Some Line Boring Pics

[RayF]

Its a lot less fiddly. I prefer it to smaller work. You have to have powerful equipment especially for the facing and heavy mounting brackets. Also because of the distance between bores you can't rely on the bar for alignment. Must be able to accurately align the support bearings.

 

[dabsfabs]

Talking of the alignment is why you use the piano wire trick, looked it up on internet but can't really find any info on how you do it or its explained so complex you can't make head nor tail of it.

Would be useful to find how extactly you do it?

I take the tolerances increase slight due to size and wieght of pins but the bearing not much room for that.

Your machine is Hofman would the be correct and hydraulic.

 

[RayF]

Yes we do use Hofmann equipment and have done so since 1988. My hydraulic power pack has an 8 hp motor on it.
The piano wire system we use is accurate and easy to use. Have a look back earlier in this thread and there is pics and info. Have a look at that and and if you want to know more I'll try and explain it.
The tolerances on the bigger equipment varies according to brand. The Caterpillar and Japanese gear are easy to machine for.Liebherr and O&K can have tight tolerances. O&K is the most challenging because they use very little interference on the bearings and there is only a few thou clearance between the fitted bearing and pin.So if you are a thou up on bore size the bearing will not be tight and if a thou tight the pin might not fit. Also on their buckets because the bores are so far apart,unless your alignments are spot on you won't get a pin through. I have seen some disasters where a line borer never took advice and botched the alighnment on a RH400. It cost him 8 new bearings at 20K a pop and 70K for a new pin flown in from Germany. Lucky he had a good insurance company! He still had to rework it at his cost.

 

[MitchSA]

View attachment 82512View attachment 82508View attachment 82509View attachment 82510View attachment 82511This is a Komatsu WA 700 rear axle pivot I bored a while back. It was simple enough. I machined up a lining up jig that bolted up to the bolt circle of the tractor.Made it a little undersize and used jacking bolts to dial it up centre. It was a bit cramped working under there but it finished up OK. The bores take nylon bearings which seem to wear out bores quicker than anything else.

Was just going through this thread again I know this post is old but I'm sure that's my workshop? Well the workshop I work in

 

[RayF]

Kurnall Road??

 

[dabsfabs]

Can I PM you please to ask some more questions about piano wire alignment, and some other bit you use.

 

[RayF]

No problems

 

[MitchSA]

Kurnall Road??

That's the one mate, have you done alot of work for that compnay? I'm sure I know where that loader is aswell. Dont suppose you can remember the unit no? I think it might be 59?

 

[RayF]

I did do quite a bit for them for a while.Mainly stuff like WA600 buckets.Blokes in the shop were good. Then the company ginned me around on a job at Laverton and I lost interest

 

[MitchSA]

I did do quite a bit for them for a while.Mainly stuff like WA600 buckets.Blokes in the shop were good. Then the company ginned me around on a job at Laverton and I lost interest

Sounds about right...... They had a massive reshuffle, there are only 4 of us left in that workshop.

 

[kshansen]

Ray and others here.

I have been working around quarry equipment for over 40 years pulling wrenches so I have seen my share of welding and boring work. All I can say is you guys are like artists to me. I only wish management where I work could understand the difference between the quality of work your kind of people do compared to what they think is good work. We have a 988H bucket being worked on this last week and I can imagine what I will see monday when I go to the shop. Like cracks in the underside of the bucket with 2 foot long crack that will probably have a quick hit with a four inch grinder and some what I call cosmetic weld over the top to make it look good. Think that will last for a couple days in easy digging.

 

[RayF]

There is a lot of that mentality here as well. Patch up and she'll be right for another week. I keep away from that sort of work. There is no money in that and I'm in business to make a living.
I've been fortunate that I have done most of my work in the mining industry where you don't often see quick patch ups. The job is properly repaired and its expected to go into work 24 hrs a day without worrying whether or not its going to fail.

 

[CraneInnovation]

Ray, I keep coming back to this thread for shear enjoyment. I have a basic understanding of welding and machining....just enough to really, really respect what you guys do. I know its the daily grind for you all, but this is stuff most of us will never see in our lifetime. Thanks for sharing the pictures and the expertise. Seeing you guys tackle projects like this encourages new guys like me that there really is no job out of reach if you have the right tools and the humility to keep learning. Thanks so much!

 

[Alex2]

Cast iron



Hi guys,

The owner of this Russian machine doesn't want sleeves to be installed. He insists on building up the holes with welder and then cut them to the size.
I was through the internet discussions and found two ways for performing the job:
-oversize the hole, then use two layers of steel (S6) wire, then cut the second layer down to pin's size
-use special type of wire, but not quite clear which one
I am afraid of “weld material peeling out when bearings are installed", "You will also get fair under bead cracking", "nearly all cases where a heavy preheat, maintained heat, and post heat isn't done there will be a layer of very very hard carbides where the weld meets the original cast ".

I'm confused. Don't know what to do.
Any advice gratefully accept

 

[RayF]

Alex,nice to talk to you on Skype. Further to that conversation I take it you have checked to make sure its cast iron and not cast steel?
If it is cast steel it turns into a straight forward job.
If its cast iron the only way I would repair it would be with hardened sleeves. The only way I would even put Nickel welding wire on that would be if I could stress relieve/anneal it after welding.Looking at the casting thats not practical especially as your client is after a budget priced job.
Hope it goes well with the job

 

[UK pie-can]

A few here of a Liebherr 996 backhoe stick. Bores at 310mm X a foot and around half long. I think there is a truckload in the levers and pinsView attachment 105512View attachment 105513View attachment 105514

 

[RayF]

I think we had about 50 hours in that job from memory. The pins will be 4140 or something close to that. The hardening is done with an induction hardener.Only the outer 6mm or so is hard,leaving the core strong and flexible.

 

[UK pie-can]

Thanks....it looks interesting kit to work on. :cool2

 

[SE-Ia Cowman]

Any new pics Ray?

 

[RayF]

Not much happening mate. All I have line bored lately is some 20 and 30 ton quick hitches so pretty ho hum stuff. I've done a good sized lathe job but thats about it.