Old exturder. I've replaced the cogs but retained the motor. The motor is compact if a little 'vintage'! :)
What else have I changed?
Cut a new MDF x-carriage which receives the extruder easily, allowing removal for maintenance or swap-out.
I printed PLA bushings before I dismantled the old extruder, and bolted those to the new x-carriage. I chose these ones (http://www.thingiverse.com/thing:8282) with the bolt holes. I wanted to compare the PLA bushings to the steel bushings I had been using.
I rotated the extruder through 90 degrees, to give a narrower width and hence greater x-travel.
I cut a new hobbed bolt, this one an M8. The old one was in a 6mm bar. This fits the new large cog nicely and grips the filament a lot better.
I built new belt clamps and a fan mounting bracket. Some photos below...
It's all still a bit 'rough and ready' but it works, and works better than the previous version of my extruder.
So.. why didn't I just print a new x-carriage while I had the original extruder working? Well, my design has the x-rods at 60mm between centers instead of the usual 50mm so I would have had to modify a drawing, and I'm just not up-to-speed on that end of things yet. If I were to change my x-rods to 50mm I'd need to print new x-mounts, z-motor-mounts... and so on, and with my printer so slow it would have been Christmas before it would finish!
It's chichen 'n' egg as to what I do first or next to improve the speed and accuracy of my printer. Once I get it printing consistently at a moderate speed then I can get it to print a whole new printer rather than swapping out any more parts on itself!
Oh... finally for now, to make life easier the one accessory I really needed was a spooler, so I knocked one together from some scrap wood and a pair of 608 bearings. Works a treat!
Thanks for viewing!