Crack , crack not ?

[Iron Horse]

My 2.2 cents inc gst is that it is where 2 sheets of steel have been joined to make the boom web . The sheets have not had the Arris removed (vee'd out) before the weld was laid over the top . The weld has then been overground as the surrounding metal shows and the paper thin weld left after grinding has split .

 

[RocksnRoses]

I reckon you might have something there, Iron Horse, we had the same problem with a Furukawa loader frame quite a few years ago. The crossbar was two halves welded together and then welded to the arms, all done by robot in the factory. The material was 3/4" thick but only butt welded with very little penetration and with the twisting of the loader arms it just broke away. We ground the edges right back and penetrated the weld as far as we could and never had any more problems with it.
I think if Alfapillar investigates that crack with a grinder, he might find the same thing.

Rn'R.

 

[qkoop]

If you look at the area around it ,it looks smoother than the rest of the boom.I would say it has been welded there before and grinded smooth and is cracken again.

 

[Iron Horse]

Not that my opinion means much , but i think if that join had been welded after the assembly of the top and bottom straps were welded to the web plates there would be evidence of a vertical weld or a grind mark on the horizontal strap plate welds . But to my eye the strap plate weld is uniform , neat and with no signs of a grinding wheel ever been near it . If on the other hand the vertical welds were done latter , you would see were they started and stopped and also you would see were the welds were ground at the intersection .

 

[Alfapillar]

guys for your point of view and advise, the machine is not operating at the moment, and she'll be sold probably in the next few days, the seller is almost advised about this, and send him a couple of photos, i've thinks about grinding the area and see what heppens under the paint, if the customer agree i'll do it and send you some pics

the strange thing, is that the machine didn't work at all since we got it, i didn't inspect it before, just trust the ex-owner, and that was a bad idea to act like this !!! :Banghead :bash

Regarding to this boom and the repair , it could be easyier and less expenssive if we fit / or supply another used boom with the 330 ? if i've undrestand all your point of view, this boom is probably in bad condition, that's why i've think about changing / supplying another boom :beatsme

 

[ncbschzzt]

Another boom will cost you a ton and if its used you could end up in the same place you are now. We had a customer do exactly what you are thinking about and the used boom ended up worse than the cracked one. You are going to have to have it repaired by a certified welder. Should take one to two days max if done right, Cat has all the welding procedures for this kind of repair. I would make sure that the welder follows them very closely.

 

[gmads01]

Just last month had the boom on our Cat 308C fall off - cracked completely thru at pin-boss. Will post pics when I'm allowed.

These are the pics of our cracked boom incident.

 

[dayexco]

i might be missing something in those pics...but looks to me as though that machine never got greased?

 

[Iron Horse]

i might be missing something in those pics...but looks to me as though that machine never got greased?

Your looking at the outer tube that houses the bush it's not the pin that looks rusty .

Alfapillar , Just have it ground out to create a 'V' and weld it with a mig . If you do find a baffle at that point , simply grind it out a little wider so that the weld can penetrate all three pieces . It would be a better , prettier weld if the boom was laying on it's side but a good "vertical up" stitch weld in situ will be ample .

 

[ncbschzzt]

Hopefully we can see some new pics of the boom....

 

[Alfapillar]

Hi Guys,

Thanks for your advises and help, i've speak to the buyer of the machine, and he prefere to get it as it is, so i'll not grind it but i'll ask him to send me some pics once he'll weld it and put a plate on the boom.

I've got another advise concerning this crack, wich consist on drilling a hole on the two extremity of the crack, in order to stop it, and then proceed to the welding, and finaly weld a plate on the boom, what's your point of view ?:notworthy

 

[mouse]

what's your point of view ?:notworthy

ah an easy question. such procedure usually stops a crack spreading but doesn't get to the cause of the crack.

i'd not go down that path personally, but then i'd hate to see the boom let go completely

 

[Alfapillar]

i'll not do it for sure, the futur owned come and see it, and prefer to buy it as it is, and proceed to the maintenance localy, as it'll cost 1/3 of the cost here in france will ask him for some pics once it's done

 

[ncbschzzt]

I would call your local Cat dealer and have them send you the repair specs from the factory. This the BEST method to follow, I have done it several times

 

[Construct'O]

These are the pics of our cracked boom incident.

Looks to me to be more in the quality of the weld then the grease at this point.The weld from factory was chessy to say the least.

Note hardly any weld or penetration in the weld to the base plate.Just my thought.Not good for sure.Good luck:usa

 

[ncbschzzt]

Looks to me to be more in the quality of the weld then the grease at this point.The weld from factory was chessy to say the least.

Note hardly any weld or penetration in the weld to the base plate.Just my thought.Not good for sure.Good luck:usa

The repair specs (at least with Deere/Hitachi) are usually better than the original welds from the factory. Not really clear why the factories just don't make them that strong to begin with. Okay actually I do.

 

[Iron Horse]

Alfapillar , equiring minds are still in a holding pattern .

 

[Iron Horse]

Alfapillar , equiring minds are still in a holding pattern .

DOH ! enquiring .ointhead

 

[Alfapillar]

me too
the machine is actually at the destination sea port, i'll ask the customer if he can take some shots of the welding / repair once it's done

 

[Iron Horse]

You da man , looking forward to the pics .