Chain brake?

[tiredone]

Working on my PM-340 McCulloh, I found a steel band that wraps around the clutch, like a brake band. I've used electric saws and rentals in the past but never had a brake that I knew of. Could folks explain how this is used while cutting and trimming? I gather it activates through the guard handle on the front, but as a noob, I have no idea of proper operation. I'd like to understand safe operation of the saw. I friend cut his hand open with an electric saw when he cut beneath a branch with the top of the bar which caused the saw to jump. He blamed it on underpowered equipment. I blamed it on misuse. If there is a safety FAQ other than common sense, send me the right direction.

 

[Four Paws]

Consult your operators manual for an explanation, and possibly even a pictoral view of how the brake works. Basically, if the saw kicks back, your leading (left hand) will contact the chain brake handle and activate the brake. Pull the handle back towards you to reset it. Adjust the band so when activated, the saw can't spin the chain from idle when the throttle is applied.

 

[tiredone]

Thanks! I don't have a manual since I picked up this very old saw used. Today I put in a new clutch and cleaned the oily sawdust out of the brake. The handle you describe has a detented operation. So as you say, if it goes forward, it toggles and the chain stops. Thanks for your explanation. I have the saw in nice condition now.

 

[younggun]

the brake is also supposed to engage from the Inertia of a kickback if your hand cant (such as when making a back cut wile felling)

Edit: fixed it

 

[Sprig]

What the heck was that word lol, inursua? Inertia? Gah, doesn't anyone around her use 'Spellcheck' ? any more than less discomjbobulatshuns.

:bang:

:rockn: :rockn: :rockn: serge

 

[younggun]

kinda hard to use spell check when the original is so miss spelled it doesn't recognize it as any thing close. No wonder I never passed a spelling test in skool.

 

[cbfarmall]

kinda hard to use spell check when the original is so miss spelled it doesn't recognize it as any thing close. No wonder I never passed a spelling test in skool.

What's even funnier is that you also misspelled 'wile' in that same sentence.

Don't worry. My tendency is to forget whole words. My thoughts get ahead of my typing.

Chris B.

 

[GASoline71]

kinda hard to use spell check when the original is so miss spelled it doesn't recognize it as any thing close. No wonder I never passed a spelling test in skool.

It's okay dood... ther have always been lot's of ex-grammar teechers hear.:hmm3grin2orange:

Gary

 

[hamradio]

I was going to comment on the spelling, but I figured I'd keep my mouth shut.

 

[maveric944]

Thanks! I don't have a manual since I picked up this very old saw used. Today I put in a new clutch and cleaned the oily sawdust out of the brake. The handle you describe has a detented operation. So as you say, if it goes forward, it toggles and the chain stops. Thanks for your explanation. I have the saw in nice condition now.

hi tiredone, i'm a newbie with chainsaws and have just aquired my first, its a mac timberbear 849. i have serviced it and every thing runs fine apart from the clutch which will not dissingage at low revs. how is the clutch drive unit removed from the shaft, is it a press fit or left hand thread. any help would be much appreciated. thanks mav

 

[Sprig]

Hiya maveric944 and welcome to AS. Just a quick thought/ stab inna dark here before you start taking things apart, have you tried to slow the saw down a tad with your idle adjustment (throttle) screw? Could be its just a tad out (idling too fast), turn it out slowly till the chain stops, if the saw stops first maybe it is a bit gummy in there (clutch shoes sticky, bad terminology lol gah), try that first as the clutches are centrifical. To the best of my knowlege most clutches are on a keyed and slightly tapered shaft, the nut holding it there would be reverse threaded (tightening opposite of the chain's direction) removing requires a puller most times and as usual I definately stand here to be corrected.



Serge

 

[maveric944]

hi sprig, ive slowed it down till it just about stalls and the chain still turns, i need to strip the clutch down to check it over, or try and get a replacement. thanks for the info, will have a go at removing later when i get home.

thanks mav

 

[SawTroll]

It's okay dood... ther have always been lot's of ex-grammar teechers hear.:hmm3grin2orange:

Gary

PBtree may be able to help him.....:biggrinbounce2:

 

[maveric944]

hi guys got clutch off ok,, left hand threaded, broken spring on the centrifugal clutch bit, thanks for the help,

mav

 

[Sprig]

Gald to hear that maveric, cheers mate! I really have my dithers about those wrap-around spring setups for clutches, they seem to be a pain, but for the most ( according to folks around here) they work well, replacement is a bit of a trial till you've done it once or twice. Have good safe fun/work with yer beast once she be running!!!



Serge

small edit here>
and oh, before you assemble your clutch clean the pawls and housing with a bit of ISO and if a bit rusty I think some nice wet/dry (used dry eh) 120 grit to touch things up would work well for you. assssss usual, there may be better suggestions out there in the 'wiseones' envelope (jk guys). I am not correcting 'gald' but I meant glad, gald just seems funnier.......GAH!

 

[maveric944]

sprig,, in the uk this saw is obsolete so i couldnt replace any of the parts, but with a bit of make do and mend every thing is working as it should, already getting the urge to go out and but a new one this weekend, just have to sneak it in the workshop so the wife dont find out. thanks again to all,

mav

 

[(WLL)]

Working on my PM-340 McCulloh, I found a steel band that wraps around the clutch, like a brake band. I've used electric saws and rentals in the past but never had a brake that I knew of. Could folks explain how this is used while cutting and trimming? I gather it activates through the guard handle on the front, but as a noob, I have no idea of proper operation. I'd like to understand safe operation of the saw. I friend cut his hand open with an electric saw when he cut beneath a branch with the top of the bar which caused the saw to jump. He blamed it on underpowered equipment. I blamed it on misuse. If there is a safety FAQ other than common sense, send me the right direction.

always keep both hands on saw always apply break whenever saw is running and not cutting make this a good habbit

 

[Urbicide]

If there is a safety FAQ other than common sense, send me the right direction.

Here are some links for some information that may be of use to you.

http://www.usa.husqvarna.com/files/cs/banners/chainsaw_cons.pdf

http://www.tiltonequipment.com/ChainSawOperatorsSafetyManual.pdf

http://www.osha.gov/SLTC/etools/logging/mainpage.html

 

[maveric944]

thanks for the advice WLL, i need all i can get,, dont fancy makin the wife a widow just yet,,lol. Urbicide many thanks for the links i have printed them off and they are now in the workshop to keep with the saw. i got the saw to cut up logs for my wood stove in the workshop, its my retreat away from the wife and kids, . i just love the feeling of using the saw,, don't know why but i just do. thanks again you guys for the help, and would like to say what a great forum,,, nothing like it in the UK.


mav