Jinma 6" or 8" PTO chipper for my 28 HP PTO?

[Lagonia]

The title pretty much summarizes what I want to find out. I know the 8" HP recommendation is 30-45HP and I think the 6" is 20 to 35 HP. I could probably run the 6" just fine but I am wondering if anyone is running the 8" Jinma on a sub 30 HP tractor?

Thanx

 

[inveresk]

I have the 6" on a Kubota L3130 and it wouldn't handle 8" material.

 

[RonMar]

I have never seen an 8" Jinma chipper. I have a 6" chipper on a Jinma 284, and it chews thru most stuff wonderfully up to it's capacity when the blade and anvil are sharp and set properly. In fact, bring a friend or 2 along, as it takes at least 2 people to keep it fed I have been able to overload it under certain circumstances(blades getting dull), so an 8" chipper on my 28HP machine would probably do this more frequently.

Here is the problem with overloading this type chipper. The main rotor, besides carrying the cutter blades, also has the blower fins that move the massive ammount of air that carries the chips thru the housing and out the discharge chute. Overloading, or slowing down the rotor in ANY way is a BAD thing, and can result in the rotor completely freezing on jammed chips. This happens quicker than you can jump up on the tractor and disengage teh clutch/PTO. This can take a lot of time(I am talking HOURS here) and a lot of patience to clear the jammed chips from the housing. It can also possibly damage bearings or knock the shafts out of alignment if allowed to occur... I found a broke pillowblock bearing on the mainshaft after the first time this happened. it could have been a defective casting, as the second time it happened I had no failures. The first time it happened due to me feeding a dull blade too much, the second time, the throttle friction loosened and allowed the RPM to drop off and I didn't catch it. I have only allowed it to happen twice, and listen very carefully to RPM changes while chipping.

For 28HP, my reccomendation would be the 6". With sharp blades and the blade to anvil gap set to no more than .030", it is a chipping monster that will run 2 people ragged trying to keep up. Quite frankly, anything larger han 6" gets cut into fire logs for the backyard fire pit or daughters woodstove

Good luck

 

[greg_g]

Not that they don't exist, but I've never seen an 8" either. In this country anyway. I've got the Jinma 6", and it worked great on my previous tractor (~45 PTO hp equivalent). But my new John Deere only is only spec'd at 35 PTO hp, which I find insufficient for hardwoods. There's no way to regulate the speed of the feed roller, it's an on/off design. At 540 PTO rpm, 45 hp was sufficient to keep the flywheel at speed. But with no way to slow down the feed roller, 10 less hp from the John Deere can't always keep the flywheel at speed. I can run 6" softwoods through it with impunity, but sometimes the bigger hardwood limbs and trunks bog it down. At first, I thought the blades needed maintenance. But the edges and gaps turned out to be fine. So even though the chipper itself is rated to accommodate up to 6" stuff, I now selectively limit it to 4" stuff when powered by the John Deere. And running anything less than full flywheel RPMs is just asking for a breakdown. I'm currently waiting for parts to repair the feed roller driveshaft.

//greg//

 

[KevinMcD]

I would also stick to the 6". I have a 6" and it works well with my Kioti 30 HP chipping softwoods, but it will bog down on the bigger softwood and I had it stall on me once when trying to chip a 3" hardwood limb. And it does take time when you have to service them. I also have a crack in my pillow block housing on the main shaft but not sure how it happened. RonMar, did you buy a "Jinma" pillow block through a dealer or get one through a surplus store or wholesaler? The dealers seem a little pricey.
Kevin

 

[RonMar]

Dealer I bought it from replaced it under warranty...

 

[grsthegreat]

I have the Jimna 6" and ran it for years on my JD870 28 HP tractor with 25HP PTO. It worked fine but did lug down on the 4-6" range considerably. Using the same chipper on my 45 HP DK45 there is NO drop in RMP chipping the larger stuff. I wouldnt recommend the 8" for your unit from my experience. Besides, 6-8" makes nice firewood

 

[grsthegreat]

By the way ranchhand supply (a tbn member) sells the Jimna 8" and 6" chippers. http://ranchhandsupply.com/woodchippers.html

 

[Lagonia]

Thanx guys for your suggestions. The 8" Jinma is also on eBay:
WOOD CHIPPER PTO DRIVE TRACTOR farm 3 PT SHREDDER -8" ! | eBay

It looks like the 6" is about $300 cheaper.

Of course, the one that really caught my attention is the Woodmaxx 8" hydraulic but is a cool grand more expensive than the Jinma. But then, hydraulic, adjustable in-feed control is not bad either....

 

[DeeDubya]

I run an 8" Liberty Pro on my Branson 2910i which is 25hp at the PTO. Works just fine.