Valuejet 1604 print problems, encoder issue?

[grafixhenk1]

This is an issue with our Valuejet 1604, it will print but skips part of the print when printing. What would cause this. Encoder wheel, PF disk?
Sometimes it will print a foot or two just fine and then is pops up every 4-6 inches.

 

[guitarguy69]

PF disc. Use 90% isopropyl and a lint free cloth. Release the pinch rollers and spin using the center hub of the PF holder spinning it in a direction that the alcohol rag spins away from the sensor and not directly into it to allow alcohol to somewhat dry on the disc before it enters the sensor area. Should work, I have had pretty good luck with this method. Sometimes it works for a while, other times only lasts a few hours to days. Depends on the issue, usually it's powdered residue on the encoder disc. If you need a new one, they are fairly inexpensive and always good to have a spare around, just like the steel belt.

EDIT, looking closer to the picture, this may be the T-Fence. The PF encoder you can feel it skipping if you feed material using the advance button.

 

[grafixhenk1]

Another example

 

[heyskull]

Hi

I have had had similar problem to this.
Does it jump when it does this, sometimes throwing an error?
Most definitely an encoder disc problem.
We eventually fitted a new encoder disc as the old one had warped and was causing all sorts of problem when it came close or touched the sensor.
Also their is an update for how the encoder disc is centred and their is a updated part that fits over the shaft that centres the disc.
This part was not added until very late manufactured 1604s and later 1614s.

SC

 

[Solventinkjet]

Hi

I have had had similar problem to this.
Does it jump when it does this, sometimes throwing an error?
Most definitely an encoder disc problem.
We eventually fitted a new encoder disc as the old one had warped and was causing all sorts of problem when it came close or touched the sensor.
Also their is an update for how the encoder disc is centred and their is a updated part that fits over the shaft that centres the disc.
This part was not added until very late manufactured 1604s and later 1614s.

SC

+1 Although I have never seen such a clean skip in the print when the encoder disc goes. Usually it is kind of fuzzy. Can't think of anything else it could be though.