I BET!

[ARKANSAWYER]

  I am willing to bet that I am one of the very few that have broken this part on a WoodMizer mill.   Now I have torn off landing legs, busted gear boxes and even a hydralic hose.  A few things have even worn out on Wanda but yesterday I busted a part that I am willing to be that very very few have.  And let me tell you when this little darling goes it does so in a big way.  I mean your cutting will go south most quick.






 Like they say on the RED GREEN Show "If the women don't find you handsome, Let them find you handy!"  So I slapped a Godzilla weld on that little darling and did some adjusting and went back to sawing cedar.





  So can anyone else bragg about being in the ranks of them that can shatter a 1 inch hardened steel rod.  ( noticed that it broke about where the orange paint quite,  maybe there is something to that)

[Fla._Deadheader]

 That's really strange. There are 2 bars that hold the tracking. How would one have that much pressure   We built Homey the same way. 

[Bibbyman]

Well,  I beat you to the first break on our Wood-Mizer by a couple of months.  Last September I found this crack in the board dragback frame.  After 5 years and a million board feet it just let me down.     But then again,  I've had boards bind up on the drag back action and realy put a jolt on the whole rig.  One time a cedar 1x6 just exploaded when it hit against the end of the dragback table. 



I'm no good at welding but I got to say my welding looks a lot better than your's. 

[isawlogs]

  A little grinding on both of those welds will make um look just like mine 

[farmerdoug]

Arky,  Since those rods are usually under compression I marvel at the break.

There are two possible causes that I can think of off of the top of my head right away.

One-the rod cracked from being under compression and suddenly released from said compression by the breaking of blades.  Of course this probably involved the breaking of alot of blades but considering the amount you saw that it is right up your alley.

Two-There is a vibration in the idle wheel that is causing the rod to be torqued in a way it is not built to handle.  Maybe it needs to be checked out a little closer by you.

Of course maybe Wanda is looking for you to get off your duff and start bringing in some younger help for her too.

Farmerdoug

[Murf]

Arky, it broke where it did because the steel had been weakened there by the welding.

That's also why it broke on an angle leading away from the weld and up to the right in the picture.

That is what is known as a "heat affected zone (HAZ)" and resulted from both the heat itself, and the fact that it was applied to just one side of the metal. The temper was changed in that part of the steel rod.

Not picking on your welding skills, but the original weld allowed a failure, the repair will too, eventually, probably soon too.

Not that I want to second guess anyone else's engineering, but IMHO if there was enough load on that rod to require a hardened steel rod of that size, it shouldn't have been secured in that way, it created a load that was not inline with the fastening point.

IMHO it should have been fastened by putting it through a hole in a plate, then running a bead of weld around the rod on the side opposite the load.

[beenthere]

I'm also gonna support Murf's idea what and why it happened. True, it lasted a long time, but welding on that rod likely caused the inevitable. Maybe welding is the only resort for fabbing that joint, given the room and restrictions of the part. Metal fatigue and weld affects are both fascinating and mysterious at times.

[farmerdoug]

Murf is right on why it cracked at that location and the form of the crack.  The cause was probably a combination of the things leading to the failure.   I wonder if Woodmizer has seen this problem much?

All I know for sure is Arky needs to get a part ordered before it breaks again or gives out on the other side. 

Farmerdoug

[ARKANSAWYER]

  Well I sent WM a photo of the break and asked if it was a problem.  Does not seem any one else on here has broken that part and there  are lots of these Orange mills out there.  Keep about 2300 psi on that shaft most of the time and break about 50 blades a year.  As for design it is just fine because it got me out of a 5 year warrenty period.        
  Pa always said  "Boy! you could tear up a steel wedge in a sand pile".  Maybe so but I got good at a fixing things.

[TexasTimbers]

That's funny Arky. My pappy always told me "Son! I believe you could tear up salt water!"

[Cedarman]

I broke one on our old LT30 manual in the late 80's.  Have no idea why it broke, but it did at the same place Arky's did.  I just got a new one and welded a bearing race to the top of the broken rod and used it as a hitch pin.  Never ever broke the pin or bent it.  Best hitch pin I ever had.

Never broke another one.

[LT40HDD51]

That is a weird one, Arkansawyer. Mainly because those rods dont hold THAT much endwise force, either compression or expansion. The piston coming out of the tensioner is the piece that pushes on the square assembly (the wheel's axle). Those chrome rods are only there to slide back and fourth and keep everything lined up. Even when a blade breaks, the rods should just slide out when the pressure is released (but we all know there are little gremlins out there running around...  ). Should keep them clean and lubed, WM now recommends a silicone spray in a rattlecan. Trans fluid in a squirt bottle is what I use on most everything on mine...

Arky, it broke where it did because the steel had been weakened there by the welding.

That's also why it broke on an angle leading away from the weld and up to the right in the picture.

That is what is known as a "heat affected zone (HAZ)" ... Not that I want to second guess anyone else's engineering...

I think we've all second-guessed some engineering here and there  . I agree on the cause of the rod breaking where you say, the weld is almost always the weak link, especially with a hardened rod... Murf knows his metallurgy  . Prob will break again, too... Best get a brand new one, IMHO. Something that has been fixed is usually the next thing to break again...

[Furby]

Sounds like a twist factor.

[Cedarman]

When a blade breaks there is a sudden movement of the idle blade assembly.  With assembly pulling on the two rods in sudden acceleration even a small amount of friction on the rods will put a sideways force on the two rods at the well point.  After many of these sudden explosive band breaks any weakness will be found. As stated, keeping these rods lubed is a good idea.

[ARKANSAWYER]

  Talked to a WM parts guy today and he said that they have the part in stock but does not look like they have sold any in quite some time.  Must not be a problem then.  We will have to just see how good the weld is because I sawed 2.2 mbdft today and all was well.  I have been taught that if it is working to leave it alone.
  I guess that Cedarman and I are the toughest ones out there. 

[Hi-Country Orange]

LT40HDD51: if the welds are most generaly the weak point the welding is not getting done properly, they should always be stronger than the metal that they are being applied to.   

[Cedarman]

I think the rod is stainless steel and the plate it is welded to is regular steel.  The plate makes a right angle to the rod at the point of welding so this is the area of greatest stress when the blade snaps and the idle wheel tries to fly out the end of the mill.  The sudden stop also puts a good bit of stress at this point.
My old LT30 sat outside all the time and with the spring tension device and me not lubing the rod as often as I should have, well, it broke.
The new mill with almost 10,000 hours is doing just fine.  But it stays indoors and gets lubed regularly.

Arky, like teenagers, aren't we supposed to test the limits.

[Bibbyman]

I wonder how much vibration may have to do with it.  I know when there is some gunk under the belt, it'll sure put up a lot of noise and vibration.  It's mostly on the drive side that happens though.

[LT40HDD51]

I'd say, IMHO, that all of the above broke it  .

LT40HDD51: if the welds are most generaly the weak point the welding is not getting done properly, they should always be stronger than the metal that they are being applied to.

True enough  , but when a welder makes a whack of one part at once (like WM does) there's bound to be one or two that shouldnt make the grade, but do (welds are hard to visually inspect). Like Forrest Gump says, "s%*t happens  . I had an up/down gearbox once in a brand new mill delivering it to the customer that was no good right from WM's supplier. Accuset wouldn't work right and seemed like the head was binding going up and down. Gears were galled up inside. Quick talk with Sparks and I had it figured.

I wonder how much vibration may have to do with it. I know when there is some gunk under the belt, it'll sure put up a lot of noise and vibration. It's mostly on the drive side that happens though.

Maybe lots  . I've found my idle side B57 with stuff under it before, prob because I don't check it as often as the drive side...

[Hi-Country Orange]

LT40HDD51, don't get me wrong i was not getting down on WM i love my 70 i was just speaking of welding in general   

[WH_Conley]

I have been accused of being a welder a time or two, don't know if it means anything or not, pretty sure Arky's Gorilla weld will hold for a while. Maybe a couple of years  . Maybe the fix aint perminant, might last long enough that nobody will care. I am not critizing the professional opinions expressed before on this thread, might be a bandaid, if the bandaid lasts half as long as the original I would consider it a good repair.

[LT40HDD51]

LT40HDD51, don't get me wrong i was not getting down on WM i love my 70 i was just speaking of welding in general

No worries  . I know what you mean.

...if the bandaid lasts half as long as the original I would consider it a good repair.

Right on, me too. I've been known to goober something back up on occasion  . Lots of times you have no other choice. Gorilla weld  . I like that  .