# Bandit 250XP feed roller shaft repair



## arborlicious (May 21, 2015)

It's finally time to sort out the top feed roller shaft on our 250XP. I'm normally up the tree so not feeding the chipper so was shocked to see the amount of play in the coupling. Pulled off the rubber cover and discovered a bolt where I thought there was supposed to be a tapered pin? The hole in the shaft is actually more of an oval slot.

A mate had a look and reckons he could fix it up by making the taper bigger and re-machining the hydraulic motor side of the coupling to suit.

Any pointers for removing the shaft? Is it welded or keyed to the feed roller? I guess it's time to pull the whole slide box apart and take a look for myself.

Would be sad if the old girl died before reaching 6,000 hrs...only 300 to go.


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## imagineero (May 22, 2015)

You need to come down from the mountain and have a beer with me. 

I'm going to guess that your 250xp has the same problem that mine (and most) end up with - the stator is kind of flopping round on the shaft as it rotates. The shaft has a taper pin in it which isn't a particularly brilliant design. The entire mechanism - stator coupler, shaft and tapered pin pretty much sucks. There's a removable coupler on the stator, and it really ought to be a taper fit on the shaft, or at least keyed. It's neither, the fit from new is kind of loose slip fit. So obviously over time the taper pin doesn't cut the mustard and the shaft and coupler flog themselves out till the stator is wobbling round like mad. At that point the pin often shears, and since the taper is so flogged out it's a common repair to drill it out and replace with a bolt, which keeps you going for a while. Till that shears, Then replace etc etc... Till eventually the coupler itself flogs out real bad. 

There are various solutions, the cheapest takes the most time. The shaft is welded to the feed roller assembly. It isn't particularly a hard job to remove the lift cylinder, raise up the box, remove the bearings then remove the whole shaft/roller assembly. From there the cheapest option is to have the shaft welded back up to good material and machined true again, and same story with the coupler. They can both be welded/machined back to good for about $400-$600 but you'll probably lose a few days of use of your machine at least. Leave the feed roller on the shaft for this. I know a couple of machinists that can do this work, and I can weld it for you if that's the way you want to go. 
The fast expensive alternative is to replace the entire feed roller/shaft assembly and coupler. I can't remember exact prices off the top of my head but somewhere around $2k not including bearings which were not expensive as they're off the shelf from any bearing supplier. Call marriott for pricing/availability. The third option is to replace the shaft only, and coupler but you will need an oxy or a plasma cutter and a steady hand. The feed roller is about 6mm from memory or might have been 8mm. You need to do a neat job of it so you can weld it all back together again. I went this way as marriott had a shaft in stock that they'd had forever and nobody wanted it so they sold it to me for half price. From memory the bill for shaft, tapered pin and coupler came up to about $800 and I was able to do the job overnight and be back to work the next day. The feed roller need not be super concentric/balanced as it rotates so slow, but within 1mm for sure. Again, I'd be calling marriott to check for availability/pricing on the shaft before making any decisions. The coupler alone is about $400 from memory. 

My service ute has a genny, MIG, TIG, plasma and plenty of tools etc if you want a hand. I work for beer.


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## arborlicious (May 22, 2015)

Hey Shaun, thanks again for all the info and offer to work for beer. I certainly owe you a few beers. I've got a Blackbutt to do in Beecroft next month (contract climbing) so I will catch up with you then.

I thought the coupler was supposed to be a tight fit on the shaft. Maybe the design has changed again on later models since they don't seem to have any noticeable movement - at least on a newish 1590.

My mate who works locally (see picture below and you'll know where) has access to all the good machinery too and has suggested the same. I.e welding then machining. Maybe I'll pay him extra to put a taper on the shaft and make a new coupler to suit.

Probably a good time to weld up any rust holes in the feed rollers too.


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## CalTreeEquip (May 24, 2015)

Here's another solution. Remove the coupler and tap two 3/8" holes in it. Fit a grade 8 bolt where the tapered bolt was. Work that bolt as best you can
to get a tight fit. Use the 3/8 bolts to take up any slop.
I have seen this done a lot and it works pretty well.


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## arborlicious (May 25, 2015)

CalTreeEquip said:


> Here's another solution. Remove the coupler and tap two 3/8" holes in it. Fit a grade 8 bolt where the tapered bolt was. Work that bolt as best you can
> to get a tight fit. Use the 3/8 bolts to take up any slop.
> I have seen this done a lot and it works pretty well.



Thanks for the pointer Matt. I think the shaft is too far gone for that to work now though. Need to re-drill the (former taper) hole bigger since it's now more of a slot or weld and machine.


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## arborlicious (May 26, 2015)

Got some prices on parts.

Shaft/Coupler/Pin $544
Feed Roller + Shaft/Coupler/Pin $1,900

6-10 week wait on the parts though so looks like I'll be getting the shaft machined.


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## imagineero (May 27, 2015)

It can be done in a weekend if you get your ducks in a row. It's only a couple hours work to get the roller out if its the top roller. You need 2 guys to lift the top box though (with the roller unbolted). If you have a machine shop that will work saturdays you can get it turned around quick snap. Get the roller out after work on a friday and welded up, down to the machine shop for saturday, and put back in on sunday.

You're better off leaving the feed roller on the shaft as long as their lathe has the capacity. Need to machine it at low speed since it's probably out of balance. Buy bearings before taking the roller out. They're not expensive but from memory the bolt hole size is small on the OEM ones and you cant get the same size bearing with those small holes off the shelf. You could drill and tap the box out which is a lot of work, or get sleeves for the bolts which is what I did. You might be able to find a bearing with the right size holes if you look around. From memory I think the OEM was maybe 12mm or half inch and the off the shelf ones I found were maybe 14mm. 

If the machine shop guy has the bearings and shaft he can make sure the shaft OD suits. I remember you saying you were thinking of making the shaft OD oversize and just machining the coupler out to suit but it sounds like a pain, the bearings then won't fit. On the other hand, welding the coupler is also tricky. Best bet is probably to get just a new coupler and then machine the shaft to suit. It's too hard to make a new coupler, they're splined etc. If you get a good machine fit on the shaft/coupler and drill the taper out and replace with a bolt or maybe 2 bolts it will work well and last a long time (10+years). Key is a tight slip fit, the OEM shaft coupler are a loose slip fit which is the start of all the problems in my opinion.


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## arborlicious (May 27, 2015)

I'll be starting this afternoon, assuming can get a new coupler...surely they'd have one of those in stock!

Thinking to get a stubbie holder permanently mounted to the slide box for these afternoon fixit sessions.

Will post some progress pictures.


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## arborlicious (May 28, 2015)

Coupler + taper pin in stock and about $400. Mate in machine shop is away this weekend so it'll have to wait another week or so. No problem as it keeps on chipping.


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## Hort03 (Jun 12, 2015)

I work with a Bandit industries chipper and we recently had the top feed roller bearings go as well. I was not on the job where the issue occurred but was examining the problematic roller after the job. That led to me finding the loose taper pin. I was wondering how many of of you who have had this issue use mechanized VS hand loading of material? I suspect the bearing damage in my specific case derives from the use of mechanized equipment to feed large diameter material without someone present to manually lift the upper feed roller. The log diameter being too large to fit between the radii of the feed wheels resulting in excess linear stress on the bearing.... Any opinions on this?


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## imagineero (Jun 16, 2015)

Certainly possible. I've seen the rollers on many 1890s bent/cracked because of guys winching while trees on and going too hard on the winch. I've welded a few back together. Trouble is you can't operate the winch and the lift cylinder at the same time, so what a lot of guys do is hook chain to end of tree, winch to the bed, then move the chain back into the crown and winch the tree up hard against the rollers, lifting the whole tree up off the ground. Then flip the lever and operate the lift. It's a huge amount of stress on the rollers/bearings. I don't see any way around it though. Some bigger machines have a remote so the skidder operator can lift/crush and reverse the rollers from the cab.


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## arborlicious (Jul 1, 2015)

The old 250XP is back in action.

Worn end of feed roller shaft was welded and re-machined. The guy said it was fun with the whole feed roller spinning at 600rpm on a big lathe. He only charged me $300 and did a great job of making it a nice tight fit with the new coupler. He even fitted new bearings to the old dodge housings.

Took about an hour and a half to reassemble (with a help to lift the slide box in.) Smacked the taper pin in good and proper before welding the tip to stop it shaking loose.

Thanks again to Shaun for all the tips and tricks.

Now we can start dismantling this largish _Eucalyptus fastigata_ a mere 8' DBH


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## imagineero (Jul 2, 2015)

Glad to hear it all went well and that sounds like a very fair and reasonable price to me considering the time involved. Certainly a lot cheaper than marriott $$$. 

You're gonna be ripping for a while to punch that 8' barrel through a 250XP mate, good rollers or not ;-)


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