OT: How can I glue a broken nylon gear?

Joerg wrote:
Hello Folks,

We were given a coocoo clock.
Click to expand...
[...]

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
When I need to work with nylon parts, I use a small soldering iron with the
temperature reduced so it doesn't burn the plastic. I simply melt the parts
back together and add more nylon to reinforce it wherever possible.

Practising on some scrap parts might help give you the confidence needed to
tackle this.

A backup plan might be to have another part made from brass. Someone who
works on these clocks should be able to help.

Mike Monett
 
Mike Monett <no@spam.com> wrote:

Joerg wrote:

Hello Folks,

We were given a coocoo clock.

[...]

Regards, Joerg

http://www.analogconsultants.com

When I need to work with nylon parts, I use a small soldering iron with the
temperature reduced so it doesn't burn the plastic. I simply melt the parts
back together and add more nylon to reinforce it wherever possible.

Practising on some scrap parts might help give you the confidence needed to
tackle this.

A backup plan might be to have another part made from brass. Someone who
works on these clocks should be able to help.

Mike Monett
Click to expand...
Following the same principle (of first trying on similar material), I
wonder if chloroform would work?

I came off the bike I'd just had as a Christmas present when I was 14
(over enthusiastic braking) and cracked a plastic mudguard. I was into
Chemistry as a hobby then, so when I got back to school a few days
later I helped myself to a little chloroform from the lab. I recall it
made a reasonable repair. Not sure about nylon. Try as many similar
solvents as you can. Of course, the challenge will probably be finding
those scraps of test material first!

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
Terry Pinnell wrote:

[..]

Following the same principle (of first trying on similar material), I
wonder if chloroform would work?

I came off the bike I'd just had as a Christmas present when I was 14
(over enthusiastic braking) and cracked a plastic mudguard. I was into
Chemistry as a hobby then, so when I got back to school a few days
later I helped myself to a little chloroform from the lab. I recall it
made a reasonable repair. Not sure about nylon. Try as many similar
solvents as you can. Of course, the challenge will probably be finding
those scraps of test material first!

Terry Pinnell
Hobbyist, West Sussex, UK
Click to expand...
Hi Terry,

On the chloroform, what kind of bottle was it stored in? Maybe nylon? As
I understand it, nylon is not affected by most solvents. Here's one
reference:

"Solvent Resistance: Nylon is resistant to practically all commercial
solvents."

http://www.thermoclad.com/HTML/pr-nylon11.html

For experimenting, I found lots of cheap nylon fittings and pipe in the
plumbing section of a large hardware store. You could probably get a
lifetime supply for the price of a cup of coffee:)

Mike Monett
 
Mike Monett <no@spam.com> wrote:

Terry Pinnell wrote:

[..]

Following the same principle (of first trying on similar material), I
wonder if chloroform would work?

I came off the bike I'd just had as a Christmas present when I was 14
(over enthusiastic braking) and cracked a plastic mudguard. I was into
Chemistry as a hobby then, so when I got back to school a few days
later I helped myself to a little chloroform from the lab. I recall it
made a reasonable repair. Not sure about nylon. Try as many similar
solvents as you can. Of course, the challenge will probably be finding
those scraps of test material first!

Terry Pinnell
Hobbyist, West Sussex, UK

Hi Terry,

On the chloroform, what kind of bottle was it stored in? Maybe nylon? As
I understand it, nylon is not affected by most solvents. Here's one
reference:

"Solvent Resistance: Nylon is resistant to practically all commercial
solvents."

http://www.thermoclad.com/HTML/pr-nylon11.html

For experimenting, I found lots of cheap nylon fittings and pipe in the
plumbing section of a large hardware store. You could probably get a
lifetime supply for the price of a cup of coffee:)

Mike Monett
Click to expand...
This was a long time ago, Mike, shortly after the invention of
electricity and indoor plumbing <g>. So the chloroform was in the same
sort of bottle as the concentrated nitric acid, ammonia, and
everything else - GLASS!

My bike's mudguards were a sort of brittle white plastic.

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
On 2005-05-31, Joerg <notthisjoergsch@removethispacbell.net> wrote:

That's a great method and I would have done it. But this gear is only
5mm in diameter and 3mm long.
Click to expand...
Why don't you look if it is a standard size/module and just buy a
replacement?

BTW, nylon gears are often used to reduce noise.

robert
 
On 2005-05-31, Joerg <notthisjoergsch@removethispacbell.net> wrote:

That is another option but the gear is longer than most RC stuff. I
haven't seen a US supplier but in Europe there is a company called
"Selva" that supplies spare parts to watch makers. However, if you order
just one part and have it shipped to the US that gets expensive.
Click to expand...
I often buy from Maedler in Germany. They have all the standard
size gears, timing belts, everything. Maybe there's a rep near
you.

robert
 
On 1 Jun 2005 08:05:15 -0700, the renowned avr2005@vip.gr
(apprentice_nerd) wrote:

Hi

This could be useful to you
http://www.machinedesign.com/BDE/FASTENING/bdefj1/bdefj1_5.html
especially look at fusion bonding and solvent bonding
but to be on the safe side measure and sketch the gear
before you attempt anything :)
You might need to have it machined at your local shop if
it fails to bond or if you were wrong about it being made
from nylon.If it is very old clock it may be made from bakelite
and this is very difficult and costly to fix in a reliable way.
Click to expand...
Old-style horologists ("clockmakers") can create pretty much any
repair part from scratch with little more than a lathe, hand tools,
skill and experience.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Joerg wrote:
We were given a coocoo clock. I fixed it but must say that I was not
enthused about the quality of its innards. Long story short it all works
now except for the music and the dancing figurines. A nylon gear is
broken length-wise on one side.
Click to expand...
Try http://www.smallparts.com/ They have an impressive assortment of
Delron gears.

Ted
 
Spehro Pefhany wrote:

You guys in Canada will slowly kill yourselves with all that melted
cheese stuff, poutine and so on. Ever checked cholesterol levels ...?

Mine's okay. ;-) In moderation, that sort of stuff's not so bad.
McDonalds, potato chips and donuts are probably a lot worse for you.
Click to expand...
Right on! It's the trans-fats that are the really bad news. As far as
the other fats go, it depends on your metabolism. I can't think of
anything more variable than humans. As for me, at 70 I way the same as
I did at 20, eat the skin off my serving of chicken as well as that from
my wife's and consider it sinful to remove the fat from a steak unless
you give it to me. At my last cholesterol check my doctor was unable to
rate my "risk factor" because it was too low - lots of "good"
cholesterol, very little bad. Eat your heart out. :))

Ted
 
<cbarn24050@aol.com> wrote in message
news:1117602769.282696.156010@g49g2000cwa.googlegroups.com...

Place infor an hour, the nylon should melt thus reforming
the gear. Allow to cool and remove from the resin.
Click to expand...
Clever!
 
Terry Pinnell wrote:
This was a long time ago, Mike, shortly after the invention of
electricity and indoor plumbing <g>. So the chloroform was in the same
sort of bottle as the concentrated nitric acid, ammonia, and
everything else - GLASS!
Click to expand...
Except HF. Back then it would have been a wax bottle. :)

Ted
 
In article <429D5C62.3068@spam.com>, Mike Monett wrote:
Terry Pinnell wrote:

[..]

Following the same principle (of first trying on similar material), I
wonder if chloroform would work?

I came off the bike I'd just had as a Christmas present when I was 14
(over enthusiastic braking) and cracked a plastic mudguard. I was into
Chemistry as a hobby then, so when I got back to school a few days
later I helped myself to a little chloroform from the lab. I recall it
made a reasonable repair. Not sure about nylon. Try as many similar
solvents as you can. Of course, the challenge will probably be finding
those scraps of test material first!

Terry Pinnell
Hobbyist, West Sussex, UK

Hi Terry,

On the chloroform, what kind of bottle was it stored in? Maybe nylon? As
I understand it, nylon is not affected by most solvents. Here's one
reference:

"Solvent Resistance: Nylon is resistant to practically all commercial
solvents."

http://www.thermoclad.com/HTML/pr-nylon11.html
Click to expand...
I believe the same is true of at least most grades of polyethylene, also
polypropylene and PTFE ("Teflon", etc).

- Don Klipstein (don@misty.com)
 
Don Klipstein wrote:

[...]

I believe the same is true of at least most grades of polyethylene, also
polypropylene and PTFE ("Teflon", etc).

- Don Klipstein (don@misty.com)
Click to expand...
I don't know about the rest, but I found ordinary hot glue seems to work well
on polyethylene. I cut strips from a distilled water container and glue them
to the bottom of my mouse. Then if the pad is cleaned, it is almost
friction-free. A strip across the front stops the rocking motion when you
press the left button, so the cursor stays in place.

The new pads are moderately difficult to remove.

Mike Monett
 
Hello Tim,

Check out alt.horology for nearby clock-repair parts places. It's not
clear to me from your description if this is in the movement or in the
music box. I think you're talking about the gear which couples from
the music box to move the figurines? Entire replacement music boxes
run $10-$20 (governor mechanisms are like half the price, and maybe
that's what you need), entire replacement mechanisms run $30-$40 at the
low end, and these would probably be a step up in quality from what you
have.
Click to expand...
Thanks for the newsgroup hint, I'll subscribe to that one.

It isn't the link to the figurines but the last gear on the music box.
The gear drives the air brake to achieve a somewhat regulated speed. The
tap off to the figurines happens a few gears earlier. It's a special
music box and I might be able to squeeze in another. But the ones for
coocoo clocks (able to tap off for the figurine gears) are quite pricey
in single qties.

Well, I'll either try to cast one or ask my friend to mill one for me.

Regards, Joerg

http://www.analogconsultants.com
 
Joerg wrote:
Actually I have "cut" a larger and slower running gear using a scroll
saw. If the saw still has decent bearings it can be done. Just not with
such small gears.
Click to expand...
Find an old-time watchmaker. I visited my uncle's shop one time
and he was putting the finishing touches on a 7-tooth watch gear
after 2 1/2 hours under the loupe shaping it by hand with tiny
files. It was under 1.5mm in diameter...! This sort of effort is
justified for a $25,000 antique of course :). It had to be pretty
much perfect as it was the final gear against which the oscillating
escapement wheel acts. Just goes to show what is possible given
sufficient determination and dedication.
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:VQ4ne.874$wy1.195@newssvr13.news.prodigy.com...
Hello Luhan,

Your only hope may be superglue. Even better if you first clean it
using something they called 'cyanoprep'.

That's what I was afraid it would be. I have seen superglue "eat"
portions of a similar part before.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
I have just done a similar repair. The gear was a press fit onto a motor
which operated a cd tray.
Pushed the gear onto a screwdriver - around 2mm diameter - to open the split
a little.
Squeezed in some superglue and removed screwdriver.
When set pushed back onto motor shaft.
So far it works fine - but this only needs to stand up to intermittent use.

Regards,
John.
 
On Wed, 01 Jun 2005 18:20:33 -0400, Mike Monett wrote:

Don Klipstein wrote:

[...]

I believe the same is true of at least most grades of polyethylene, also
polypropylene and PTFE ("Teflon", etc).

- Don Klipstein (don@misty.com)

I don't know about the rest, but I found ordinary hot glue seems to work well
on polyethylene. I cut strips from a distilled water container and glue them
to the bottom of my mouse. Then if the pad is cleaned, it is almost
friction-free. A strip across the front stops the rocking motion when you
press the left button, so the cursor stays in place.

The new pads are moderately difficult to remove.

Mike Monett
Click to expand...
I think hot glue is actually molten polyethylene, so this is not
surprising. From what I gather, heat fusion is the most reliable way to
get polyethylene to stick to itself. There is also a relatively new
adhesive put out by 3M, called Scotch-Weld 8005. It apparently sticks well
to polyethylene (but not nylon :-( ). It is a two part acrylic which
pretty much requires special ($45) pumps for dispensing. McMaster Carr
caries it for those who might be interested.

I found all this while researching a way to join two polyethylene sheets.
I don't have first-hand experience with the adhesive.

I'm going to try just using a hot iron. Luckily, polyethylene is cheap.
;-)

--Mac
 
On Wed, 01 Jun 2005 08:41:34 +0100, Terry Pinnell wrote:

Mike Monett <no@spam.com> wrote:

Terry Pinnell wrote:

[..]

Following the same principle (of first trying on similar material), I
wonder if chloroform would work?

I came off the bike I'd just had as a Christmas present when I was 14
(over enthusiastic braking) and cracked a plastic mudguard. I was into
Chemistry as a hobby then, so when I got back to school a few days
later I helped myself to a little chloroform from the lab. I recall it
made a reasonable repair. Not sure about nylon. Try as many similar
solvents as you can. Of course, the challenge will probably be finding
those scraps of test material first!

Terry Pinnell
Hobbyist, West Sussex, UK

Hi Terry,

On the chloroform, what kind of bottle was it stored in? Maybe nylon? As
I understand it, nylon is not affected by most solvents. Here's one
reference:

"Solvent Resistance: Nylon is resistant to practically all commercial
solvents."

http://www.thermoclad.com/HTML/pr-nylon11.html

For experimenting, I found lots of cheap nylon fittings and pipe in the
plumbing section of a large hardware store. You could probably get a
lifetime supply for the price of a cup of coffee:)

Mike Monett

This was a long time ago, Mike, shortly after the invention of
electricity and indoor plumbing <g>. So the chloroform was in the same
sort of bottle as the concentrated nitric acid, ammonia, and
everything else - GLASS!

My bike's mudguards were a sort of brittle white plastic.
Click to expand...
About 10-15 years ago I worked for Environmental Health and Safety at my
University. I was responsible for collecting hazardous waste from all the
campus labs, and the campus health center. The strong acids (except
hydrofluoric, of course) were in glass bottles, but the glass is actually
much more robust than it looks. You can hit it with a sledge hammer and
even though the glass shatters, not a drop of acid will leak out, as long
as the neck and top remain intact. I think the bottles are made from
sequential layers of glass and some elastomer or something, like
bullet-proof glass.

I'm pretty sure that strong acids still come in glass bottles. What else
would they use? They certainly can't use polyethylene, and Teflon is even
more expensive than glass, I think.

--Mac
 
On Fri, 03 Jun 2005 02:11:25 +0000, Mac wrote:

On Wed, 01 Jun 2005 18:20:33 -0400, Mike Monett wrote:

Don Klipstein wrote:

[...]

I believe the same is true of at least most grades of polyethylene, also
polypropylene and PTFE ("Teflon", etc).

- Don Klipstein (don@misty.com)

I don't know about the rest, but I found ordinary hot glue seems to work well
on polyethylene. I cut strips from a distilled water container and glue them
to the bottom of my mouse. Then if the pad is cleaned, it is almost
friction-free. A strip across the front stops the rocking motion when you
press the left button, so the cursor stays in place.

The new pads are moderately difficult to remove.

Mike Monett

I think hot glue is actually molten polyethylene, so this is not
surprising. From what I gather, heat fusion is the most reliable way to
get polyethylene to stick to itself. There is also a relatively new
adhesive put out by 3M, called Scotch-Weld 8005. It apparently sticks well
to polyethylene (but not nylon :-( ). It is a two part acrylic which
pretty much requires special ($45) pumps for dispensing. McMaster Carr
caries it for those who might be interested.

I found all this while researching a way to join two polyethylene sheets.
I don't have first-hand experience with the adhesive.

I'm going to try just using a hot iron. Luckily, polyethylene is cheap.
;-)
Click to expand...
Be sure and put aluminum foil on top of the poly, so it doesn't stick
to the iron! (probably also underneath, so it doesn't stick to the
bench/floor).

Cheers!
Rich
 
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