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Fings wot broke

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I broke a crowbar:blushing::confused1:

 

Did the wee tack of weld upset the temper or sommat, it literally snapped when I first took the weight of the 0.5m3 billet bundle, guessing an abs max 300-400kg.

 

Perhaps better to buy a bale spike.

 

I will first try boxing around (after first removing) the stub, then only welding at the back, leaving the front merely supported by the 30mm dia hole, which had been my plan, but I got lazy/hasty to try it out.

 

P.S.

The 4 tack welds were each done at timed intervals so as not to unduly risk softening the crowbar by tempering it, the last thing I expected was an overhard brittle failure.

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597674ccb13e5_DSC00029brokenbalespikeforarbforum.jpg.fbb6be3c9e40335e81862d4816c520c1.jpg

Edited by difflock

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It doesn't soften it makes it brittle, look up hydrogen embrittlement. A thicker piece of ordinary mild steel would probably work better as it doesn't temper.

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Thanks Peatff, I was vaugely aware of this phenomena, I did not imagine it would/could be so definitive, or so critical or fast acting I suppose.

I then take it, that this is what is so special about Hardox, being readily weldable, despite being high strength.

But on reflection I was, for whatever reason, unwilling to weld, but I thought I ud get away with a teensy weensy little bit, BUGGER, should have listened to my male intuitions.

cheers

mth

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I don't think the weld changed anything, I think it was just a very brittle bar, that would have snapped without the weld.

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I don't think the weld changed anything, I think it was just a very brittle bar, that would have snapped without the weld.

 

It only needs to affect a bit of the bar not all the way through, once you create a stress riser it makes it a weak point if that's where all the weight is concentrated. It would probably have gone anyway but the weld won't have helped matters.

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"Stress propagation at the root of a crack"

being the title of some homework I remember doing for Structural Analysis.

The reason gun action parts were finished with all those overlapping circles, so that the cracks could not propagate, if I recall.

cheers

mth

Anyway got it sussed, a ground in notch will suffice to hold a welded on locking tab, at the unstressed rear.

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I have a similar tool for moving turf found the best bar was the axle from a old set of Cambridge rolls welded at the rear like yours but just fed through the front hole

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A good local Ag Engineer friend of mine used to make 'C' hooks out of axle shafts as the steel was very resilient. Never saw one break or stretch but the risk assessment on using un tested fixings like that would never allow it nowadays!:sneaky2:

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A good local Ag Engineer friend of mine used to make 'C' hooks out of axle shafts as the steel was very resilient. Never saw one break or stretch but the risk assessment on using un tested fixings like that would never allow it nowadays!:sneaky2:

 

If the man still has some Pete I would like to buy a few http://arbtalk.co.uk/forum/stolen-equipment/74268-meooksgawn.html

 

 

 

Quite few small items broke so I am going to bore the tits off you all with the repairs , going to attack a few bits every week. :001_tongue:

 

The wacker engine threw a con rod so I stripped it down and gave it a tidy up, replace the Honda with a generic replacement Loncin unit.

 

image_zpslbl6odcb.jpg

 

Pulled it to bits and drained the oil out of the exciter.

 

image_zpsuoirglq1.jpg

 

A couple of the mounting rubbers needed replacing.

 

image_zpswl0lzxiu.jpg

 

The new Loncin engine uses a bolt to hold on the pulley vs the large nut of the Honda. Strange but the internal thread of the Loncin is 5/16" unf, cant remember the last time I saw a unf thread on modern engines:confused1: Bored out a thick washer on the lathe and used thread lock, should be OK.

 

image_zpsikkrveei.jpg

 

Found a rattle can of red touch up paint and gave it a coat :001_smile:

 

image_zpsodc7bfqq.jpg

 

image_zps7lijrjxz.jpg

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