Can We SAVE This $20K Cylinder Rod!? | Gouging SEIZED Nut

how you going guys Kurtis from Cutting Edge engineering today's  job is one of those jobs I don't enjoy doing on   components this expensive so what we have here is  an ex 1200 excavator bucket cylinder rod that's   come in because the nut has seized onto the rod  when the customer was trying to disassemble it   this cylinder rod connects onto the bucket of the  excavator and it is used to control the pitch of   the bucket so they are a high cycle cylinder and  they are a high turnover cylinder which means they   do get damaged just because of where they are  on the machine and the environments they work   in the reason the customer was disassembling the  cylinder is the piston seals had failed and it   was bypassing internally which leads to loss  of production so it does have to be resealed   in order to get it back up to a standard where it  is being productive and as you can see the wear   bands and the seals are basically non-existent  they have been obliterated it's a good thing   they caught it when they did because if it had  actually blown the wear bands completely off   the piston the piston would have contacted the  barrel and it would have been a lot worse so the   damage we're actually seeing on the piston it  is not caused for from wear and tear this was   caused from a process called dieseling which is  where there is air trapped in the cylinder and   it is cycled without bleeding the air from the  system and as the air rushes past all of those   parts it tears them apart just to replace the  rod from the OEM is upwards of twenty thousand   dollars the nut is three thousand dollars we are  going to be gouging that off in order to try and   salvage the cylinder rod so when the customer  was disassembling this they did manage to undo   the nut about 20 mil and then it locked solid  I went over there we did then try to wind it   back on just a little bit to see if it was just  one area that had gone tight but it consistently   stayed tight for the little bit that we turned  it so rather than do any more damage we stopped   so the nut being seized onto a cylinder rod it  is not very common but it doesn't take much in   order to start what can cause that is a mix match  between the threads or a tiny piece of swarf has   broken free and got in between the nut and the rod  and that is all it takes to completely lock a nut   onto a rod and ghoul the threads and destroy them  so I I don't know what condition the threads are   in you can't actually see up inside there rather  than do any more damage trying to tighten it back   on or take it back off again we're just going  to gouge the nut off to try and salvage the   cylinder rod the reason I'm going to be using  air arc to gouge the nut off is I do need to   get up underneath the piston because the nut is  actually encapsulated by the piston you wouldn't   try and do this with oxy or LPG because you would  probably accidentally hit the piston or you might   hit the rod with air arc gouging you have a lot  more control and you can be a real surgeon with   it and just remove the material you're trying  to remove without doing damage to anything else   plasma gouging is one of those things that I  would not be interested in getting involved in   the machine itself and the consumables is just far  too expensive and you have no control with plasma   you can't really point it in a direction and just  remove the material you want you sort of pull the   trigger and get what you get so we're going to  stick with what works best and just use air art   gouging for those of you who don't know what air  art gouging is air arc gouging is an electronic   process of removing material very quickly so what  it is is a power source we have a 400 amp idealarc   in there and it is run on constant current you  attach your earth lead onto the job and then you   use a handpiece on your positive lead coming out  of your welder that then attaches to your gouging   carbon they are just a carbon rod with a copper  layer on them to help create the circuit carbon   rods are available in many different sizes you  can get round carbons from I believe 6.5 mil   we have here in Australia up to 12 mil and they  can come either round or flat so the flat carbon   rods they are generally used for just washing  or wiping down a high area in order to flatten   them out for grinding where the round carbons are  used for penetrating and digging into something   so you can then remove the weld after you create  the arc the material becomes molten and there is   air that runs through the handpiece out the side  of the jaw that holds the rod and that air then   blows down the side of the rod and blows away  the molten material and you can point the air   jet and the rod pretty much anywhere you want so  they are quite versatile but you do need to make   sure you put the rod in the center of the jaw  if you don't and the air jet is blowing off to   the side of the rod it doesn't actually work all  you end up with is a big mess this handpiece does   look very sad I do need to put a new cheek plate  on it for what we're doing here today it's going   to be fine they are very handy they are very  quick at doing the job but they are extremely   noisy because they do make such a mess I do it  outside I don't like doing it in the workshop   because it just blows molten material everywhere  so the rods I'm going to be using today they   are a six and a half mil gouging carbon although  this is an extremely quick process I am going to   be taking my time and using a very small rod so I  only remove exactly what I need to going in there   with a larger diameter rod I do have the chance  of the arc jumping away from where I'm trying to   cut and I could actually cut into the rod itself  we're going to take our time and do it properly you can't really see anymore I  just found the tips of the threads so now that I've exposed the tips of the threads I  do need to come back into where the piston is and   try and expose and wash underneath the piston  so I can then hopefully drive a wedge in that   gap and split the nut it might not work I might  have to gouge the other side and actually take it   out in two halves but we'll get that out of the  way drive a wedge in there and see what happens started to split it wedge isn't biting anymore I'm having a few  issues getting my wedge to actually lock itself   into that groove I've made these wedges are  made out of a Cutting Edge so they're about   an AR 500 grade material so they're very hard  they don't deform what I'm going to do is use   a mild steel wedge because it will actually bite  into the material and it won't actually allow it   to release so I should be able to drive it all  the way in without it trying to pop out again I think we have to split it all the way righto so we've got one side split I can't just open it up because it is  still inside the piston so I really need to   split it into two halves in order to retrieve it  I've got a little bit more gouging to do on this   side and then I'll try and wedge it open and  then hopefully it'll just fall on the ground it's so close so close to coming out right oh so we've managed to get the nut to  start to move again unfortunately because it   is tucked in underneath the piston I can't  get it out I've sort of got to unscrew it in   order to get it to clear the piston so what I'm  going to do is open up this groove a little bit   more and that I should be able to unscrew  them by hand and pull them out of the way righto guys so we successfully got the nut off it  did take a lot more than I thought it would   but because it was trapped inside the piston it  did make it very difficult in order to get it   out so we could then split it now that the nuts  off we can really see what actually started this   problem and the culprit to it all going wrong  so we have got one area of the thread that is   basically just torn off and it has galled up the  inside of the nut so there was no hope of ever   getting that off without destroying probably  both parts unfortunately I did touch one part   of it with the gouging rod but that's not really  a big deal so the next course of action will be   set this up and delayed and chase these threads  but there is quite a lot of damage on the faces   of the threads so trying to clean them up  I'm probably going to undersize it a little   bit because a nut has already bound up on this  before the likelihood of it happening again   after it's been undersized is very high so  my recommendation will be machine off all   these damaged threads put a new thread on the  rod and make up a custom nut to suit this rod   because these are a very high turnover rod they  do get damaged and changed out quite often I'm   not too worried about putting a non-genuine  part back on the rod to keep it going and it   would actually be a cheaper option than the  customer having to buy a genuine nut anyway [excited Staffy noises] oh no oh it's it's pretty simple right oh  well if you're all for that we'll do it righto I'll talk to ya see ya mate bye righto guys so I just spoke to the customer  he's in agreeance with my recommendation so the   next thing I'm going to do is take this  inside and get it set up in the lathe righto guys so we've got the rod set up in the lathe  what I'm going to do now is machine off those   damaged threads I don't want to go too deep  I just want to remove enough material that   I've got nice clean fresh surface to start  with again after I've got that cleaned up   that will then determine the diameter of the  thread that we'll be putting back on the rod so I've taken a cut it hasn't quite cleaned  up just yet I still have one little mark in   there it's measuring at 125.8 so I'm  going to machine it down to 125 mil   that will make it a much more of a standard  size and it's going to be easier to work out   your major and your minor dimensions when  I go to make up the new nut rather than it   be something unusual round numbers make it  easy and simple so you don't make mistakes we've machined down the damaged area it came in  at 125.01 I think that'll do there is one little   mark in it from where the gouging rod touched it  so it has created a little bit of a hot spot but   that's not going to be an issue we will be able  to thread straight through that there are other   areas on this end of the rod that I will need  to re-machine the reliefs on either side of the   thread and the very end of the rod as well so  they are in scale with our new nut but I'm not   going to machine any of that just yet I would  like to manufacture the new nut first it'll be   a lot easier to test a pre-made nut onto the rod  as I'm machining it rather than have to pull the   nut out of the lathe check it on the rod on the  floor put it back in the chuck dial it back in   and then chase that thread but I have to order  in material for the nut and I have been looking   for an excuse to upgrade some of my tooling  that's going to take a couple of days to get   that from my supplier so you're just going to  have to wait for part two thanks for watching [sigh] [sigh again] best way to explain this oh [ __ ] I've already [ __ ] it up does that sound right that didn't make sense right you ready yeh right ready wait how'd you start that [Laughter] [Karen] let's try that again are you [ __ ] serious [Karen] that was so just disjointed   disjointed right you ready yep right so the cost oh [ __ ] meee wait [ __ ] what was I gonna say oh wait how am I going with that wait how did how am I starting that so I'm gonna hmmmm so I'm gonna machine it down to 125 mil   [ __ ] [Karen] just restart that whole sentence [ __ ] off [Karen] it's a sentence [Laughter] right so ugh mmm where we starting from thanks for watching [giggle] [Karen] on [gets blasted with air] WAAaahhh [Laughter] [Karen] you asshole you knew that would [giggle] [ __ ] God are you serious hot as [ __ ] [giggle] put it on the eyes need to stick up more there we go I've got a new hat [Karen] I can't I can't [giggle] what hang on hang on hang on hey hey drop it oi this isn't how it works homeless homeless drop there we go no that's oh [sigh] really

Channel: Cutting Edge Engineering Australia

Views: 1,296,439

Keywords: cutting edge engineering australia, machinist in australia, machininst, abom79, cee australia, machining, Can We SAVE This $20K Cylinder Rod, gouging seized nut, gouging, arc gouging, carbon gouging, air arc gouging, Hitachi EX1200, EX1200 excavator, mining excavator, hitachi ex1200 mining excavator, machining a big cylinder rod, hydraulic cylinder fail, cylinder rod repair, cylinder rod, seized nut removal, seized nut, nut stuck on cylinder, removing seized nut, big lathe work

Id: -S6IMTOuLYQ

Length: 29min 5sec (1745 seconds)

Published: Fri Jun 23 2023