Introduction: Makerbot MK6+ Heater Replacement

this is a easy heater core  that will get you up and operational from readily available materials for under $1US per core. 

Step 1: Tools and Consumables

hookup wire 
30-31gauge coated nicrome wire 
kapton tape 
soldder preferably high temp 
1/4" OD copper tube 
furnace cement 

TOOLS 

file 
sciors 
tooth pick 
lighter 


Step 2: Prep for Build

cut approximatively 1" of copper tube i use the edge of the file. !!!warning!!! if you crush the tube you will have to restart!!! 

cut about 300MM of nicrome wire or 6 ohms worth so long as you are within 1 ohm it doesn't really matter  but the closer the better 

strip 1/4" of insulation off the nicrome ends 

cut 2 lead wires about 12" and strip 3/8" off the ends 


Step 3: Nicrome Time

fold the exposed nichrome in to a U shape than thread the lead around and through the U

wrap silver solder arround the twisted lead as shown below 

melt the solder with a lighter not iron (too slow and fails more than half the time for me)

repeat fr the other side of the nichrome wire

once everything is soldered bend the leads opposite directions parallel to the wires as shown below  

wrap each lead individually with kapton tape 

Step 4: Packing the Nichrome

with kapton tape wrap the leads together  as shown 

fold the nichrome loosely into fourths 

than fold it like a letter 3 times and this will be close to an inch long 

Step 5: Insulating

squeeze some furnace cement out onto a paper plate of similar surface 

the goal is to work the furnace cement in between all the nichrome wire 
so work it in it doesn't matter what it looks like at this point so long as the wire is still in a bundle similar to what is shown below 

Step 6: Packing the Core

take the bundle from the last step and add more cement to it gently press it inside the copper tube use the toothpick to fill any voids

cleanup the cement on the outside

let it dry for a day or 2 than proceed to the next step


or apply a low voltage current (1.5-3V) to it fr a few minutes at a time  untill it stops steaming this makes a weaker core but will get you up and running faster  


Step 7: Installation

you NEED anti seize compound for this or it WILL get stuck in the core 

coat the heater in anti seize than insert it as you would a regular MBI core and put the screw in with anti seize only finger tight 

wrap the end with the leads coming out with kapton tape for reinforcement 

insulate just as you would for a standard MK6+

Step 8: Results

after 20+ hours of printing the core is fine i think this is a rather robust design 

the major con it that it takes 50 to 10 min to get up to temp depending on conditions in the room 

the picture is my core after about 20 hours of printing there is a 608zz bearing for comparison 

UPDATE (4/29/2012):

The original made in this instructable lasted about 50 hours of printing. a new version made with 4 ohms of nichrome wire it heats up the MK 6+ heater core in under 2 minutes and has been printing since September  2011with no maintenance. i have printed off 4 full sets of prusa mendel parts and lots of miscellaneous printing. which totals more than 100 hours. 

Comments

author
AgeingHippy made it! (author)2011-05-09

Hey Dude

Why not simply use a Vitreous Enamel power resistor such as this one

http://uk.farnell.com/vishay-sfernice/rwm04106r80jr15e1/resistor-ww-3w-5-6r8/dp/1109220

?

It is commonly used in the Reprap heater block design pioneered by Nophead.

Much cleaner and you don't need the cement, nichrome wire etc.

author
max mulholland made it! (author)max mulholland2012-06-04

I would have but the time did not allow for shipping. I bought one of the first MK6+ upgrade kits and the heater core broke in the first 15 seconds and I needed the printer the next day for a presentation so I made one with what I had.