DCC Conversions produce coffee grinders - help

[Bob Horn]

Follow Ron's instructions and remove the inner bearing. Be sure the motor cradle is in properly. The bearings are marked with either  a single stripe or nothing.  Bob.

[u18b]

Whoa .... are you guys telling me that the bearing block are not symmetrical and  have a specific way they must be installed ?   Is there any way to tell "which side is up"

If they need to go in a certain way that is probably the cause of my problem.  Now to figure out the "right' way !

thanks

No, we mean they are not made by NASA for the space program.  They are not perfect. 

Or to put it in manufacturing terms, the tolerances are not sky high.  There are slight imperfections.  For example, another source of slight imperfection is the little hex nut that goes onto the worm shaft and then into the flywheels.  That hex not often has a little flash and thus is not perfect-- thus introducing a bit of wobble all by itself.

Personally, like Bob said, if you try my technique, you never even have to give a second thought to any this.

[victor miranda]

Hi u18b,
petesky has a knack for avoiding the diplomatic way of making a statement.
... far as I can tell, that part is not in his ability.

Eja,
causes of noise after having a perfectly quiet loco...

worm thrust bearings flapping around
hex-nut mis-alignment
motor mount miss-installed
and
frame to shell fit different

any of these can add to the noise and fixing one does not fix the others.

the bearing removal usually removes the first two as causes.

the motor mount... pay attention?

the shell .... I try tightening or loosening frame screws.

looser is often the fix.

miranda

[garethashenden]

Something got lost in the typing here.

But I think you are correct.  Plastic bearings are usually not 100% perfect.  Or at least they don't wear perfectly either.  So when putting a loco back together a bearing may get rotated.  or it may not seat as perfectly.

Or the motor is no longer 100% in line.  Think of the typical motor saddle.  The little fingers get damaged the first time to disassemble the loco.  Maybe those have an effect.

But just removing the inner bearing blocks solves ALL of this  (as a posted stated above IF you carefully follow directions).

Yup. Should be "I'd" rather than "is". That's what I get for replying on my phone...

[mmagliaro]

I have never had to use Ron's technique of removing the inner bearing block from a short wheelbase diesel, but I have read his paper and I must second the notion that this is not a work-around.  Here's my reasoning.

As delivered, you have a rigid shaft from the motor to the worm.
The shaft is supported in THREE places, the motor bearing, and the two worm bearings.  By definition, unless all 3 of those bearings are in a perfect line, you are going to have friction, binding, noise, or all of the above.

When I say "in a perfect line", I mean within the tolerances of the manufacturing process for the motor, the bearings, the frame, and the assembly of all the parts.  In fact, the more I write this, the more I think, "How do these EVER work?"  I suppose it's a compliment to Kato that they can assemble these things consistently enough to make it so.

3 supports for a shaft are not necessary, and only create the conundrum of trying to get them all in a perfect line. 
So removing the center one is a good idea.
It introduces the complication that without that inside bearing, there is nothing to keep the worm from shoving in that direction and putting pressure on the flywheel or motor armature, so you have to adjust for that.

Ron also discusses this in his paper.  But....

What do you think of this?  (probably mostly for Ron):
It might be easier to take out the inner bearing, drill it out a little so that it no longer actually carries the shaft, and then put it BACK IN.  The shaft will no longer bind in it, but most of it will still be there so you won't have to worry about adjusting for the lateral motion of the worm.  That inner bearing will just become a lateral "stop".

[wm3798]

While Ron's solution is handy, any noise that the mechanism made after surgery is the result of something going together incorrectly.  As noted, either a bearing block is turned to the wrong position, or worse, something is binding against the motor causing the alignment to be out.  Usually this is a wire or a solder blob that results from your decoder install, if it's a hardwire installation.  I've found the best solution is to take it back apart, and be extremely careful in the re-assembly.  I'm not a fan of leaving out factory parts as a long term fix.

Lee

[mmagliaro]

This is not the same as leaving parts out.  I have to disagree.  This is removing a part that should never have been in there.
This has piqued my interest enough that I am going to have to do a scientific A/B test.
Tonight, I will take a Kato 4-axle diesel, which I have never disassembled, run it, and measure it's current draw.
I will remove the shell, loosen the frame halves enough to drop out the trucks, and then just run the frame with the motor and worms in it, so there will be no other influence.

Then I will remove the inner bearings and see if the current drops.  I am betting that it will.   If so, then the mechanism is actually running more friction-free than it did with that bearing in there, and running more friction-free than the factory-assembled engine
did.  3 bearings in a line with no u-joint just seems like a recipe for trouble to me.

[strummer]

Will be interested in your findings...

Mark in Oregon

[peteski]

To clarify my original post (on which Victor commented), here is an explanation of a fix vs. workaround.  I already exchanged a PM with Ron on this.

What I was trying to state was that IMO, fixing a problem is trying to use all the parts which were originally used when the loco ran fine (and all the parts the model designer intended to be used).  Your method involves removing parts of the original design. While it it works very well, to me it is a workaround, not a fix.  Not that there is anything wrong with that.   I guess that in the end it is just semantics. Fix vs. workaround.  Either one will result in the desired outcome.

[victor miranda]

Hi Max,

please do not ream out the inner bearing!

I can tell you that will not quiet the loco.
I did try it.

those blocks are already quite loose on the shafts.
the noise from the blocks is often the thrust washer (that should be in there) flapping.

it can shift the shaft and a bigger hole only lets it move about more.

I hope I get back here later.

victor

[u18b]

Reaming out the bearings has been proffered before by someone.

The problem I foresee in this is....

--- True, with the inner bearing opened up (enough for the shaft to not even touch it) you are doing the same thing as removing it. 

--and yes, leaving it in (in theory) would provide a stop.

--BUT....... you are also changing the mating surface of the bearing as the worm rubs up against it-- especially since the bearing is plastic.  It will deform slightly.... thus introducing a new source of noise.

[u18b]

As the author of this general topic (though not the true inventor... my research into Kumata locos made me very pleased to see that they removed the inner bearing on the Trainmaster in about 1984... my article was about 7 or so years later in the early 90s I think)....

I have no doubt at all that Max will find that current is lower since friction is clearly being reduced.

And that has been one of my main points.

Removing the inner bearing blocks not only "works around" a pesky problem of drive alignment (to use Peteski's term) but it actually improves the loco by removing some friction.

Max's illustration was actually only focused on the worm.

Let's look at the whole loco.

2 motor bearings.
4 worm bearings.
8 needle bearings at the wheels.
friction in the gears.
friction where the hex nut goes into the flywheels x2.

I love needle point bearings on the wheels.

I assert that most of the friction will come from the 6 bearings in the drive line.

If you remove 2 bearings, then you have just reduced 1/3 (33%) of the friction in the driveline.

How much overall is friction reduced?  I don't know.

I think Max's experiment is great.

[u18b]

Oh.  Sorry.  One other thing.

I wish Laboda could tell us how many times that file has been downloaded since he so graciously posted it for me about 2 decades ago.

Hundreds (?) of people have tried this technique and found the results amazing.

I don't like to advertise this, but over the years, a number of people on the Atlas board, Railwire, and Trainboard have complained that Beardenizing doesn't work.

In many of those cases (including a few people on this board), I have privately suggested that these folks send me their loco and let me look at it.  In every case without exception (no offense to anybody here), the person was not doing the procedure correctly and I fixed the loco in about 10 minutes.

Fine tuning the lateral movement by hex nut placement is the key to success.

I have been planning for quite some time to write a second edition of this article.  I will try to do a better job explaining techniques (and trouble spots) better.

And I will some day, but I have too many irons in the fire right now.

[spookshow]

And I will some day, but I have too many irons in the fire right now.

Ya think?? LOL 

Cheers,
-Mark

[eja]

As the guy who started this conversation, I have found it very informative.  Since my initial post, I have been too busy to try any of the suggestions.  Hopefully next week I can.

At the moment, my plan of attack is to reasable the loco very, very carefully as it was originally designed paying close attention to alignment issues.   Plan B is to take it apart again and do Ron's fix on it.


I'll report back when I have had the time to work on it again.

Thanks to all who have commented so far.

ed



edit: spelling  correction