First Brake Band fail happened today...

[pining_fir_yew]

So, just how silly should I feel for not catching the wear on this earlier? Second, is this a fairly common point of failure in any one else's experience? I did measure the material width afterwards (.046" or 1.168 mm) which is thinner than the recommended minimum .. but jeez not a whole lot thinner.

it's a 2019 550 XP, the saw sees near daily use, and I don't think the brake band has been replaced up till now. It's also used by multiple people, so I can't promise how well it's being treated.

 

[lone wolf]

So, just how silly should I feel for not catching the wear on this earlier? Second, is this a fairly common point of failure in any one else's experience? I did measure the material width afterwards (.046" or 1.168 mm) which is thinner than the recommended minimum .. but jeez not a whole lot thinner.
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it's a 2019 550 XP, the saw sees near daily use, and I don't think the brake band has been replaced up till now. It's also used by multiple people, so I can't promise how well it's being treated.

I would not say its awfully common in my saws. Now broken brake handles are more common.

 

[pining_fir_yew]

I would not say its awfully common in my saws. Now broken brake handles are more common.

ha I replaced the handle on the 200T only just yesterday

 

[lone wolf]

ha I replaced the handle on the 200T only just yesterday

There it is!

 

[pining_fir_yew]

There it is!

damn these kids sure are rough on stuff....

 

[ammoaddict]

I've never had one wear out, but the only time I use it is when I'm sharpening the chain. I never apply it when the saw is running.

 

[lone wolf]

damn these kids sure are rough on stuff....

You bet.

 

[Bubster]

I filed the drags super low on a full chisel chain once and after about the fifth cut it kicked so hard it broke the brake band. Never knew one to break other than that.

 

[lone wolf]

I filed the drags super low on a full chisel chain once and after about the fifth cut it kicked so hard it broke the brake band. Never knew one to break other than that.

You are lucky that's all that got broken!

 

[pining_fir_yew]

I've never had one wear out, but the only time I use it is when I'm sharpening the chain. I never apply it when the saw is running.

I would hope that no one is doing that...notably, I am not seeing any of the other tell-tale signs that this is a regular occurrence.

 

[pining_fir_yew]

I filed the drags super low on a full chisel chain once and after about the fifth cut it kicked so hard it broke the brake band. Never knew one to break other than that.

yeah, so that's terrifying. lol luckily it happened on start up, the brake was engaged and then suddenly wasn't. i haven't gotten all the details from the operator yet, but from the sound of it, the brake was on, they started the saw and tapped the throttle to engage idle which is when the brake snapped.

I never apply it when the saw is running.

so, either the operator made the recounting a lot more dramatic (they said it was really confusing because the chain started "going") or they were applying throttle (for some reason...) after they started it? what am i missing here? does the idle need to be adjusted down, possibly? causing the chain to rotate on idle with the brake disengaged. that could cause wear over time to the brake band, right?

 

[ammoaddict]

If the chain is turning when saw is idling, then yes idle is too fast. It will turn right after the saw is started and is still on fast idle until you blip the throttle.

 

[pining_fir_yew]

If the chain is turning when saw is idling, then yes idle is too fast. It will turn right after the saw is started and is still on fast idle until you blip the throttle.

That makes sense, thank you.

 

[huskihl]

Crud falls behind the band every time the brake is engaged. Over time it eventually prevents the band from opening far enough and the drum wears on it. It helps to blow it out often. Difficult on that type of saw because it’s tough to engage the brake with the cover off the saw, but that’s the best way to clean it

 

[pining_fir_yew]

Crud falls behind the band every time the brake is engaged. Over time it eventually prevents the band from opening far enough and the drum wears on it. It helps to blow it out often. Difficult on that type of saw because it’s tough to engage the brake with the cover off the saw, but that’s the best way to clean it

Yeah it's something I'm trying to keep on top of but with 15 saws bouncing around it's a battle. I'm in the process of revamping the saw maintenance program around here, but little details like that got passed over for more years than not. I better go check the brake band wear more closely on the other saws now too.

 

[huskihl]

Yeah it's something I'm trying to keep on top of but with 15 saws bouncing around it's a battle. I'm in the process of revamping the saw maintenance program around here, but little details like that got passed over for more years than not. I better go check the brake band wear more closely on the other saws now too.

Given the amount of time you would have in maintenance doing what I suggested earlier, it’s probably as cost-effective to put a new clutch cover on it every XXX hours for $50? $75 and be done with it

 

[sean donato]

If the chain is turning when saw is idling, then yes idle is too fast. It will turn right after the saw is started and is still on fast idle until you blip the throttle.

Don't forget worn or broken clutch springs could cause the chain to rotate at idle as well.

 

[ammoaddict]

It sure can. Had it happen before.

 

[Del_]

I've never had a brake band break but then I don't use the chain brake very often.

I've never replace a clutch shoe either but have replaced a few clutch shoe springs.

 

[pining_fir_yew]

I did measure the material width afterwards (.046" or 1.168 mm) which is thinner than the recommended minimum

WRONG. I was wrong. The minimum is .6 mm - which, I converted to just over 1/64th of an inch (.0236 in) bc I can’t find a metric micrometer (‘Merica). And the thinnest point measures a hair over 1/32. Or .795 mm.

So..what the heck.

Additional note, apparently the brake band snapped after applying a the brake right after a cut - without allowing time for the chain to slow. Which is not unusual. Something of a bad habit among the crew. The click is just too satisfying I guess.

I guess I’m just confused now.