Chipper Jinma wood chipper disk moved within cage

[fawcekj]

I need some advice on my JM6. I've run about 10cuyds of wood through it in the last couple weeks, mix of dry and green wood, up to about 5" dia. long leaf pine mostly (over 4.5" and my tractor stalls. ) Anyway its been great, and besides I stall trying to lift a 5"x 30' pine tree too. I installed the set screws in the feed roller drive and it has been working well. My current problem is that this weekend after running for a couple hours, it started making a banging noise, and I quickly shut it down. /forums/images/graemlins/confused.gif When I got it back to the barn the chipper blades were hitting the base anvil. So I adjusted the anvil to 0.20 mid way between the spec. 0.10 to 0.3. I also rotated the blades to the good side, about a quarter inch on the outer edge was dinged and the rest of edge was slightly rounded I assume due to impact with the anvil. put the unit back together and engaged the PTO. Slowly increased PTO speed and by the time I got to about 300 rpm it started banging again. It looks like the main shaft for the 24" disk has shifted on its pillow blocks, and the disk has moved forward in the chip cage. There are two set screws on each pillow block bearing, and one was almost falling out, the others were not tight.
Has anyone else had this problem?
Does anyone know what position the disk should be within the chip cage? I was thinking that I would just center it front to back , but then maybe it should be closer to the front to keep the chips cleared to the back of the disk?
Any recommendations to keep it from happening again? LocTight?

 

[beenthere]

From the mental 'picture' I get of what you described, there should be a whole lot more holding the chipper head in its place than a couple set screws. The mass of that head must be pretty big, and set screws seem like would not hold it very well.

Again, just the 'picture' I am getting here. /forums/images/graemlins/wink.gif

 

[fawcekj]

See attached picture, showing the pillow blocks and main shaft.

 

[Affordable]

The flywheel should be centered,the set screws are all that hold the shaft in position ,also make sure that the pillow block bearings are secured in place.We have sold over a hundred of these woodchippers this year,you have to keep the rpms up to keep the woodchipper from clogging up,also check to make sure the main shaft is not bent.Get it centered and slowly turn it by hand to make sure the flywheel is turning straight.We have all the parts for these woodchippers if you every need any

Tommy
Affordable Tractor Sales

 

[fawcekj]

Here is a picture showing the access to the back of the chipper disk. My question on this is how far from the cage to the edge of the fan blades should the disk be adjusted to? /forums/images/graemlins/confused.gif

 

[fawcekj]

Thanks, Jim.
I thought that I would just center it front to back but wanted to get a second opinion. I've read most of your post on this unit (you and others on this site have been a great resource) and I agree it was running great until the set screws worked themselves loose. I guess I need to get some more loctite.
Thanks again for you advice,
Keith /forums/images/graemlins/laugh.gif

 

[inveresk]

Fawcekj, I'm considering buying a Jinma 6 chipper so did a search on TBN on reliability. This thread notes the various custom modifications recommended by TBN members to ensure trouble free running. I seem to recollect that the problem you are facing was dealt with somewhere in this thread but I can't recollect where.

Jinma chipper

 

[Ranch_Hand_Supp]

fawcekj, I think???.... When the shaft walked back it took the flywheel with it...as you know. When that happen it closed the gap between the knive and anvil and before it started hitting [noise] the wood chips were getting smaller and it could not keep of with the feed roller....engine stall.

If the flywheel is still tight on the end of the shaft ?......and if the belt pulley has has not moved on the shaft.....when you move the flywheel that should bring the belts back into alignment ..close. I justed looked at one I have in the shop I kept for a demo and it looks like it is as close to the tractor side as you can get without touching...... looks like it would have to be that way so it could make a fan box and blow.

Play with your gap setting on the knives....try to match size of chip to HP.....RPM's have to stay up...... using a dime will get you close to start and maybe OK on some wood or all??

Try to turn by hand before PTO engagement. [slide pto off]

Sharp knives are a must.

Watch Fingers !!!!!

Let us know

Ronald
Ranch Hand Supply

 

[fawcekj]

Tommy,
Sorry about the post calling you Jim. I must have had someone else on my brain. Anyway I got the chipper adjusted by moving the pillow blocks so that the flywheel fan bars are about 3/16" from the back of the shroud (or cage) at both the inner and outer arc of the flywheel. thighen all set screws with loctite applied. powered her up and she's back eating up trees like crazy. Thanks again for your quick reply.

Ronald,
About 3/16" was as far back as I could get the flywheel to the shroud, and it seems to be blowing the chips out about the same as it did when first used. All fingers still intact, just one little nick. Thanks for the info.

Goerge,
thanks for the info, I read through the old post and there was a mention of the main shaft pulley moving and that helped in getting the pulley back in line after getting the flywheel back in line. For the money this is a great machine. I researched chippers all over the net and was not able to find any other chipper that was as well built (simple design,heavy duty steel, mechanical feed roller, 6" dia, off the shelf bearings, belts, bolts, ect) But it does require keeping an eye on set screws, and nuts bolts are tighten. I think Loctite will help.
Keith /forums/images/graemlins/laugh.gif

 

[VT_Kioti]

I don't want to go too far off topic but I am a little confused. What did you mean by "I installed the set screws in the feed roller drive and it has been working well."
I have the same chipper (Jinma 6) and I have not read anything about set screws in the feed roller drive. I have made the mods on the ends of the roller drive shaft and it has been working quit well. Have I missed something?

Thanks
Al

 

[fawcekj]

Al,
I found this post on another site that one guy was talking about the knuckles on the driveshaft popping out and getting damaged. He replaced the ends with socket universal joints. the second poster commented that there is a hole in the end of the driveshaft square scoket ends. See attached picture. He suggested taping the holes and puting set screws in each to keep the square shaft ends from pulling away from the gear box and the roller shaft. It made since to me that this was the real problem with the driveshaft, that was causing the knuckles to break. So I picked up two 3/16 set screws and a 3/16-24 tap from TSC and tapped the holes.
I've run about 14cu-yards with no problems with the driveshaft.
See link to TractorPoint.com
TractorPoint.com JM6 driveshaft problem
Userid: kwschumm :
"I believe the big problem is that the female square end can cock and cause the male end to round off and eventually shear. The female square end of the driveshaft has two holes in it that can be tapped for set screws. That should keep it from sliding back and cocking. It looks like it was designed for this but for some reason they didn't bother."
Hope this helps,

 

[VT_Kioti]

Kieth
Thanks for the response. I see what you are saying but I thought the holes were to allow grease to enter the end housings. I found a post where the male and female ends were not cast the same. The poster discribed grinding the long end to match the short end and that elminated the binding on my shaft. Ginding Ends to Match It is still a pain getting grease into the ends but I use a needle injector and that seems to get the grease in. If I have a problem in the future I am going to consider the 1/2" impact u-joints.

Al

 

[rswyan]

</font><font color="blue" class="small">( It made since to me that this was the real problem with the driveshaft, that was causing the knuckles to break. )</font>
While it may make sense I think that it's only part of the problem ... I put the set screws in mine and ended up grinding off one of the male ends that fit in the ball and socket joint (probably the one that was described as having a poor fit and binding.) I picked up the 1/2" impact u-joints to do that as a fix but have been too busy to get around to it.

 

[mark1]

Hi fawcekj ;Just a note about those set screws on the pillow blocks..They do not lock the shaft to the bearings,they lock the collar to the bearings.. @let me explain,,if you loosen the set screws the collar will turn on both the bearing and the shaft,the bearing has a hub that is concentric inside the collar When you locate the correct position that you want to maintain you turn the collar (*some have a couple extra holes that you give a GOOD SMACK with hammer and punch) or one of those funny spanner wrenches with the pin in the end!This is what locks the shaft in place to the bearing.Then you tighten the set screw or screws which locks the collar to the bearing hub. These type of pillow blocks are used the world over and if installed correctly work great. Check it out,,loosen the set screws,rotate the collar,you will see it gets loose or tighter.because of the concentric.
Hope this helps.

 

[fawcekj]

Randall,
I agree, I also made sure the ball joints were operating smooth. I still believe that if you can keep the sq. socket joints from sliping off, the ball joints won't bind and jump their circlip's. time will tell, I'll keep the impact u-joins in the repair list if /when it fails.

Mark,
Where were you 5 days ago, just kidding. The locking collar explains alot!!! Explains why one pillow block would move on the shaft and the other one would not. I'll get the loose one locked down in the morning, you may have just saved me from having to replace my blades, when they slam into the anvil again. The last time I got it shut down before they got distroyed, but might not have been so lucky next time. I hope to get a few yards chiped tomorrow.
Thanks guys,
Keith

 

[mark1]

Hi Fawcekj:
Glad my info helped..Sorry for missing your post a few days ago..I do try and monitor these post a lot but musta missed it.There is also a ton of Info about Chinese tractors and implements on the regular CTOA boards that may help
http://d832691.u37.infinology.net/ldu//index.php
Also a New York CTOA
http://nortrac.proboards26.com/index.cgi?action=login
/forums/images/graemlins/smile.gif

 

[botaman2]

Are the set screws inserted into stay collets,or are they inserted into the inner race of the pillow block bearing?

 

[fawcekj]

Well I tried to lock the main shaft bearings to the shaft and it does not appear that the bearings on my unit have a eccentric locking collar. The pillow block with bearing is listed as P/N GB/T7809-1995. It looks like it has a solid stanless steel race (with 2 set screws) pressed into the bearing and then that slides onto a machined ridge on the shaft or axel. I'm not sure if maybe they changed the pillow block assembly on newer units (mind has a build date stamed on it as 07/2005) If I do a web search on that P/N, I get the following chinese page info :
Standard number: GB/T 7809-1995
Chinese name: Outside rolling bearing spherical surface &#29699;&#36724;&#25215;&#24231; external dimensions
English name: Roliing bearings - Housings for insert bearing boundary dimensions
Uses the degree: eqv ISO 3228-1993
Issues the date: 1987-5-28
Revises the date: Revises the date 1995-12-14
Implementation date: 1996-8-1
Replaces the standard: GB 7809-1987
The ISO equivilent P/N ISO 3228-1993 corresponse to a standard non locking race with two grub screws (set screws) that are offset from each by 120 deg. these grub screws go straight through to the main axel shaft , not to a second bearing ring.
It looks like the planed positioning of the bearings is based on sliding the first bearing onto the shaft until it contacts a raised machined collar, on the shaft, that the bearing will not go past (closes bearing to the flywheel) The bearing closes to the pully side sits on a machine ridge or race on the shaft then there is a spacer collar or washer that slides on the shaft, then the pulley butts up to the washer and it has a tappered locking ring with three bolts that pull the pulley onto the locking ring. (pulley also has a keyway pin to keep it from rotating on the shaft).
Anyway I got it all put back together yesterday morning and went to the woods ran it for about 5 hours and it ate everthing as fast as I could feed it into it. (I need to get the wife out to help more it works faster than one person can collect and feed) ended up with about 2 cuyds of chipes, and a lot cleaner floor out in the back 5 acres. I'm really looking forward to thinning out the pines on that acreage. Planning on maintaining it as a wooded nature trail area, but want it to be healthier for the larger trees and the deer, turkeys that live back there.

Thanks to everyone for all the info, it really helps to brainstorm with others.
Keith /forums/images/graemlins/smile.gif