My work has recently purchased a 2nd hand line boring setup. I have got it fairly well figured out but i have a couple of questions. 1. How long would it take weld up and bore the holes on a Volvo L150 loader bucket? Have just done one and want to see how for off industry standard i am. 2. I you have multiple sets of holes to bore (eg. loader or excavator bucket) how do you get the axis of the holes aligned? 3. how much out of roundness id normal for the finished hole? i seen to always get .02-.04mm. Thanks in advance
The fella that did buckets for us was usually in at about 6-8 hours for all 3 holes in a bucket. His rig had a wire feed that made steady continuous build up. I had asked lots of questions. He said the key to minimizing run-out was to keep spherical bearings as close together as possible, make smaller and smaller cuts as you get closer to the desired bore diameter. You have to look at what is left of the bore. If you clean and study it, you'll see where your original bore was. Across the bottom, at your boom tips, you want your bar to span both sets of bores. Square up both sides and weld your bar bearings in place. This way you have a constant. One last thing. Volvo is interference fit. Your bore should be either dead on at 70-80 mm or a couple thousandths under. Ideally you want to freeze your pin to install. Good luck
I suggest you get into contact with RayF of this parish. Send him a PM (conversation) if necessary. He should have all the answers to your questions because he's a line-borer for a living. He's based in Perth WA.
I do quite a bit of line boring in the winter months. Pretty slow during the summer as everyone wants to make a $1. There are a lot of things to think about when setting the system up. You usually "if you look closely" can tell which part of the bore is worn. You should have gotten line up cones with the system. Throw a bar threw the the holes slice the cones on and that center your bar. You can always shim the cones on the worn side to help hold things together. Don't be afraid to get the cones tight. You should not be able to feel any movement or wiggle in the bar with the cones tight. Slide the bearings on the bar and tack weld them to the bucket or boss, the pull the bar out and get the cones out of the way and things should be centered enough. I usually put the 2 outer most bearings on and then add more after. As far as fit goes if you are boring a bucket that the pins slides into add .001 for every 1" in diameter. If you are boring something like the end of the stick that takes bushing you deduct .001 for every 1". You want the bushings to be a press fit. That is a general rule of thumb for fit of bushings and pins. It has always worked for me. Anything else you would like to know just ask. More than glad to help. .
Weldor, When you say deduct .001 for every inch, what are you deducting it from? What is the rule of thumb for bearing bores? Say you have a bearing that measures 3” ODx 1” long, what would you make the bore to accept it with the proper interference? Sorry to hijack the thread, just always wondered if there was a general rule.
TNB I am refering to hardend bushings for bucket pins and such. I have always cut the bore small to hold the bushings tight. If the OD of the bushing measure 5" cut the bore somewheres near 4.995. You can shrink them if they are not very thick to the point the pin will not slide through them when done. Of course there is a fix for that also.
I suggest joining Facebook Group: Portable Line Boring established Perth WA. Rule-of-thump 0.001" per inch of diameter interference fit IS WRONG for most every application pertaining to Heavy Construction-Mining Equipment.
Respectfully disagree in this application. Otherwise it wouldn't take a 30 ton press to extract pins from a brand new machine.
@funwithfuel Sorry I did not read your' reply, LOL I use OEM's specifications and assembly procedures.
When I was hired on at the Liebherr dealer, I was shocked at the lack of pin pulling equipment. They put a bucket on by pushing pins in. No liquid nitrogen, no dry ice. Just a little oil and a push. And for 10 years I had been fighting pins to come out with rosebuds ,lances and sketchy pullers. I plum wore out my RCH20 hollow ram.
Sounds like the dealership needs a few OEM certified solutions Mickey Mouse solutions can give basically good machines a crappy reputation. Pushing pins in without shrinking alters the bore's interference fit due to metal displacement. Makes more work for repair line boring.
No. No. I'm talking little stuff, in comparison. Loaders excavators. Not those giant one off critters. We ain't got none in my area that I'm aware of. I'm saying Volvo loader pins are interference fit in the bucket. That's all. When I came to this place, these bored are machined to accept the pins without freezing. Hope this clears up any misunderstanding.
An interference fit is going to take dry ice, liquid nitrogen or power to get the pins in or whatever such as track pins. Boom base pins, boom to stick pins, bucket pins and any linkage is going to be a slip fit. So you can easily "hopefully" pull them for maintenance. If all of those were an interference fit they would not be changeable. You would simply have to waste them. Sometimes that happens anyway. It is attributed to that form of grease that eats steel. LOL The Liebherr service tools look very nice, get out both checkbooks when you go after that stuff.
Bruce eng. Best of luck to you. Sorry that this got so far off topic.