Circular saw running backwards

[WhiteD3]

All,

I have a Makita model 5008B 210mm powered circular saw that has been a faithful and reliable servant for 28 years.

I went to use it today and found that the blade is spinning backward. This is a double insulated saw which I use maybe once a year these days. Last time I used it would have been over a year ago and it worked fine.

I have checked the polarity on the GPO. As far as I can recall it have never been worked on and has the original lead and plug. One thing that may be related is that it is leaking 30vac to the metal shield.

I'm about to toss it out for safety's sake but some insights would be educational.

Cheers.

[d@rk51d3]

Could always just flip the blade around the right way. :D

[scarry]

More than likely a short in the windings,could be a faulty capaciter if it has one.If you can get to the cap,and have a meter that can test it,do that first.If it is OK,windings are stuffed,bin it.

And if it has leakage to frame,is windings for sure,there is a danger factor here,so don't use it.

[goingbush]

All,

I have a Makita model 5008B 210mm powered circular saw that has been a faithful and reliable servant for 28 years.

I went to use it today and found that the blade is spinning backward. This is a double insulated saw which I use maybe once a year these days. Last time I used it would have been over a year ago and it worked fine.

I have checked the polarity on the GPO. As far as I can recall it have never been worked on and has the original lead and plug. One thing that may be related is that it is leaking 30vac to the metal shield.

I'm about to toss it out for safety's sake but some insights would be educational.

Cheers.

AC is not polarity conscious, does not matter which way its hooked up , infact it changes polarity 50 times every second anyway (alternatig current)

try stalling it and see if it starts up the other way. (jam it in a saw cut)

I often put a circular blade on backwards to cut corrugated iron, works a treat.

[Homestar]

A series wound motor will run in one direction only if is working correctly. I would doubt it would be a cap start motor, the brushes on these sort of motors are offset so they start spinning - and the correct way.

As mentioned above, a winding fault could cause this. If it is leaking voltage as well I'd bin it - and cut the lead off so no one else can be hurt by it.

[blitz]

please don't get offended by what is possibly a silly question, you haven't put the blade in backwards? looking at it from the blade side it should be turning in an anti clockwise direction.

these motors are a universal motor as they have brushes so it wont have a start winding or capacitors

[WhiteD3]

The direction issue was solved with the culprit being the idiot operator :angel:

The leakage to the chassis was and is a worry so the saw is still sitting on my workbench send me subliminal "help" messages. I've had that saw for 27 years; longer than the Mrs and the kids.

[superquag]

The direction issue was solved with the culprit being the idiot operator :angel:

.

An honest idiot, so all is not lost. :D