Ripper 37 Blades breaking on weld

[Youngstu]

1 minute ago, trigger_andy said:

Define "quite a bit of cutting"  from an almost one year old blade,

Probably 3 16ft larch logs into 2x4 and 2x6 over the last week. It was still cutting well until it snapped. 

[trigger_andy]

3 minutes ago, Youngstu said:

Probably 3 16ft larch logs into 2x4 and 2x6 over the last week. It was still cutting well until it snapped. 

That’s one band or all three?

 

If one band that’s a lot cutting. 4m+ multiple times in one sappy log. 
 

Id suggest some kitchen cleaner like Detol or Flash in your lube as a cleaner/friction reducer when milling Larch/DF. 

[Youngstu]

2 minutes ago, trigger_andy said:

That’s one band or all three?

 

If one band that’s a lot cutting. 4m+ multiple times in one sappy log. 
 

Id suggest some kitchen cleaner like Detol or Flash in your lube as a cleaner/friction reducer when milling Larch/DF. 

Over the last year I've milled about 30 tonnes of larch. I've worked through plenty of blades, some have ended up very sappy, some pretty blunt before changing without any other issues, but I've now had three from one pack of blades break on the weld for no apparent reason. When they broke the blade was appropriately lubricated, they were not sappy, or blunt or going through anything unusual, they just snapped without any warning. 

 

[trigger_andy]

7 minutes ago, Youngstu said:

Over the last year I've milled about 30 tonnes of larch. I've worked through plenty of blades, some have ended up very sappy, some pretty blunt before changing without any other issues, but I've now had three from one pack of blades break on the weld for no apparent reason. When they broke the blade was appropriately lubricated, they were not sappy, or blunt or going through anything unusual, they just snapped without any warning. 

 

If you’ve worked through 30t of larch in the last 12 months it’s a little odd you’ve only just started on a batch of ‘37’s. I guess we all have our own rotation policy. 
 

You’re clearly intelligent so no point in telling you to suck eggs. If you’ve done everything correctly then perhaps you’re “that guy” with a bad batch? 
 

 

[Stubby]

8 hours ago, Youngstu said:

 

I'm not really up on metal treatment etc, would I be right in assuming that this would improve a poorly finished weld and do no harm to one that should be ok anyway.

Thanks very much for the helpful responses Stubby and Khriss. 

When the bands are welded together if they cool too quickly the area around the weld will become harder therefor more brittle . When the rest of the softer more forgiving part of the band passes through the timber any knots deviations sideways forces are absorbed by it i until you get to the weld it can then snap . You just need to anneal the weld area . This will soften the hardened teeth but only 2 or 3 in the weld area . 

Edited June 26, 2021 by Stubby

[Youngstu]

1 hour ago, Stubby said:

When the bands are welded together if they cool too quickly the area around the weld will become harder therefor more brittle . When the rest of the softer more forgiving part of the band passes through the timber any knots deviations sideways forces are absorbed by it i until you get to the weld it can then snap . You just need to anneal the weld area . This will soften the hardened teeth but only 2 or 3 in the weld area . 

Thanks for that Stubby.

I'll see if the same thing happens to the current one, if it does I'll give it a go on the next. I assume there's no definite way of knowing beforehand whether or not this process has been done wrong or testing the hardness of the different parts of the blade without particular tools/equipment.

Thanks again

[Watercourse management]

If you do re anneal the band support it well either side otherwise as you heat it it can bend very easily.

[Johnsond]

I’d be inclined to get in touch with the supplier rather than try a home fix even though annealing is not exactly rocket science, 3 from the same batch would strongly  suggest a QC issue. I never had any issues at all with 37s on the 130. 

[openspaceman]

I never did enough milling to experience a band snapping but in 1974  I was assisting Eric on the forestor horizontal mill and he was explaining  how a band jumped off and sliced a chap in half so I kept my distance after.

[gobbypunk]

Sounds like an iffy batch of 37,s to me apart from having to re tension from the factory settings on band tension I have not had this happen on either of my hm130,s if you go back to your supplier he may send you some replacement ones ,Hope you get it sorted 

  Cheers. Mark