I bought an ancient Skil Saw for a few bucks, thinking that I was going
to use it with a metal cutting blade to cut steel plate. (Obligatory
metal content).

When I got it home and plugged it in, the blade spun, but slowly and it
seemed to pick up speed gradually, kind of like a fan, not like circular
saws that I was familiar with. Then I heard and smelled a "pop" in the
cord near the saw, complete with a small burn hole in the cracked
insulation. It tripped the GFI outlet it was plugged into, so my guess
is that there was a short to ground in the cord.

The saw has an AC/DC motor, 12 amps, and is a model 825. My guess is
that it is around 50 years old. It is massive and heavy. It has an 8
inch blade, which seemed unusual to me.

My question is what to do with it. If the only problem was the cord,
that is not a big deal. I could visit my local repair depot and buy a
cord and perhaps brushes. However, the way it wound up slowly made me
think that there was another problem with it. I am not real enthused
about messing around with it if it is not likely to work more or less
right after a little work. What do you think? Should I throw it in the
trash or give it away on Craigs list? Or should I invest a few more
bucks in a cord and hope that solves the problem? I don't want to throw
good money after bad, but perhaps I can get it working right without too
much trouble.

I know a moderate amount about electricity, but am not familiar with
troubleshooting motors. I do have a VOM, and know how to use it.

Richard

If it is a cap start motor, the cap may be dried out at this point. This
will cause the motor to start slow until you hear the click of the switch
cutting out the start cap.
The wiring will be not problem and my favorite source for wire is old
extension cords that have a bad far end on them or cut/rubbed sections in
them. You can put on a short piece of cord as well as many saws and such
come with just a 1' long cord on them.

--
Why do penguins walk so far to get to their nesting grounds?

"Richard Ferguson" wrote in message
...

When I got it home and plugged it in, the blade spun, but slowly and it
seemed to pick up speed gradually, kind of like a fan, not like circular
saws that I was familiar with. Then I heard and smelled a "pop" in the
cord near the saw, complete with a small burn hole in the cracked
insulation. It tripped the GFI outlet it was plugged into, so my guess is
that there was a short to ground in the cord.

The saw has an AC/DC motor, 12 amps, and is a model 825.

If it has an AC/DC motor (what's typically called a "universal motor") then
there is no capacitor start nor centrifugal switch. Universal motors are
fairly simple devices: the only things to check are the brushes, the
commutator, the windings, and the bushings/bearings.

From your description, I'd guess that you have two unrelated problems:

1. The power cord is bad (obviously).

2. Your bushings/bearings are gummed-up or varnished from old oil. That
could account for the slow start.

Have you tried turning the blade by hand (with the saw unplugged of course)?
If it feels stiff or has a lot of drag (like stirring molasses), then you
might be able to solve the problem by disassembling, cleaning, and
re-lubricating.

Of course, if this is the heavy-duty Skill saw with the worm gear drive,
then the problem could be in the gearbox. The oil in there may have turned
gummy, or there may not be much oil at all, or a previous owner may have
packed it with sawdust.

- Michael

On Sat, 22 Oct 2005 21:37:59 GMT, Richard Ferguson
wrote:

I bought an ancient Skil Saw for a few bucks, thinking that I was going
to use it with a metal cutting blade to cut steel plate. (Obligatory
metal content).

When I got it home and plugged it in, the blade spun, but slowly and it
seemed to pick up speed gradually, kind of like a fan, not like circular
saws that I was familiar with. Then I heard and smelled a "pop" in the
cord near the saw, complete with a small burn hole in the cracked
insulation. It tripped the GFI outlet it was plugged into, so my guess
is that there was a short to ground in the cord.

The saw has an AC/DC motor, 12 amps, and is a model 825. My guess is
that it is around 50 years old. It is massive and heavy. It has an 8
inch blade, which seemed unusual to me.

My question is what to do with it. If the only problem was the cord,
that is not a big deal. I could visit my local repair depot and buy a
cord and perhaps brushes. However, the way it wound up slowly made me
think that there was another problem with it. I am not real enthused
about messing around with it if it is not likely to work more or less
right after a little work. What do you think? Should I throw it in the
trash or give it away on Craigs list? Or should I invest a few more
bucks in a cord and hope that solves the problem? I don't want to throw
good money after bad, but perhaps I can get it working right without too
much trouble.


Try a temporary new cord first - a bad cord could cause it to have low
voltage / current- causing it to wind up slowly.
However, the chances are even better on that saw that you have a
shorted armature. If you don't now, you WILL if you use it to cut
metal. The chip exhaust is too close to the armature cooling air
inlet. I've fried a good saw (shorted the armature) cutting aluminum.
Now I only do it with ny Beaver table saw - with drip-proof motor
mounted where it doesn't see many chips.
I know a moderate amount about electricity, but am not familiar with
troubleshooting motors. I do have a VOM, and know how to use it.

Richard

On Sat, 22 Oct 2005 16:24:05 -0700, "Bob May"
wrote:

If it is a cap start motor, the cap may be dried out at this point. This
will cause the motor to start slow until you hear the click of the switch
cutting out the start cap.
The wiring will be not problem and my favorite source for wire is old
extension cords that have a bad far end on them or cut/rubbed sections in
them. You can put on a short piece of cord as well as many saws and such
come with just a 1' long cord on them.

It's a "universal" motor, like all circular saws - so obviously no
cap.

I have done a few of these. Take it apart. Clean well. Polish the
armature. Replace the bearings and brushes. If a worm drive clean out
the gear box and relube.

Bob AZ

"Bob AZ" wrote in message
oups.com...
I have done a few of these. Take it apart. Clean well. Polish the
armature. Replace the bearings and brushes. If a worm drive clean out
the gear box and relube.

Bob AZ


The 825 is a worm drive saw....and I think Bob's advice should do
it....These saws are pretty hard to kill !

Jeff

Thanks to all for the tips. I ended up taking it apart and attaching a
temporary power cord. The coils measured less than one ohm, but both
were about the same. It did nothing at first, but then I unplugged it
and rotated the blade a bit, plugged it in, and it fired right up to
high speed, like a circular saw should, sounded normal. Not sure if I
have a bad spot on the commutator or not, or just needed to seat the
brushes. I will go down to the repair depot next week to buy a
replacement cord, and I should be in business.

It is different to be taking apart old equipment, with cloth insulation
on the wires, everything built like a tank, etc. Not designed for ease
of manufacturing, at least to my eyes. One of the surprises was that the
trigger switch interrupted both hot and neutral, not just the hot side,
but maybe that is more common than I think.

Richard


Richard Ferguson wrote:
I bought an ancient Skil Saw for a few bucks, thinking that I was going
to use it with a metal cutting blade to cut steel plate. (Obligatory
metal content).

When I got it home and plugged it in, the blade spun, but slowly and it
seemed to pick up speed gradually, kind of like a fan, not like circular
saws that I was familiar with. Then I heard and smelled a "pop" in the
cord near the saw, complete with a small burn hole in the cracked
insulation. It tripped the GFI outlet it was plugged into, so my guess
is that there was a short to ground in the cord.

The saw has an AC/DC motor, 12 amps, and is a model 825. My guess is
that it is around 50 years old. It is massive and heavy. It has an 8
inch blade, which seemed unusual to me.

My question is what to do with it. If the only problem was the cord,
that is not a big deal. I could visit my local repair depot and buy a
cord and perhaps brushes. However, the way it wound up slowly made me
think that there was another problem with it. I am not real enthused
about messing around with it if it is not likely to work more or less
right after a little work. What do you think? Should I throw it in the
trash or give it away on Craigs list? Or should I invest a few more
bucks in a cord and hope that solves the problem? I don't want to throw
good money after bad, but perhaps I can get it working right without too
much trouble.

I know a moderate amount about electricity, but am not familiar with
troubleshooting motors. I do have a VOM, and know how to use it.

Richard

Get a longer cord and make it up as necessary. Ace hardware or the
like. The two pole switch is probably because they needed just one
switch type both for 110 and 220.

Bob AZ

Or maybe because it's not a double-insulated saw.

Bob AZ wrote:
Get a longer cord and make it up as necessary. Ace hardware or the
like. The two pole switch is probably because they needed just one
switch type both for 110 and 220.

Bob AZ