Line boring & Bore welding CAT 740 Truck A-frame | Sir Meccanica WS2

how you going guys Kurtis from cutting edge  engineering today's job we have a front   a-frame off a 740 articulating dump truck on a 740  dump truck there are three a-frames there are two   mounted on the rear of the machine with the two  rear diffs and there is one mounted on the front   with the front diff so the weight is connected  to the dump truck there is a pin and a bearing   that goes down through this hole and that is what  gives it its oscillation movement so it can freely   move and then this end is mounted to the diff of  the machine and you might remember from a previous   video where we did a disassembly and reassembly of  a 740 front strut to give you an idea on where the   front struts are mounted once the diff is bolted  onto the a-frame the front strut would be about   here on the machine the customer's brought it  in because the main pivot point has worn out   it's one of those parts on a machine that is  sooner or later going to wear out because the   bearing is so much harder than the parent material  that the bearing is in and the amount of movement   these do when they're in operation sooner  or later they're going to wear out there's   no other damage to it it's not severely worn out  where it's been totally chopped out and destroyed   it's actually still in pretty good shape so it'll  be a quick easy job to set up a line borer bore that out put a new layer material in and cut it  back to spec so we're going to get started on that what i'm going to do i'm going to tack a trestle  to the a-frame i don't want this to fall over it   is quite heavy and if you were to try and hang  a line borer off this it would all end up on   the ground and you would break something i  have seen it happen once before to another   line borer for another company i was working for  same sort of job put a line borer on it turned   his back and the whole thing fell ass overhead  and it damaged his line borer to the point it   could not be repaired so to avoid such problems  do things as safe as possible line borers are not   cheap just tacking this to a trestle will  stop any chances of this thing falling over as you can see in the hole now there  is a lip that the bearing has worn   and it is all the way around it so the customer  did really well to catch this because after it   gets to this point the bearing will then start to  break down and after it starts to pull the bits   it just trashes the end of the of the a-frames  it just rips them apart the bearing is actually   tight on this outer lip you can't push it in  well you could probably hammer that into place   but once it gets past that first lip  it falls into that bit of a recess that   the old bearing has worn and it will just  flop around so rather than just throwing   your bearing in that and send it on its  way they're going to repair it correctly   and put a new bearing in it one of the interesting  things about a lot of the spherical bearings that   are out there on the market you do have some bearings that have a completely split cage so you can see on this bearing here there are two  points where it has been chiseled and then broken   into two and that way the two halves always go  back perfectly together because they weren't cut   or machined if you were to try and put them in  the wrong way nothing will fit so they only go   the one way but the bearing we have here it is a  single split bearing it has one little split here so it always makes me wonder how they got this  part of the bearing back inside its case and   made it look that good considering how hard this  material is in my years of experience in earth   moving repair when you're doing bearing areas  like this it is always best to go with genuine   bearings the genuine bearings are a much higher  quality they last longer you don't have to do the   repair again in a couple of thousand hours time  if you can afford to put genuine parts back in it   it might be a little bit more expensive today  but it will save you a lot in the long run solid see nice and sturdy doing it out here right so we're about to start welding that  bore we've just cut out the wire i'm going   to be using is er 70s6 in a 0.9 this is a  bronze coated wire not a copper coated wire   i prefer this over conventional wires because  it has a lot less spatter in it and it just   welds really nicely leaves a nice clean layer  and there's not a great deal of spatter gets   caught in the shroud backing that up we'll be  using argo shield universal which is 80 percent argon 10 percent co2 and 10 percent oxygen so the oxygen really helps  with keeping that weld really hot and allowing   everything to wet in so it keeps it like a puddle  and everything just flows really really well so   i'll be using that at 19 volts four and a  half meters of wire a minute and that seems   to be the perfect setup with a big machine  like this to bore weld something like that go come on the welding is all cooled off now  it's been cooling for the last two   and a half hours now that it's nice and  cool we're going to get into boring it righto guys so i've done my first roughing  cut and i've run into a bit of a problem   which i knew this was coming i don't have a  great deal of room in here because the bore   that i'm working on is actually sunk inside  the a-frame so it is quite difficult to get   a measurement in order to advance the tool for its  final cut the reason i set it up like this is the   shorter the bolts that we weld onto the job this  machine is a lot more rigid when the bolts are   very very short so if i was to go and try and use  longer bolts here you'll actually see the machine   starting to bounce while it's working the bolts  i'm using here to fix the bearing blocks to the   job they are 14 mil in diameter and 50 mil long  so if i was to try and make this easier to work on   and use an extra long bolt it'd have to be about  130 mil and that's just too much there's just not   enough support it's not rigid enough to do what  i'm trying to do you take the good with the bad   and you sort of put up with it so what i usually  do in a situation like this is i will take the   tool holder off altogether i will then take the  measurement with the snap gauge and i will then   reset that tool out here on the other end  of the bar and then i will put it back in   place and take the final cut this is just one of  those things you run into when you're a line borer very tight we have one mil to come out righto guys so i have got one mil to come  out of the id of the area we're boring at the   moment for the crush spec on the bearing  what i've done is i've advanced the tool   half a mil that's the way this setup works half  a mil here equals a complete mill in there so   we've got that done let's get it  set back up finish this hole off don't bump it righto guys we're just about ready to freeze fit  our new bearing into the a-frame some of you may   have noticed i did not machine in a grease  groove inside the bore and that is because   the bearing has a grease groove on it already the  oems generally when they do a part number upgrade   or they do a variant of a bush or a bearing the  upgraded part number will take you to the latest   thing that has been designed so in this case  the bushing now has the grease groove on it   not the bore of the a-frame so i've just marked  where the split is in the outer cage of the   bearing and the reason i do that is i don't want  to put that split on the load point when this   machine will be in operation so you don't want  them at the front you don't want them at the back   because when the machine is working those are  the load points so you want to try and put this   off to the side at about three or nine o'clock  it just helps prolong the life of the component this helps melt the ice so you don't get any rust righto guys so everything went exactly to plan  the bush went in it didn't lock up nothing at   the end of the machining we actually put a 0.2  crush onto the bearing so that's about eight thou   the tighter we can get these bearings without  going extreme the longer they're gonna last   that there is about as tight as  you'd like to get a bearing like   that and everything went exactly to plan  so this one's done and thanks for watching what are you doing [giggle] how you going guys Kurtis from cutting edge  engineering today's job we have a front a from [Laughter] [ __ ] first take here we go   right so ugh where we starting from so it mounts at the [ __ ] right so it mounts on the front ugh [ __ ] be safe with your gear don't mess it up you always say random one-liners   now that that's cool enough we're going to get in oh cool enough if only i was cool enough [giggle] let's get it set back up finish this hole off [giggle] does that sound bad   righto guys so all that went exactly to plan everything just went uh [ __ ] to plan [Laughter] at the end of the machining oh i just bit my tongue my god gawd jeezus tighten these so that they [noise interruption]   so it it keeps it a lot [noise interruption again] and after that happens it just chops the a-frame [phone call] [ __ ] so you want to try and put them off [train] argghhh now that it's nice and cool we're going to  get into boring it oh that was just in time [Laughter] [ __ ] off train how dare you can't see [ __ ] can't even get in there to get the screw aahh [giggle] [achoo] got your hammer ugh eh oohhh are you ready [giggle] yup [sigh] that won't crack hmmm sure hang on i want to try something oh woah [ __ ] [giggle] is that alright good boy oh look at muddy  get chicken ah what you got oh almost slipped over ewww

Channel: Cutting Edge Engineering Australia

Views: 366,327

Keywords: cutting edge engineering australia, machinist in australia, machininst, abom79, cee australia, Line boring and Bore welding Cat 740 A-Frame, Sir Meccanica WS2, sir meccanica line boring machine, Sir Meccanica, Line boring, Line boring machine, caterpillar wrenching, caterpillar 740, line boring tool, portable line boring machine, line boring and bore welding, bore weld, 740 articulated truck, boring machine, shrink fit bearing, cryo freeze install bearing, bore welding, A-frame

Id: OQkw96htVLk

Length: 27min 6sec (1626 seconds)

Published: Fri May 27 2022