Anybody regear a Williams 2R Challenger?

It's not geared too low, it's geared as a proper scale model should be.  How long are your straightaways?  I guarantee, if you put a camera car in front of your Challenger at 45 mph, the video feed would resemble a roller-coaster ride! 

The noise is not an indicator of poor gearing, it's an indicator that the manufacturer didn't take the additional steps to attenuate NVH (noise, vibration, and harshness.)  This is especially important with Brass locos.  (If the loco had a die-cast boiler, we probably wouldn't be having this conversation.  There's a reason they don't make tubas out of die-cast metal!)

Three things you can do:

1. Remove the motor and flywheel from the train.  Balance the flywheel by lightly holding a finishing file against it while the motor is running.  Don't use a lot of pressure, let the file do the cutting, and stop when you feel it smooth out.  By all means, take care that brass chips don't get in the motor bearings!  (Perhaps an easier option would be to install a balanced flywheel that you can purchase as a spare part from one of the current manufacturers.  You might have to file a small flat spot onto the motor shaft for the Allen screw to seat securely.)

2. Install a square of DynaXorb in the crown sheet area of the boiler (above the motor and flywheel.)  This soft latex material is used for car audio installations, to attenuate unwanted vibrations.  It usually has a self-adhesive backing.  It'll add a little weight too!

3. Cushion the motor mount.  Use rubber grommets under the four screws that mount the motor, if they're not already present.  You could also remount the motor to the chassis with an adhesive foam pad under it, and a pair of zip-ties to hold it in place.

Properly geared locos are a rare and beautiful thing.  IMO more of them should have been made this way.  If you want a Challenger capable of toy-train speeds, there are plenty of other options available, beginning with the MTH version from 1993.  You would then have to use gimmicky electronics, tach sensor, etc., to make the train run smoothly at slow speeds.  My $.02.

Many of the Williams brass locomotives have a 44:1 gear ratio, it appears they use a common gearbox.  At around 43 scale MPH, the motor is turning at around 8,000 RPM.  I've run across four in the last few months, all had the same 44:1 gear ratio. 

I don't care how well you balance the flywheel, it's still going to make some noise at that speed.  When I run a Pittman motor without the flywheel attached at 8,000 RPM, it starts to get noisy.  The cheap motors that Williams used in those are bound to be even more noisy.

They run great at low speed, just don't expect freeway speeds out of them.

Take the flywheel out.  Try it.

Yes, I put NWSL in a Williams Challenger.  Be careful - the recent cases need to be re-sized for full worm engagement.  As I recall, a # J drill wrapped with sandpaper corrects the axle bearing hole.

Thanks for the help. I will try some suggestions soon. Some seem easy to try.

It actually runs great with MTH control in it. I just don't like the extra noise.

So I have to ask, what gearing does the MTH version have?  Mine is very quiet and runs great at all speeds, even slow. I have to wonder if it's just the shell?

Bob, I need to look at the NWSL catalog again. Did that quiet her down?

Joe, if you’re happy with the way it runs, a Pittman swap will help knock down most of that noise......any motor screaming at the top of its lungs will keep some noise, but those bigger Mubachi’s sound like they’re gonna fly apart at speed .......my brass Williams Niagara is a great runner, but man, it sounds like things are gonna come apart at anything above 40 SMPH.........Pat

harmonyards posted:

Joe, if you’re happy with the way it runs, a Pittman swap will help knock down most of that noise......any motor screaming at the top of its lungs will keep some noise, but those bigger Mubachi’s sound like they’re gonna fly apart at speed .......my brass Williams Niagara is a great runner, but man, it sounds like things are gonna come apart at anything above 40 SMPH.........Pat

What Pat says, and any motor that is completely enclosed (most Pittmans I have seen)  will be much quieter than those vented motors Williams used.  They form a bit of a siren with air passing around the armature turning at high speed.  At 44:1 the motor is never loaded up so they run cooler and a vented case is not necessary. A Pittman and sound deadening material around the motor will likely cure your noise problem. Some of those Williams motors had a very low static resistance 1.2 ohms or so and will heat up fairly quick.  If you want to go nuts you could install a Maxon coreless and get rid of the flywheel.  However they don't get along with some PWM motor drivers.  The H bridge needs to operate above 20khz for coreless motors to be happy.   Don't quote me but I think at least some of the ERR drivers are above 20k.  Coreless motors run virtually silent and don't cog at low speeds.            j

I respect Bob2's knowledge of brass.  But these are 3-rail locomotives with as many as eight (8!) rubber tires if they're all still intact.  No skidding.  If you take the flywheel out, and some inveterate postwar Lionel operator hits the "DIR" button, even if the train is running slowly you'll have a bone-jarring stop, and a spectacular derailment.  Even worse you could bend a driving rod, break a crank pin, or cut a burr into the brass worm wheel.  Flywheels are a good thing!

Pat is a wizard, I love his conversions!  But with your stock gearbox, the Pittman motor will be too slow.  Although it's noisy and a little cheap, your stock motor is good for 13,000 RPM at 24 volts (which you could get back in 1990 with a Right-of-Way transformer or a prewar Type Z.)  This would equal the 70 mph speed of the prototype.  The slow-turning Pittman redlines at about 6800, so your loco would be lucky to hit 40 mph with that.  If your current motor is a 3-pole RS-550 you could replace it with a 5-pole RS-555, but it would still have to be the high-rpm winding.

The MTH Challenger has a 12-volt, 6800 RPM Pittman motor and self-locking 16:1 worm gears.  This combo is good for about 90 mph on the top end, which is faster than the prototype, and IMO faster than anyone needs to go.  With 30" of loco, how long are your straightaways?  In a few seconds you'll need binoculars to see the darn thing!  It also has a flywheel that's really too small to be effective at the low RPMs it's turning.  I had the PS1 version.  Again, if a kid hit DIR while it was running at normal speed, you would get a bone-jarring stop.  The old 773 was much more friendly in this regard.  The Challenger was hyped as a "scale model" when it came out in 1993, but it had shiny driving wheel tires and handrails, oversized smoke box hinges, no sprung drivers, etc.  Despite all the hype and the high price it was still very much a toy train, and in some ways a step backwards from the products offered by Williams and Weaver.

With 16:1 gearing, the PS1 version had to be coaxed to run consistently at anything below 10 mph.  For example: pull out of the engine house (no trailing consist.)  As soon as the drivers got on a curve it would slow noticeably or stall.  With all that weight over the rear tires the wheels couldn't skid, and there just wasn't enough torque or stored energy in the flywheel at 800 RPM to overcome the sudden increase in friction.  I gradually became disappointed and traded mine, lost a lot of money.  Instead of installing a separate 30:1 gearbox like they should have, MTH (and Lionel) applied the band-aid of electronic speed control, which gets us to where we are today.

What you have is actually very good, and I encourage you to work with it.  Flywheels aren't expensive.  Order the largest one you can from Lionel or MTH, or try the trick I recommended with the file.  Definitely add the DynaXorb and the rubber grommets, this isn't hard to do.  Then come back and tell us if it worked!

Ted, coreless motors without flywheels will coast down much slower than an iron core motor without a flywheel when the power is removed.  I have some Maxons the size of a 385 and some 385s with flywheels that I bought to add power to a dummy DL-109 I have the Maxons in hand but will have to open a few boxes to find the 385s.  I will try and set up a test with them running side by side and make a video.  I have an optical tach and will  adjust them to the same RPM.  Never tried a side by side coast down between a coreless and iron core motor with flywheel.  Just a guess but I bet their close.   And sure you can use a flywheel on the coreless but it is not vital as on an iron core motor.  Another mod I would like to make to all my Williams steamers is to cut some metal bands to replace the traction tires on one side of the loco I think they would run through curves smoother and with rubber tires only on one side the steel wheel side could slip a bit putting less stress on the rubber tire and likely deposit less rubber on the rails.  I'll likely sell them before getting around to that.  At 73 some projects are just not worth the time they take.  Do hate rubber traction tires though. Geez it's ten till 5am           j

Hmmm. So first off, I'm happy with the MTH PS2 board inside right now. So I'd have to figure out if it would run a coreless motor.

This engine is 2 rail, and no traction tires.

I'm tempted to get in there again, and check the flywheel for balance. I built another engine and had the homemade flywheel make most of the noise. It was plastic and easy to fix. I just needed it for the tach tape.

I really believe that this particular engine has low gear issues and that's where the extra noise is from. The flywheel spinning that fast must be a big part.

I don't wish to run this engine much faster than say 60MPH myself. Our grandsons push it more than I do and have learned that 45 is a good top speed. It's still loud at 45. I don't wish to fight with the 2 rail crowd over fantastic 2 MPH operation. I think my MTH Challenger runs fine. I considered swapping the main engine frame for a faster fix. I just don't want another carcass laying around in waste.

 My layout goes completely around the basement. I have long straights that can handle long trains. I'm not sure what that has to do here, but I will answer that question. I am not a high rail, high speed runner. Having to run at 30MPH to hide motor drive issues seems ridiculous. It is easy here with DCS, as I can set the top speed of any engine to whatever I wish. I also can build a consist in seconds and every engine gets along with each other. So I wish to retain that and not change my motor control for one engine. It would be easier to get rid of it than change command controls, or just carry on at 30MPH for this one.

Take the flywheel out.

My Williams "J" (2-rail, no traction tires) was really, really noisy.  I thought it was the gears.  Nope, flywheel.

I made the mistake of putting a Pittman in and losing the original motor.  Dead smooth, but way, way too slow.

Take the flywheel out.  Not opinion.

If you have a conventional iron core motor it's almost imperative to have a flywheel. Especially if it has a non coasting gearbox.   A lot of the Williams locos had a flywheel that the hole in the middle was too large for the motor shaft and they just tightened down the set screw and held it on in a non concentric position. These things would almost vibrate the detail off the boiler. The way I fixed the ones like that was to press the smallest pinion gear on the motor shaft that I could. Then hold a file against it,while running, and turn it down till I had a brass collar a couple of thousands thick that took all the slack up in the flywheel hole to the point that you "almost" have to tap the flywheel on. Be careful to keep the surface of the file flat against the gear you don't want a taper. Perhaps rig some sort of tool rest keep the file square.   I tried shims and with enough tinkering you can make them work but turning down a brass pinion gear really does the trick. It does take a bit of time and patience.       Off to see if I can put together that coast down shoot out between a coreless motor without a flywheel and a Mabuchi 385 with a flywheel.  Someone mentioned Coreless with MTH board.   Wonder if anyone at MTH can tell us the PWM frequency of their boards.  20Khz is about the minimum for coreless motors.  Some of the ERR boards claim that.          j

I'm sure you probably know this John, but just in case someone reading along takes your statement the wrong way about tapping a flywheel on. 

NEVER tap anything on a motor shaft without the opposite end of the shaft being supported!  What is likely to happen is you'll slide the commutator along the shaft and kill the motor!

This is the 2-rail section, right?  Two rail locomotives almost never had flywheels before Williams, and the old hands will tell you they ran fine.  Even the Lionel scale stuff from 1939 ran beautifully, although they sorta had coasting gearboxes.

Take the flywheel off, test it, and if that was the problem and you want a flywheel, balance it and re- install, or make a new one.

Well for one thing, this engine comes apart so easy and fast, I should have done that first.

I got the engine on the bench and removed my tach tape. I removed the flywheel and ran the motor in my hand. It's a very loud motor to start with. It screams with only a few volts DC directly to it. That seems like the exact noise that's bothering me. I re-installed it back into the engine. I noticed that it already has a rubber type shim against the mount to the motor housing.

 I put a file against the flywheel as square as I could by my eye, and ran the motor. It filed the edges of the flywheel only and not the center? It felt very smooth. When I've had problems in the past, I could actually feel the flywheel out of balance. I tried the flywheel against the edges and it appears to be balanced.

 So in my opinion, there's 2 things already that I've found. A very loud motor, and the lower gearing so that this motor needs to crank up more. I'm sure it would be quieter without the metal flywheel. I considered making one out of plastic so I could still mount my tach tape needed for command. I don't have the proper tooling to make one better than what's already on there in plastic. My home made ones are usually are slightly off balance.

 So I'm tempted to either lower the gearing, or swap out the motor with another engine I have lying here. Maybe a quieter motor would help the most I feel.

 I can always put the stock motor back in. I really feel that it's the motor making this annoying noise I hear! It's tuff for me here because I respect Bob2's opinion so much already.

here's the before video ( I should have parked the cars!)

here's just the main drivers. The clicking is from the plastic drive coupling flopping around.

BTW there's some type of adjustment that seems to angle the gear box drive? Maybe changes the pitch of the main gears?

I'm not sure what it does or how to adjust it properly.

Joe, the air-raid museum called, they want their motor back....😉

good god that’s noisy!...I take Bobs suggestions as gospel as well, but I’d try a motor swap and see if you could get happy with the speeds......my Niagara is noisy, but not that noisy.......Mubachi’s are land fill material IMO .....I hate them!....I hope you get it fixed, that’s a sharp looking video, although I didn’t see the Cessna come by?........Pat

So what informed your decision to not remove the flywheel?  That is exactly the noise my "J" made until I pulled the flywheel.

Yes that motor is an extremely high rpm deal - we think it is a windshield wiper motor.  A 9000- series Pittman will slow that thing down to switcher speeds.

Show us a video without the flywheel, and I will publicly "eat crow" if it is not lots quieter.

I did remove the flywheel. I ran the motor disconnected from the engine.

It now has the flywheel back on with a new tach tape. I will remove it again and make a video for you later tonight. I'm getting a motor from Norton.

I got around 43-45 scale MPH from a Williams Niagara with the 44:1 gearing at full speed.  While not exactly "warp speed", it was sufficient for the job and the customer was happy with it.  OTOH, I'd like my locomotives to top out at at least 60 scale MPH, not that I'll run that way a lot, but it's nice to have gas in the tank.