FireFighterZero
Captain Zero!
Cat bolts are Okey dokey.
Parts delay
- Thread starter Page
- Start date
- Replies 38
- Views 2K
Altissimus
TreeHouser
Had no idea those bolts had replacement intervals ... no idea , bought Chipper new and been through many knives. One time I removed and replaced (with difficulty) one bolt that I over torqued the rest are original. Morbark included an eleven page manual that never mentioned it ... hmmmmmm
Do you have the grade of bolt and torque specs? Does it have spring washers? They might have a low enough preload or grade that they don't need to be swapped, which is the case sometimes too. God bless that engineer if that's the case because he actually thought about servicing it during the design phase, and didn't resort to high performance bolts to get the forces he needed. I'm not a chipper mechanic studying manufacturer documents during rebuilds and maintenance, but that's why some manufacturers call for it on various types of equipment and why some mechanics do it while working on stuff. I'm not saying you need to swap them everytime, but if it said to do so that's the reason. Are you saying those bolts are original to the machine, the machine that you've run everyday for years and years now? Did you ever once inspect the bolts, and if you did how did you do it? Ever once mic the shaft to see if it's necked down, or dye check it for cracks? Check the thread with a new nut to see if the threads are stretching?
I hate to tell you this, but the people writing the owners manual usually can't wrench on stuff correctly. Depending on what you're working on, you might be expected to know stuff that doesn't come in the instruction manual, and is considered basic mechanical knowledge. An example would be that if you are torquing to an actual value you have to have lubricated threads or the reading is going to be wrong, it's not gonna spell that out to you but to do it right you have to know that. Swapping out hardware kinda fits in that category depending on what it is and how tight they're getting it. I work on all sorts of different stuff, and on different piping systems and equipment we replace bolts every time you have it apart, other times if the threads didn't rust away they're fine, you have to know the difference and when to do each. Head bolts and studs on engines are always swapped too, and it sometimes sucks because they often get stuck in the block so the temptation is to say eff it. But you'll come unglued if that's what causes it to blow up, trashing other parts or causing injury. It sometimes fits in the might as well type of thing too, especially for engine rebuilding, since you are doing it you might as well do it right.
I got a buddy who wrenches on stuff far more than me. He's got a big tub grinder, and i saw he had a pile of bolts and new teeth for it. I asked him how often he changes the bolts and he explained it like this: the old bolt may survive being beat to shit (remember hardened bolts don't like impacts), and it might be fine. Or it can snap off, throwing a chunk of steel thru different shit you now have to fix, and then when you're done you get to try to get the rest of the hardened bolt out of a tapped hole so you can replace it the hard way. For the 200 bucks or whatever it is to swap the bolts he prefers to just do it right and not do that, saving money and time in the long run. It all just depends.
I hate to tell you this, but the people writing the owners manual usually can't wrench on stuff correctly. Depending on what you're working on, you might be expected to know stuff that doesn't come in the instruction manual, and is considered basic mechanical knowledge. An example would be that if you are torquing to an actual value you have to have lubricated threads or the reading is going to be wrong, it's not gonna spell that out to you but to do it right you have to know that. Swapping out hardware kinda fits in that category depending on what it is and how tight they're getting it. I work on all sorts of different stuff, and on different piping systems and equipment we replace bolts every time you have it apart, other times if the threads didn't rust away they're fine, you have to know the difference and when to do each. Head bolts and studs on engines are always swapped too, and it sometimes sucks because they often get stuck in the block so the temptation is to say eff it. But you'll come unglued if that's what causes it to blow up, trashing other parts or causing injury. It sometimes fits in the might as well type of thing too, especially for engine rebuilding, since you are doing it you might as well do it right.
I got a buddy who wrenches on stuff far more than me. He's got a big tub grinder, and i saw he had a pile of bolts and new teeth for it. I asked him how often he changes the bolts and he explained it like this: the old bolt may survive being beat to shit (remember hardened bolts don't like impacts), and it might be fine. Or it can snap off, throwing a chunk of steel thru different shit you now have to fix, and then when you're done you get to try to get the rest of the hardened bolt out of a tapped hole so you can replace it the hard way. For the 200 bucks or whatever it is to swap the bolts he prefers to just do it right and not do that, saving money and time in the long run. It all just depends.
Tim_B.
TreeHouser
Hello, Kyle.
@Tree09; This is going to sound like I’m massively sucking up, but I consider it a real privilege to be able to read what you write. Your presence on this forum adds a lot to the value of coming here, and I just want you to know I appreciate your contributions.
The same goes for Jim, aka @FireFighterZero. Thanks to you both for your continued involvement here. Tim
@Tree09; This is going to sound like I’m massively sucking up, but I consider it a real privilege to be able to read what you write. Your presence on this forum adds a lot to the value of coming here, and I just want you to know I appreciate your contributions.
The same goes for Jim, aka @FireFighterZero. Thanks to you both for your continued involvement here. Tim
Tim_B.
TreeHouser
I replace my my nuts washers and bolts every time the blades go in for a sharpen. So one set for two edges of the blades. I touch up the blades with a tungsten sharpener after every job so they are lasting fairly well.
I buy mine at the local nuts and bolts store, high tensile. The nuts are nylocks so I don't like to reuse nylocks more than once.
I have seen and heard the story of a chipper that threw a blade, damn near killed the operators coming through the steel and landed a long way away, I NEVER want that to happen to me.
I buy mine at the local nuts and bolts store, high tensile. The nuts are nylocks so I don't like to reuse nylocks more than once.
I have seen and heard the story of a chipper that threw a blade, damn near killed the operators coming through the steel and landed a long way away, I NEVER want that to happen to me.
SeanKroll
Treehouser
You can say that twice and mean it!
Al Smith
Mac Daddy
Grade 12 is a metric usage measurement which is about like SAE grade 8 .Just wanted to interject that a properly torqued fastener will not loosen up .On something like a chipper the use of anti seize compounds is very necessary if you ever want to take it apart again .Any good bolt supply company should be able to get you any thing you wanted but I suppose Fastenal and McMaster -Carr are the most popular ..Fact I've ordered through the later ,late at night and received it the next day as they have a branch in Cleveland Ohio which is around 120 miles from me .
Mellow
BCMA
Yes, and it's actually Class 12.9, not Grade 12.
Al Smith
Mac Daddy
Well for that matter they have a 10.9 class also but that just confuses things to even mention them .While one source might give grade 8's to 150,000 PSI tensile another might give them 186,000 which exceeds metric 12.9 .The info is as confusing as rated HP ratings alleged by engine manufactures and tonnage ratings on for example log splitters .So all that said a brush chipper is not an item to use cheap bolts on . Nor for that matter is it a piece of machinery to be careless around .
vharrison
Island Girl
Al to the rescue!!
Al Smith
Mac Daddy
I'm not trying to be a know it all but some back ground .While it's true I am a union journeyman electrician with about 50 years experience that was only part of my job .Another part was programing CNC type automatic machines that installed screw type fasteners .A threaded fasteners acts like a spring under tension .Each thread acts like the coil of a spring with the loading .To get proper torque it has to be taken under enough force to actually stretch this "spring " called the yield point then taken few more degrees of rotation .This is the final setting .I can't remember exactly how much but there are tables on the subject .It's simple ,tight is tight and too tight is broken .
Similar threads
