Author Topic: Rivarossi Berkshire refit advice wanted  (Read 2265 times)

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nickelplate759

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Rivarossi Berkshire refit advice wanted
« on: May 28, 2018, 12:01:16 AM »
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I have an old Rivarossi (not Rowa)  Berkshire that I want to make usable on my NKP-ish layout.
Primary problem is that the driver flanges are too big - so I'm going to (carefully) turn them down.

It occurs to me that I need to remove the driver rods and valve gear as part of this process (heck, I need to strip the whole loco down).  I've never done that on this particular engine.  It looks like the drive pins are press-fit into the wheels - mostly - except where the main rod is attached there appears to be a screw.

I'd appreciate advice from someone who has done this before (meaning disassembled this engine) so as to minimize my mistake.

« Last Edit: May 29, 2018, 06:15:45 PM by nickelplate759 »
George

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I'm sorry Dave, I'm afraid I can't do that.

peteski

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Re: Rivarossi Berkshire refit advice wanted
« Reply #1 on: May 28, 2018, 12:56:05 AM »
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I have couple of these abut I have never taken the side-rods off.   The main crank pin does indeed have a screw holding the eccentric. That screw has to be removed to free up the main rod and side rods.  As for the other crank pins, I'm pretty sure that they are press-fit into the plastic driver spoke inserts.  Internally, all the drivers are gear-driven with idler gears between them.  If the drivers are removed, the drive train is a real pain to get realigned properly.

How are you planning on turning down the flanges? On a lathe?

I have read several times that modelers successfully turned down steam loco's flanges while the drivers remained in the model. They powered the model using alligator clips and hold it upside down, using a file to gently file down the flanges on the spinning drivers.  Not for the faint of heart, but it should be doable.   Make sure to clean off all the filings afterwards.
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eja

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Re: Rivarossi Berkshire refit advice wanted
« Reply #2 on: May 28, 2018, 01:00:57 AM »
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How do you keep metal filings away from electrical parts if you do this ?

mmagliaro

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Re: Rivarossi Berkshire refit advice wanted
« Reply #3 on: May 28, 2018, 01:30:22 AM »
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I've turned down a Rivarossi Berk flanges that way (with a diamond file, running on its back in a foam cradle).

The important keys are a LIGHT touch and a DIAMOND file. 
With a regular file, you have to apply a certain amount of pressure to get it to cut, and that pressure might be enough to make a driver slip on an axle.  With a diamond file, you are almost "sanding" off the flanges, and you can go very lightly.  It might take you 30 minutes to get a flange turned down.  Tedious.  But really, what's your hurry?  Make a project out of it.  Expect to spend several sessions gently doing this so you don't get fatigued.

As for keeping the filing dust out of the gears and internals... good point.   I set the engine in the cradle so it leans slightly to one side.  One side is now leaning lower than the other.  File on the lower side, so the dust tends to fall away from the engine and not into the gears and bearings.  When you're done, brush it off a lot with a soft paint brush.    Then lean it the other way and do the other side.  It ain't perfect, but it's pretty darn good.  I've done this on Berks and Trix K4's and never had a problem with residual dust getting into the gears or wrecking anything.  I'm not saying it's spotless inside.  There's probably some metal dust in there, but the tolerances on engines like that are loose enough that it never caused me any trouble.

Remember, you're going to get flanges that will clear the track and run.  They may not be perfect, but you probably won't notice.  If you want perfect flanges, the only way to do that is to pull all the rods off, axles out, and press all the wheels off the axles so you can set each driver individually into a lathe (or in my case, a mill, since I don't own a lathe) and then turn them down.  It's a big project if you have never done it.




Doug G.

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Re: Rivarossi Berkshire refit advice wanted
« Reply #4 on: May 28, 2018, 02:40:57 AM »
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I have turned down many a flange and not really worried about the filings at the time and then completely cleaned the mechanism under water and scrubbed with dish detergent and then force dried with an air compressor. Relube. Done. Some are over 40 years old and still run.

Doug
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www.irwinsjournal.com/a1g/a1glocos/

nickelplate759

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Re: Rivarossi Berkshire refit advice wanted
« Reply #5 on: May 28, 2018, 10:15:48 AM »
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Thanks!

First off, all the "electronics" is going to be replaced anyway - but there isn't much, just the motor, wires and a light bulb.  They will go in the trash in the rebuild.  Heck, the Rivarossi motor is very nearly the definition of trash!

Pete - it turned out that one of the driver axles was ALREADY one gear tooth misaligned :)

I do have some diamond files, and have used them to dress the flanges on the Minitrix ICE-3 power car  after I turned them down manually (as Max suggests, they are far from perfect but they work). Even that (dressing) took a while, and the result is very fine metal dust.  I took the easy way and replaced all the non-powered axles in the other cars with Fox Valley 36" wheelsets.

My initial thought was to just run the mechanism upright on a sharpening stone, but even stripped down the engine weighs enough that there is too much friction.  I'll try Max's technique.

« Last Edit: May 28, 2018, 05:25:52 PM by nickelplate759 »
George

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I'm sorry Dave, I'm afraid I can't do that.

thomasjmdavis

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Re: Rivarossi Berkshire refit advice wanted
« Reply #6 on: May 28, 2018, 03:36:54 PM »
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Quote
Pete - it turned out that one of the driver axles was ALREADY one gear tooth misaligned :)

Not necessarily a bad thing. All the steam I currently have came used with an issue like that. I find that it knocks about $50 off the price of a "like new in box-never run-30 year old" :? "runs a little rough" locomotive (have you ever noticed how often the seller of a "never run" locomotive knows how well it runs?) on the big auction site (I bought one a few weeks ago with exactly that problem).
Tom D.

Some things are better left unsaid. Which I generally realize right after I have said them.

nickelplate759

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Re: Rivarossi Berkshire refit advice wanted
« Reply #7 on: May 28, 2018, 11:26:29 PM »
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Well I spent a couple of hours with the diamond files - that's REALLY slow going.

Then I hit on a faster method (figures - after I spent 2 hours with the files).   It uses a sharpening stone that I bought from the hardware store - not a fancy natural one, just a $10 manufactured stone.  It has a course side and a fine(r) side.

Take the motor OUT of the engine so it is free rolling, and take off trucks, leaving only the drivers.    Now, put the stone flat on the workbench, hold the chassis so it is standing on the stone at about a 30-degree skew (upright, but not rolling straight), and scrub it across the stone.  [ edit ] Do NOT press down hard on the engine - you still need this to be a gentle process. [ /edit ] If you do it right, the wheels will turn as the chassis scrubs across the stone.  This is important as it avoids flat spots.  I then turn the engine to skew the other direction and repeat - trying to even out the the wear.  I alternated every couple of minutes until the flanges were shallow enough.

When you get the flanges shallow enough the edges will be all scratchy and they will have sharp corners. NOW get out your diamond files, put the motor back in the chassis, crank it up and gently dress the flange edges with the file.  About 1 minute per wheel should do it.

Here's a thousand words to make it clearer...
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« Last Edit: May 29, 2018, 11:19:28 AM by nickelplate759 »
George

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I'm sorry Dave, I'm afraid I can't do that.

peteski

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Re: Rivarossi Berkshire refit advice wanted
« Reply #8 on: May 28, 2018, 11:35:04 PM »
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Very creative George!  I like it! Thinking out of the box. And the metal dust stays out of the mechanism.
« Last Edit: May 28, 2018, 11:36:55 PM by peteski »
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mmagliaro

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Re: Rivarossi Berkshire refit advice wanted
« Reply #9 on: May 28, 2018, 11:59:30 PM »
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George, that is an outstanding idea!  I have a sharpening stone very similar to that and it never occurred to me to try that on flanges.
After my last post, I broke out an old Rivarossi Berk and decided to grind down a flange and actually time it to see how long it would take.

As you noted (and as I warned), it's a SLOW process with a diamond file.
I then found that using a piece of 100 grit sandpaper is actually better.  The drivers are not hardened metal and they will sand down.  But even so, it took about 30 minutes to do one wheel.

I will try your method the next time I need to turn flanges and don't feel like pulling all the drivers off and chucking them in the mill.  Nice work.


nickelplate759

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Re: Rivarossi Berkshire refit advice wanted
« Reply #10 on: June 09, 2018, 03:17:39 PM »
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Now that the wheels are solved*, on the next challenge - a new motor!  The original Rivarossi motor is junk, and has a bad coil.  On a 3-pole motor that's fatal.  It's a first generation Rivarossi Berkshire, so it's the short round can motor - 14.5mm diameter, 14mm body length, 20mm over the rear bearing (not counting drive shaft).     I found a used frame on eBay milled out for a longer motor, so I can use a motor with up to a 20mm body.
A Kato GM-5 is a bit too long (of course, because I have several).

The OTHER problem is that the motor needs a long shaft - the Rivarossi motor has a 23mm shaft, but in the modified chassis I can use one as short as 19mm.

Any suggestions?



* non-drive wheels were replaced with Fox valley wheelsets for all 33" (tender & pilot) and 36" (front axle of firebox truck) wheels. For the rear axle of the firebox truck I will assemble my own needlepoint wheelset from NWSL parts - the only compromise is that it will have 42" wheels rather than 43".  Close enough for me.
George

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I'm sorry Dave, I'm afraid I can't do that.

mmagliaro

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Re: Rivarossi Berkshire refit advice wanted
« Reply #11 on: June 09, 2018, 05:04:58 PM »
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The long shaft is going to be a problem.   I'd use a sleeve and just extend it.  Find a piece of brass tubing that is close to 1.5mm ID and bore it out with a 1.5mm drill bit.

For the motor, I'd use a 12mm Mashima if you can find it.   The Mashima shafts are 7mm long, so that is plenty of length to put a sleeve on and have it really stay true.  They are getting hard to find because they are no longer made, but there is a place in the UK selling them on eBay that has a good selection of them for about $40 each.  Just search for "Mashima 12mm motor".  They are really excellent 5-pole can motors with lower RPMs and tons of power. 

NWSL sells some motors that would fit what you need.  Just look on their website.  I don't think they are as good as a Mashima, although they are less expensive. 

What about the smaller Kato NW-2 motor?  That is shorter than the GM-5.








nickelplate759

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Re: Rivarossi Berkshire refit advice wanted
« Reply #12 on: June 10, 2018, 07:48:30 PM »
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Well, in rummaging through my parts box I found an old, never used, Sagami 14x20 motor (sold by NWSL years ago).  The shaft looks to be just long enough.
Assuming it still works after 20+ years in storage, I think I'll give it a try.

I also found a Sagami armature that NWSL sold as a retrofit-upgrade for those lovely Rivarossi motors, but that's WAY more trouble, and the shaft isn't quite long enough.
George

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I'm sorry Dave, I'm afraid I can't do that.

peteski

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Re: Rivarossi Berkshire refit advice wanted
« Reply #13 on: June 10, 2018, 09:31:15 PM »
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I also found a Sagami armature that NWSL sold as a retrofit-upgrade for those lovely Rivarossi motors, but that's WAY more trouble, and the shaft isn't quite long enough.

The idea seems like a good one, but the armature is only a half of the weak-motor problem.  The other half is the magnet.  It is just a strip of flexible vinyl magnet material (similar to what the flexible refrigerator magnets are made of). It is inherently very weak (much weaker than the ceramic magnets most motors use, and drastically weaker than the rare-earth magnets). I have some of those armatures but I have not yet found replacement magnets suitable to use in that motor.
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mmagliaro

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Re: Rivarossi Berkshire refit advice wanted
« Reply #14 on: June 12, 2018, 02:26:40 AM »
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If you want to go the Sagami route, I've got some of the long ones lying around - 12 x 25 with double shaft. If that would be useful, send me a PM. You might have to grind out the inside of the frame deeper to get a 25mm motor in there, but that would take 5mm of your shaft length requirement. And the 12mm Sagamis were pretty darn good.