Lionel TMCC K4 to Legacy upgrade questions

Encoders are part of the flywheel. You need to get a flywheel that resembles your current one. Big Pittman and Canon motors share the same shaft size. Couplers are compatible. The trick will be determining which RCMC is programed for your gear ratio and wheel diameter. Otherwise chuff rate and speed matching could be off.

FYI a ERR Cruise M will eliminate the lurch.

Pete

Joe,

Unfortunately I am not going to be able to help you with your problem.  What caught my attention was your first sentence.  A Lionel sale half off sale?

Can you please elaborate a bit for those of us (maybe only me) for which this is news?

Thanks and good luck.

@Former Member posted:

Joe,

Unfortunately I am not going to be able to help you with your problem.  What caught my attention was your first sentence.  A Lionel sale half off sale?

Can you please elaborate a bit for those of us (maybe only me) for which this is news?

Thanks and good luck.

Lionel half off?…….when how ?

Can I buy the RS boards in the tender? I like those sounds!

@ThatGuy posted:

Lionel half off?…….when how ?

https://ogrforum.com/...5#177539554884488885

@MartyE posted:

https://ogrforum.com/...5#177539554884488885

Yes I forgot, but that his sale is mostly just stuff

@ThatGuy posted:

Yes I forgot, but that his sale is mostly just stuff

That is the only 1/2 sale from Lionel.

@ThatGuy posted:

Yes I forgot, but that his sale is mostly just stuff

What else were you expecting to be on sale at 1/2 off?

This particular sale has occurred every year for a number of years.  Usually it's in the fall, but the specific month and date very a little so we have to keep a close eye out for the formal announcement as it approaches.

Mike

You want to convert to Legacy.  Your best bet is to talk to @Bruk or @Sid's Trains for a parts list.  You will have to build your own harnesses, maybe some brackets to hold the boards. This won't be cheap but worth it in the end.  Check out my Youtube channel for several of my engines that have been converted.  I'm most proud of the MTH conversions.  Best of both worlds.  MTH ruggedness and Lionel electronics.

And yes buying the components during the half off sale is the best time to do it.

I've converted a few diesels and one steam to Legacy.  Diesels work, but some will have some very low speed jerky operation.  It's not bad, but it's something you'd have to select the RCMC to eliminate.  The trick is, you have no guideline how to select the RCMC for a smoothness as you have no matching criteria for the board to the engine.  I've been told that every Legacy diesel gets "tuned" to the board, which is why they're so smooth at low speed.

Steam is a lot easier to get low speed running.  Here's the MTH DDA40X that I converted to Legacy.

@Norm Charbonneau posted:

Can I buy the RS boards in the tender? I like those sounds!

@Norm Charbonneau  Email me and we can discuss details.  I will have no use for the boards once I do the upgrade.

@superwarp1 posted:

You want to convert to Legacy.  Your best bet is to talk to @Bruk or @Sid's Trains for a parts list.  You will have to build your own harnesses, maybe some brackets to hold the boards. This won't be cheap but worth it in the end.  Check out my Youtube channel for several of my engines that have been converted.  I'm most proud of the MTH conversions.  Best of both worlds.  MTH ruggedness and Lionel electronics.

And yes buying the components during the half off sale is the best time to do it.

Best to let Sid or Bruk just handle it!….they are the Legacy Dr.’s as far as I’m concerned…….Like you Gary, I’m the proud owner of one of Sid’s creations,……absolutely top shelf work, and a prize in my collection……..let the masters do their thing!….

Pat

@superwarp1 posted:

You want to convert to Legacy.  Your best bet is to talk to @Bruk or @Sid's Trains for a parts list.  You will have to build your own harnesses, maybe some brackets to hold the boards. This won't be cheap but worth it in the end.  Check out my Youtube channel for several of my engines that have been converted.  I'm most proud of the MTH conversions.  Best of both worlds.  MTH ruggedness and Lionel electronics.

And yes buying the components during the half off sale is the best time to do it.

I am excited to do this project.  I think the tender will be very simple.  Most of the work will be in the engine but with help from the forum, I think it will be very doable.  I'll email Bruk for his recommendations.  Thanks

Can't speak for Sid but I know Bruk isn't taking any work at the moment.  Their advise will be priceless.  Find out what your gear ration is so either guy can recommend which RCMC board part number you buy.

Joe.............. Following, interested in Legacy upgrades.

Richard

@Joe Fermani posted:

I am excited to do this project.  I think the tender will be very simple.  Most of the work will be in the engine but with help from the forum, I think it will be very doable.  I'll email Bruk for his recommendations.  Thanks

For your Legacy conversion, you'll certainly want Bruk's excellent Legacy documentation package!

Bruk's Legacy Documentation

One small error in the wiring of the Legacy thermistor for the smoke units, it should go to pin-3 of J6 & J7 instead of instead of pin-4.

Here’s a K4 Bruk converted to legacy

@gunrunnerjohn posted:

One small error in the wiring of the Legacy thermistor for the smoke units, it should go to pin-3 of J6 & J7 instead of instead of pin-4.

Thanks John.  I already had Bruks docs printed out.  I have nice binder will all the various docs from the forum.  Did not know about the thermistor change.  I've made notes in my docs.

I found that when I was designing my Legacy test sets.

Building a Lionel RCMC Board Test Fixture

He's At It Again: My New BEMC/RCDR Test Fixture

@Joe Fermani posted:

I am excited to do this project.  I think the tender will be very simple.  Most of the work will be in the engine but with help from the forum, I think it will be very doable.  I'll email Bruk for his recommendations.  Thanks

The hardest part is assembling the wire harnesses. Best if you get the pre crimped wires for any connector smaller than 2mm pitch. You can also get the raw LED and Photo transistor for the drawbars. The existing ones would likely work but they are cheap and should eliminate any risk.

Good for you doing it yourself. Best way to learn anything new.

Pete

@gunrunnerjohn posted:

I've converted a few diesels and one steam to Legacy.  Diesels work, but some will have some very low speed jerky operation.  It's not bad, but it's something you'd have to select the RCMC to eliminate.  The trick is, you have no guideline how to select the RCMC for a smoothness as you have no matching criteria for the board to the engine.  I've been told that every Legacy diesel gets "tuned" to the board, which is why they're so smooth at low speed.

Wow, individual tuning, that's interesting if it's really true.  Lionel (re)introduced back-drivable gears circa 2008, in part to tame the Odyssey Lurch.  No prior Lionel diesels with can motors had them, and MTH, Atlas, etc., still don't have back-drivable gears.  They allow the dual motors to "help" each other instead of fighting each other at the first few speed steps.  They also allow the entire mass of the loco and train to act as a damper (to some extent.)  This makes up for the puny flywheels often mandated by the vertical-motor setup.

I'm mostly a Steam guy.  But if I had my heart set on a diesel, for ^^these reasons, I would hold out for an OEM Legacy version.  If cost is no object I suppose you could buy the trucks and motors too, even the frame if necessary.  Basically buy a new one and do a shell swap!

Joe......I have a MTH PS1 Premier K4 That I am going to convert (hopefully} to Legacy also. It also has a Pittman motor. Have you developed part numbers yet for ordering needed boards and other parts? I have put RCMC and railsounds boards plus a pittman reader in my Lionel parts cart for future purchase. No clue if these are correct. The two boards are for Lionel Legacy K4. Perhaps we could share info via e mail. I don't want some one ordering unless we know they are correct. Anyone else that has infomation please let me and this goup know. I have done conversons usin TMCC and ERR but I think Legacy is the way forward.

Richard

Also

Joe.....I meant to say railsounds lite.

Ricard

@Rppoind posted:

Joe......I have a MTH PS1 Premier K4 That I am going to convert (hopefully} to Legacy also. It also has a Pittman motor. Have you developed part numbers yet for ordering needed boards and other parts? I have put RCMC and railsounds boards plus a pittman reader in my Lionel parts cart for future purchase. No clue if these are correct. The two boards are for Lionel Legacy K4. Perhaps we could share info via e mail. I don't want some one ordering unless we know they are correct. Anyone else that has infomation please let me and this goup know. I have done conversons usin TMCC and ERR but I think Legacy is the way forward.

If you posted the actual part numbers of what you're considering ordering, we could be more help.

The RCMC for the Legacy K4 should work fine as will the RS-Lite board.  You'll have to add some parts however, you need a flywheel with the Legacy toothed wheel for that Pittman that matches the existing drive components.  I suspect that Pat @harmonyards would be a really good guy to ask for specifics.  You'll also need the 691LTC1A01 PCB / TRACK I.R. DECODER-DRIVER / UBER / LEGACY, that operates the markers, backup light, and coupler and connects to the RS-Lite sound board.  Note that you'll be making all the cables, so I recommend dropping in to Aliexpress.com and buying some pre-made JST-ZH cables of the sizes you'll need.  Also pick up the 1.25mm cable for the option switches.  Crimping those are a bit of a PITA, so you'll be better off just buying them.

I spent way more time than I’d like to admit converting a Lionel TMCC Scale PRR T1 to Legacy.

Bruk’s advice was super helpful.

The key like others have said is finding an RCMC that is programmed for Pittman sized motors and the correct gear ratio. If you pick wrong, it will still work, but slow speed operations and double heading might not work as well. The other thing to consider is the smoke units you are using. If you don’t want to buy thermistor controlled smoke units, that will limit board choices too.

Finally, you’ll need a flywheel with the plastic tachometer piece. The challenge is finding one that works with your existing driveshaft set up AND a sensor that fits between the motor and flywheel with the right size holes to mount it to the motor.

Here’s a list of the parts ordered for my Lionel class A some years back.  Skip the first two part, prices are before the 50% off sale.  Of course you will need a different RCMC and railsounds lite board.

you will need more, misc hardware, the harnesses, homemade brackets for the boards or smoke unit, etc, etc

@rplst8 posted:

The key like others have said is finding an RCMC that is programmed for Pittman sized motors and the correct gear ratio. If you pick wrong, it will still work, but slow speed operations and double heading might not work as well. The other thing to consider is the smoke units you are using. If you don’t want to buy thermistor controlled smoke units, that will limit board choices too.

The thermistor issue is somewhat overblown.  If you have a smoke unit without a thermistor and a RCMC that supports the thermistor, simply connecting a 4.7k resistor between pins 3 & 5 of the smoke output from the RCMC will solve the missing thermistor issue.

There’s two caveats  when using the sensor PCB with the encoder flywheel on certain Pittmans, …1. You have to watch what store bought flat head screws you use (usually 6-32 ) when securing the PCB to the motor. I have seen some larger flat heads get mighty close to some of the surface mount components on the PCB. 2. Some Pittmans have a mighty short shaft. This puts the grub screws ( set screws) of the Legacy encoder flywheel right on the very edge of the Pittman’s shaft. In some instances, I’ve had to bore new set screw holes to get a good bite on the Pittman’s shaft. Just some observations I’ve been through, so check your components compatibility before just winging it,…..

Pat

WOW! to all that responded many thanks. I will post my curent part numbers  for review plus a more detailed responce for those that posted. I have no problem making cables .I will order the pre crimped wire for the small stuff. OGR is the best!

Richard

@harmonyards posted:

There’s two caveats  when using the sensor PCB with the encoder flywheel on certain Pittmans, …1. You have to watch what store bought flat head screws you use (usually 6-32 ) when securing the PCB to the motor. I have seen some larger flat heads get mighty close to some of the surface mount components on the PCB. 2. Some Pittmans have a mighty short shaft. This puts the grub screws ( set screws) of the Legacy encoder flywheel right on the very edge of the Pittman’s shaft. In some instances, I’ve had to bore new set screw holes to get a good bite on the Pittman’s shaft. Just some observations I’ve been through, so check your components compatibility before just winging it,…..

Pat

I agree Pat.  I ran into those very issues when I replaced the Canon motor in the PRR S1 with a Pittman motor.  I had to do some grinding on the screws to make sure they fit properly.  I also had to ditch the plastic insulator as it was too thick and did not leave enough room for the flywheel to mount on the shaft. I used electrical tape to insulate the pcb and it worked well. Canon's have a longer shaft.

I've been emailing Bruk as to which RCMC will work best.  I calculated the gear ratio at 16:1 for the K4.  I just got his recommendations on the RCMC.  So now, I can put together the shopping list and show it here to make sure all is good before I order next month.

GRJ....Part numbers in cart.HEAT SINK / RCMC / SCALE K-4 - 6101264032 RCMC / RECEIVER / DRIVER / SCALE K-4 / 6-11264 - 691RCMC050/ B REV RAILSOUNDS LITE / STEAM / LEGACY SCALE K-4 - 691RSL1013 BRACKET / RAILSOUNDS LITE PCB MOUNT  BRACKET / METAL / RAILSOUNDS BRACKET / SCALE K-4 - 6911264122 FLYWHEEL W/ DRIVE COUPLING / AT&SF NORTHERN - 6101332180 MOTOR SENSOR BOARD / PITTMAN (OPT) Note last 2 are for A SF Northern w/Pittman. I will add 691LTC1A01 PCB / TRACK I.R. DECODER-DRIVER to my order. Many  thanks.

Pat....Thanks I will watch for clearance on the sensor board.

RPLST8 ......My choice is a shot in the dark. Norhern w/Pittman.

Gary.....Thanks for parts list and comments. I agree with your comments on the MTH "core" for this project.

Joe....What brand is your K4? Sorry for high jacking your thread. Seems to be interest in this topic.

Pete.......Thanks for your comments.

Richard

Joe....I see your K4 is Lionel. duh right in the title. I'll check my gear raio. thanks.

Richard

Joe...... MTH K4 Premier PS1 gear ratio is 16-1 same as your Lionel Scale K4.

Richard

@Rppoind posted:

Joe...... MTH K4 Premier PS1 gear ratio is 16-1 same as your Lionel Scale K4.

Richard

Bruk suggested 691RCMC868 for that ratio

Thanks Joe.....It's in my cart. He is the man on this subject.

Richard

This is one of those great topics where all the right stuff comes together. I can't wait to see what comes out.

@gunrunnerjohn posted:

If you posted the actual part numbers of what you're considering ordering, we could be more help.

The RCMC for the Legacy K4 should work fine as will the RS-Lite board.  You'll have to add some parts however, you need a flywheel with the Legacy toothed wheel for that Pittman that matches the existing drive components.  I suspect that Pat @harmonyards would be a really good guy to ask for specifics.  You'll also need the 691LTC1A01 PCB / TRACK I.R. DECODER-DRIVER / UBER / LEGACY, that operates the markers, backup light, and coupler and connects to the RS-Lite sound board.  Note that you'll be making all the cables, so I recommend dropping in to Aliexpress.com and buying some pre-made JST-ZH cables of the sizes you'll need.  Also pick up the 1.25mm cable for the option switches.  Crimping those are a bit of a PITA, so you'll be better off just buying them.

I found this kit on Amazon for jst-zh connectors.  Will this work? Amazon jst-zh kit

@Joe Fermani posted:

I found this kit on Amazon for jst-zh connectors.  Will this work? Amazon jst-zh kit

That will work for the harnesses but there are no mating connectors for the boards like the one for the switches, program/run, smoke, etc.

Pete

The most important connectors to have are the smaller pitch, the 1.25mm and the 1.5mm connectors.  Most of the times the other end gets a larger easy to crimp connector or is soldered to switches, etc.

I buy my cable assemblies on Aliexpress, but since they get cranky here when you post a link, I can't really do that.  I get a lot more for my money on Aliexpress for the smaller connectors, and also I can buy them with longer wires so there's less splicing.  There's a huge difference between 150mm (6") than 300mm (12") when you're wiring up a locomotive.

Here's a sample.  I bought 10 8 pin 1.5mm cable assemblies 300mm long for $2.48, and shipping was $1.79.  Also, when you buy a bunch of different sizes, the shipping is combined so it ends up being considerably less.  On this order I bought $40 worth of cable assemblies and shipping was around $8 for the whole order.