Another Fabtek Gremlin

[Corley5]

It started as an intermittent problem.  The head would stop measuring.  I only use the independent wheel.  I could open and close the limbing knives and it would start working again.  I limped through the end of the last job and got it done just as it quit reading altogether.  It won't do anything now.  Today we checked the connections at the junction box on the head and the continuity of the wires from the wheel to the box.  It all checked out fine but as I'm typing this I'm thinking that we should have checked for voltage too.  I think the issue is in or near the wheel because of it working for a while after cycling the knives which also cycles the wheel's arm but I don't know    Maybe it's the encoder ???  Is there a way to check them  ???  New ones from Jorral are 500 buxs.  Any ideas  ???

[furltech]

I am not sure if i can explain myself and i should also state that i am only familiar  with encoders on timberjack equipment .But any time i have had an encoder go bad i could sort of feel it when i took it out and spun it by hand.Felt sort of grindy like a bad bearing  .Also one time i thought i had a bad one go on my patu and i found a place online that would rebuild them it seemed like a cheaper alternative .Dont know if i am any help but it is what it is .

[1270d]

I agree with furl on how a bad encoder can feel.   Check continuity on the wiring harness while moving it around to see if it has an incomplete break somewhere.   Another wire could be bad elsewhere and be back feeding causing funny stuff to happen.  For example when my measuring wheel shorts the saw sensor acting up is the first sign.

[snowstorm]

i took an encoder apart just to see what is in there, this one had a plastic disc glued to the steel shaft. on the disc there are diodes and all kinds of printed circuits. on mine when i turned it by hand i could feel the disc all a drift in there 

[Corley5]

I did switch to a different wire after checking continuity.  The blue had a lower reading than the rest and it's a 3 pair wire using two pair so switched out the blue for the orange.  It made no difference.  Between firewood loads tomorrow I'm going to switch out the yellow wire for the green which is the other unused one and check the continuity from the junction box in the head to half way up the boom.  Then I'll pull the encoder and see what what's going on.  Thanks guys  8) 8) 8) 8) 8)

[deastman]

If you take the cover off of the measuring wheel  with the power  on there should be some lights lit up on the encoder itself and if you turn the wheel by hand there should be an encoder light that flashes on and off as the encoder turns. It's been a while since we worked on mine and I can't remember what color lights or how many lights should be lit up on the encoder when it is working right.

[ABTS]

My brother and I have had our issues with this . Have found wires to be the problem 99 % of the time have repraced wires from encoder to the jct box because of flexing . We  have a 2001 153.Yiu will get good conntinuinty  with one strand of wire but it won't carry enough voltage so I would start with the wires.

[Ken]

I agree with ABTS.  I try to keep spares of those simple wires.  When a problem like yours shows up it does not take long to switch wires to eliminate possible causes.  Good luck.

[Corley5]

  There aren't any lights on this encoder.  The wires from the encoder to the junction block are the usual offenders  ??? 
  I haven't had time to tinker with it again.  Been running firewood while we were waiting for forwarder parts to come in and back.  Car Quest got the clutch, pressure plate, throw out bearing and pilot bearing and resurfaced the flywheel.  Weller Truck got the tranny back to me today after a total rebuild $$$$$.  We're going to reassemble it tomorrow.

[barbender]

Hopefully this is the year of big profits for you, Corley. You've sure had a lot of big repairs lately :(

[Corley5]

This clutch issue has been expected and we just came up to point where it was a good time to change it.  I knew the tranny needed work but not that much ;)  I was just looking at my Deutz manual and it's recommended that new flywheel bolts be used.  I hope CQ has the right metric bolts in stock otherwise it'll be Monday before reassembly.

[Corley5]

After more continuity testing, hooking up new wire externally and talking to a couple more Fabtek four roller owners I ordered a new encoder from Joral today.  It'll be here in a couple days.  The old one was apparently just that, an old one.  No LEDs and it's silver.  Newer ones have LEDs and are red from what I've been told. The new ones can be tested by turning the shaft.  If the LEDs flicker it's working if they don't it's not.  Joral's price was a 100 bux less than Cat's and some Cat dealer's sell Joral's encoders. 
  I hope to be producing wood again by the weekend.  I meet with the DNR forester Friday to get started on the new job.  I'm hoping to be able to set up the landing in an old wildlife opening after opening/brushing the access road to it.  That'll give us lots of room for decking, trucks and setting up the firewood machine.  We were going to a private job but an access issue has developed that needs to addressed.  We can't have that meeting until the first part of September.

[wannaergo]

Glad you got it figured out. I just went through the same ordeal with my 501. Independent wheel wouldn't measure, and all the wires seemed good. Pulled the cover off the wheel and realized that it was smashed in and had broke the key off the cover, and wrecked the encoder shaft  : good thing for warranty!