Friday, August 20, 2010
The Makerbot Mk5 Extruder has exited the Botcave
-Idler wheel loosening up over time
-Idler wheel snapping in half
-PFTE popping off (before the bolt became standard)
-Nicrome frying itself
-Broken retainer rings
-Gunked up drive pulleys
I looks like Makerbot has eliminated the possibility of all the common Mk4 failure modes.. Now don't get me wrong, I am absolutely sure we (at least me :) ) will figure out how to break this thing, but it looks like the weak link of the Cupcake, the extruder, has been solved (we hope).
I though it would be a fun excersize to play "find the fix" with this design. Like all good ideas, it's a copy's a lot of other designs that work well.
The Mk5 drive gear:
Hobbled gears have been around for a while in the hobby, but they where made famous by Wade's wonderful geared extruder. The 1st time I ever saw one works was Nophead's Tiny Stepper Torques Big post. Ever since the 1st time I saw it, I wanted that for Makerbot. I have used my Mk5 drive gear in my Mk4 Makerbot since the 1st day they offered it, and honestly it really does improve the Mk4, but it didn't fix it. The Mk5 looks like the final Fix.
The Tensioner was 1st introduced by Charles Pax for his Paxtruder 0.1. I remember reading his blog and thinking, god I wish I could buy that thing... well it only took a year :) I still think the spring and 608 approach is better, but for a laser cut design, this is likely as close to perfect as you can get.
The Power Resistor Heater
Pear Shaped Post. Cool thing is if you want something like this on the Mk4 you can buy a kit over at Makergear, but it does not require a relay, and only uses 1 smaller Power resistor. I have not used it yet.. My hot end is still working, and I have a backup that Rick over at Makergear put together, but I hear it heats up slower than Nichrome. The Mk5 looks like it will heat up nice and quick with it's relay:).
Rapman Blog. Unfortunately it's not "Fab-able". But as the Rapman has shown for over a year now, it's a rock sold and relaible design.
Makergear Big Head Nozzle than the old mk4 nozzle. I know the people who have tried the larger headed nozzles have found that the larger head acted as a thermal battery, holding the heat and allowing for a more consistent extrusion.
Plastruder Mk5 looks like the a true changing point for Makerbot. There was very little difference between the Mk1 and the Mk4 Plastruder. Sure there where changes, but in the end it was always the Child of the Hercules. Mk5 brings marks the end of the Hercules generations of Plastruders, and begins the Paxtruder generations of Plastruder..
As much as I like this design, it does mark 1 real change for Makerbot. No longer can it be said that you can build the Makerbot extruder with a laser cutter and a drill press. The hot end has now entered the only makeable with a lathe world. Guess I can't get too bent out of shape over it, Adrain's new nozzle is a Lathe only design. At least RepRap and Makerbot both did a LOT OF WORK making the fab-able nozzle design as relaible as it could possibly be.
Makerbot now has a Paxstruderesque tensioner, Wades Extruderesque drive gear , a Rapmanesque thermal barrier, a Nopheadesque heater core, and a Makergear big head nozzlesque nozzle.
That's why open source is so great, we all build on the shoulders of Giants. How long before we see this hot end on a Wades Geared extruder, for the ultimate extrusion Machine! :)