what is the best extruder for abs? Struggling with mk8 direct drive...

Hello, I have mk8 direct drive extruder. it is chewing up filament no matter what I do. Half of the parts for the extruder are printed parts, the bearing arm that is spring loaded melted, I made another from the stl files but this design is flawed. What is the hands down best extruder for ABS? I print a lot of large objects, a lot of the time, I need something that will not slip on the filament.

I've had good results with my BullDog XL pushing 1.75 mm ABS through an E3D V6 hot end.

good to hear looking it up now, have a E3D coming in the mail already ;-)

Edited 1 time(s). Last edit at 03/16/2015 12:27AM by lunarkingdom.

If you get a BullDog XL you'll have to make some minor modifications to the E3D v6 to get them to fit together properly.
1) file a couple small flats in the part of the hot-end that goes into the shoe on the extruder.
2) file a groove in the heatsink fins on one side of the hot-end to allow access to to the smaller screw that holds the foot on the extruder
3) grind down a 1/4" washer to act as a spacer between the hot end and the extruder so that the hot-end is held firmly in place. You can leave the bowden tube lock piece in the top of the hot-end.

Total time for these mods is about 10 minutes, so they are no big deal.

Thanks for the tips! I have both the bulldog xl and 2 E3D tips in the mail, those modifications will be a piece of cake, thanks for the detailed directions! At this point I would love to hear more about your experiences with the bulldog xl, there are not a lot of reviews on it on the net, I ended up paying 160 usd for it plus shipping, I hope it is worth it, I am soooooo over chewed up filiment and failed prints due to my old v8 direct drive extruder that came with my prusa i3.

The BullDog XL runs at 600 mA and never gets more than a little warm. I've never had it chew up the filament, but only used it for a month or two. The springs that push the pinch wheel against the filament are very strong and you'll need to keep an allen wrench handy to change filament because it is really hard to compress the springs by hand unless you reduce the tension on the springs by backing out the screws.

If you're looking for design info to make sure your extruder carriage will accommodate the BullDog XL, see [www.youmagine.com]

I plan on making my own out of diamond plate aluminum I have laying around so I do not destroy or drill holes in my original just in case, thanks for all the tips!!

My printer is using a 1.75mm genuine e3d v6 bowden, and my drive is just a stepper/gear assembly from a scanner with the hobbed pully mounted to the final gear.

I have great success with bulldog lite and hexagon after I realised that the hexagon shone mount that screw to the extruder was wobbling.
A sliver of ABS later and alls good.