Anybody regear a Williams 2R Challenger?

Here are a couple photos.  Sorry about the quality on the second one - Log Mallet, with 54" drivers, and NWSL gears.  Note the speedometer cable.

The first one is the MM-2 of OSN fame.  The big motor is a 9236 Pittman, and is just resting there.  The gears are 24:1 and 25:1, which makes the engines go in and out of synch.  Runs like a dream, noiselessly!

Joe I sent both emails to the address in your profile.  Just checked my sent folder to make sure I got your address correct and looks as though I did.  If you have another email address send it to me and I will resend both links to motors.  I am aware that there are better solutions but changing gearboxes is a major undertaking that I have done twice and both times I ended up having to requarter all the drivers. No two quartering jigs are exactly the same and one quarter degree out will run but have a very slight bind at slow speeds. Changing gearboxes is an expensive option however If a $10 motor can get the job done why not give it a try. I would still like to know what the final drive ratio is. If it is indeed 40:1 or more a 385 has the torque to get the job done but anything less than 40:1 and you need more motor.  Perhaps a 395 but I have been unable to find a 395 on ebay with a 12000rpm no load speed at 12v.  However someone is selling a gearbox with a 12000rpm 395 on that auction site I will try and find it. If I remember it is only about $15.       j

@bob2 posted:

The gears are 24:1 and 25:1, which makes the engines go in and out of synch.  Runs like a dream, noiselessly!

That's a cool idea to make the running a bit more interesting.  Given it's 2-rail with no traction tires, I'm sure the slight speed mismatch doesn't make any difference, and it's neat that it'll have a more realistic visual effect.

John, got your email. Great information. Thanks for the help!

John - it works really well - slippage is one revolution every 25.  I bet it would work with traction tires.  Slippage is on the order of a quarter inch per revolution.  I have limited space, but the locomotive pulls 14 heavy cars without breathing hard.

The other solution to articulated and Mallet-type synchronization is two motors.  I regard that as difficult, mechanically, since you have to cut so much out of the boiler and rear cylinder block to make it work.  I invented a "twin-spool" solution that might work great with tooth belts.  The chains were noisy.  The motor stack will only fit in a giant firebox, like the Northern Pacific Challenger:

Bob, I think the slight mismatch in the gears is the classy way to do this, much less messy.

Ohhh! Twice the available power though!

I bet belt drives would make that quiet?

@bob2 posted:

John - it works really well - slippage is one revolution every 25.  I bet it would work with traction tires.  Slippage is on the order of a quarter inch per revolution.  I have limited space, but the locomotive pulls 14 heavy cars without breathing hard.

The other solution to articulated and Mallet-type synchronization is two motors.  I regard that as difficult, mechanically, since you have to cut so much out of the boiler and rear cylinder block to make it work.  I invented a "twin-spool" solution that might work great with tooth belts.  The chains were noisy.  The motor stack will only fit in a giant firebox, like the Northern Pacific Challenger:

I have one of there NWA and a frend switched the gear in the gear box. With a 9000 pittman it ran faster and not verry loud.

@prrq2 posted:

I have one of there NWA and a frend switched the gear in the gear box. With a 9000 pittman it ran faster and not verry loud.

I don't know what a NWA is? Did it have the 4 gear tower?

Wow guys, that's advanced stuff! Two motors is surely the coolest thing in an articulate.

Bob, do you have a close up of that drive shafts? Looks magic! How do you get the front engine supplied?!

Looks like we're in the same kind of trouble :-) I still work on the gear ratio for my Challenger.

There are so many things to consider! Speed, Power, Space, Noise

So far I tried a Faulhaber 2342 but found it a bit small.

Also the ratio is too low. The wheels turn too fast at that low voltage. I try to be in the 1:25 / 1:30 range, that would mean nice slow speed and still some 50 scale miles at 5000 rpm.

That's my space concept for the bigger Faulhaber 2642. First I thought that a gear head would be a cool thing but I think it could be quite noisy so I now try to figure a way to get the power reduced with a timing belt / pulley arrangement.

Kohs Challenger - technically perfectly done! Note the not huge motors by Pittman

I could use the Kohs dropdown technique.  The chains are really noisy.

I could never put up with the boiler cutouts to accommodate that arrangement.

My front driveshaft goes straight through the rear driveshaft, right through the rear gearbox.  The idea came from the triple spool Rolls Royce engines I was flying at the time.

The NWSL gearboxes, 24 or 25:1, coupled to an 8000 series Pittman with a rubber tube, is about as quiet as you are going to get.  Ball bearings on the worm shaft are imperative, and you cannot have loose axle bearings, either on the gearbox or the frame bearings (driving boxes).

@bob2 posted:

I could use the Kohs dropdown technique.  The chains are really noisy.

I could never put up with the boiler cutouts to accommodate that arrangement.

My front driveshaft goes straight through the rear driveshaft, right through the rear gearbox.  The idea came from the triple spool Rolls Royce engines I was flying at the time.

The NWSL gearboxes, 24 or 25:1, coupled to an 8000 series Pittman with a rubber tube, is about as quiet as you are going to get.  Ball bearings on the worm shaft are imperative, and you cannot have loose axle bearings, either on the gearbox or the frame bearings (driving boxes).

Very impressive! so you use a hollow shaft - omg. I would love to learn more about your invention - isn't there a lot of friction involved? Do the two shafts have contact over all the length or just on entrance / exit points? You're a great modeller!

Yes - lots of friction.  And the outer tube is brass, so structurally not great.  But that part is not a problem.  The friction is not a problem in reality, because when running they barely move with respect to each other.

The big problem was the special ball bearings for the rear worm shaft.  They were list price around $60 each.  I got "comped" for two - they offered, and I accepted.

again, those chains are the only serious problem - the design is otherwise good.  You would need smaller diameter motors for the UP Challenger.

The better solution is the Mod 0.6 in the rear and Mod 0.5 in front.  Guaranteed in and out of synch.  Works on even the smallest Mallet.  See photo above - those are 54" drivers, and note that you cannot see the drive shaft.  All drivers are powered.  (All drivers ride in ball bearings as well, but I will not be doing that again soon.  Made no difference.)  Oh - 17/64, Auel tender trucks.  Front cylinder block is aluminum for weight balance.

I am excited to try a belt system. I think it will solve several issues at once. I maybe wrong. Scott at 3rd Rail has helped me here again. Thank you.

I need to get a new 3mm? shaft about 6cm long? Possibly a new flywheel too? I'm thinking cutting one from the plastic dowel I bought for an Aristocraft Dash9 conversion I did years back. I may even hollow it out?? Lots of ideas and much testing.

Now it will just take some accurate workmanship by me and to see if my idea is on track!

You all are WAY over my head on all this.... but it's a fascinating read.

Mark in Oregon

I'll be at this soon. Parts are starting to show up. Either it will work or it won't.

I'll be setting what's acceptable as a solution to my standards. Quiet, smooth, and strong comes to mind here.

Our grandson will also let me know if my work is acceptable. I can always put in a better motor if this goes in the right direction. If not, she's a shelf queen for our grandson.

Well? I'm pretty happy with some of the work. It runs very quiet now! Not like she's falling apart trying to achieve 40 MPH or more.

Gearing maybe too low but workable. I think this needs that Pitmann with bearings Pat sent me. I want to use that in another project so I'm waffling. The stock motor (rs545?)  is rough.

Here's just a quick video runby. I pushed the handle up to 8 or 9 volts and she took off. It doesn't mean she can't go slow. It's running on a bridge rectifier and nothing more!

A good motor control board would be interesting now.

She now has a thin plastic flywheel just for a tach tape that not used yet. Belt drive. I have to decide to put more money into her or not. MTH PS3 board set? old PS2 set and upgrade a different engine? Better motor now?

It was fun to play with.... engineering wise.

and a slower runby

track noise is way louder since I ballasted it.

Well, we can attest to the fact that it will run fast!   Looks decent from the glimpse I got as it flashed by.   Maybe stick a board in it and see how well it does?

I ran the engine around last night for our grandson. We agreed that it runs much quieter now. On the third lap it screeched to a halt? I tore it apart today and all that's wrong is a broken wire! I figured it would be my work on the drive.

Here's a pic inside of my hot rod lincoln.....

I figured I should take a video while it's apart to show what it runs like now.

I put the old Williams board back inside and now it runs much smoother around the layout. It doesn't have the huge power spikes and the speed is more controlled now. I'll post more videos soon.

slow runby

fast runby (nice and quiet now!)

Good job on the re-gear, glad to see that's a practical solution.

How does it do with a train behind it Joe?......looks like you’re taming the beast!...great work!

Pat

I have to confess that I haven't attached a train to her yet. At first, I was worried about any drive failure. Then came trying to achieve smoother control. Now it will be if my pulleys slip under the load of a train. I came up with solutions for securing the pulleys better. I didn't do them as other things kept failing. So far, the pulleys haven't slipped.

I grinded a slight flat on each shaft under each pulley. If they were metal, I'd tap them and add set screws. I also considered casting new ones with tiny holes and drilling them for a tighter fit. I had a mis-communication over the shaft size they were designed for.

If they slip as is, I may convert the top shaft to 4mm, and add that Pittman you sent that has a larger shaft to match up. They are a friction fit right now. I tried to drill pin holes to insert pins but the shafts wouldn't drill easily. I need new micro (wire) drills I guess?

Joe, consider Loctite Retaining Compound for the friction fit pulleys, I can about 99% certify they won't slip!   I've used Loctite 680 and 638, not sure what the major difference is between them.  I used the 638 to lock a slipping gear inside a K-4 locomotive drive block, so far it's holding, that was a pretty good test.

Heheh, we have one of those...noisy gearboxes.  Not a challenger, I believe its a Niagara.  We call it the coffee grinder at NYSME.

@Sarah posted:

Wow guys, that's advanced stuff! Two motors is surely the coolest thing in an articulate.

So far I tried a Faulhaber 2342 but found it a bit small.

If you think two motors is cool, check out the Westside Triplex.  I used to own one and it had 3 independent motors which ran nicely.  I probably have photos deep in archive, think it was a decade ago I played with it.

Don't let size fool you, coreless motors can be pretty powerful.  I've put one of those faulhaber to good use with an NWSL drive and its been running for years.  It's so powerful it can run on 1 volt and has great low speed control because of all the torque.  Same goes for the tool industry if you look many of the premium brands top line use coreless, eg Milwaukee Fuel.  Not many brushed motors, they're bigger, less torque.

Plastic pulleys on metal shafts:

Yes, Loctite said it would work, and "comped" me some "type N" prep fluid.

Nope - did not hold.  You need to "pin" or set screw.  I can assure you Pittman and NWSL shafts will drill.  Use a drill press, a new drill, and cutting fluid.

Usually, plastic pulleys will hold threads.  You just need a big enough "flat" to avoid distortion under load.

Thank you! I already put the Loctite on the shafts and will test. I don't have faith in it because of the actual issue. The shaft is only 3mm and the hole is 3.8mm. Too big on it's own for positive locking. A 4mm shaft would have been ideal.

I did not machine a bushing to fill the difference. I used what I had laying here and is not ideal. The only thing going for me is that the wheel slips easily on the rails. When the power is killed, the engine probably slams to a stop. So the pulleys won't stay locked for long.

I did look for new tiny bits while shopping yesterday and came up empty. I need to order some and pin the pulleys. I do have spare lock screws from the universal joints that I could install in the pulleys to give them help locking on the shafts.

I installed a MTH PS2 board set back into the engine and will test it today. I am always amazed at what these toys actually go thru, trying to do their job for us.

@Engineer-Joe posted:

Thank you! I already put the Loctite on the shafts and will test. I don't have faith in it because of the actual issue. The shaft is only 3mm and the hole is 3.8mm. Too big on it's own for positive locking. A 4mm shaft would have been ideal.

WOW, too much slop for retaining compound, you're right!  Retaining compound is only for close fitting parts, it does have limits.

I don't have that big of a gap John! The problem is I did not have a proper way to fill it though. That's why I thought about casting new pulleys. When you cast, that stuff is so sticky, I figure it maybe enough to lock it to the shafts. Add to that, I grinded the shaft to have a flat for locking.

I also considered just pouring resin in the gap. I figure that might just be a mess and still not get in there enough to do the job. There might also need to be some type of recess in the pulley to allow the resin to lock on better?

A proper (brass or plastic?) shim machined and heat fit onto the shaft I feel might do better?

I was originally instructed that I may have to drill out the pulleys to fit. I believe that was just a misunderstanding on what sizes these are. You don't drill out a 3.8mm hole to fit on a 3mm shaft. This should not be a big deal overall. I just need to do it properly.

So the pulleys are holding and even though I have a PS3 steam kit just about here in the mail, I stuck another PS2 board in for testing. Of course, the engine is way too fast. So I put a tach tape on with way more stripes and still too fast.

I'd probably need a custom sound file for much lower gear ratio to get it right. I tested the tach and it is working. I got a good change when I added several stripes. I don't think I can go much smaller on the stripes?

Does the PS3 HO board set use the same tach? I wonder how small are those stripes? and how is their gear ratios compared to O scale?

I take it you do not have a lathe.  I can make you a bushing and knurl the outer diameter if you want.  You would owe me postage.

I'm not sure how many stripes you can put on the tape, but I suspect you could probably go for about 38-40 on a 30mm flywheel and still have the sensing work.

The HO boards use a true PS/3 tach sensor, totally different than any of the O-gauge ones.  The HO motor on the PS/3 test set has the sensor under the flywheel like a Legacy, the stripes are actually facing the motor, very compact design.

The tach sensor used for the PS32 board in the steam upgrades is just the PS/2 tach sensor.

@bob2 posted:

I take it you do not have a lathe.  I can make you a bushing and knurl the outer diameter if you want.  You would owe me postage.

Thanks for the great offer! It's actually working right now. I would need 2 bushings for 3MM shafts and 3.8+ holes. Maybe I could heat the plastic gears and cool the shafts for tighter fit on those bushings?

It's just around 4 times too fast! It was around 4 times too slow. I over shot it! At 10 MPH it seems like it's doing 40MPH. At 15 MPH, she's flying and maybe 60MPH or more?

John,

It think if I had some type of adjustable command control, or for conventional use, it would be fine. I noticed that when I added stripes, the sounds think the engine is running much slower? (chuffing slower, engine's fast)  So maybe they're not all being read at higher speeds? I did just change the sound file.

I may have to work on the tach reader and flywheel?

My first tests had the diesel sound set inside so I don't have the sound comparison to go by. I only had a Challenger sound set for a G scale on my computer to try. Every time I try and get a sound file, I get a page of gibberish on my search from MTH.

This engine runs smooth and fast as I want now. I just have to get the control speed synced right.

Spacing is critical on the tach sensor.  The Omron EE-SY124 sensor has a fairly tight optimum sensing distance specification.  The "sweet spot" is around .8mm to 1.0mm, vary from that and the sensitivity drops pretty quickly.  Half an mm in either direction really drops the sensitivity, especially on the closer side!

Yeap!

I answered my own question when I typed it above. It hit me that the tach was missing the count at higher speeds. So first, I colored the stripes darker. No improvement. I pushed the tach closer while the engine ran and it slowed down!

So I closed the gap quite a bit. Now the engine seems like it might be twice as fast as it should be. However the chuff seems to match up much better.

Another note, I have a bad habit of saving everything. I had a tach go bad years back and I saved it. I didn't know for sure if it was bad, or it's circuit?

Now this used one I put in, seems very weak reading the stripes. I bet I have this in about twice as close as normal.

Whoever posted the thickness of a dime before? I disagree as all the ones I put in seem to like less than .3"

A dime on my bench measure like .5!

Actually, the thickness of a dime is about 1mm, the diameter of a dime is about half an inch!  .3" will not work at all, spacing that wide would be a runaway.  I space my sensors and the MTH ones a .9mm with a home made feeler gauge.

Ooops. The dime is .05" thick. or like 1.18 mm? I set the gap at .03 at first and that was too wide. I bet it's like .015 to .02 now?

I have other issues popping up and I'm ready to scream. I got the speed closer and the engine runs rougher? I even hear the belt skipping? I checked for binding and there was the usual that was there before. The whole gear assembly seems to be wobbling around much more. I had left it unbolted from it's spring mech and that was a mistake. I just reattached it now. and will see if that helps. The pulleys are still tight!

I hear some odd chuffs. The headlight goes dim with the smoke on and flashes on full like a beacon? I hear the belt skipping. I fix one thing and three more break?

Urrggg!

I can't believe the overall traction this thing has. I tried to hold it in place while running. It pulls pretty darn well. Remember, there's no traction tires!

You really want the tach reader spaced between 0.9mm to 1.0mm from the tape.  If you go too close, refer to the previous plot I posted, the sensitivity falls off VERY FAST below about 0.8mm, so I shoot for around 0.9 to 1.0mm for my spacing, that gets me near enough to the max on the peak of the response curve.  If you're still stuck in English measurements, 1.0mm is .039", and 0.9mm is .035".