morbark model 13 cracked drum bearing housing

[williamd]

I give them a pump of grease about every 5 hours of operation. I've been rip cutting in half logs that seem over a foot in width. If the halves are still wide I'll cut about 3/4 of the way through and they split as soon as they contact the knives. Then I chip each piece separately. I had 2 cracked bearings last year that were a result of abuse. Didn't realize the machines limitations. The last job was tupelo n.sylvatica. Just replaced the knives. I chipped a bunch of ripped logs. No stall outs. I did the chipping. Put them in very carefully a little at time. Went to grease yesterday and Hello, big crack on the bearing housing that sits behind the hydraulic pump, behind the fuel tank. I'm hoping some one will tell me it's me and not some inherent flaw in the drum or shaft. Machine ran smooth when engaged.

 

[nuthin_special]

Are the bearings seizing up or just the housing cracking?

If the bearings are ok which they should be with regular greasing, then you likely have a bigger problem. I'm assuming that all the bols are tight. Maybe the drum isn't spinning perfectly?

From what I understand as long as the wood you're feeding in is small enough to fit, the machine should handle it. There may be more efficient ways to deal with wood if you're ripping and chipping lots.

Your closest morebark dealer should have answers.

Vince

 

[flyingsquirrel25]

Might be something to check on, but might your belt be too tight. Causing torq on the shaft and thus cracking the bearing. Just a thought not sure if it would or not. We use to run the 13 hard at my old job, only problem we ever had was the tray (solid tray) seperated from the chipper due to the repeated crane picks being set (slammed) on it. But morbark fixed that by placing jacks on the back when they installed the winch.

 

[williamd]

No seize. Just cracked housings. I checked the belt tension in the past using a tension meter tool. It seemed to be about right according to specs. I'll re check it. How about the bearing mounting bolts being too tight? I didn't do them last time. Morbark tech said that the repetitive impact of the drum knives on pieces that are too large will cause a cracked housing. So I started ripping pieces to what I thought were reasonable size and fed them carefully. This crack is big too. The others were faint hairline cracks only seen up close. This latest crack you can't miss. The largest pieces I've fed were almost as wide as the mouth and maybe half as tall. Mostly pine and the recent tupelo. Should this machine with sharp knives be handling them? Or am I overdoing it?

 

[wheelloader123]

This is one of the major issues with large, drum chippers. Although they are rated for 14",18",20" diameter material-it does not mean the machines can handle a relatively steady diet of maximum diameter material (they are simply not built heavily enough to take it). Stuff will begin to break and fail. If you look at "true" all day/every day 14"-18" machines, they are enormous and make our little, single-axle machines look laughable. I am speaking of the full time, chip harvesting machines and the like. Your machine is simply not heavy enough for the application. Possibly, though, a contributing cause could be an out-of-balance drum or your shaft retaining bolts (at the bearings) may have loosened creating side to side play. Also, make certain your knives are sharp and your knife to anvil (bed knife) clearance is correct.

 

[williamd]

Thanks for the feedback. Whatever the cause I will ease up on the log chipping and go back to cutting and loading the larger pieces. I'll check the drum for water. But it seemed to run smooth last time I used it. I've seen that thing buck when water infiltrated the drum after it went unused for a little while. No notable shaking or vibrating since I drained it. (Drilled and tapped 3/8 holes, drained it, then plugged them with set screws which I can remove if I have to drain it again). Loose mounting bolts? I'll check that too. Once the bearing is replaced I'll check( very carefully) to see if the drum spins true. I would think if it wasn't there would be a noticeable shaking of the entire machine. As it was a bottle of water would stay put on the machine with the drum engaged. If that tells you anything about drum balance. I hope it's not that$$$$