Itty Bitty Double Extruder

[clough42]

I have already started printing and sourcing parts for this project. I'm truly excited to get started on it. I have been using your hexagon cooling shroud and z-probe servo mount and am very impressed with the solid design. My question is have you had any issues with the 3cfm fan cooling both hotends on extended prints? It has been doing a good job on my single hexagon hot end, but I would be doubling the heat in that area.
Also how critical is the spring tension used on this build? I have a hardware store across the street with a good selection and I'm hoping I could bring my completed extruder over there and find something that would work.

Thanks.

I haven't had any trouble with the 25mm hexagon cooling fan so far. The shroud is designed to concentrate the airflow around the heat sink fins. I've run a couple of 8-hour prints with no issues--one with $10 Sunon maglev 3CFM fan (which I highly recommend) and one with the 25mm fan shipped with the Hexagon. The cooling fins get warm, but I can easily hold a finger on them. Printing with both hot ends at 250C over a 110C bed, the heat sinks get up to around 45C, with no jams.

For the springs, I recommend 1Kgf per spring as a starting point. I found some springs in a Harbor Freight spring assortment that I cut in half and bent new hooks. These grip the MakerFarm ABS very well with the MakerFarm bolts. I.e. they can transfer more torque than the motors can deliver. I haven't sourced anything specific yet.

[OldSourKraut]

Good to hear, I'm also using the Sunon maglev 3CFM fan and those are the Temps I'm printing at and about the same temps i'm seeing on the heat sink fins for my single extruder.

One mod I did make to the single hexagon shroud was to remove the plastic at the bottom between the hot end and cooling fins and replace it with a piece of brass that is cut to go around the hot end and wrap up the sides, this is attached with a couple of m2 bolts and nuts. This stays cool and avoids the melting plastic issue. Looks like I'll be doing the same to the double shroud as well.

Thanks for all the time and effort you have put into this project.

[clough42]

One mod I did make to the single hexagon shroud was to remove the plastic at the bottom between the hot end and cooling fins and replace it with a piece of brass that is cut to go around the hot end and wrap up the sides, this is attached with a couple of m2 bolts and nuts. This stays cool and avoids the melting plastic issue. Looks like I'll be doing the same to the double shroud as well.

Thanks for all the time and effort you have put into this project.

You're welcome.

The brass is a good idea. I have been making insulators out of fiberglass tape and Kapton and they work pretty well. The bottom of the shroud gets smooth and shiny, but it stays put.

[Errol]

Hello can I order a hardware kit to be shipped to New Zealand?

[clough42]

Okay...I just placed orders for parts.

I'll be offering a hardware kit with the screws, nuts, washers, pulleys, belts, bearings, springs and fiberglass for the insulator. It will take a couple of weeks for everything to arrive, and I'll be able to post final pricing. Right now, it's looking like it'll be somewhere in the neighborhood of $25 shipped in the US.

[TopJimmyCooks]

Also, for those who didn't notice in the pics - Hexagons have started shipping with a molded silicone insulating jacket for the heater blocks which is a very nice feature that hasn't shown up on other hotends so far.

[clough42]

Also, for those who didn't notice in the pics - Hexagons have started shipping with a molded silicone insulating jacket for the heater blocks which is a very nice feature that hasn't shown up on other hotends so far.

Yeah--and they also come with both 40mm and 25mm fans now. The insulator is nice, once it stops stinking. My first 8-hour print at 250C was pretty smelly. After that, I don't notice it any more.

Does anyone know what the insulator is made from and what temperatures are safe?

[kd7eir]

Okay...I just placed orders for parts.

I'll be offering a hardware kit with the screws, nuts, washers, pulleys, belts, bearings, springs and fiberglass for the insulator. It will take a couple of weeks for everything to arrive, and I'll be able to post final pricing. Right now, it's looking like it'll be somewhere in the neighborhood of $25 shipped in the US.

You can count me in for one.

[TopJimmyCooks]

I'm sorry I missed the hardware kit. I have been printing parts and accumulating stuff over the last few weeks and I just ordered the few remaining bolts from Mr. metric. I've got HIPS and PVA coming to use to try dissolvable support. I'm looking forward to running this. Thanks for the hard work on the design. Looking at the printed parts, it's intriguing how tiny (itty bitty) everything is. I actually double checked once to make sure I hadn't mistakenly applied scaling during slicing of the idler blocks.

I hate it when people ask for updates on something that just came out - However, something to consider for the future: A lot of the flexible and exotic filament users are recommending PTFE liners in the extruders. In the extruder block you have a longer filament pathway than many greg's type designs. Doing a version with a wider filament pathway and a little retainer shelf at the bottom for that might be something to look at later. If it's found to be needed. I don't know if any the flexible filaments can print into useful parts like washers, light duty valve seats, gaskets, grommets, etc. But if they do I will be using them.

[clough42]

I hate it when people ask for updates on something that just came out - However, something to consider for the future: A lot of the flexible and exotic filament users are recommending PTFE liners in the extruders. In the extruder block you have a longer filament pathway than many greg's type designs. Doing a version with a wider filament pathway and a little retainer shelf at the bottom for that might be something to look at later. If it's found to be needed. I don't know if any the flexible filaments can print into useful parts like washers, light duty valve seats, gaskets, grommets, etc. But if they do I will be using them.

Don't worry. It's just a part of the development process. Every design undergoes (or should undergo) iteration after first contact with users. I'm already planning on doing a flexible filament version with PTFE liners and perhaps a simplified version with just the extruder for people who want to try other hot ends or don't want to deal with all the options.