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Discussion Starter · #1 ·
Earlier this year I purchased a Jinma chipper and thought I'd post a review of it. This testing was done with a JD 4310 tractor with 25.5 pto hp and the wood I chipped was mostly Douglas Fir with a smattering of vine maple thrown in the mix. A smaller tractor can run this chipper but you may not get the full 6" chipping capacity with less power.

The Jinma chipper appeared to offer a lot of capability for the money. Comparable big-name chippers generally cost $3500 and up, so this $1550 unit seemed like quite a value. Features of this 780 lb. chipper include 6" cutting capacity, heavy 24" 175 lb. flywheel with two 10" cutting blades and anvil, a 24"' square feed chute that is positioned horizontally at hip level for easy feeding, a chip blower that makes it easy to blow chips into a wheelbarrow or truck/trailer, and a belt driven feed roller that pulls material right into the cutting blades. This chipper runs on a standard Cat-1 540 pto output and a pto shaft is included. The flywheel assembly is driven by a set of five belts from the pto shaft, and the feed roller is driven by a single belt. The chinese belts are of suspect quality, but good quality replacement belts are available at any NAPA store.

I bought the chipper new for $1550 site unseen in January from Adams Tractors in The Dalles, Oregon. In addition to the chipper I purchased an accessory kit for $120 that includes an extra NAPA feed roller belt and an extra set of blades.

Initial inspection upon arrival revealed a few shortcomings.

During operation the feed roller may need to be raised a bit when feeding larger material (thicker than 4" or so). Unfortunately, the lever that is used to raise the feed roller is located awkwardly above and behind the feed chute. To use this the operator must reach up and over the chute to reach the lever while simultaneously trying to feed material. This back-tweaking operation is nearly impossible and generally requires two people. I had a footpedal fabricated that makes this an easy one person operation.

Also, the 3 point hitch geometry would not work with my JD Top-and-tilt kit. Although the lower pins are dimensionally a Cat-1 standard 26" apart, the top pin is 20" above the lower pins and set 6" back. My hydraulic top link did not extend far enough to reach the top pin. Furthermore, I wanted to use the chipper with my JD I-Match quick hitch, which requires 15" between the top and lower pins. The fabricator made a removable drop-hitch adapter that put the top pin in the same vertical plane as the lower pins and dropped it to meet the I-match dimensional requirements. It is necessary to remove this new drop-hitch when changing drive belts.

Before starting it up for the first time I did a once-over, greasing everything and tightening all the bolts. Boy am I glad I did! The main shaft off the pto rotates in two bearing pillow blocks, each of which is held in place by two bolts. One of these four nuts was missing and another was very loose! This could have been disastrous. A trip to three hardware stores finally turned up the 14mm 1.5 pitch metric nuts that were required. Unfortunately, one of the grease zerks broke off during this maintenance so I'll have to fix that.

Once this work was complete I hooked the chipper up to the 3-point hitch and discovered that the included pto shaft was at least 12" too short! A new pto shaft was purchased and cut to size and I was up and running.

The first item fed into the chipper was a dry 10 foot 2" thick douglas fir tree. I was amazed at how easily the chipper pulled the tree into and through the chipper and voila, it was gone. The blower blew chips into a fairly small pile with good force, so it would be easy to place the chips directly into a wheelbarrow or small cart. The next tree was about 3" thick. This was fed into the chipper without raising the feed roller which caused the feed roller to jam (due to loose belt) and the cheap chinese belt started squealing and smoking. I lifted the feed roller and it then grabbed the tree and pulled it right through. Very impressive, but I had to do something about that belt.

Removal of the feed roller belt cover was fairly simple, and revealed the gearbox and belt adjustment and clutch mechanism. While installing the replacement NAPA A-36 belt I decided to drain the chinese oil out of the gearbox and replace it with some fresh gear oil. The old oil was pretty sickly looking and after draining it there were some fine metal particles in the pan so changing it was a good call. Reassembly was easy and the new belt was adjusted good and tight.

After using it extensively for five hours or so I must say that I'm very impressed. It handled everything we through at it, at least a couple dozen Douglas Fir trees and a lot of pruned deadwood. The largest material run through it was about 6" thick and the chipper didn't have any trouble with it but 25 pto hp is a bit marginal for material that large. It was amazing to put some 25-30 foot 5" trees through the chipper, without limbing them first, and have them gobbled right up. Trees that large required a little pushing since the feed roller didn't quite have the bite to pull them through with all the side branches. The wide feed chute helps immensely with this situation but these small chippers can only handle so much. They are not the 200 hp monsters that are used commercially.

Near the end of the day I screwed up and backed the chipper into a stump that I couldn't see from the drivers seat. The base of the chipper was bent fairly badly but it didn't affect operation, and it looks like its an easy piece to unbolt and flatten out. Oops.

Overall, I'd say this chipper is an exceptional value. Parts availability was a concern, but most of the parts can be bought off the shelf. In fact the manual that comes with the machine lists North American part numbers for many components - bearings, belts, and pulleys are all off-the-shelf items at most industrial supplies. A rumor is floating around that the blades have been cross referenced to those of another manufacturer, but I have not validated this yet. My dealer has no trouble supplying spare blades though, and he says the few parts that are proprietary are available but there may be a wait on them.

If you are looking for a turnkey chipper with strong dealer support this one may not be for you, but if you're not afraid to do some of your own maintenance and repairs I'd highly recommend this chipper.
 

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Good review to bad you had to do all the modifications to it before you could use . But it made easy work for what you needed it for.
Jody
 

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Discussion Starter · #3 ·
If I didn't have a hydraulic top link and was willing to not use the I-match the hitch wouldn't have been an issue.

Similarly, I discovered the foot pedal isn't as big of an issue with a good feed roller belt properly adjusted. So this wasn't a must-have modification, but raising the feed roller without it would still be a back-tweaking movement.

I figure we opened up about 1/4 acre or a little less. If the chipper makes it through the remaining 14 acres without major repairs it will certainly have earned it's keep.
 

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Have you made enough chips to start selling mulch? Great review Ken. How does the 4310 like running the chipper when you put some hefty size pieces through it?
 

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Discussion Starter · #5 ·
We probably have about six yards of mulch so far. We're gonna use it as a floor for the trail we're building! That way we can walk the dog in the rain while staying (somewhat) dry under the canopy :)

When a six inch wide piece is chipped the 4310 bogs down pretty good. No problem for me since six inch stuff is firewood, but if somebody needs to chip that stuff on a regular basis another ten hp would be a good thing to have!
 

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Can you reverse a log out? How is it on safety features? Is there an emergency stop incase you get a sleeve hooked on a limb?
 
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Discussion Starter · #7 ·
There is no backing a log up mechanically, but there are two mechanisms to handle emergency situations.

There is a big easy to reach lever above the feed chute that controls the feed roller spider clutch. Push this lever and the feed roller stops.

There is also a hard to reach lever up and behind the feed chute that raises the feed roller up. Pull this lever toward you to raise the feed roller - this allows you to pull material out from under the roller. The problem with this mechanism as shipped is that it is so awkward to use it almost takes two people. That is why I retrofitted a foot pedal on it. Now I can just step on the pedal to raise the feed roller. I use this foot pedal every time I chip and can't imagine not having it.

Also, I had a problem with the feed roller drive shaft. Anyone with one of these chippers should make a small modification to it. Each end of the drive shaft has a female square socket. Each of the square sockets has a hole in it. This hole should be drilled and tapped to hold a set screw to keep the socket from sliding off the square drive ends of the feed roller and gearbox. If it gets a little gummed up and the socket comes off it will round off the square drive ends in short order. The setscrew fixes that problem. Also, the two feed roller drive shaft universal joints should be kept well greased even though there isn't a zerk fitting for it.

My chipper now has about 40 hours on it and I still think it's a HECK of a good value, but you will probably have to maintain it more than a $10k pto chipper. I think it will outperform most $5k chippers though.
 

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Discussion Starter · #8 ·
Using a piece of equipment long term sure exposes it's warts. Maybe my Jinma chipper is a bit too small or too consumer-quality for my needs but it seems that every 15 hours of operation requires 5 hours of maintenance. Here's some more issues that have come up.

The feed roller drive pulley is mounted on the main flywheel shaft which passes through a hole in a sheet metal panel. This hole is about a half inch larger than it needs to be, which creates a gap between shaft and panel. The ends of small brush can enter this gap and they then get wrapped around the shaft and pulley. Eventually they bind the shaft, and removing them is a tedious and time consuming operation. You have to pull off some sheet metal covers and half the feed chute and grab one end of the brush while manually spinning the flywheel backwards and avoiding the knives. This probably could be prevented by pulling the pulley and riveting another piece of sheet metal with a smaller shaft hole to reduce the gap.

This problem may have been exacerbated by a too-large gap between the anvil and knives. The manual calls for 0.010-0.030 clearance and I suspect the clearance from the factory was much larger (but didn't measure before I had already removed the anvil). I replaced the anvil and set the clearance to 0.020. We'll see if this helps.

Also, the knives don't seem to stay sharp more than 10-15 hours. Changing or reversing knives also takes a couple of hours. It's a real PIA to dig the sap/dirt out of the four hex head screws and associated nuts that hold each knife, but they have to be cleaned up before they can be removed. I spoke to a guy who makes chipper knives out of high quality alloys, and he said he could make some knives for me for around $100/set. I may take him up on this since the price isn't that much higher than factory knives.
 

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How much mulch have you processed vs. how many hours of maintenance total so far? I am not sure how much better the American made chippers are compared to your Jinma. I know they are over double the cost. Thanks for the review Ken. VERY good info. to have.
 

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Discussion Starter · #10 ·
That's a different way of looking at it. I'd guess I've processed about 15-20 yards of mulch and had about 15 hours of repair and maintenance. Not a very good record. If a few more mods were made I'm sure I could reduce the maintenance load, but I'm not sure if I want to spend the time and effort. It turns out that a 6" chipper is sort of marginal for my needs anyway, so I'm thinking of ponying up the bucks for a 50-75 hp trailer mounted machine. In Oregon we get a 35% tax credit for buying chippers, plus we can write it off on our federal taxes so the $10-12k price on a good used one can be swallowed easier. After 2-3 years of use the bulk of our chipping will be done and I could probably sell it for a good amount when done with it.
 

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Bj

I have Jinma model 6 chipper I bought used last year. Before I purchased it I read an article on line which talked about the weekness of the feed roller shaft. Today the end broke off the shaft and i can't find the modification, which I thing was to replace it with a short shaft with universals at each end.

Can someone help as i don't want to replace the shaft with a new factory shaft as this proble is likely to reoccur.

BJ
 

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I have Jinma model 6 chipper I bought used last year. Before I purchased it I read an article on line which talked about the weekness of the feed roller shaft. Today the end broke off the shaft and i can't find the modification, which I thing was to replace it with a short shaft with universals at each end.

Can someone help as i don't want to replace the shaft with a new factory shaft as this proble is likely to reoccur.

BJ


We are in our 5th year importing the China MFD PTO driven wood chippers. Since China has no Copy Right Laws there are several Jinma chipper clones/copies here in the USA.

We offer service & parts for most all the China MFD chippers. There has been several types / styles of factory feed drum roller drive shafts put on these chippers. Some better than others!.

The new chippers we sell have a new improved greaseable , pin style flex joints with a heavy duty/STRONGER spring. We also offer this shaft as a up-graded replacement for the weaker designed factory shafts.

Many times our customers have to email us pictures so we can see which set up/chipper they have and go from there.

Let us know if we can help you.

Ronald
Ranch Hand Supply
 

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I just purchased a Jinma wood chipper from Ranch Hand Supply in Chesapeake, Va. Ronald Macon goes through these machines before shipping them out. While assembling the base and infeed/outfeed chutes (which took about two hours,) I checked the various nuts/bolts and he had made sure every one was tight. He also replaced the chinese belts with good industrial belts, greased everything and set the blade gap. I had been concerned that the PTO shaft would be too short, but in fact I had to cut a couple of inches off it. It only took a few minutes to complete. I extended the top link connector on mine as it was set back a couple of inches too far. I also took some 3/4 in electrical conduit and made a foot pedal to raise the feed roller. After bending it in the right shape, I simply took out the plastic plugs in the end of the feed roller arms and slid the conduit in. Tension keeps it in place and I can slide each side out when I'm done, but in all honesty, I really don't think I would have need of it. I've used the chipper about three hours and have only needed to raise the feed roller once. After using this machine, I realize it is a better machine than I thought I was ordering. I'm convinced that Ronald and Ranch Hand Supply will do everything necessary to keep his customers satisfied. I'm using this unit on an I-H 684. Carey Knight
 

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Very good review. I have used mine for 9 years now. i have had the same issues as you.The last thing I replaced was the roller drive shaft with a new inproved pin style flex joint type.
I have done hundreds of trees and am still pleased with it as i can work through the small problems. Still on the first set of knifes. Just keep sharping them. Some welds have cracked which I had to reweld
There is no backing a log up mechanically, but there are two mechanisms to handle emergency situations.

There is a big easy to reach lever above the feed chute that controls the feed roller spider clutch. Push this lever and the feed roller stops.

There is also a hard to reach lever up and behind the feed chute that raises the feed roller up. Pull this lever toward you to raise the feed roller - this allows you to pull material out from under the roller. The problem with this mechanism as shipped is that it is so awkward to use it almost takes two people. That is why I retrofitted a foot pedal on it. Now I can just step on the pedal to raise the feed roller. I use this foot pedal every time I chip and can't imagine not having it.

Also, I had a problem with the feed roller drive shaft. Anyone with one of these chippers should make a small modification to it. Each end of the drive shaft has a female square socket. Each of the square sockets has a hole in it. This hole should be drilled and tapped to hold a set screw to keep the socket from sliding off the square drive ends of the feed roller and gearbox. If it gets a little gummed up and the socket comes off it will round off the square drive ends in short order. The setscrew fixes that problem. Also, the two feed roller drive shaft universal joints should be kept well greased even though there isn't a zerk fitting for it.

My chipper now has about 40 hours on it and I still think it's a HECK of a good value, but you will probably have to maintain it more than a $10k pto chipper. I think it will outperform most $5k chippers though.
 

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JINMA quality control is nonexistant

I bought an 8" JINMA from Ronald at Ranch Hand. He does a great job of preparing these things, but even he cannot prevent all problems. Mine is still unused as the PTO shaft that came with it had the keyway where the release pin fits drilled too close to the inside of the shaft and so the pin does not clear the keyway and the shaft cannot be mounted.

I have bought PTO shafts lots of times and have never had this happen. This is truly an example of crap Chinese engineering. Now I have to spend $235 for a new shaft or try to fix this piece of junk. JINMA will not honor the warranty as I shortened the shaft by 1" before I discovered that it would not go on the tractor spline.

With this shoddy work I am now concerned about the longevity of the entire unit. You have to be an idiot to drill a keyway in the wrong spot and have absolutely no quality checks not to catch it!

Count me as a worried user.
 

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hi, I bought a 2003 jinma model 6 wood chipper. It's in quite good condition. I am looking for replacement knives.
Where to buy these knives? I am from belgium
 
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