Couple of questions on an early Lionel TMCC SD70MAC

I had one of those with an ERR in it as the magnet on the motor cracked. It ran smooth as silk!

I fooled with the smoke unit a bit:

1) Removed the sock from the resistor

2) Opened up the air intake hole as large as I could without hitting the trace.

3) Replaced the resistor with a MTH resistor. Some will say it's too big a change in ohm, and while it may be, I had no issues.

4) Replaced the batting with the Lionel wick style.

After that it smoked like a monster!

 Here's the guideline I followed:

https://www.youtube.com/watch?v=ZkDlQ5Cwwlk&t=12s

I'd be looking at mechanical binding issues in at least one of the trucks.  A dual can motor locomotive with no cars behind it shouldn't require nearly 2 amps to keep moving.  Your experience with other similar locomotives is more in line with what I'd expect.  If both trucks turn freely when manually rotating the motors through a full rotation of the drive wheels, then I'd be thinking either a bad motor or a problem with the DCDR motor driver board.

The smoke issue is probably the fan motor.  If you have 5VDC at the connector, it's likely the fan motor is defective.  There is no reason to replace the whole smoke unit, the casting doesn't go bad except in extreme cases.  I have seen a couple that needed a new PCB, but only a couple.  Most of the times a smoke unit full rebuild would consist of the resistor, wick, and smoke motor.  Those are the "consumable" items.  If it has a gasket, you may need one of those as well, some Lionel smoke units have them, some don't.

Jeff T posted:

I had one of those with an ERR in it as the magnet on the motor cracked. It ran smooth as silk!

I fooled with the smoke unit a bit:

1) Removed the sock from the resistor

2) Opened up the air intake hole as large as I could without hitting the trace.

3) Replaced the resistor with a MTH resistor. Some will say it's too big a change in ohm, and while it may be, I had no issues.

4) Replaced the batting with the Lionel wick style.

After that it smoked like a monster!

 Here's the guideline I followed:

https://www.youtube.com/watch?v=ZkDlQ5Cwwlk&t=12s

 

 

That's an excellent video -- thank you for posting it!

gunrunnerjohn posted:

I'd be looking at mechanical binding issues in at least one of the trucks.  A dual can motor locomotive with no cars behind it shouldn't require nearly 2 amps to keep moving.  Your experience with other similar locomotives is more in line with what I'd expect.  If both trucks turn freely when manually rotating the motors through a full rotation of the drive wheels, then I'd be thinking either a bad motor or a problem with the DCDR motor driver board.

The smoke issue is probably the fan motor.  If you have 5VDC at the connector, it's likely the fan motor is defective.  There is no reason to replace the whole smoke unit, the casting doesn't go bad except in extreme cases.  I have seen a couple that needed a new PCB, but only a couple.  Most of the times a smoke unit full rebuild would consist of the resistor, wick, and smoke motor.  Those are the "consumable" items.  If it has a gasket, you may need one of those as well, some Lionel smoke units have them, some don't.

I'll take the trucks apart again but besides the gears being a little worn nothing looked wrong or like it was binding to me. Maybe I'll snap a few photos and will post them up. I'll try turning the wheels a full rotation again and see if I can isolate the problem better.

Hopefully I can get it narrowed down and if it does need a motor or the DCDR board then I'll order it along with the smoke unit rebuild parts.

Thank you for the input!

I was looking for a video on Lionel's site, but the link to it was either slow or not going to happen. So after I saw that your link went to youtube, I copied the title of the video and searched for it on youtube and it came up instantly.

Seems like a better way to view Lionel's product videos. I hope Mike's videos continue to exist for many years even with him no longer at Lionel.

Do not put the 16 ohm MTH resistor in place of the 27 ohm, it is too big a change.  My experience has indicated that 20 or 22 ohms is as low as you can reasonably go without much greater risk of cooking the R2LC smoke triac.

Good advice -- I was planning to keep it stock, but perhaps do the Mike Reagan modification posted in the video above just to improve the output.

If I really want to fill the basement with smoke I do have plenty of Legacy and DCS locos that are up to the task!

And if the motors/gearing are okay, I suppose it would it be a good excuse to upgrade from the DCDR board to a ERR Cruise Commander M...

Yep, a CC-M is a nice and easy upgrade for this locomotive.

So I did some further investigation -- the motors/wheels/gears turn consistently in both directions. I did clean off a little more old/hard/crusty grease I missed and lubed everything up a little more, but alas, no change. While I had it on its side I did run power to it and throttled it up and down, changed directions, ran it slow and also didn't see anything out of the ordinary.

Is there a good way to narrow down if it's one of the motors vs. the DCDR board?

What I do is unplug the motors from the DCDR, the larger black plug.  Then you can flip it over and connect a low voltage DC supply to them and try running them.  They should be turning in the 2-3 volt range, when you just barely get them turning, see if they run smoothly.  You can also apply friction to one of the trucks at a time and see if you can feel any mechanical hesitation.  With no load on the trucks, they should draw now more than around 500-600ma max for the two motors, and probably somewhat less.

If you don't have a bench DC supply, something like this is handy for testing a lot of stuff around the workbench, eBay: 371580598599 $4.99 shipped.

Hey...those ARE my workbench DC power supplies! I have assorted styles too!  

And that one looks like it might be a nice addition, and it's AC/DC! 

I should have a DC power supply available -- on the black connector on the DCDR it's pin 3 & 4 (the bottom left/right pins) which are motor positive and negative, respectively, correct?

Johns test is good for motors, but I recommend running on track with shell off and watch motors.  The coupling effect of both trucks via track can make a difference.  One motor may start slower and bind as the other turns it and applies backlash to the slow starting motor.   Also measure resistance of motor leads to motor.  I would start also with a good cleaning of the motor internals with a solvent designed for electrical motors.  CRC makes one.  Good at cleaning commutators and brushes that can get corroded or dirty from sitting.  G

With the current he's drawing, assuming there's no mechanical binding, I predict he'll find something amiss with at least one of the motors. 

Regarding the power supplies above , I put in that number and get nothing, is that the right number???

Marty

You're obviously doing something wrong.  I just copied/pasted that number into the eBay search and got this.

It also worked for me yesterday and just now.

Me too...

371580598599

The Chinese can sell that electronic component at a super reasonable price, what happened with engines?! More directly, the cost of replacing electronics in engines. The old worn out "we are a niche consumer base" is starting to look more and more questionable IMO. In fact, the price we pay for engine electronics stinks on ice. I'm done now. Rant completed.

Rich 

Rich, I have to believe some of it is subsidized, I can't buy the components, even in quantity, for the price I can buy completed boards shipped from China!  How is that possible?

I would think it's subsidized and also I think there is some kind of shipping agreement between our countries...like China gets it to here and we get it to the buyer's address...and conversely...but I'm not sure what the balance of trade is on that .

GRJ's number worked for me last night. Unfortunately, so did the Add to Cart and PayPal buttons.   There was still plenty available when I left the page.

The prices really are amazing for some of this stuff. The shipping should be more than the stuff, but it's free!

gunrunnerjohn posted:

With the current he's drawing, assuming there's no mechanical binding, I predict he'll find something amiss with at least one of the motors. 

You sir have been spot on! Thank you so much for your assistance (and everyone that's chimed in)!

I had one of my DVOMs setup as an amp gauge inline while running the motors directly off of a DC power supply. At 3-4V the front motor wouldn't even turn the wheels (loco on its side), it was humming though! The rear truck was nice and smooth even less than 5v. If I stepped it up to 5-6V the front motor would eventually start turning after humming a bit.

I did separate the the trucks again and cleaned the gears on the motor/center set of wheels and applied some fresh Lucas white lithium grease to them (just to make sure everything was meshing) and then put it all back together. Same result.

Just for grins, I then shot some QD in the slots on the side of either motor, no change either.

So is it best to replace the motors in pairs or can I get away with just replacing the defective one? Can I assume the DCDR is in good shape?

IMO, the DCDR is fine, you just need one motor.  I don't replace motors in pairs, it's a waste of money, again IMO.  I don't know anyone that replaces both motors when one goes bad.

Sounds good -- thanks again for all the assistance! Now to see if I can source a motor and the smoke unit parts locally...

I'd order the motor from Lionel, they do have it listed for $20.  You'll be sure to get the correct motor, the gear is obviously fairly critical.   Since you'd be getting that, the smoke unit parts get a free ride on the $10 shipping charge, so order all of them from Lionel.

Here's the Lionel 6-18250 TMCC SD70MAC Parts Page, all the parts are there.

Oh I've been looking at the parts diagram and getting part numbers. Unfortunately the smoke unit fan is unavailable, so that either leaves reservoir/fan assembly or a complete assembly.

Use an MTH smoke fan motor, they're readily available and work fine in this unit.

Good to know -- also appear the gasket for the smoke unit isn't available either, of course.

The gasket isn't normally bad, but if it is, I just omit it, most smoke units don't have one.

gunrunnerjohn posted:

The gasket isn't normally bad, but if it is, I just omit it, most smoke units don't have one.

Huh? What gasket is normally missing on smoke units? G

Many smoke units don't have a gasket between the smoke motor and the fan chamber.

Front motor replaced, fan motor replaced, and smoke unit overhauled (and upgraded with the Mike Reagan TMCC video posted above and new ). I kinked the gasket between the PCB and smoke unit reservoir when enlarging the hole to match the PCB (hence the extra puff of smoke besides from the main stack). Going to run out and get some gasket material and make a new one today. Other than that it seems to be running much smoother (although still doesn't do much from speed steps 1-3 in TMCC mode), but much less amperage draw!

https://youtu.be/N2iwI0CedAE

Thanks to everyone for the assistance!

Not unusual for a TMCC locomotive without cruise control to not start up for a few speed steps.  You can set the stall speed to improve the startup, though it still doesn't have cruise.

Setting the stall speed definitely helped! I made a new gasket (got some by-the-foot gasket material from an auto parts store) and that seemed to cure the smoke fluid seeping/wisping too. While it's not a fancy/great Lionel locomotive, it's good to get an old one fixed up and running again!

Thanks for all the pro tips!

I guess I have a thing for the Lionel MACs...