Faulty blade bolts...

[john87]

21 minutes ago, tree_beard said:

Id put it down to lack of maintenance... The first blade change on a second hand machine..

 Who knows the history of use and abuse?

 

On an 8"+ capacity high hp machine I'd say that blade is well used and overdue a sharpen.. on a gravity fed garden chipper it's crazy to let it get that mullered, looks like a hire machine

I do.. I bought it from a man who had only used it to do one job in his own garden. It had never been used commercially. The rest of the thing is literally like brand new, it was used for the one job and lived in a garage ever since...

That is why the bolt problem is a big deal.. something like a bolt should not just crack, stretch perhaps if overloaded, but not crack and fail in a brittle manner.. Funny how the other four "seemed" ok..

 

john..

[Will C]

I would say the blade shows the machine has had a hammering and not used as intended, or had done more work than you were led to believe. 
One job? What was it a heap of pallets inc the nails?

 

 

[Moose McAlpine]

Jeeeeeesus. It might be a manufacturing defect. It's one single bolt man! 😂

 

15 years as a mechanic you head might explode if you'd seen some of the defects and failures i've seen and i don't consider any of it particularly shocking.

 

(Have a look at car manufacturer recall campaigns. All sorts of stuff can have issues.)

[john87]

4 minutes ago, Will C said:

I would say the blade shows the machine has had a hammering and not used as intended, or had done more work than you were led to believe. 
One job? What was it a heap of pallets inc the nails?

 

 

I saw the house and land the bloke had and so had no reason to disbelieve him. The rest of the machine is absolutely immaculate, so i do not think it has had a hammering.. Put it this way, the paint inside the chute is not even worn.. They "could" have fed it handfuls of gravel or nuts and bolts!! That is something i will never know obviously.. Might have been pallets!!

 

john..

[tree_beard]

Well, the state of the blade shows pretty clearly someone has been feeding it with things that aren't wood...

[john87]

46 minutes ago, tree_beard said:

Well, the state of the blade shows pretty clearly someone has been feeding it with things that aren't wood...

You could very well be right. Why someone would do that though is beyond me.. Either too much money and not enough sense, or never paid for the thing themselves is all i can think of..

 

john..

[roys]

26 minutes ago, john87 said:

You could very well be right. Why someone would do that though is beyond me.. Either too much money and not enough sense, or never paid for the thing themselves is all i can think of..

 

john..

Or all of the above

[Conor Wright]

18 minutes ago, john87 said:

You could very well be right. Why someone would do that though is beyond me.. Either too much money and not enough sense, or never paid for the thing themselves is all i can think of..

 

john..

To be fair, it takes surprisingly little to knacker a blade. A few bits of gravel, wire, a bit of embedded metal and that's your edge gone, keep feeding it and you'll have blades like what you showed by lunchtime on the first day.(bit of an exaggeration, but not much) Blunt blades add a serious amount of stress to a machine.

As a rule I always check over new machinery for loose bits after a few hours. This "bedding in" scenario is often overlooked and occasionally causes issues such as yours. Although the condition of the blades is a major contributing factor in my opinion.

I reckon you're lucky that it happened as you were changing the blades, not when it was at full revs. 

It's annoying but it's not like these machines are built to aerospace tolerances, they're built down to a weight and price that makes them versatile and affordable. 

 

[john87]

11 hours ago, roys said:

Or all of the above

I would think so too..

 

john..

[john87]

11 hours ago, Conor Wright said:

To be fair, it takes surprisingly little to knacker a blade. A few bits of gravel, wire, a bit of embedded metal and that's your edge gone, keep feeding it and you'll have blades like what you showed by lunchtime on the first day.(bit of an exaggeration, but not much) Blunt blades add a serious amount of stress to a machine.

As a rule I always check over new machinery for loose bits after a few hours. This "bedding in" scenario is often overlooked and occasionally causes issues such as yours. Although the condition of the blades is a major contributing factor in my opinion.

I reckon you're lucky that it happened as you were changing the blades, not when it was at full revs. 

It's annoying but it's not like these machines are built to aerospace tolerances, they're built down to a weight and price that makes them versatile and affordable. 

 

Yes, exactly right, which is why the very first thing i did when i got it was to check the entire thing, new oil, new air filter, i checked the belt tension with a proper belt tension gauge too..

 

I would hate to see what happens if a blade came off; It would destroy the machine in a big way, probably the engine too, as the sudden stop and the flywheel then twists the crank, seen that a few times on rotary mowers..

 

I had to go and help remove what was left of a centrifugal fan exploding once.. It was in a paper mill and was something to do with drying the paper.. The fan broke up and despite the housing being a welded construction of about 10mm thick steel, that was just torn open like a papaer bag.. The one piece that burst out of there, cut completely through a steel beam about a foot deep in the roof of the place, then made a large hole in a brick wall and shot off god knows where. All around was just wrecked.. Someone was walking past at the time. They were untouched, but i bet they crapped themselves!!!

 

john..