Did I kill my Makita circular saw?

[damiansd]

I made a big mistake and cut some wet timber on the weekend. In the process I think I killed my circular saw.

Whenever the saw cuts now, it billow smoke out around the blade. The blade is all blackened now too, I assume from spinning too slowly and not cutting but attempting to grind.

I assume the motor is done for. Hopefully you'll tell me I'm wrong.

As a check, here are the brushes for the saw. They look fine to me.

Tell me the bad news...

Damian.

 

[TireTracks]

Blade dull?

Smoke from the blade, and the blade being black means your buring the wood, not cutting it and the blade is getting HOT!.Blade is dull in that case,
. When you smoke a motor, it's horrible acrid smelling smoke, and you only do it once.

Got another blade to use? Mabey post a pic of the saw?

 

[damiansd]

I tried a brand new blade and same result. Here they are.

Here is the saw.

Here is the manufacturer plate.

Thoughts?

 

[neophyte]

Where you trying to cut a type of softwood typically used for building construction, or were you trying to cut some type of ultra hard piece of native Australian timber. If you were trying to cut a wet section of native Australian timber, some of those woods are extremely hard, and might cause blade burning, especially if the wood warped during the cut.

As for the saw. Have you tried running it without the blade on, and did it look like it worked OK? Do you have any dry scrap plywood or particle board you can run the saw thru to test whether the saw, and the blade are still able to cut light material.

 

[uart]

It doesn't sound like a burnt motor. As TireTracks says, a burnt motor has a very distinctive small, plus the smoke would come from the motor not the blade, plus it would heat up really bad and soon stop working.

It sounds like it's just the wood getting too hot during cutting. It may be the type of wood you're cutting.

 

[damiansd]

I trialled cutting some super soft pine and I get the same result. Seems anytime the motor has torque applied to it, the smoke starts.

 

[uart]

Are you sure the smoke is coming from the blade and not the motor? Once the motor starts smoking it normally wouldn't last long and you'd certainly know about it.

 

[neophyte]

You may have let the "magic smoke" out.

 

[damiansd]

I assume when the blade spins it pulls the smoke from the engine. Magic smoke bye bye. :'(

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[Haukur]

Did the guard get full of wet saw dust? Is the bearing for the blade shaft clean and lubed, or full of sawdust?

 

[dadsEH]

Its a Makita.... what did you expect?
Seriously, you're having a lend , right?

 

[Mohawk Dave]

both those blades are burning up. I see the rough blade is missing a bunch of teeth. Are you running them backwards?

 

[Pumpman1968]

You may have let the "magic smoke" out.

Yeah........once you let the factory smoke out of the motor, it's usually all over.

 

[Rust]

both those blades are burning up. I see the rough blade is missing a bunch of teeth. Are you running them backwards?

^this

Ive had a makita saw for 20+ years..dropped it from 2 story roofs..abused the snot out of it and it still purrs...now its my dedicated masonry saw.

I've tried to kill it, and couldn't.

 

[uart]

Are you running them backwards?

Man it would be funny if that's the reason.

 

[tarbellb]

Sounds more like a blade not spinning freely. Run it w/o a blade. Then......

I would really look to see is there is any residual wood chips/dust in the guard area. The blade could be gumming up in somewhere. Next I would see if you knocked something out of alignment?

 

[ctb]

If the smoke's blue you're burning the wood.
Don't know how much experience you have with running a circular saw, but if you're new at it it's a common mistake to install the blade backwards. That's what your symptoms sound like.
Another thing could be running the saw from too long an extension cord, robbing you of power.

 

[b7labelle]

Man it would be funny if that's the reason.

My neighbor found out for the last 10 years his mower blades were on backwards, yet the mower still cut decently well...

Though with being able to see the blade on this tool.....i doubt this is the case. However a small part of me is still hoping its on backwards.

 

[PugetDude]

Try a new blade, make sure it is running in the right direction (Counterclockwise when looking at the blade on that sidewinder saw).
From the smear patterns on the pitch deposits, it looks like the blades might be installed backwards...

 

[-Brent-]

I'm betting it's not the motor, sounds like the blade clutch.

 

[damiansd]

I will disassemble today and let you know.

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[Hiball]

Those Brushes look Good, Im betting the blade is on backwards.. Been there done that.

 

[Hawk]

Show us a pic of the blade installed as you used it.

 

[damiansd]

All right. Thanks all for the diagnosis.

First up, I span up the saw without the blades and it was fine. No smoke. Next up, check the blade direction and it was right (that could have been embarrassing). Span up with no smoke. Then I cut some light weight pine and the smoke returned.

With all the comments you had me worried. I hadn't touched the blade from factory. Thankfully they had done it right. I don't think I loaded the new blade the wrong way, but it is possible.

Finally I got the compressed air in to clean out all the old sawdust. I didn't see an awful lot come out, but there was some.

Then I fired it up again and that fixed it. No smoke!

Thanks for the many replies. I'm not going to assume all is ok yet, I'll give it a better spruce up.

Thanks heaps,
Damian.

 

[damiansd]

A link to a video of the blade direction.

 

[Hiball]

A link to a video of the blade direction.

Private video.

 

[damiansd]

Fixed - sorry.

 

[Hiball]

Blade direction looks good based off the video. Any kind of play/Deflection on the Shaft when you install the blade?

 

[PugetDude]

Clean all the pitch off the blade and see if that helps.