Plastic gear on a metal shaft

I bought a toy at a garage sale that is a "American Classic Express" toy railroad with about 8" large cars etc. It is a bunch of rails,
cars etc, big in size etc. Very good appearance.
This is for my own kids.
The engine is broken. It makes a tooting sound, shakes a little but does not move.
I took it apart, there is a geared transmission system with a bunch of plastic gears stuck on metal shafts. One of the gears (5mm diameter) that was supposed to be firmly stuck on its metal shaft (1 mm or so), is now rotating around the shaft, therefore this system is not transmitting rotation.
As a side note, I am really pissed off by the disconnect between great appearance of this toy railroad, and really cheap construction thereof.
Anyway, I would like to know if there is a simple way to fix this (other than making a replacement gear from metal, which is a PITA in this size).
i
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I would think that the "quick" answer is...maybe.
2 ideas come to mind. First, you might be able to drill a hole thru the gear and shaft and place a spring pin to lock them together. This depends on the pins you can get and the size of the gear and shaft. Second, and I know this is scandalous to say here, but, since this is for the kids to play with, have you considered epoxy?
Both of these methods will prevent you from having to machine a new gear.
Hope this helps,
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On Tue, 21 Aug 2007 09:39:47 -0700, paul snipped-for-privacy@excite.com

I would love to use epoxy if I could. The problem is that the gear looks like it was made from the kind of plastic (like polyethylene) to which epoxy would not stick under these conditions.
As for drilling a through hole, it is rather difficult, considering the size involved. But I could try, esp. considering that I have a nice Albrecht chuck for tiny drills, where you guide the drill by hand.
It is similar to this ebay item 110147169045:
http://cgi.ebay.com/ALBRECHT-KEYLESS-SENSITIVE-HAND-FEED-DRILL-CHUCK-0-1-8_W0QQitemZ110147169045QQihZ001QQcategoryZ41947QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
The drill bit would have to be about 1/3 mm.
i
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wrote:

You could file a flat or 2 or 3 on the shaft, and file/scratch a few 'keyways' on the gear, and use epoxy or loctite sleeve retainer.
If you put a good flat on the shaft, and line that up with a flat/ keyway in the gear, and maybe file a small groove around the shaft, or file the flats so that they ramp the right way, it wouldn't matter of the epoxy stuck to the gear or not.
Dave
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snipped-for-privacy@yahoo.com wrote:

Just putting in my two bits in favor of the Locktite sleeve retainer!
Cheers Trevor Jones
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This guy may have something in stock that works http://www.odometergears.com /
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Ignoramus2170 wrote:

penetrating loctite? /mark
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Iggy welcomw to the real world!!!! just this Christmas past got that feeling of nostalgia and went and bought a lionel train set for the kids not cheap either chinese made of course what a POS. it lasted exactly 1 1/2 days i was supervising transformer went; got nothing but a raft of shit from seller and ignorant response from manufacture they sent me another transformer like it was a matter of routine have'nt tried it yet... Lionel is a chinese word that means "cheap shit sold at high price" as an after thought it should documented of all the american manufacturers that went belly up because of new age thinking starting with Bridgeport, and south Bend batw

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I share your feelings 100%, but what happened with Bridgeport?
i
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It is my under standing that it taken over by Hardinge i heard this about 2 yrs, ago just as south bend was taken over by leblond. i.m pretty certain that it was hardinge i'll look it up for you later if you want batw
wrote:

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batw wrote:

Yes, it is Hardinge. But, to my distant knowledge, they have not moved production to a junkyard in China, and have no intention to do that. Our shop hasn't bought any new Bridgeport gear since the sale, so that's why I can't say anything more than an impression of what went on there.
Jon
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On Tue, 21 Aug 2007 11:24:21 -0500, Ignoramus2170

The plastic gear is probably made of nylon. Loctite will stick to nylon after a fashion. Not as well as it does to metal, but perhaps well enough for the train to work if there isn't a lot of torque on that gear.
Knurling the shaft would help but you'd need a very fine knurl on a 1mm dia shaft. Laying the shaft on a flat surface and rolling it with a fine file and heavy pressure might produce enough of a knurl to help.
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Gorilla Glue? Is there room to put a blob of glue on either side of gear to catch the edges of teeth?
Small collars locktited on both sides with a cross pin through the gear.
A picture with gear meshed would be helpful.
Wes
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I will try to take a picture tonight.
i
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Ignoramus2170 wrote:

Welcome to the modern world of "quality". You might be able to solder a metal disc to the shaft, and then pin the loose gear to the disc. I've done things like this a few times to fix stuff that was horribly designed.
Jon
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On Tue, 21 Aug 2007 11:24:21 -0500, with neither quill nor qualm,

My friend, Terry, makes replacement teeth out of a a kit with powdered nylon and some sort of resin. The output is quite strong. I don't recall what brand he uses, but you can try something like this: http://www.whitehorsepress.com/product_info.php?cPath=4_49&products_idA23
-- Books are the compasses and telescopes and sextants and charts which other men have prepared to help us navigate the dangerous seas of human life. --Jesse Lee Bennett
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devcon plastic adhesive epoxy will fix it - don't bother with regular epoxy, and degrease carefully first

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