Hi all. Purchased this awesome loco this time last year. Only used it for a few weeks over Christmas. Now this year its having major problems pulling the load.
I had purchased 7-8 super liner cars to go with it. Never had a problem until now. When it gets to a turn its basically skidding in place. I don't think these wheels have rubber bands or shoumd they? It runs great by itself and with about 4 cars. But add more and it's just skids.
any ideas on where to start troubleshooting?
https://www.katousa.com/HO/P42/index.html
If the wheels and/or track got contaminated with oil or grease it would behave this way.
If something became detached/broken in the driveline so one truck did not have a connection to the drive shaft it would also act this way. If you slip a piece of paper under the front truck, those wheels should still turn under power. Same with the rear.
If it's not the driveline then you need to clean the track and wheels. All the wheels not just the loco, because if there is oil/grease problem, it's on all the wheels..
Henry
COB Potomac & Northern
Shenandoah Valley
I'm in with Henry on all of the above.
Cleaning the wheels, and checking each car as to how it rolls.
Driveline/electrical contact wise, I've had the wire that goes from the side of the truck , come loose at the truck, as it depends on a "slip-on" cover", the same way the connection is at the board.
The contact strip, on the inside of the wheels on each side, also need to be clean.
I use a tiny bit of CRC 2-26, applied with a tiny pointed paint brush, where the axle makes contact with the strip.
Mike.
My You Tube
Penn Centralany ideas on where to start troubleshooting?
Keep in mind that the Kato P-42 uses coreless motors on each truck.
If, perhaps, the wiring to one of the motors has been damaged you may only be applying traction with one pair of axles while the other is being dragged along.
The motor wiring is very delicate so use caution if you decide to disassemble them.
Kato Trucks by Edmund, on Flickr
Kato Photo
I have a pair of the Kato P-42s and they are indeed strong pullers. The pair can easily pull twenty Walthers Superliner cars up my 2% grades.
Good Luck, Ed
gmpullmanKeep in mind that the Kato P-42 uses coreless motors on each truck.
I didn't know that! Thanks Ed. I have a few Katos, but nothing "new" with motors on each truck.
In the Rapido thread I started earlier tonight, Rapido is going to coreless motors.
mbinsewiI didn't know that! Thanks Ed. I have a few Katos, but nothing "new" with motors on each truck.
BigDaddyIn the Rapido thread I started earlier tonight, Rapido is going to coreless motors.
When I first saw the demo of the Kato design (was it almost ten years ago?) I thought this was going to "revolutionize" model locomotive design. Imagine having the entire carbody for weitht/speakers/fancy lighting, etc.
Seems like the technology didn't really take off the way I thought it would. I know coreless motors have less tolerance for overheating but the industry has seemed to not go in that direction, save the recent Rapido design.
I wonder why Jason didn't go that route with the RDC?
IF the engines Penn Central has are not sound/DCC equipped he should be able to snap each truck off and each individual truck should run, like a Stanton Drive. If the wiring/pickup is OK then the motor may be toast. Perhaps Kato has parts?
Regards, Ed
Hi all thanks so much for all of this. So I spent all my time tonight cleaning the tracks and wheels of all engines and rolling stock. But it didn't help one bit. So I was happy to hop on here and see so much help.
First the loco is not DCC or sound enabled. I guess I really need to read up on how these coreless motors work. And now that I remember last year a few days past the warranty period the loco did this a few times. Skidded in place. Then the problem disappeared. Seems to be permanent now.
So will re read the above and learn how to rest the motor assembly. Will be back with more questions!
My immediate thought was to check for tight gauge or cross-level faults where the engine starts slipping. Do both trucks slip together?
I'd test progressively more weight, balanced between the trucks -- it could be taped or stuck on the shell temporarily -- with some sort of gauge on the power to avoid overloading.
Is Bullfrog Snot or equivalent still available?
I have loved coreless motors for model locomotives since being introduced to them in MR right at the beginning of the '70s (in the article with the Delrin chain drive; the author used 'skew-wound' in the text and I looked for that in motor references long afterward to little avail before stumbling across 'coreless' as the term). With modern magnetic material I'd expect these to do very well at 'underfloor' size; of course they have no real cogging effect to speak of and are essentially freewheeling apart from any effects of gear backdriving. I would relish seeing these costed-down in volume production... .
Penn CentralFirst the loco is not DCC or sound enabled.
That should help your diagnosis. The reason I asked was because the DCC version has wiring from the motors into the carbody to the decoder.
With the straight DC version you should be able to snap the trucks off and run them on powered rails individually without being attached to the carbody.
Be sure to note which is the front and rear trucks (arrows on the bottom should point to the couplers and they are marked F - R).
Skew wound motors are a thing too, they are conventional iron core rotors with the windings run at an angle to the shaft instead of parallel. The tend to run a lot smoother than a conventional straight wound motor.
I do fear with a more mass shift to coreless motors, there will be more returns for damage - a low frequency PWM DC power pack will over heat them, and setting one without a decoder on DCC track will very quickly overheat and destroy a coreless motor. They are fantasically smooth, but also rather delicate. Even early DCC days, there were problems, before pretty much all decoders became "silent running" or "supersonic" which used high freqnecy PWM. Most of the early DCC decoders did not use a high frequency PWM, and coreless motors could be damaged, even if a decoder was installed.
Unless they go the Atlas route, some Atlas locos had a capacitor that caused a short if set on DCC track, installing a decoder bypassed this. Also, Rapido said they were going coreles, they didn't say they were going truck mounted like the Kato, so they may well be using a conventional drive but putting a coreless motor in palce of the previous iron core can motor. If Kaot has patented their truck mounted coreless motors, no one can copy that without making arrangements with Kato, so it may be a few years before we see others duplicating this - more time for improvements in micro-sized motors, so future efforts may end up being even better.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
How sharpe is the radius of the curve that causes the slip. Seven or eight Superliners on a tight radius can cause a lot of drag.
Have you been able to determine if both motors are working. A 9v battery or a pair of transformer leads touched to the wheels (+ one side, - on the other) should tell you if both trucks are operating.
If they aren't I don't know that I'd do any more digging around beyond that if KATO has a warranty or gaurantee.
Visit the Chicago Valley Railroad for Chicago Trainspotting and Budget Model Railroading.
Penn CentralAnd now that I remember last year a few days past the warranty period the loco did this a few times. Skidded in place. Then the problem disappeared.
Mike
I only mentioned 'skew-wound' because that's the term I remember the article author using -- for what was obviously in the pictures a form of coreless motor. I was still a kid then and trusted what I read in Kalmbach implicitly.
I wonder if you could implement a voltage limiter and current clamp that would limit flow through any winding loop of a coreless motor to a safe percentage of its insulation integrity... or read a small temp sensor as the suspension pump on my Audi does to throttle back if the critical parts start getting too hot in service.
Didn't the video show a 'hand built' prototype of their coreless in a chassis?
Suspect a truck-mounted coreless might be too long for end-mounting, or require counterbalancing on the other end of the frame due to the long effective moment arm of the motor case.
Is there anything patentable about motorized trucks any more? Even pancake motors have been tried there (sorry if this brings up traumatic memories!) and a design patent should not include much that a good or devious engineer could not 'get around'...
Penn Central Hi all. Purchased this awesome loco this time last year. Only used it for a few weeks over Christmas. Now this year its having major problems pulling the load. I had purchased 7-8 super liner cars to go with it. Never had a problem until now. When it gets to a turn its basically skidding in place. I don't think these wheels have rubber bands or shoumd they? It runs great by itself and with about 4 cars. But add more and it's just skids. any ideas on where to start troubleshooting? https://www.katousa.com/HO/P42/index.html
These factors could jointly or individually confound your locomotive's best efforts to tow your full string of cars:
Uneven tracks, or even a different 'lie' if laid in another place or oriented differently from previous season;
Rail bearing surface is no longer 'toothy' from extrusion/tooling and now looks like real shiny rail, but is also more slippery;
Vertical curve into a grade that is to sharp and may lift an axle free from traction;
Dried-out lubes..any of them, anywhere;
Dirty bearing cups at the ends of axles, or just dry;
Grades, even if unintended;
Wheelsets out of gauge; and
Driver tire finishes are no longer conducive to good traction, even if they were when you put the train set away for the season.
Ok thought about all of the comments above today and came home from work on a mission. Just as noted the trucks popped right off and do indeed run by themselves. Very cool!
I took them down to my bench and applied power to each motor and set of wheels. All 4 wheels do turn on each truck. Hard to say if they all turn at the same speed.
Then I placed them on my layout independently. Again very cool as they raced around the track. I noticed that one truck and motor was faster than the other going in on direction. I also inspected with a magnifying glass albeit not sure what I was looking for. Saw nothing alarming.
Anyhoo popper everything back on except the shell and, amazingly, it pulled the full load of cars with ease. No problems. Popped the shell on and started having the issue again. I thought it was the shell but wasn't. Was able to get it to work and not work with and without the shell.
So right now its very inconsistent. Before I shut it off for the night ot worked fine. Not sure what the next step in troubleshooting is. Not sure if it's a defective motor or just how I pop it all back in place.
Both trucks should be running at the same speed. Otherwise the one with 'less' traction net of applied load will preferentially slip, and if the other can't handle the whole load being thrown on it, it will slip too.
Likely there is some binding or misalignment in the 'slower' truck - get advice for what to check to get it equal to the other.
With the trucks installed, put the model on a flat sheet of glass and look at the flange contact. If one of the axles is cocked or truck frame misaligned, etc. it can compromise traction just as a low joint under a T1 can, facilitating the above. Rotate each truck under the assembled chassis or locomotive to different positions on the glass to be sure this doesn't cause a misalignment or bind.
Ok so I'm getting somewhere, kind of. I did the glass test as suggested by overmod. Looking closely I could not see any of the flanges off.
So then I took the trucks off again and tried applying different power on and off the tracks. Again I noticed the rear truck, moving in one direction, was slower than the other truck. Only bad in one direction.
Next I held the trucks in my hand and applied power to the wheels. First I could tell the rear truck in one direction didnt "sound" like it was moving as fast as in the other direction.
More importantly, tho, i did this about 20+ times per truck. applied the power, watched the wheels spin, removed the power. repeat. Reversed the wires to reverse direction. Finally I found sometime. Every once in awhile the rear truck wheels would not spin at all. The engine would make noise but the wheels wouldnt spin. I would remove the power, and/or change direction, not sure what but eventually the wheels would start spinning again.
So not able to reliably reproduce means its still random. But at least I know where its happening.
And from the looks of it these dont look like something I can open up and poke around with. Either need to send back to Kato or take to my local shop (which happens to be Nicholas Smith Trains).
Thoughts?
Penn CentralThoughts?
Finding a replacement truck might be a challenge. As far as I can see Kato only has the Front truck with black side frames in stock:
http://search.cartserver.com/search/search.cgi?cartid=s-1078&keywords=HOP42&maxhits=100&go=List+Parts&bool=AND&bool=AND
The rear truck in dark gray is 959200R.
Sometimes you find them on eBay but they can fetch some pretty high prices. There was recently an HO P-42 there "for parts" but it also needed the rear truck.
Nicholas Smith is good, maybe they can help. I doubt Kato will be able to do anything but I guess it wouldn't hurt to ask.
I vote for a track issue, key being it is only run at xmas so not permanent track setup.
My first thought is a cracked gear, on an axle or in an intermediate train; I fact I'd think loose motor pinion if this design has one that could slip.
I'd contact Kato customer service, describe the issue, and see if you can send them the TRUCK that needs attention (saving the cost and risk to skip the whole engine) if they approve. They might have the parts to do an exchange.
Someone here might be able to walk you through disassembly of the truck and possibly either a repair or identification of something needing replacement.
rrebellI vote for a track issue, key being it is only run at xmas so not permanent track setup.
I believe Penn Central says the problem occurs while holding the truck in his hand —
Penn CentralNext I held the trucks in my hand and applied power to the wheels. First I could tell the rear truck in one direction didnt "sound" like it was moving as fast as in the other direction.
This would seem to eliminate track as contributing to the problem.
I think you're remembering one of my favorite MR articles: ca. 1971 by Robert Higgins..."Loco w/ Double chain drive"..October 1971 MR. Essentially, Mr. Higgins eliminated the worm gear and made the "right angle turn" using a bevel gear and two sets of chain sprockets. The loco was an 0-10-2 HO PFM brass unit and ran smoothly at 1.58 scale miles per hour (with no load). The motor was a big "Swiss" instrument motor (coreless and skew wound). Mr.Higgins weighted the engine up from about 20 oz to 33 oz. A novel approach...never duplicated since as far as I can tell.
Sounds like a cracked axle or two to me also.
If you can dismantle the drives and check for cracked axles you should do so. Cracked axles can behave just like you described.
Faiing results from the above. I would do a slip test. Hold the locomotive stationary and apply voltage to spin the wheels. Then use a force gauge (they are available on the net and I consider them a must have measurement tool. Get one with a measurement range from 1-20ozs ($20-60). Then measure the pull force at 12V with the shell off. Measure the start voltage and current as well as the slip current at 12V. Also measure the weight of the chassis w/shell off. Then pop the shell on and weigh the loco. Apply 12V...are the wheels spinning. Measure the slip current. Also measure the stall current.
If someone can use this loco to pull 9 passenger cars up a 2% grade I would think that the 12V tractive force of the drive train is greater than 2 ozs. Also the stall currents for the chassis w/o shell should be around 1.0 ampere at 12V and the slip currents at 12V should be around 0.5 amperes. Do these tests en groupe and independently.
Don't worry about 1 motor being a bit faster than the other. It's not a problem and they'll run together just fine.
If you don't have cracked axles and some obvious obstruction (dried up grease, loose screw, etc.) then I think you have some"sick" motors (insulation breakdown, magnet problem, etc.).
Keep us posted