KATO 787 Incline Track Challenges

[cteno4]

@JJ1892 picture wont show much for this, the thing to test is running it upside down like that and making sure all wheel sets are turning and keep turning with some pressure applied to them. When a drive shaft gets stripped or a gear cracks it will still sort of function and spin the wheels but when resistance starts to be applied the drive shaft or gear then spins freely and those wheels its attached to in the drive train stop spinning.

 

jeff

[cteno4]

@JJ1892

 

So here is what my logic tree would be for this

 

A. Wiggle the trucks to make sure they are well seated into the chassis and not tipped a bit to one side. Also make sure they swivel freely. Sometimes trucks get a bit out of joint in their socket in the chassis and this can lead to poor traction and/or drive chain slippage.

 

B. Check to see all the wheels are spinning properly under power with resistance, if not something busted in the power train. Do this by applying power to the wheels with a stripped wire attached to your throttle or even a 9v battery with the power car upside down. Probable solution would be new trucks as these usually are sold as a pair with the driveshafts from Kato, thus replacing the whole drive train and getting you traction tires.

 

C Check other cars to make sure they are all rolling freely and easily and about the same. One may just be dragging.

 

D. Try adding some weight to the motor car to see if that helps it up the incline and stop slipping. If that works then you can just add some weight internally to the car. Or get new trucks with traction tires to run on the incline.

 

E. Measure the lap time [at the same throttle setting running trains at a reasonable speed on a level loop] of the motor car alone and the 4 car train against another motor car alone and 4 cars of that train. This should tell you if the motor or drive train is just not giving the power to pull up the incline with enough momentum before breaking free. If this train is running a lot slower at the same throttle setting than other trains something is probably not right in it. This would then say look at tearing it down and reassembling and if that didnt help perhaps a new trucks or motor chassis.

 

There are a number of variables at play here so the solution could be a number of small things that then add up and fixing 2 or 3 little things then get it up the incline.

 

This hobby has a fair dash of fiddling and problem solving like this. These are toys being made for a pretty inexpensive price for what they are, so things are not going to be perfect, nor like working with electronic components where there are sharp tolerances and few mechanical things that can have a wide range of variables to deal with. I actually enjoy the fiddling parts as it s a great critical thinking loop that is fun to do and rewarding when you get things working. Its also why i think its a great hobby as it really does teach critical thinking and problem solving skills well.

 

cheers

 

jeff

[JJ1892]

This problem starts to look as one of those problems that once I'll figure this out, I'll also figure how to solve 50 other problem. Reminds me of a Kaizen practice where's a new employee is presented on the first day with a problem to solve that teaches him the many facets of his work.  

 

Thank you @cteno4 and all.

 

JJ1892 

[RS18U]

7 hours ago, JJ1892 said:

Here are images of the two wheels components. Maybe I am missing something.

 

I took a look at mine and don't seen any difference although the driveshaft in the right picture seems a bit thicker than the other, but that could be the angle of the photo.

[cteno4]

Unfortunately most all of the potential mechanical issues will be visible without removing the trucks and even disassembling them. But you will see the result if you power the engine and put some resistance on the wheels and that set stops moving easily while others keep going.

 

Ive only seen a few snapped drive shafts and then you will see the drive shaft dangling sort of, but usually the tiny bumps on the universal ball joint on the end of the shaft get stripped off and then just spins in the socket on the ends of the motor shaft or trucks. Cracked gears end up letting the gear slip on its shaft when there is some resistance put on the drive chain.

 

jeff

[RS18U]

I don't have a scale so take these observations with a bit of a grain of salt as all these are based on handling and trying to compare them by feel.

 

The motor car of my recent release of the KIHA 283 (Kato 10-1894) seems to be noticeably heavier;

81 Series (Kato 10-325, part of a 7 car set) also seems to be noticeably heavier, and has traction tires as it should for the number of cars;

Same with 251 Series (Kato 10-177, 6 car set);

My Tomix 183 6000 3 car set (98523) is about the same weight, but it has traction tires.

 

My general sense just by handling my units is the 787 motor unit is a bit on the light side, especially for a 4 car train and no traction tires.  Now I am intrigued and may look for a scale that can get me answers since I don't like to be guessing like this.  But I don't have any grades to try these out on.

 

[RS18U]

On 3/9/2025 at 8:05 PM, RS18U said:

I don't have a scale so take these observations with a bit of a grain of salt as all these are based on handling and trying to compare them by feel.

So I now have a scale and as it turns out these are on the light side, especially considering how many cars are in the train and they do not have traction tires (TT):

Not sure this helps though.

 

 

[cteno4]

Bit light. Couldn’t hurt to try and add some weight to see if that helps, but I still think worth making sure there are no problems in the drive train first, easy to do and if there is slippage at all thats a sure thing to definitely fix and i would expect is the cause of the issue.

 

jeff

[RS18U]

Hey @cteno4 a little off topic, but do you know how interchangeable wheel sets are for Kato?  Just wondering about swapping one traction tire set for a non TT from the KIHA 58 for one on the 787.  At least give it a wee bit more traction.

[cteno4]

Nope, sorry dont have any specifics on that sort of stuff. In the past it’s been mainly just getting the proper replacement parts to fix trains. I did do some swapping of driveshafts from other trains and even manufacturers in the past trying spares i had and finding something that would work rather than waiting weeks for a replacement drive shaft [if that could be found].

 

Kato drive shafts are well retained in the universal joint of the trucks, so usually the whole truck and drive shaft is replaced as they sell it as all one part. On older katos ive pulled drive shafts and replaced just the drive shafts with Kato or tomix spares ive had. If memory serves me right the Kato models that sell the trucks/drive shafts sets i dont think sold just drive shafts as i sort of remember only being able to get a couple of specific Kato driveshafts by buying the set.

 

You can easily pop the truck and drive shafts out and measure them out to see if they are the same sized and wheel centers. Im guessing the wheel sets are pretty much the same on a lot of Kato models so you could pop open a truck if the trucks and/or are dramatically different from each other and swap the traction tires wheel sets if they have the same diameter and gear sized and tooth number. 

 

I’ve never really had traction issues with any of my trains, but I’ve not done a lot of incline running. On level things are usually good and the only time was a few single power car 16 car shinkansens requiring a lot of voltage to get to full shinkansen speed and being a bit more prone to issues and maintenance.

 

jeff

[Little-Kinder]

1 hour ago, RS18U said:

So I now have a scale and as it turns out these are on the light side, especially considering how many cars are in the train and they do not have traction tires (TT):

Not sure this helps though.

 

 

Just for comparison my tgv are 101g and they have two traction tires 

 

 

@RS18U

 

You can always use bullfrogsnot

[cteno4]

Yeah ive felt the whole range of motor car weights, but never had any particular issue with anything that felt heavy or light, but again little incline running.

 

bulfrog snot works best on wheels that have the traction tire slot cut in them and missing the traction tire. If you apply it to one regular wheel of a non traction tire wheel set its going to make your wheels not rest squarely on the rails as the wheel with the bullfrog snot will be larger diameter w.o the traction tire slot in the wheel. Bullfrog recommends you coat two normal wheels on an axle, this keeps things even, but it will tilt the truck a small bit but probably no problem. You do go down to pickup of only 6 wheels then, but thats what happens when you add traction tires.

 

i used bullfrog snot once on a club member’s loco missing a traction tire. It worked pretty well just had a little bit of wiggling on that end which i think was the bullfrog snot being not totally uniform thickness. But they thought it fine so i didn't try a redo to see if i could get it smoother. I meant to try some on a regular wheel set to see if it would cause issues with one larger wheel but never got to that, but i would expect not good.

 

But the stuff comes off easily so no issues with experimenting with it. Just not cheap stuff and i think does not last super long in the bottle. I have no idea how long it lasts once cured onto a wheel.

 

jeff

[RS18U]

OK, now really into the weeds, and probably really useless info.  What is really needed is traction, 🤔

 

The 787 is the second lightest total train/car, so I can see why traction tires were not used.