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-   -   Belt sander: Smoke escape! (https://www.diybanter.com/metalworking/234087-belt-sander-smoke-escape.html)

Dave, I can't do that February 18th 08 01:24 AM

Belt sander: Smoke escape!
 
Hi people,

I have an old HF 4" x 36" belt sander that has provided probably 12
years of reliable service. This afternoon, just when I really needed
it, smoke escaped from the switch at turn on.

The motor and everything else works fine but the switch is mushy and
smelly.

This is an older unit and does NOT have a cap-can on the outside of
the motor. Instead it has a small device with a coil of quite heavy
copper and a black bakelite surroundings. I assume this is some sort
of delay for rotation direction at start up.

I thought I'd just buy another one but even HF want $70-bucks and a
little out of my league at the moment. Can someone please tell me how
to wire a switch into this thing?

I think the little coil and bakalite thing are OK as the smoke came
out of the switch itself and now it feels like there is nothing inside
the switch..

I have a picture of the setup but not sure where to post it.

Dave

Winston February 18th 08 01:42 AM

Belt sander: Smoke escape!
 
Dave, I can't do that wrote:
Hi people,

I have an old HF 4" x 36" belt sander that has provided probably 12
years of reliable service. This afternoon, just when I really needed
it, smoke escaped from the switch at turn on.


Does it look like:
http://www.harborfreight.com/manuals...3999/93981.pdf

You could order a replacement switch:
1-800-444-3353

Prepare to wait ~30 - 45 days.

--Winston

Winston February 18th 08 01:44 AM

Belt sander: Smoke escape!
 
Dave, I can't do that wrote:

(...)
I have a picture of the setup but not sure where to post it.


http://www.metalworking.com/dropbox.html

--Winston

RoyJ February 18th 08 03:50 AM

Belt sander: Smoke escape!
 
To check out your switch theory, remove the remains of the switch, tie
the two wires to the switch together, see if the unit starts up and runs
normally. If that works you can order the parts from HF (use the new
model number, the switch is pretty much a universal fit) or you can
replace the switch with an aluminum plate and a heavy duty toggle
switch. You want a SPST switch rated at least 10 amps, 20 amps would be
better for a motor circuit.

Dave, I can't do that wrote:
Hi people,

I have an old HF 4" x 36" belt sander that has provided probably 12
years of reliable service. This afternoon, just when I really needed
it, smoke escaped from the switch at turn on.

The motor and everything else works fine but the switch is mushy and
smelly.

This is an older unit and does NOT have a cap-can on the outside of
the motor. Instead it has a small device with a coil of quite heavy
copper and a black bakelite surroundings. I assume this is some sort
of delay for rotation direction at start up.

I thought I'd just buy another one but even HF want $70-bucks and a
little out of my league at the moment. Can someone please tell me how
to wire a switch into this thing?

I think the little coil and bakalite thing are OK as the smoke came
out of the switch itself and now it feels like there is nothing inside
the switch..

I have a picture of the setup but not sure where to post it.

Dave


Dave, I can't do that February 18th 08 05:10 PM

Belt sander: Smoke escape!
 
Hi Roy and others,

Thanks for the replies, but I had already checked HF's manual. I
mentioned the NO cap-can as this is not a cap start motor. The switch
HF shows is a simple two wire thing that I could easily manage to
fudge around.

I have uploaded the pic to the drop box and you can see the switch has
4 connectors to integrate the coil thing into the circuit.

The main lead at the bottom is the power lead coming in and the Blue,
Brown, Black and Ground lead goes to the motor.

The top two terminals on the switch (Red and Black) are bolted to the
switch body so I assume they are carrying big current, the bottom two
(White and Black) are riveted.

Unless I can get some other information I will assume that the Black/
Black make contact and the White/Red but can't be sure as the switch
is fried totally.

Dave

Dave, I can't do that February 18th 08 10:30 PM

Belt sander: Smoke escape! : MORE Smoke {grin}
 
OK, replying to my own postings.

Unless I can get some other information I will assume that the Black/
Black make contact and the White/Red but can't be sure as the switch


I guess the switch had some different internal wiring. I plugged in a
10A DPDT switch I had lying around. The lights dimmed the motor ran. I
put a clip-on meter and it was drawing 18+ Amps! Hasty turn off as a
wisp of smoke curled out of the back of the motor.

looks like a scrap job to me unless I can find a cap start motor to
fit in the available space. {sigh}

Dave

Gerald Miller February 19th 08 02:00 AM

Belt sander: Smoke escape!
 
On Mon, 18 Feb 2008 08:10:13 -0800 (PST), "Dave, I can't do that"
wrote:

Hi Roy and others,

Thanks for the replies, but I had already checked HF's manual. I
mentioned the NO cap-can as this is not a cap start motor. The switch
HF shows is a simple two wire thing that I could easily manage to
fudge around.

I have uploaded the pic to the drop box and you can see the switch has
4 connectors to integrate the coil thing into the circuit.

The main lead at the bottom is the power lead coming in and the Blue,
Brown, Black and Ground lead goes to the motor.

The top two terminals on the switch (Red and Black) are bolted to the
switch body so I assume they are carrying big current, the bottom two
(White and Black) are riveted.

Unless I can get some other information I will assume that the Black/
Black make contact and the White/Red but can't be sure as the switch
is fried totally.

Dave

What you have there is a current activated relay which energizes the
start winding on turn-on, then, once the motor is turning, the run
winding current decreases to the point where the solenoid releases,
disconnecting the start winding; this relay appears to be combined
with the on/off switch. These relays are commonly found on sealed unit
refrigeration compressors where it is not convenient to use a
mechanically actuated start switch.
Gerry :-)}
London, Canada

Gerald Miller February 19th 08 02:14 AM

Belt sander: Smoke escape!
 
On Mon, 18 Feb 2008 20:00:52 -0500, Gerald Miller
wrote:

On Mon, 18 Feb 2008 08:10:13 -0800 (PST), "Dave, I can't do that"
wrote:

Hi Roy and others,

Thanks for the replies, but I had already checked HF's manual. I
mentioned the NO cap-can as this is not a cap start motor. The switch
HF shows is a simple two wire thing that I could easily manage to
fudge around.

I have uploaded the pic to the drop box and you can see the switch has
4 connectors to integrate the coil thing into the circuit.

The main lead at the bottom is the power lead coming in and the Blue,
Brown, Black and Ground lead goes to the motor.

The top two terminals on the switch (Red and Black) are bolted to the
switch body so I assume they are carrying big current, the bottom two
(White and Black) are riveted.

Unless I can get some other information I will assume that the Black/
Black make contact and the White/Red but can't be sure as the switch
is fried totally.

Dave

What you have there is a current activated relay which energizes the
start winding on turn-on, then, once the motor is turning, the run
winding current decreases to the point where the solenoid releases,
disconnecting the start winding; this relay appears to be combined
with the on/off switch. These relays are commonly found on sealed unit
refrigeration compressors where it is not convenient to use a
mechanically actuated start switch.
Gerry :-)}
London, Canada

You just might get away with separate components, go see your
appliance parts shop.
Gerry :-)}
London, Canada

Dave, I can't do that February 19th 08 04:51 PM

Belt sander: Smoke escape!
 
Thanks Gerald,

All a little too late, as you suggested, I think there was something
in the switch that went with the relay. When I tried a conventional
DPDT switch, got 18 Amp draw to the motor and shortly thereafter, more
smoke. Ahh well. It served it's life well.

In fact I bought this at a HF sidewalk sale the used to have twice a
year at Thousand Oaks. It had dropped-damage and I got it for about 15-
bucks as I recall. I also bought one of the 4-1/2" x 7" bandsaws with
drop-damage for 50-bucks, and it still goes today. It must have done
5,000 hours and still it keeps on keeping on.

So much for those HF knockers, some of their stuff is good, not all,
but some. {grin}

Thanks for the suggestions anyway.

Dave

DoN. Nichols February 20th 08 06:43 AM

Belt sander: Smoke escape!
 
On 2008-02-19, Dave, I can't do that wrote:
Thanks Gerald,

All a little too late, as you suggested, I think there was something
in the switch that went with the relay. When I tried a conventional
DPDT switch, got 18 Amp draw to the motor and shortly thereafter, more
smoke. Ahh well. It served it's life well.


It might not be dead yet -- a short bit of smoke from the
windings is not always a sign of it dying -- though if you let it run
too long, it will die.

Two possibilities:

1) Bearings or drag somewhere in the mechanism, so the motor is
having to work a lot harder than normal.

2) As someone else mentioned, a current relay which is supposed to
switch off a start winding of some form is not working -- welded
contacts or debris (swarf) keeping the armature from moving to
break the circuit.

But -- it might be time to replace it anyway.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Dave, I can't do that February 21st 08 05:58 PM

Belt sander: Smoke escape!
 
Thanks Don,

The motor spins freely, I suspect the 18A problem was something to do
with the switch/Relay combo. Maybe using just the start winding when I
wired in a conventional switch.

The motor works fine if I just connect direct to the two main wires,
it is just that I can't guarantee direction. {grin} Not all that good
for a belt sander. The motor obviously does not have a centrifgual
start-switch so I can't just add a start cap.

Perhaps you are right, time to replace it. Bummer. The best 15-bucks I
ever spent.

Dave


DoN. Nichols February 23rd 08 03:11 AM

Belt sander: Smoke escape!
 
On 2008-02-21, Dave, I can't do that wrote:
Thanks Don,

The motor spins freely, I suspect the 18A problem was something to do
with the switch/Relay combo. Maybe using just the start winding when I
wired in a conventional switch.


Was the original switch provided with more than one pair of
terminals? Is there a mechanical linkage to the relay? If neither is
the case, I suspect that it is a problem with the relay itself. Either
welded contacts or a build-up of sandings to keep the armature from
moving, in which case it is applying power to the start winding full
time -- or never.

The motor works fine if I just connect direct to the two main wires,
it is just that I can't guarantee direction. {grin} Not all that good
for a belt sander. The motor obviously does not have a centrifgual
start-switch so I can't just add a start cap.


So -- dig into the relay and see what isn't working there.

Perhaps you are right, time to replace it. Bummer. The best 15-bucks I
ever spent.


Worth a try with the relay at least.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---


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