dribble, drizzling j-head problem

hello again reprappers, i've been trying to get rid of this annoying drizzle i am getting, after each layer i get build up as it lifts the z axis (major known problem but i cannot find the fix) and after a print finnishes or i pause it to change colour i get about 15mm of dribble coming out of my
j-head, any ideas?

im running a prusa mendel with: heated bed, abs filament, 0.35mm j-head nozzle, printrboard and slicer.

the nozzle is running at 230 degrees and heated bed at 110 degrees.

i have tried changing my extruder extraction rate higher and speed of extraction for my z axis drizzle trouble, but have had no success getting rid of that.

i have also played with temps on the j-head, i tried, 210, 215, 220, 225, 230. and i didnt see much of a diference in my drizzle. but at 210 i started having print issues as it didnt bond very well.

is this just a problem with j-heads or should i be able to tune this out?
also will changing to skienforge give me greater control over this drizzle, most people seem to be using it anyway.

thanks everyone, ash.

No it isn't a problem with J-heads. I have a 0.4mm one running ABS at 250C and a 0.35mm one running PLA at 200C. Neither dribble enough to leave hairs on the print when retraction is set correctly.

They do dribble during warmup but I park them over the bed to stop that: [hydraraptor.blogspot.co.uk]

They also dribble at the end of the print but I do a rapid XY move to the edge followed by raising Z to the top so it doesn't affect the print.

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[www.hydraraptor.blogspot.com]

Try adding a fan across the cooling fins of the J-Head? I did this and it really improved the ooze comming out of the extruder. Mind you that was PLA, which is quite different from ABS I guess.

I don't use the J-heads but I did notice this on the wiki:

" Nozzle orifice length

Mk IV hot-ends (up to the middle of May 2012), and earlier models, had a nozzle orifice length of approximately 1.25mm.
Mk IV hot-ends (after the middle of May 2012) and Mk V hot-ends have a nozzle orifice length of approximately 0.50mm.

Note: Due to the nature of 5c collets, the nozzle orifice length can vary as much as 0.25mm. "

I don't know how this will affect there operation, but the nozzles i have made show a bit of ooze on the lower end of that spec, i.e. if you take the new shorter length of 0.50mm and add in the variation of 0.25mm the orifice length the length can be as short as 0.25mm (0.0098 in)