KATO GS-4 remotor project ? ? ?

[carlso]

I purchased my Gs-4 out of the very first production and it has been running poorly. Max has put in the new drivers  and made his "fixes". He sent a video that showed it running quite well. I have been discussing with Max and Eldon about putting in a coreless motor with gearhead. Should be a very good runner.

So tonight I took the chassis apart again. As you all know, the thing is in four pieces with the bottom pair containing the gears and drivers and the top pair containing the motor. While tearing it down, I discovered the brush cap on the grey wire would not stay attached. The last picture will show why. That loose cap may have contributed to some of the running problems. The grey wire was glued into a groove on the frame so it did not fall out entirely, 'till I took it apart. Here are some pictures and you will see why the cap will not stay on. I may  just have no choice now but to switch a coreless with gearhead into this beast. I have not done any measuring but I can see the combination will fit. I will post as I go if there is any interest.

Here is a view of the top chassis half....


To give you an idea of the space available in the motor/flywheel/drive shaft area in 1/2 of the top frame....


Now here is the reason I may just have to re-motor. I think you can see the problem and what ticks me off is this has to be from the original build.........


Let the thinking and the fun begin ? ? ?

Carl

[victor miranda]

I recommend you get one of the FEF motors and  try that.

the new FEF motor is smaller and should fit once you set it into a couple of slabs of styrene

I am not sure how one might get the power to the worm.

but I am thinking something can be done.

victor

[eja]

 I think you can see the problem and what ticks me off is this has to be from the original build.........


Carl

Sorry, I am very interested but, I don't see the problem.  Can you please explain a little more or annotate the photo?

Thanks and good luck.

eja

[delamaize]

Sorry, I am very interested but, I don't see the problem.  Can you please explain a little more or annotate the photo?

Thanks and good luck.

eja

Unless he's referring to the boogered up brush holder hole, I don't see it either...

[victor miranda]

the boogered up hole is the problem.

some one did harm to it and now the brush barrel will not stay in place.

[mmagliaro]

That looks to me like somebody tried to solder directly to the brush holder.  I know people get away with this, and I admit that in my life I have actually done it a time or two.  But not for a long time.
And that photo is why.

You are much better off solder a wire to a strip of phosphor bronze with a hole in it and slipping that under
the brush cap, the way the original connections are usually made.

You have many choices, Carl.  You know my suggestions on the subject.
The FEF motor would certainly fit and would need to be shimmed up to take up the excess room in there.
But personally, I think the GS4 runs too darn fast, and since I'm a nut for slow running,
I would go with the 6v over-revved gearmotor. 

The GS4 with the stock motor tops out at about 110 mph at 12v (I clocked yours).

That's a normal top speed for the prototype, but that's not the point.  It looks ridiculous running faster than
about 60 on a model railroad.

So... a 4:1 gearmotor, now you are down to about 27 mph.   You overdrive a 6v motor and you might
get up into the 50s for top speed, which I know may not please some folks, but I'd consider that perfect.
And you'd have oodles of torque.  That thing would start up slow and smooth, and it could
pull uphill, around curves, and anywhere without struggling.

So I would vote Maxon 1017 + 4:1  or Faulhaber 1016 + 4:1

If you don't care about the gear reduction, then yep... an FEF motor.  (But ya know... motorman has
some really good prices on Maxon 1024's ... so you could use that with no gearhead ... that's another option).

All of those would have a 1.5mm output shaft, or could easily be sleeved to a 1.5mm.  So you should be able to adapt the drive shaft with some NWSL couplings or a rubber tube.

[carlso]

Thanks guys for the comments and suggestions. Yes the problem is the brush cap holder. However, I think I am only looking for a good and reasonable reason to put a good coreless in the loco. Yes Max, I know your thinking from previous posts and that combination or another similar is the way I am leaning. Besides, who now has any of the FEF motors in stock. Not KATO and as a matter of fact they have very few important GS-4 parts anymore. So value and take good care of what you have now.

The next photo is to show the overall power cage, from worm to the far right flywheel. The motor is not in the cradle properly and all of it is not cinched up tight so the alignment from left flywheel through the driveshaft and bearing is not level. I know that, but I am trying to get a rough feel for the amount of work needed. My main concern is, can I get that left flywheel off and added to the end of the gearhead because that would allow the KATO bearing/drive shaft that I have (new) to attach to the flywheel in the normal way. Just a lot of food for thought and thinking (I smell the sawdust burning) for now. I will do some measuring and attach that photo later.

[mmagliaro]

Forget that flywheel if you use a gearmotor.   The output shaft of the motor will be spinning 4x slower
with a ton more torque and the flywheel won't be worth anything.
The thing to do will be to pry that gray coupling off the worm shaft, and then join the motor to the worm
shaft with NWSL U-Joints or a simple silicone rubber tube.   Then you can put any motor in there
that you want.

And honest, with a Maxon or Faulhaber and a 4:1 gearhead on it, you aren't going to need the flywheel. 
Truth be told, remember my SP&S 4-6-2, with the Faulhaber and the flywheel?  I have since gotten rid
of that flywheel because it allowed me room to make a nicer, sturdier brass bracket that I
could screw to the frame to provide the boiler attachment, and it made zero difference to how
well the engine runs.

If you get lucky enough to have enough room to put a flywheel on te BACK of the coreless motor, and
you are luckier still to find a coreless motor with a backshaft, then that would make a wonderful
improvement.  You would have a flywheel spinning 4x faster than the output shaft and it would give you
some great coasting power.

As for the FEF motor, since you wouldn't be putting a gearhead on that one, you might want the flywheel,
but that would be very hard to keep.  For one thing, there isn't much of a shaft on that motor,
and I don't know if the bearing on the front of that motor could withstand the weight and forces
 of a flywheel.  I would tend towards not risking it.

[victor miranda]

I'll need to go measure it
I am pretty sure the FEF motor is 1mm shaft.

it comes with a joint to drive a hex shaped hole

the FEF flywheel has the hex shaped hole.

I am thinking you will want a some flywheel...
there is room for it.

the easiest is to put a cut down hex onto the FEF motor and
use the rest of the GS4 drive train.

cut the gs-4 flywheel down to an arbitrary 6mm (7 could work)
and put a sleeve on the FEF motor shaft to hold it to the  trimmed flywheel.
A heavy flywheel may not be a good idea in this method.

I would not trust the worm bearing blocks to hold a flywheel.
to do that the worm bearing blocks would need to be replaced.

victor

[peteski]

You still have an option to just replace the stock GS-4 motor - these are available as parts from Kato USA (but a bit pricey).  Just be more careful when soldering leads to it.    You can also try to glue or heat-weld the original brush back onto the defective motor.

While the FEF-3 motors are all sold out, the Kato H0 P42 motor is the same as the one used on FEF-3 (the only difference is the coupling and the termination of the leads). 

If you do decide to dispose of the defective motor, I would be happy to take it off your hands (if the price is reasonable).   I am interested in its magnets, but buying a new motor just for magnets is a bit crazy!

[carlso]

Thanks for the comments.

Victor - I do not quite understand your comment regarding worm bearing block holding a flywheel. The KATO build includes a flywheel before the bearing block and worm.

Peteski - Send me a PM with your address and I will send you the motor. I am not going to try to jerry rig it and I am not going to put an under powered motor back in there, so the motor is yours for grins and future expertise.

Carl

[victor miranda]

this is the problem?
"I would not trust the worm bearing blocks to hold a flywheel.
to do that the worm bearing blocks would need to be replaced."

a flywheel rides on bearings.
In the gs4 the flywheels ride on the motor bearings.

one possible way to install a flywheel in a remotor job of the gs-4
is to put the flywheel on the same shaft as the worm.

this is not a good idea because the bearing blocks of the worm are a little loose.

victor

[carlso]

Sounds good Victor. thanks

Carl

[mmagliaro]

Following along guys...

Yes, putting the flywheel on the worm shaft, and allowing the worm to still have its normal bearing play,
could let the flywheel vibrate and rattle around.  I had not thought about that.
But on the other hand, I am not so sure that little FEF motor's bearing was ever intended to carry
the weight of a flywheel, so I don't like that solution either.

There are experimental things you could try, like putting in a shim to lock that forward worm shaft bearing so
that it does NOT have any play in it, and put the flywheel on that shaft end.  Yeah, it might not work.  That's why it would be an experiment.  I'm betting that you just need to get it shimmed right and the worm would still engage fine with the driver gears, and the flywheel won't vibrate around.

You can still leave the other worm bearing as-is so the worm would have some "give" to it, even with one bearing locked.

[carlso]

I have pretty much decided that I will not put an FEF or P-42 motor in this engine. I am leaning heavily to the 1017 with 4:1 gearhead. The Motorman indicates some models can be had with double shaft so perhaps a flywheel could be put on the backside of motor opposite the gearhead and then connect direct to the drive shaft and worm from the gearhead.
carl