Kato Mikado jerkyness help needed

[Powersteamguy1790]

Replace the draw bar with another new one. Be careful not to compromise it by inadvertently bending it when installing it on the tender truck.

The draw bar is the problem according to the problems that exist when trying to run this steamer.(Sporadic running)

What else haven't you told us about this loco? How many times have you removed the draw bar from the tender truck and re-connected it?

Excessive handling of the loco and tender can cause the draw bar to become compromised, if you don't support the steamer and tender properly.

As I said Initially the draw bar is the weak link in the Kato Mikado .


Stay cool and run steam....

[victor miranda]

something is interfering with the pickup.

Rails to wheels  -- checked
wheels to axles  -- rarely a problem
axles to sideframes - - checked
sidefrmes to tender pickup strips - - checked
tender pickup strips back to sideframes - - checked
side frames to drawbar - - checked/replaced
drawbar to loco frames - - checked/replaced
loco frames to decoder wires ----> only thing left

you say you attach the jumpers to the frames
but to you attach to the decoder wires instead?

v

[kiwi_al]

Brian said he took the  boiler off and tried to run it, 1st by alligator clips which was smooth and then under it's own weight. Unfortunately he hasn't put the boiler back on. So it'll run like a 3 legged dog going uphill sideways.

[bsoplinger]

OK, let's see what I can add to be helpful.

This loco was returned to my customer from another installer completely stripped down with even the running gear disassembled and removed from the wheels. I had to completely rebuild it and that took a bit of effort. I didn't realize for example that the link pin was squared so it would only fit 1 of 4 ways. I thought it was keyed and would only fit 1 way. But when I tested my partial reassembly of the wheels and running gear without the motor I had it bind. A bit of fiddling and comparing to a new loco showed me about the link pin and I got the running gear reassembled properly. (And turned right side up, I'd installed it upside down.) It ran OK on DC when I tested my rebuild. OK here means it ran forward and backward on DC, just a pass say back and forth on the 6' test track. I probably should have made 100% certain it ran perfectly on a real layout before I went further and did the install (Hindsight is so 100% but now I'm wondering if somehow the frame itself got bent or some sort of other issue is involved. Something that makes the mechanics of the loco 'off.'

It makes sense that the thing is designed as a unit, a whole. So when I run with the boiler and its weight off I can see how the loco would be 'tipped' backward, the balance point of the loco moving back toward the rear of the engine. And when I use the pair of alligator clips not only does that provide 100% certain power to the frame but it also adds weight to the front of the engine. So I can see how that'd guarantee the loco would run like a Swiss watch, which it does. So I'll do all the rest of my testing with at least the weight sitting there where it belongs instead of just the naked underframe.

I think that would also explain how adding a .003 shim to the 4th driver would help, it'd counteract (at least somewhat) the tendency of the loco to tip backward since I was doing all my testing without the loco weight.

But...

I've since put the whole thing back together. And pretty much still the same miserable poor performance. Stops on completely straight track. The loco will almost immediately start again and move, go a few more inches and then stop again. Putting the shim back in was the only thing that seemed to make the loco run decent. Now I'm down to about 1 stop/start in 6 passes back and forth on my 6' straight test track. So things are improving. But it sure doesn't run super smoothly like the new one out of the case does on DC.

something is interfering with the pickup.

Rails to wheels  -- checked
wheels to axles  -- rarely a problem
axles to sideframes - - checked
sidefrmes to tender pickup strips - - checked
tender pickup strips back to sideframes - - checked
side frames to drawbar - - checked/replaced
drawbar to loco frames - - checked/replaced
loco frames to decoder wires ----> only thing left

you say you attach the jumpers to the frames
but to you attach to the decoder wires instead?

There really isn't any wheel to axle conduction in the design of the Mikado. Power goes right from the wheel to the bushing/bearing then to the frame. I also think seeing it runs perfect with the alligator clips tells me I have the power pickup for the decoder correct also. If that was bad/intermittent I don't think it'd make a difference if the loco was picking up power from the rails or my clips. So I don't see how attaching the clips directly to a decoder wire would show me anything more but I'd gladly try it if you help me understand what it might show so I can look for it when I try that test.

One of the first things I did was to add a second power pickup to the loco. I'd originally wired it just to pick up power from the contact strips in the tender, soldering the red/black wires to the center of each pickup. But when my test runs proved to be so bad I immediately added another pair of pickups wired to the lightboard in the loco also. So now the decoder is wired to both a contact strip and one side of the lightboard for each pickup.

So we're back to the drawbar. I've barely handled the new one. I put it on my way, with the brass contacts under the crosspiece of the truck. I then looked at Chris33's pic and tried it with the brass wire contacts over the crosspiece. No change so I put them back to the under side instead because that matched the way the contact was on a new loco I took from stock and compared against. That isn't much handling. I've put the loco up on the test track from the bench a dozen or so times. Again not too much handling. I've never lifted just the loco (or the tender) and let the tender (or loco) dangle so I don't see how I could have bent the drawbar.

I took a file to the nub on the underside of the loco when the drawbar attaches making it all nice and shiny instead of the blackened metal. I checked the tender cups for lint and made sure the tops of the contacts where they touch the brass tender strips are nice and shiny. But I'll redo all this again tomorrow just to make 100% sure that isn't the issue.

I ordered 3 drawbars. 1 for this loco, 1 for me (I've one here in pieces waiting for the GHQ PRR kit to be installed) and a spare.

I'll try the spare tomorrow but I can't believe I could have ruined the one I just put on yesterday (Friday) with the few times I've lifted the loco to my test track and back to the bench or when I installed it or moved the location of the pickup wires from over to under and back again on the tender truck.

But I really do appreciate all your folks suggestions of things to try and your attempts to help me. This really is quite the puzzler and I'm totally stumped and all your input has been so very helpful to me.

Again, thanks
Brian

[Chris333]

I doubt the frame is bent, I just man handled both sides of my frame and they are still straight. Since you have the old drivers that don't do much for electricity, then I can't see how a shim helped.

The sure fire way to tell if it has anything to do with the drawbar is to clip wires to the frame halves and clip the other ends to the tender strips. I really don't think it is the draw bar and you cleaned the post.

BTW I have no experience with DCC at all. I use Direct Current Control 

[Powersteamguy1790]

Your first mistake was when you wired the decoder to the tender strips for power. That always results in haphazard performance, especially if the strips aren't put in place correctly .

Wiring the decoder to the light board is the only way to insure proper performance of this steamer. I've done over 60 decoder installations on the Kato Mikado to date and this is the only way to insure proper performance.

It doesn't take much handling to compromise a draw bar. You must also make sure you didn't over tighten the two screws that hold the gear plate in check. This can also cause erratic performance of the Mikado.


Stay cool and run steam.....

[victor miranda]

in terms of electrical pickup,
 the tender does the heavy lifting.

the engine is quite variable.
the "wheels to axle" was meant for the tender side.
get the tender pickups working.

using the tender pickup strips to attach
wires is very tempting.
it must be done with Great Care.
the way the strips are held it is easy to lift the ends
if you solder near the center.
soldering at one end will usually make that end stiff and half functional.

victor

[Powersteamguy1790]

"I'd originally wired it just to pick up power from the contact strips in the tender, soldering the red/black wires to the center of each pickup. But when my test runs proved to be so bad I immediately added another pair of pickups wired to the lightboard in the loco also. So now the decoder is wired to both a contact strip and one side of the lightboard for each pickup."

Now we hear the rest of the story. By soldering to the contact strips in the tender and then unsoldering the decoder wires from the contact strips resulted in a distortion of those strips. They probably aren't seated properly on the tender frame. Looks like you need new contract strips in the tender.Make sure you seat them in place properly.

That's why you don't solder the red and black motor wires to the contact strips in the tender. You solder them to the light board in the engine.

Stay cool and run steam....

[bsoplinger]

Your first mistake was when you wired the decoder to the tender strips for power. That always results in haphazard performance, especially if the strips aren't put in place correctly .

Now we hear the rest of the story. By soldering to the contact strips in the tender and then unsoldering the decoder wires from the contact strips resulted in a distortion of those strips. They probably aren't seated properly on the …

I still have the wires soldered to the contact strips in the tender. I just splices in the new pickup wires that came from the light board of the loco into the red/black wires of the decoder. I soldiered the pickup right next to the hole in the contact then made a half hollow in the black piece that holds the strips down to allow the wire to pass. I soldiered the wire across the pickup so that the wire runs on the outside 'around' the black bit. It sure doesn't seem that I compromised their movement any.

And I know I mentioned it here, but after somebody suggested making sure the tops of the truck pickups for the tender were nice and bright, I reported that I did check and I mentioned that I looked at the pickup strips and they looked bright and moved OK. I wasn't too clear, when I checked on the tender pickups I removed both trucks (necessary to make sure the tops of the pickups weren't corroded) and took a small screw driver and poked gently at the strips to make sure they moved freely within the tender, double checking that when I replaced them after soldiering a pickup to them that they still moved well.

So can it really be those contact strips being my problem? Because now I'm looking at needing to buy a whole new engine to get a set of contact strips, i.e. it isn't a listed part on the Kato site

[Powersteamguy1790]

"So can it really be those contact strips being my problem? Because now I'm looking at needing to buy a whole new engine to get a set of contact strips, i.e. it isn't a listed part on the Kato site."


Why don't you try finding a tender on EBay?

Then again, perhaps you're better off to buy a new Kato Mikado. That way you know that it works correctly.

Stay cool and run steam....

[victor miranda]

yeah the strips are not listed separate.

take the strips out and lightly curve them toward the truck contacts.

it had been awhile since I have been into a tender.

the strips have a lot of free space.
they should be flat againt the floor of the tender.
and it helps if they are a little pre-loaded.

you don't need a new loco yet.
but after going around this a few times
I can tell you the tender is the electrical pickup for this loco
the the drawbar is to get power to the motor in the engine.

Most mikes have reliable pick up  only from the front tender truck.
so for your loco to be as bad as you describe,
that front tender truck is not getting the power up to the truck side frames.

I am not joking here, clean out the pick up cups, you have something in there.
from all you tell us it is the most likely place.