Repair Craftsman electronic radial arm saw?

jm51 · Post by **jm51** » Tue Jun 07, 2011 8:03 am

The 3 legged rectangles look like some form of semiconductor, triac maybe?

tdubnik · Post by **tdubnik** » Tue Jun 07, 2011 8:18 am

jm51 wrote:The 3 legged rectangles look like some form of semiconductor, triac maybe?

Greek to me, maybe?

albie · Post by **albie** » Tue Jun 07, 2011 8:21 am

Hall effect sensor?

JPG · Post by **JPG** » Tue Jun 07, 2011 9:24 am

albie wrote:Hall effect sensor?

Quite likely! The skewed positioning of one is unusual. I assume the round 'magnet' is polarized or at least has a localized magnetic point.

The overload device would 'look normal' after it acted like a fuse. i.e. no visual indication that it has opened . If you have an ohmmeter function on your 'meter', check for continuity across it.

P.S. a resistance measurement across the winding and also the brushes would also be of interest.

dusty · Post by **dusty** » Tue Jun 07, 2011 9:29 am

jm51 wrote:The 3 legged rectangles look like some form of semiconductor, triac maybe?

With regard to the 3 legged rectangles - I do not believe they are three legged. We are being mislead by the photo image and an inability to ascertain where the "three pads" on the circuit board go.

I believe the black rectangles are ceramic capacitors - providing filtering to eliminate noise in the circuit.

dusty · Post by **dusty** » Tue Jun 07, 2011 9:41 am

tdubnik wrote:Greek to me, maybe?

Do the two little black cubes have any identifying markings. If so, it might identify the component - be they capacitors (two leads), hall effects (three leads) or something else.

cincinnati · Post by **cincinnati** » Tue Jun 07, 2011 11:02 am

Just a thought. I bet a electronic repair place (TV, DVD, etc) could find the problem for you.

beeg · Post by **beeg** » Tue Jun 07, 2011 11:54 am

Your sure the UP/DOWN switch is okay?

JPG · Post by **JPG** » Tue Jun 07, 2011 2:35 pm

After looking some more at the pix, I believe the motor 'windings(there are two) are connected in series, and the overload device is connected between them. i.e. brown wire to winding a, black wire to winding b, and overload device connects the other ends of both winding a and b .

IMHO the input is not ac, but unfiltered dc and the polarity is reversed for direction. If ac were applied the motor would be reversing direction 120 times/second.(makes a decent brake, but kinda hard on the motor if high currents result).

tdubnik · Post by **tdubnik** » Tue Jun 07, 2011 2:59 pm

I think I've decided that I'm tired of fooling around with this saw. It's been out of service for over 3 years and I do OK without it. The reason I started tinkering with it is because every time I went into my shop it bugged me that it is sitting there taking up space and not contributing.

When I check Craigs List, I can find working Craftsman radial saws in the $100 to $150 range all the time. If I decide I want one in the future I'll go that route.

With that being said; If anyone on this forum wants this saw for FREE and is willing to drive the town of Talmo in north Georgia; then it's yours.

If you are interested, send me a PM.