Author Topic: Regearing a Kato Mikado  (Read 2773 times)

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bbussey

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Re: Regearing a Kato Mikado
« Reply #15 on: June 20, 2014, 10:03:28 AM »
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... If they were made the correct size, they could actually drop in
with no modification to the mechanism at all.  But ugh... the manufacturing costs. 
I have actually been checking into this.   I'd be looking at $500 and that's if nothing goes wrong and the first
run of gears comes out correct...

Max!  With all the scratchbuilt steam power you've built, no lathe on the workbench that can cut gears?  8)
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mmagliaro

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Re: Regearing a Kato Mikado
« Reply #16 on: June 20, 2014, 02:01:24 PM »
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So you just twisted the stock cast on pin  :scared:  Yikes what if it snapped off?

Chris,
Yes, like I said, the only risk was that it might snap off.  But as it turns out, the metal looks like some sort of
copper (odd, I know, but look at the color!)  after you scrape through the outer coating.  So it seems to be able
to bend or twist.  And remember, the bend is SO SLIGHT.  I mean .003" or .005" is so tiny!

And if it snapped off, well, my plan "B" was to just file the area flat, drill, and put in a pin.

As for the coreless motor, well, as you know, that's usually been the way I repower Mikados (a 1016 + gearhead).
But the coreless motor can't do it by itself.   In fact, my W-5 project started out with a Maxon 1024 with no gearhead,
and I was not satisfied with the overall torque and low-end start-up, so I went to a shorter motor with a gearhead.
It's very hard to make any motor behave with the same wonderful mechanical power characteristics you get
from reduction gearing.  In fact, I'd say it's impossible.

A cheap motor with lots of gear reduction will beat a coreless motor with a high gear ratio.
« Last Edit: June 20, 2014, 02:05:16 PM by mmagliaro »

Chris333

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Re: Regearing a Kato Mikado
« Reply #17 on: June 20, 2014, 03:56:07 PM »
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I said coreless motor because that is what Kato uses now (the EFE announcement), but I doubt they have upped their ratios at all.

peteski

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Re: Regearing a Kato Mikado
« Reply #18 on: June 20, 2014, 07:51:05 PM »
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Chris,
Yes, like I said, the only risk was that it might snap off.  But as it turns out, the metal looks like some sort of
copper (odd, I know, but look at the color!)  after you scrape through the outer coating.  So it seems to be able
to bend or twist.  And remember, the bend is SO SLIGHT.  I mean .003" or .005" is so tiny!


Max,
the chassis is pot metal which is copper plated, then the copper is chemically blackened.  Bachmann also does this to their blackened metal chassis'.  The copper is used because it is much easier to chemically blacken copper than pot metal.  Plus, it protects the pot metal from oxidation.

In your photos you can clearly see that after you file through the thin layer of copper, you can see the silver colored pot metal.  You are lucky that the pin didn't snap.  :)
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mmagliaro

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Re: Regearing a Kato Mikado
« Reply #19 on: June 20, 2014, 08:26:42 PM »
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Thanks, Peteski.
I didn't realize what that metal was.
Although it is pot metal, it really doesn't have to move much.  "Twisting" is over-stating what you really have to do here
to get those two gears a little closer.   If I were trying to move it something like 1/16", it would probably break off.

Next time I do it, I will probably forego the attempt to make this an "anybody can do it, drop-in", since it clearly isn't,
and just put the thing under the mill, machine off the pin, machine out the recess where the gear goes
(nice and clean with an endmill instead of just Dremeling and filing), and put a darn pin in there.

But I do like the reduced speed.

havingfuntoo

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Re: Regearing a Kato Mikado
« Reply #20 on: June 20, 2014, 08:33:17 PM »
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Hi Max, A little bit of drift here ……… thumbs up on the electric tooth brush, I have a couple that I use to get some of those laborious sanding jobs under control. I keep the old heads, trim them flat and mount sanding pads on them. I safely use them to wet sand and polish with many different types of mediums, even flammable products can be employed using this equipment provided you ensure you employ some basic safety procedures. It does a fantastic job and help me to keep my sanity. For about $50 bucks over here I can get two units and six new heads. I prefer to use used heads as they are softer and tend to sit more evenly on the working surface. If you are using them dry be careful, they spin quiet quickly and can burn the surface without much effort especially when being employed on plastic and resin materials. The other down side is they tend clog quickly when used dry.
Now back to subject. 

peteski

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Re: Regearing a Kato Mikado
« Reply #21 on: June 20, 2014, 11:25:06 PM »
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Hi Max, A little bit of drift here ……… thumbs up on the electric tooth brush, I have a couple that I use to get some of those laborious sanding jobs under control.

Guys, what brand/model do you use?  I looked at some and they all seem not to be very suitable for a sander conversion, because only part of the head moves (not the entire head).
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mmagliaro

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Re: Regearing a Kato Mikado
« Reply #22 on: June 21, 2014, 02:50:47 AM »
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I bought one on a whim for the low low price of 6 bucks at the local Fred Meyer.
Here's a link to one on Amazon
http://www.amazon.com/Butler-G-U-M-Power-Toothbrush-Crayola/dp/B00156E0Q8

You might be able to cut the bristles off and put sandpaper on there, but I really was not thinking of it for that purpose.
I just wanted something to use that would spin and let me use polishing compound.
If I could have bought packages of replacement insertable brush heads to put in my Dremel, I would have bought those,
but nothing was quite right and they were expensive.

This head doesn't truly "spin".  It oscillates.  But it does it so fast, it looks and feels like it's spinning.


havingfuntoo

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Re: Regearing a Kato Mikado
« Reply #23 on: June 21, 2014, 03:41:51 AM »
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I use the ‘Oral’ branded units, not the cheapest one, about middle of the range. These units are rechargeable and the heads are at right angles to the shaft. They do oscillate back and forth but that helps to get a more even sanding pattern. I trim the bristles level, then I mix up some epoxy and form a little mounting pad in the shape of a round disc about the same diameter as the base of the bristles. After it has cured I attach to it what ever it is I intend to sand with.  I use rubber glue or the very thin double sided tape employed by carpet practitioners. 
If you don’t have some used heads that have been softened up you can age some new ones with hot water, but not too hot or you will destroy them.

peteski

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Re: Regearing a Kato Mikado
« Reply #24 on: June 21, 2014, 01:34:22 PM »
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Good info on the toothbrushes - thanks guys!
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