Farmi 260 Chipper

[N1ck]

5 hours ago, GarethM said:

Having repaired a lot of tractors over the years, I've learnt to always start at the simple things as they're usually also the cheapest 🙂.

 

Was the hydraulic block OEM aswell, just thinking if the port opens to feed oil to the roller is the return pipe from the roller able to feedback the oil to the tank ?.

 

As both rollers are connected together, one solenoid directs oil in, the other solenoid should direct oil out. Hydraulics are a hard subject to describe.

Yes all OEM just slightly different eras. The RDS control box has replaced a simpler electronic control which just had a manual forward and reverse switch controlling 2 solenoids. 

[GarethM]

Ok, it's just a hydraulic shuttle with solenoids at either end.

 

They can get blocked internally, but it's usually rare as it's a sealed system.

 

Have you adjusted as per page 14 ?.

 

https://www.google.com/url?sa=t&source=web&rct=j&url=https://melit.ee/wp-content/uploads/2020/04/EN-HF260-EM-03487230-1.pdf&ved=2ahUKEwj6hufhrsf6AhVDgv0HHYocDGYQFnoECCEQAQ&usg=AOvVaw31OVzVgzVOZBLMAUBuJ8F4

[N1ck]

So an update. We swapped the modern RDS box with stress control for the old manual electro-hydraulic switch mechanism and we still got an intermittent top feed roller. It's not all the time and not necessarily on large bits, it just stops every now and again. This seems to rule out an electronic problem.

 

Next we removed the top feed roller motor to see if the splines were worn. While there was some wear it was definitely not enough for the motor to slip in the feed roller. My thoughts were a bad hydraulic motor, but opinion seems to be that it would either work or not and this one works intermittently.

 

The other suggestion was that the hood the top feed roller sits in was bent allowing material to jam up inside, but once removed it looks OK.

 

Anyone got any other suggestions?

[Arboraeration]

These are not specific to your chipper, more just general troubleshooting:

 

Have you tried swapping the coils over on the solenoids to rule out a faulty coil? 

 

The wiring to the solenoids looks new, are they wired correctly?

 

Does the motor have a case drain? Has this become blocked? 

[N1ck]

We could try swapping the coils although the solenoids operate the directional valve OK so I doubt it is that. To get the feed roller working again you usually need to toggle the rollers back and forth a bit.

I'm pretty sure it is wired up OK, the RDS control box came with an extra solenoid for a dump valve but our directional valve doesn't have one so this is redundant.

I can't see a case drain on the motor but I plan to disconnect the hydraulic feed and return and rotate the motor by hand to purge the oil and see what state it is in.

[N1ck]

Can you get airlocks in hydraulic circuits? If so how do you purge them?

 

Also, does anyone know if this T piece on the return hydraulic hose is a shuttle valve, and if so can they get blocked?

[GarethM]

You don't really get airlocks, bubbles maybe but you just cycle everything and they will clear relatively quickly providing you have enough oil.

 

The t joins the two rollers together, so they turn at roughly the same speed and pull the wood in the same direction, as one roller turns clockwise and the other anticlockwise.

Edited November 10, 2022 by GarethM

[herco]

Have the same problem with ch380, just reverse for a few seconds.

[GarethM]

https://www.google.com/url?sa=t&source=web&rct=j&url=https://melit.ee/wp-content/uploads/2020/04/EN-HF260-EM-03487230-1.pdf&ved=2ahUKEwi6tvzotqn7AhVhRkEAHXWvCZ8QFnoECBYQAQ&usg=AOvVaw31OVzVgzVOZBLMAUBuJ8F4

 

Page 32

 

[Treemover]

Fault finding is an art, if possible, I would wire in a volt meter into the harness somewhere, just to make sure you are getting 12-14v continously, all you need is an earth for a split second, but if you found that voltage drop at the time the rollers stop, you def know its electrical. 

 

I have coils and solinoids on my tree spade and generally they are trouble free, but they can corrode and cause problems, and internally too. I had some go on a fendt tractor so they are wear items.

 

I would also mount a pressure gauge into the roller pipes, and again see what is happening in real work situations; if youy find the pressure rises, then it might be a blockage or brearing; but if it lowers then its a leak in the system. 

 

Failing all that its either trade in for new, or get a proper pro to have a look; but theres no fun in any of those options and our missus's would castrate us if they found out