loose blade broke my chipper

[Dean O]

Just a reminder to all to check for correct blade tightness.

 

It seems that the likely cause of a big repair bill may have been a recently changed blade in our tw150.

 

It shattered having hit the anvil, bending the rotor housing, sheering the shaft in the process, and disintergrating the pocket the blade sits in.

 

It was only on putting the chipper back together that it was realised that the housing was bent.

Unfortunately it now has to be stripped down again and rebuilt with a new housing.

 

I havent had the postmortem back yet but I think loose bolts may have allowed the blade to move away from the pocket slightly.

 

I'm hoping that TW will get the part there ASAP to lessen the pain as I'm told parts alone are likely to be around £2200+VAT.

 

With the exception of the birth of my second little one its been a bit of an unlucky year so far

 

Boo hoo

 

can only get better

[Le Sanglier]

Good shout

Same happened to me but I was lucky, just cost me the pocket, turned the anvil changed the bearings while we were there.

Blades had been in for ages 'cos they had stayed sharp.

[Pete Hart]

Thank you for the heads up deano. That sounds like a nightmare.

I'm always very careful when I change the blades on my wolf to set the torque wrench to the correct Newton metres. 62 or 60 nm off the top off my head (I'll check the manual as I need to change them this weekend!).

 

Sorry to hear about your bad luck. Spring is round the corner, keep going, onwards and upwards! Last year was a complete disaster for me but 2013 seems to be better so far!

 

 

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[Breezeblock]

when you are fitting blades smear loctite between the pocket and the back of the blade on the two faces and bolt it together and make sure they are spotlessly clean to stop the fretting

[doobin]

Agreed. I had a blade come loose on a little Briggs chipper/shredder. It opened up the 3mm steel rotor housing like a tin opener!

[Dean O]

just a quick update - apparently genuine TW blades would not of caused this problem - as they "would never shatter".

 

The blades were from a well known source.

 

I'm not sure that it was the shattering that caused the problem or the loose bolts tho so still a heads up on torque settings.

[Shane]

just a quick update - apparently genuine TW blades would not of caused this problem - as they "would never shatter".

 

The blades were from a well known source.

 

I'm not sure that it was the shattering that caused the problem or the loose bolts tho so still a heads up on torque settings.

 

I wonder if they can really claim that. Think of the stress a loose blade is under when it hits the anvil with the force of the flywheel behind it - That would take some pasting. What do they do to their blades so they can claim they WILL NOT SHATTER I don't believe it myself. Are there any metallurgists here?

 

Didn't TW have some legal gripe a few years ago about pattern blades??

[GlobalNewark]

Not sure what TW's policy is but we recommend a blade bolt is never used more than three times as even when torqued correctly they will still stretch. We have had blades come off due to stretched bolts but luckily we only suffer dents.