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Author Topic: Morris Coil Winder -- How To "Unfreeze" Gearwheels From Shafts?  (Read 8262 times)
KB1WSY
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Posts: 608




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« on: March 10, 2012, 10:51:24 AM »

Greetings,

I have a 50-year-old Morris Coilmaster (coil winding machine) in basically mint condition with all its parts, except that there is a light coating of rust on some of the parts. This external rust I have been able to remove simply by spraying with WD-40 and rubbing it off. But there is a more serious problem: the principal gear wheels and cams, which are interchangeable so that you can change gear ratios and so on, have become "fused" to their shafts. This I presume is because of invisible rust or corrosion. I have removed the grub screws and sprayed WD-40 liberally into the screw holes, but the gears are still stuck to their shafts. With a pair of pliers, I gingerly tried to rotate the gears around the shafts (after removing the grub screws) but quickly gave up because I am worried that excessive force will bend the shaft (or the gears) out of true.

I assume this is something that some of the readers of this forum see frequently when fixing up vintage equipment: dial shafts "frozen" to their wheels or knobs that won't come off. I would very much appreciate advice on how to proceed, since I am keen not to damage this nice (and rare) precision tool. I have just acquired it and the signs are that it was only very lightly used. There is still a chunk of beeswax on the wire guide!! The Coilmaster is in working order, but only with the current fixed gear ratios, plus the gears are "frozen" in slightly sub-optimal positions on the shafts, so it would really help to be able to slide them along the shafts.

Tnx et 73 de Martin, KB1WSY
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KG4NEL
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Posts: 373




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« Reply #1 on: March 10, 2012, 10:58:04 AM »

WD-40 can be used for a lot of things, but it's really not "specialized" for any particular one.

Maybe try a specific penetrating oil, like Kroil? It's useful stuff to have around, regardless :p Make sure to give it lots of time to seep in - I broke off a caliper bolt the last time I did a brake job because I was in a hurry Sad
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WB6THE
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Posts: 128




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« Reply #2 on: March 10, 2012, 07:10:29 PM »

Just a shot in the dark but I wonder if a thermal method might
help.

Applying heat to the gears would cause them to expand very
slightly and of course only temporarily. Use a candle as the
heat source and apply heat to only the outer edge of the gear.
Maybe that would break or loosen the rust bond. How hot ?
Well, not red hot but far too hot to touch.

And-or get a can of freeze spray and cool the shaft where it
passes through the gear. Cold would make the shaft contract.

Another idea and I have no clue what might happen so I'd find
something of little value that is rusted together and try it on that,
is a product called One Step, manufactured by a company named
Mar-Hyde Corporation. Comes in a spray can and says it converts
rust to black primer sealer. I bought the can that I have in a hardware
store. Maybe in the process it dissolves rust.

White vinegar might be able to break the rust bond and baking soda
(not baking powder) might do the trick. Make a thick paste in water and apply
it to the afffected area. Mixing vinegar and baking soda makes a
fizzy, bubbling substance which gives off carbon dioxide gas. Might be
worth a try.

Doing a search for     how to dissolve rust    gives several answers.

Don't know if its true but I think I've heard that Coca-Cola dissolves
rust.

Graphite and oil, comes in a little squeeze-tube in hardware stores,
used to lubricate car door locks, maybe.

If the machine has any bearings in it try not to get anything in them.

WB6THE
Alan
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K8AXW
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Posts: 3593




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« Reply #3 on: March 10, 2012, 08:55:11 PM »

Kroil is the best I've ever used.  It's supposed to penetrate an opening of 1,000,000".  I'd soak it in Kroil and let it set 24 hours....wipe off and apply heat as a previous poster noted.  Sideways bumping (both directions) of the gear or cam might also be useful.
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VK2TIL
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Posts: 304




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« Reply #4 on: March 10, 2012, 10:18:17 PM »

I've never seen one of these so I looked at the manual;

http://s169.photobucket.com/albums/u205/JohnBartley/RadioInfo/Morris%20Coil%20Winder/

It looks as if the gears have a hub pressed into them; the hub may be brass and the gears may be steel (or vice versa).

Heat may loosen the press-fit between the gear and the hub; levering/pulling on the gear may have the same effect.

There is no single solution for this kind of problem; certainly try a few of the penetrating oils that are designed for this kind of problem.  Kroil has a good reputation.

Loctite has several kinds including Freeze & Release; talk to someone who sells this kind of thing to professionals, not to a hardware salesman.

To avoid putting strain on the gear, get a long (about 2 -3 inch) bolt & nut with the same thread as the retaining screws; screw it into the hub but not all the way, tighten the nut gently as a locknut and you will have a "handle".

But still be gentle; you just have to keep at this kind of problem until you solve it. 

Remember La Fontaine; "Patience et longueur de temps
font plus que force ni que rage
".
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W5FYI
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Posts: 1044




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« Reply #5 on: March 11, 2012, 01:14:08 AM »

"It's supposed to penetrate an opening of 1,000,000"."  Heck, Dallas, Texas, would penetrate an opening of 1,000,000"! Wink

Auto parts stores have several penetrating lubricants that should work for you. I've had good results using "PB Fabulous Blaster" to unstick stuck parts.

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KB1WSY
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Posts: 608




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« Reply #6 on: March 11, 2012, 04:01:37 PM »

Success! I went to auto parts stores and bought three products in increasing order of aggressiveness (except Kroil, which I could not find). And the winner is: the least aggressive product, "WD-40 Rust Penetrant Spray" (this is not the regular WD-40). I applied it in several rounds and let it soak in, then gently knocked the shafts with a hammer and the gears came off. Phew. Thanks for all your advice, I really thought I was going to need a more drastic remedy.

73 de Martin, KB1WSY
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K9YLI
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Posts: 846




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« Reply #7 on: March 17, 2012, 07:31:20 AM »

problem is solved..  but   the heat trick  is  a working  method.
I heat stuff on  cars  etc  with  propane torch,  nut and bolt both..

then   put  ice cubes on the bolt.. bolt willshrik  faster than the  nut  since  rust does not  conduct  heat very well..  usually  three cucles  will do it.

recent tests  explined in  "FARM SHOW"  MAGAZINE..

  Kroil is the very best......  second is       liquid wrench  by  gunk.
   kroil is  about  $19 a can                         liqluid wrench is  $2.59
pb blaster is  fourth..

home brew  is      50%  acetone  50%   ATF

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K8AXW
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Posts: 3593




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« Reply #8 on: March 17, 2012, 10:01:34 AM »

Quote
"It's supposed to penetrate an opening of 1,000,000"."  Heck, Dallas, Texas, would penetrate an opening of 1,000,000"!


OK, sorry about that!  Should have read:  0.000,000,1 of an inch.
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W5FYI
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Posts: 1044




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« Reply #9 on: March 17, 2012, 11:05:52 AM »

Yeah, I kinda thought so. But it was fun to see how wide a million inches was, vs. a millionth of an inch.
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KK4GER
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Posts: 54




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« Reply #10 on: March 17, 2012, 02:47:10 PM »

Not to be picky, but one millionth of an inch is 0.000001 (1 x 10 to the minus 6)  Smiley
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