I am guessing the problem is because the aluminum block that holds the stainless steel feed throat for the hot ends in place isn't cooled sufficiently. If it gets too warm, the stainless steel feed throat will get too warm, and the filament will soften before it gets to the hot end nozzle and jam. I thought I would attack this problem by creating an improved heat sink and attempt to move more heat away from the aluminum block, and thus attempt to keep the stainless steel feed throat cooler. I also attempted to improve the insulation between the hot ends and the aluminum block.
First, I constructed a heat sink using 1/8" thick copper sheet purchased from Mcmastercarr. I thought the copper would create a improved heat flow path from the aluminum block to both of the fan-cooled heat sinks, as well as increase the total mass of the heat sink. It should also allow improved heat flow from the aluminum block near extruder #1 to extruder #2's heat sink.
|Heat sink cut, drilled, and ready to go|
|Trial fit of stock heat sinks checking for hole alignment|
|Test fit on drive block|
|Test fit on drive block|
|Covering all air gaps on the top of the extruder platform|
|Sheet of self-adhesive rubber cut to fit the bottom of the aluminum hot end block|
|Adhered to the bottom of the aluminum block|
|Extruder #2 Re-attached|
|New Makerbot Replicator 2x thermocouple on the left, original on the right. The stock cable used much smaller gage cable.|
Mini-Review of the Vira Design Makerbot Replicator 2x upgrade kit, AKA: Upgrade Kit for the Hot End Insulation on Makerbot Replicator 2x-extruder-reprap
- Shipping: Slow- took about two weeks- it appears as though they paid for shipping, then make the parts, then shipped them out.
- Packaging: Poor- all the parts were tossed in a much-too large box- although since nothing it breakable it didn't matter
- Instructions: Poor- zero instructions included with the kit, although if you are capable of installing it you'll be able to figure it out
- Part quality: Good- cast silicone parts are serviceable, but required x-acto knife cleanup of all thru-holes
- Value: Good - you'll have a hard time producing these parts yourself for much less, let alone the time required to design, create molds, and make the parts. If you need replacement insulation for your hot ends these are a good option. Plus they are completely non-fragile, unlike the stock ceramic insulation.
Vira Design upgrade kit for Hot End Insulation on Makerbot Replicator 2x Mini-instructions:
1) Use an X-acto knife to clean out all of the thru-holes in the silicone insulation parts.
|New rubber insulation on the right., prior to trim|
|Using aluminum hot end block as pattern to cut white insulation|
|Cut tape using X-acto|
|Ready to go|
|Attach tape / insulation patch to aluminum hot end block|
|Insulation in place|
|Ready to go!|
|Thermal heat sink compound on thermocouple threads|
|Hot End #1 installed.|
Next up, finish installation and fire it up.
|Thermal compound on the interface between the new copper heat sink and the aluminum hot end block|
|Thermal compound on the back of the aluminum fan cooled heat sinks|
|Up and running!|