Slow Doctor Yellow Power Unit - Kato 4892-1B

[gavino200]

My Kato Doctor Yellow runs ok. But it's quite a bit slower than my other Shinkansens. I bought it new and it's always been like this.

 

Is this normal? Does the Dr. Yellow run slow so as to check the track carefully? And Kato faithfully replicated this by making a slightly slower Shinkansen?? 

 

A sales ad I read seems to argue against this. It talks about a "tried and tested power unit, etc". So did I just get a dud. I'm assuming Kato buys these motors for pennies in bulk. If you get a dud what can you do?

 

I'm interested in getting it a buddy motor to help it out. But they seem to be sold out. Anyone know where I can find one for export to the US?

 

http://chiayu.biz/catalog/popup_image.php?pID=3445&osCsid=7c78cbed18b121dee6f28d48189028cc

Edited December 17, 2017 by gavino200

[Kiha66]

I dont think it really needs another motor for a 7 car set, have you detached the trucks and made sure there is no hair or anything inside the gears?  Usually kato uses the same type of motors for these sets, so if you get a model with the same motor type you can just switch them.  If it's DCC ready I should have a spare motor somewhere if you need it. 

[gavino200]

Yes, I need to check the gears, and maybe add a bit of lubricant if necessary. The train ran slower than other Shinkansens from when it was brand new. I wanted to start by confirming that this isn't just the norm for this model. I'll check out the gears this week.

 

The second motor is for my irrational obsession with shinkansens not slowing down on the incline. As long as I still have the incline, I think I'll start buying a second motor with every new train (while they're easily available).

 

I've long been amazed by the amount of variation between supposedly identical industrially produced items. If these motors sometimes vary in quality I'd love to be able to buy just the motor from the source manufacturer rather than needing to buy a whole power unit from Kato.

Edited December 18, 2017 by gavino200

[katoftw]

Dont waste your money on a second motor. Unless your throttle system has a computer controller actual demand vs demand imput, the one or two motors will end in the same result.

[gavino200]

37 minutes ago, katoftw said:

Dont waste your money on a second motor. Unless your throttle system has a computer controller actual demand vs demand imput, the one or two motors will end in the same result.

 

I checked out the motor and drive train. All pristine. I added just a hint of lubricant to the gears and that seems to have helped. It's a bit faster now. Just a tad slower than the E5, but acceptable. I've been very reluctant to add lubricant to a new loco as Kato say that it's not necessary. 

 

Adding a second motor really does help slowing on an incline. I've done this with my E5 and E6 and it was 'day and night'.

 

I'm gonna run the Doc for a few days and see what happens as the lubricant gets distributed.

 

(wheels were cleaned yesterday btw)

[Yavianice]

On 12/18/2017 at 5:53 AM, gavino200 said:

Adding a second motor really does help slowing on an incline. I've done this with my E5 and E6 and it was 'day and night'.

How much % was your incline again?

[kvp]

On 12/18/2017 at 5:09 AM, katoftw said:

Dont waste your money on a second motor. Unless your throttle system has a computer controller actual demand vs demand imput, the one or two motors will end in the same result.

Unless the motor is heavily loaded and the speed is not limited by the voltage, but the power of the motor. This usually happens when a train gets noticably slower going up an incline even with full throttle. For shinkansen, this means an incline steeper than 2%. Having enough power will revert back to the voltage ~ speed rule we are used to.

 

ps: Why is too little power a problem when we are not running at full speed? Because this also prohibits continous slow speed running as the fixed voltage throttle has to be set to a large enough voltage to allow the train to get up the slope, but this could actually mean too high voltage for cornering and going through turnouts on the flat part of the tracks. The usual solution was to use separate throttles for each block (uphill, downhill, flat part, station) and set them to balance out the load differences (and to allow slowing down when going through stations and turnouts). A more fixed solution was to use diodes to allow full throttle on uphill parts and use diodes to drop the voltage on downhill and other slow parts, but this is inflexible and can't really be adjusted to each train. A load regulated throttle works nicely as long as the train doesn't have any lights in it, which many japanese trains have (usually with filter caps added), which throws the load controller off balance. Having enough power in analog mode or using DCC with a local load controlling decoder (one decoder per motor) solves most of these problems.

[gavino200]

2 hours ago, Yavianice said:

How much % was your incline again?

 

Not sure. It's the Kato double viaduct incline set plus the Kato incline pier add-on set. I'll measure the incline distance later and calculate the grade.

[kvp]

9 minutes ago, gavino200 said:

Not sure. It's the Kato double viaduct incline set plus the Kato incline pier add-on set. I'll measure the incline distance later and calculate the grade.

If you use the extension set with half spacing or use the basic set only, then it's 4%-4.5% depending if the track is straight or curved. If you use the add on set and the basic set with the spacing of the basic set, it doubles the length of the incline and gives 2%-2.25%. 2% is the suggested maximum for mainline track, especially shinkansen.

[gavino200]

1 hour ago, kvp said:

If you use the extension set with half spacing or use the basic set only, then it's 4%-4.5% depending if the track is straight or curved. If you use the add on set and the basic set with the spacing of the basic set, it doubles the length of the incline and gives 2%-2.25%. 2% is the suggested maximum for mainline track, especially shinkansen.

 

Thanks. Yes. That's what I've done. Add on and basic with full spacing. 

[Thankyu6300]

I have a Hankyu 9300 that's new and seems to run quite a lot slower than my 6300 and all of my other models. is this hows it's supposed to be?

[chadbag]

3 hours ago, Thankyu6300 said:

I have a Hankyu 9300 that's new and seems to run quite a lot slower than my 6300 and all of my other models. is this hows it's supposed to be?

 

Is this just comparing the power cars or the complete trains?  If the complete trains, swap the power cars and see if the problem follows the power car or not (to eliminate a problem in a normal car).   

 

I would expect there to be some variation in performances these are not high precision items