this newer FA was improved by doing away with the truck bolster pickup path, but then kept it simple by using the chassis to connect the lower motor brush. 

 Unless there's some sort of plastic shield around the truck mounting area so the wheels can't touch the metal, the way it's installed on the TCS site is just asking to fry the decoder the first time the loco derails.

                                 --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by peahrens on Saturday, June 09, 2018 3:21 PM

Thanks to the guidance from those above plus earlier threads I was able to convert the FA1 and FB1 without a problem.  I will add some info and photos to round out the topic as regards my P2K versions (Mars light, no moving fan).  In this first photo you can see the orange wire on the right side attached to the frame floor.  The trucks have wires on the left rail side, but on the right rail side there are no truck wires.  Rather, the (shiny) top of the truck bolsters are live to the right wheels and the bolsters thus make the frame hot, which the orange wire attached to the frame picks up.  

 IMG_0533 (2) by Paul Ahrens, on Flickr

The next photo shows the top of the B unit frame (the front is on the right).  The motor is shown upside down so you can see the bottom clip that powers one motor brush.  This clip can contact the (right rail hot) frame, no good for DCC.  The clip has a bend at its front that would rub against the (painted) frame.  I bent the front of the clip more severely towards the motor so it can not contact the frame there, and added Kapton tape to isolate the length of the clip and the front also, so I will be ok unless the tape wears through.

 IMG_0534 (2) by Paul Ahrens, on Flickr

The next two photos show the B unit being prepared and then finished for the DCC components.  I used a LokSound Select with dual 13x18mm CUI CDS-18138A speakers in a styrene enclosure. 

I wired the decoder motor wires color matched; i.e., with orange to orange and gray to gray, not knowing whether that would cause the loco direction to be correct (or reversed) without CV tinkering.  In this case, the direction was correct.

Given the hot frames, I paid attention to use of Kadee metal couplers regarding possible shorting (say, if the B unit were placed backwards).  While the coupler boxes are attached to the frame with a metal screw, the coupler pockets are plastic, including the vertical cylinder that the coupler surrounds, so the metal couplers (I used the standard whisker ones) do not connect with the frame.  The standard length couplers nicely keep the door diaphragms in contact which is a nice feature of these locos.  I think I need to put a longer coupler on the tail of the B unit so it can uncouple ok.  

The A unit also got LED lighting, a 5mm one for a headlight and a 3mm one for a Mars light.  The sound of each unit is very nice, as the speaker enclosures do not need to be so tiny.  

These are quite nice locos in my opinion.  I must admit that I acquired them thinking they were the earliest of EMD F units, not knowing there was a 4-axle freight equivalent to the Alco PA.  So I was pleased to learn that I have diversified my UP fleet further than I had expected.

 IMG_0583 (2) by Paul Ahrens, on Flickr

 IMG_0586 (2) by Paul Ahrens, on Flickr

 IMG_0658 (2) by Paul Ahrens, on Flickr

 

 

 

Paul

Modeling HO with a transition era UP bent

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Posted by Paul3 on Wednesday, June 13, 2018 11:30 PM

I have an A-B-B-A set of these myself.  I've installed sound in other people's FA-1's/FB-1's.  There are dozens of these that have run around at my club over a couple decades now.  We all just use the 8-pin plug.  No one to my knowledge has ever had a problem with them shorting out in a derailment and popping a decoder.  Heck, IIRC, it's impossible to get a wheel to touch the chassis on an FA-1/FB-1 due to the design of the truck & bolster.  The S-1/S-3 was different as it could touch under certain circumstances.

A hot chassis has is perfectly fine with DCC.  Heck, I've decodered and seen others install literally hundreds of DCC decoders in hot-frame locos (Athearn BB's, P2K's, brass, and many others).  It works just fine 99.9999999% of the time.  The only exception I can think of is the P2K S-1/S-3.

You also don't have to worry about metal Kadees because the P2K FA-1/FB-1's have plastic coupler boxes.  The original gold box FA-2/FB-2 did have the Kadee touch the metal chassis using a simple clip.  However, the FA-1/FB-1 and later blue/gray box FA-2/FB-2 used plastic coupler boxes.

The last time I installed sound in one of these, I took off the shell, pulled out the dummy 8-pin plug, plugged in the LokSound decoder, soldered the speaker wires to the speaker, replaced the bulb with an LED and put the loco back together (with the speaker enclosure).  You did some nice work, but it really wasn't necessary.

 

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Posted by rrinker on Thursday, June 14, 2018 7:25 AM

 The Roco-made Atlas S2's are nearly identical to the P2K S1 (and S3 - sorry, as an Alco nut, the P2K models are S1's and S3's, 660 HP models, Atlas makes S2's and S4's, 1000 HP models). To the point they are probably made in the same factory - the motors even both have the purple end caps. I have a Roco one I haven't taken apart but they must have one difference, a motor brush grounded to the metal part of the motor since they seem to require a nylon screw to replace the metal motor mount screw, which P2K ones do not. I need to dig into mine because I've been curious, it looks like the identical motor, and just cutting off the tab on the bottom connector and soldering a new orange wire is fine for the P2K, curious what's different witht he Roco that the motor frame is also connected to the brush. The end caps with the brush holders are plastic, after all.

                                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by peahrens on Thursday, June 14, 2018 8:53 AM

Paul3
The last time I installed sound in one of these, I took off the shell, pulled out the dummy 8-pin plug, plugged in the LokSound decoder, soldered the speaker wires to the speaker, replaced the bulb with an LED and put the loco back together (with the speaker enclosure). You did some nice work, but it really wasn't necessary.

Paul,

As a preference, a key reason that I usually remove the original circuit board and hard wire the decoder is that it typically provides more room and flexibility in how large (and/or where) the speaker enclosure can be.  With the micro speakers a significantly larger encloure can significantly improve lower frequency response and make a noticeable difference.  Of course, it takes significantly more time and some contend that the HO format's best speaker performance is so lacking in low frequency that differences are insignificant.  I like to problem solve each case and have more speaker size and placement options. 

An exception may be in the queue; i.e., a Genesis SD-70M that (per the diagram) has a vertical round 1.1" speaker cut-out in the frame weight.  I'm having my engineering department mull that one over.    

Paul

Modeling HO with a transition era UP bent

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Posted by Paul3 on Thursday, June 14, 2018 11:01 AM

Randy,
Atlas also made S-1/S-3's by simply making another hood with a smaller radiator and different stack.  The problem with it is that the S-1/S-3 is 12" shorter than the S-2/S-4 (and that includes the wheelbase).  Atlas didn't make the S-1/S-3 shorter.

The P2K and Atlas versions are not the same other than perhaps the motor.  On the Atlas, everything below the hood/cab is metal.  On the P2K it is plastic.  Detail-wise, it's not close.  Electrically they are very different as the P2K has an 8-pin socket and the Atlas one didn't (the newest ones that have the wire grab irons probably do).

BTW, to take an Atlas one apart, remove one end of each rear cab railings.  Grab the cab with your forefinger and thumb down low at the sill, front and back.  Pinch and pull sideways away from the loco, then pull up.  This should release the catch.  Do the same on the other side.  Remove the cab.  Then pull up on the hood near the cab and then disconnect the hood from the sill at the front (watch the tab).  Pretty easy.

The Atlas S-units have a metal screw that goes through the metal chassis and into the metal motor frame.  The metal motor frame is interally wired to the lower brush.  The printed circuit board has a metal screw that connects a trace of the circuit board (connected to one side of the truck pick ups) to the metal motor frame.  The other motor brush is isolated from the metal motor frame and gets power from a brass wiper connected to the printed circuit board trace that goes to the other truck pick ups.

What that all means is that the metal chassis on the Atlas S-units is actually electrically connected to the lower motor brush.  When converting to DCC, the chassis must be isolated from the motor (because it's also the brush) by using a nylon screw and Kapton tape, or "bad things" will happen.  Any derailment where any part of the metal chassis contacts the rail would pop the decoder.  And since that includes the steps and footboards, etc., that's almost a certainty.

peahrens,
Sure, that's understandable that you want to remove the factory board for better sound.  I almost had to but found I had room for a single sugar cube-type speaker right behind the cab (right on top of that black plastic shelf), and it sounded okay to me.  YMMV.

But there was no need to take the motor out.  Just take out the factory board and hardwire in the decoder.  As long as the motor brush doesn't contact the chassis, you're fine.  This model doesn't.  If it did, the ones I own and the ones at my club would pop decoders as soon as they hit the rail...and they don't.

BTW, I have to ask...why the two cents inside the shell?

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Posted by rrinker on Thursday, June 14, 2018 3:07 PM

 I've had the body off the Atlas, I just didn't dig into it and buzz out the motor circuit. Very interesting that their motor has the metal frame connected to the brush holder inside the palstic cap adn the P2K oen does not - not holding them up against one another but the motor in my Atlas looks the same as the motor in my P2K. I guess someone in the intervening years decided that it would be an improvement to keep the brushes isolated in the plastic (and they were right).

                             --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    January, 2010
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Posted by peahrens on Thursday, June 14, 2018 4:07 PM

Paul3
BTW, I have to ask...why the two cents inside the shell?

Paul, I decided to add 6 pennies, 3 deep, in the front of the B unit for grins since the back had more weight and there was lots of room.  I considered going to 10 pennies of weight but could not find a dime in the house. Smile

Paul

Modeling HO with a transition era UP bent

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Posted by drgwcs on Sunday, June 17, 2018 10:06 PM

Converted an Atlas/ Roco s-2 with one of the NCE board decoders. I believe that TCS made one as well but it did not have the nylon screw. MRC made a sound decoder. All of these were engineered for this model where they replaced the board. Sadly none of these are made anymore. Wish they were I have two more to convert.

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Posted by Paul3 on Monday, June 18, 2018 12:50 AM

drgwcs,
The TCS did come with a nylon screw just like the old NCE board replacement.  It's a shame neither is manufactured anymore.  They were so easy to do compared to milling out the chassis or removing the top weight or stuffing everything in the cab.

The MRC sound board being off the market is no loss.  We had a 50% failure rate at my club with them, and besides that, they recorded the wrong diesel (the MRC S-unit was an Alco 244 V-12 engine while the S-units had either the Alco 539 or 539T (w/ Turbo) straight 6 engine).  And did I mention the sound quality wasn't that good, either?

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