Itty Bitty Double Extruder

Introducing the Itty Bitty Double Extruder:

http://3dprintboard.com/attachment.p...tid=4485&stc=1
Attachment 5725
This is a completely new dual extruder system:

• Dual Hexagon hot ends on 20mm centers
• Quiet, zero-backlash belt drive
• NEMA 14 motors
• Integrated hot end cooling
• Integrated print cooling
• Integrated servo Z-probe for auto-bed-leveling
• Easy-to-install cam-lock idler bearing shafts
• 2g lighter and 2mm narrower than the standard MakerFarm hinged single extruder
• Includes all parts necessary to mount on MakerFarm Prusa i3v printers

Please use this thread for questions and discussion.

*** A hardware kit is now available! ***
Get it here

Links:

• Printable parts: http://clough42.com/go/itty-bitty-double-extruder
• Assembly Instructions: http://clough42.com/go/itty-bitty-do...ruder-assembly
• Calibration Instructions: http://clough42.com/go/double-extruder-calibration
• Hardware kit: http://clough42.com/product/itty-bit...-hardware-kit/
• HXT900 Servo: http://clough42.com/product/hxt900-servo/
• Firmware: https://github.com/clough42/Marlin
  
  • Forked from beckdac/Marlin (Roxy's enhanced G29)
  • Branches:
    
    • ​Marlin_v1: main from upstream
    • ​hardware/i3v_double_bitty: MakerFarm Prusa i3v (8") with auto-leveling
      
      • Configuration.h - https://raw.githubusercontent.com/cl...onfiguration.h
      • Configuration_adv.h - https://raw.githubusercontent.com/cl...guration_adv.h

There has been a fair amount of interest in a hardware kit, so I've been investigating pricing.

What would you want in a hardware kit for the extruder?

• Screws, bearings, pulleys, belts, springs and insulating tape (of course)
• Hobbed bolts?
• Hot ends?
• Motors?
• Z probe servo?

If you have stock MakerFarm-shipped RAMPS electronics, you might also need

• A4988 driver board
• RRD Fan extender

to control the extra motor and print cooling fan.

Everything (except the RAMPS electronics) can be sourced from a combination of MrMetric, MakerFarm, Pololu, McMaster Carr, HobbyKing, Harbor Freight and a couple of Chinese eBay sellers for around $253, including shipping to the US (2-3 weeks). I'll upload a shopping list soon.

I've been investigating volume pricing, and I could probably offer an all-inclusive kit (everything except the RAMPS electronics) shipped Priority Mail in the US for a little less (maybe $230, depending on sourcing).

How much demand would there be for such a kit, or for a cheaper kit without the hot ends and motors?

Thank-you for sharing your work, looks awesome, I'm in process of printing the parts.

Screws, bearings, and springs are my biggest concern. Maybe motors too. I've already got the hobbed bolts, servo, and hot ends.

I'm amazed, could I ask what software you're using for designing such a awsome work of art?

Quote:

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Originally Posted by Stigern

I'm amazed, could I ask what software you're using for designing such a awsome work of art?

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This particular design was done in SolidWorks. I'm glad you like it.

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.

Quote:

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Originally Posted by OldSourKraut

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.

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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.

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.

Quote:

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Originally Posted by clough42

There has been a fair amount of interest in a hardware kit, so I've been investigating pricing.

What would you want in a hardware kit for the extruder?

• Screws, bearings, pulleys, belts, springs and insulating tape (of course)
• Hobbed bolts?
• Hot ends?
• Motors?
• Z probe servo?

If you have stock MakerFarm-shipped RAMPS electronics, you might also need

• A4988 driver board
• RRD Fan extender

to control the extra motor and print cooling fan.

Everything (except the RAMPS electronics) can be sourced from a combination of MrMetric, MakerFarm, Pololu, McMaster Carr, HobbyKing, Harbor Freight and a couple of Chinese eBay sellers for around $253, including shipping to the US (2-3 weeks). I'll upload a shopping list soon.

I've been investigating volume pricing, and I could probably offer an all-inclusive kit (everything except the RAMPS electronics) shipped Priority Mail in the US for a little less (maybe $230, depending on sourcing).

How much demand would there be for such a kit, or for a cheaper kit without the hot ends and motors?

---

What would you want in a hardware kit for the extruder? answers

• Screws, bearings, pulleys, belts, springs and insulating tape (of course) = YES to all of that
• Hobbed bolts? = YES
• Hot ends? = NO but if talks with Colin go well, having an option to buy 1 or 2 heads might be cool
• Motors? = Maybe but not really right off the bat
• Z probe servo? = maybe but we can do that for now
• Fans? = Yes

If you have stock MakerFarm-shipped RAMPS electronics, you might also need

• A4988 driver board
• RRD Fan extender

to control the extra motor and print cooling fan.

if talks with colin work out hve it as an option like a drop down list check boxes,
with info on the page about whats parts are need for witch models.

most people with 3dprinters (except makerbot owners) have good Google skills and can source the bigger stuff.

Quote:

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Originally Posted by OldSourKraut

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.

Quote:

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Originally Posted by TechMasterJoe

What would you want in a hardware kit for the extruder? answers

• Screws, bearings, pulleys, belts, springs and insulating tape (of course) = YES to all of that
• Hobbed bolts? = YES
• Hot ends? = NO but if talks with Colin go well, having an option to buy 1 or 2 heads might be cool
• Motors? = Maybe but not really right off the bat
• Z probe servo? = maybe but we can do that for now
• Fans? = Yes

<snip>

if talks with colin work out hve it as an option like a drop down list check boxes,
with info on the page about whats parts are need for witch models.

most people with 3dprinters (except makerbot owners) have good Google skills and can source the bigger stuff.

---

Thanks. I think the small hardware is the real killer because you have to order so many small quantities of various bits from all over.

Quote:

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Originally Posted by clough42

Thanks. I think the small hardware is the real killer because you have to order so many small quantities of various bits from all over.

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I have a McFadden-dale hardware less then 300 yards from my front door so I don't really need a kit anyone that's been to one knows just how much that place rocks. Tack that on to the fact McMaster Carr's warehouse is 1.4 miles away from my shop. I'm set I can get anything fast. If you need any special part's made for a design pm me I own a machine shop both a real shop and one at home with 26 cnc's in all.

After I get the 12" i3v I might ask Colin if he wants to make a metal ver or if he is OK with me selling a metal frame upgrade I got a OMAX 80X water jet that I don't really use much

I will be producing hotends a little bit like the hexagon with electropolished nozzles soon..running small batch at my costs I think, I can make them for under 20$ my cost so a retail around 30$ complete.
I plan on making the nozzle and the heat break one solid piece of stainless steel and including 4 of them in 3 sizes (.3 for 1.75, .4 for 1.75, .4 for 3.0, .5 for 3.0) by making it a single piece the hotend will work with both 1.75 and 3.0 by just changing the heat brake/nozzle

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.

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.

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.

Quote:

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Originally Posted by 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.

---

You can count me in for one.

Quote:

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Originally Posted by TopJimmyCooks

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.

Quote:

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Originally Posted by 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.

---

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?

you can count me in for one just to help support the project.
Plus i had only planed to print the single hotend.
now i think i will setup dual. i have never really seen a real
reason outside of things like PVA support or printing 2 objects in two separate colors
yet i can't see a reason to care i have never really cared about color as much as print quality
and dual heads always seams to lead to problems with the ones at the school
(i took one nozzle off to fix a 2nd nozzle object crash at high Z on the schools Airwolf HDX2)


Is it just me or is reprapdiscount.com down completely today

Do you have a weight of that whole setup? I designed a belted dual extruder earlier this fall and wanted to do NEMA 14s, but a slim NEMA 17 had better torque and lower weight than all the NEMA 14s that I could find. I can still easily alter it to support 14s though.

I do think going with a belt drive is a winner.

Also: I found SDP/SI to be a handy source for belts & pulleys.

Quote:

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Originally Posted by printbus

Yeah, but I've typically found cyber Monday to be iffy as far as internet performance. Today's actually been better than usual.

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Ya I can see that a lot of sites are slow newegg is crazy slow right now. I got a new gaming laptop just now a painful 1673$ but I wanted 32gb of ram and a good gpu because I'm in both solidworks and master-cam x8 all day.. I was going to order a new hexagon 3mm and nozzles guess it's got to wait lol

Quote:

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Originally Posted by JRDM

Do you have a weight of that whole setup?

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As I was building this and testing it with 'clough42' I was interested in the weight also. I weighed my standard Wade's extruder (Magma hot end) and it was 607 grams. The dual hexagon weighed 701 grams. Not bad to add less then 100 grams to get a dual rig.

One nice side effect I've found is that if I'm careful, I can swap filaments out on the head that's not printing (if I'm not doing a dual head print) and save time. I'm printing with PLA now on my left head and I just switched out the ABS on the right head to nylon without messing up my print. That's nice.

Let's see a video of this thing printing! I'm looking forward to a dual extruder!

Do you have to really ramp up the retraction distance in order to avoid oozing when printing with the other hotend? Pull the filament completely out of the melt zone?

I haven't gotten to the point of tweaking oozing yet. That will come up soon. I'll also get some video sometime soon. That's a good request.

I've printed PLA and ABS so far. Both printed beautifully. I haven't had one jam yet. In fact, I was cleaning a head and at the bottom you can see that the melt zone is perfectly aligned to the Hotend height. So no melting is occurring where it should not that might cause a jam.

I'm printing Ninjaflex right now and it's working well, the filament path is sufficiently encompassing well such that the filament can't bend and snake out anywhere. I didn't make any modifications to 'clough42's' original design to accommodate Ninjaflex. I'll be testing Bridge Nylon and PET+ in the next few days.

Attachment 3723 Attachment 3724

Quote:

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Originally Posted by AbuMaia

Do you have to really ramp up the retraction distance in order to avoid oozing when printing with the other hotend? Pull the filament completely out of the melt zone?

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I'm currently retracting 10mm when switching hotends. This is just a setting in slic3r, and it seems to work pretty well.

The other key to preventing oozing is to tune the temperatures. I'm finding that different colors of filament have different melt profiles. I can get nearly ooze-free performance from black at 240C, but I've got the orange down to 220C, and it's still oozing more than the black.

I have confirmed the temperatures with a thermocouple, and the temperatures are correct (or at least responding the same). I'm reading 9 degrees cooler than the reported temperature with the thermocouple in contact with the top of the heat block. The thermistor and thermocouple temperatuers track together up to about 150C, where they diverge, and up in the 250C range, I see the 9 degree difference. It could just be a thermal gradient in the block, or it could be a small error.

I'm using the default Marlin Type 1 tables.

Quote:

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Originally Posted by RobH2

I'm printing Ninjaflex right now and it's working well, the filament path is sufficiently encompassing well such that the filament can't bend and snake out anywhere. I didn't make any modifications to 'clough42's' original design to accommodate Ninjaflex.

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Really? Ninjaflex? That's awesome. I thought I was going to have to do some more work to get that one working. The filament is unsupported below the bolt for about 4mm. Maybe with 1.75mm filament, it will need more support.

Yep, Ninjaflex printed really well. No issues of any kind. That photo above was the first test of it and was printed at 220C. Yea, I'm guessing 1.75 filament won't be so lucky.

Quote:

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Originally Posted by jprochnow

Let's see a video of this thing printing! I'm looking forward to a dual extruder!

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This is a live stream of a test print. It should be running for the next eight hours. Unless it fails utterly. :) After that, I'll come back and put in a better link and upload a time-lapse.

https://www.youtube.com/watch?v=UAGA5TIkg9w

I'm printing this:

http://www.thingiverse.com/thing:11687

Quote:

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Originally Posted by clough42

This is a live stream of a test print.

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You can see the home/autolevel/priming sequence starting at 06:30. I'm using Roxy's enhanced G29 code.

Here's the startup sequence:

• Heat the bed
• Start heating the nozzles
• Home and probe for autolevel (G28/G29)
• Park at Z=0 with both nozzles off the glass
• Wait for both nozzles to reach temperature
• Prime the left nozzle wipe it onto the glass
• Prime the right, retract it slightly and wipe it onto the glass
• Print alternating loops (Slic3r)
• Print

Slic3r prints the outside ring with the left nozzle first; that's why I retract the right nozzle slightly. This keeps it from dribbling while the left nozzle prints loops. After that, Slic3r automatically handles the retracts.

Excellent. What's your "Live" setup? I think I should do one too soon.

Quote:

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Originally Posted by RobH2

As I was building this and testing it with 'clough42' I was interested in the weight also. I weighed my standard Wade's extruder (Magma hot end) and it was 607 grams. The dual hexagon weighed 701 grams. Not bad to add less then 100 grams to get a dual rig.

One nice side effect I've found is that if I'm careful, I can swap filaments out on the head that's not printing (if I'm not doing a dual head print) and save time. I'm printing with PLA now on my left head and I just switched out the ABS on the right head to nylon without messing up my print. That's nice.

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OK. I had managed to build a working 600g duallie, but with J-Heads. I have lighter motors to try to reach 500g but I've been just getting my practice and testing in before I built another set. I planned on my second build to have Hexagons and the lighter motors.

My dual belt-driven design:
https://www.youmagine.com/designs/jd...-dual-extruder
600g version shown

Love the design thanks for sharing.

Quote:

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Originally Posted by RobH2

Excellent. What's your "Live" setup? I think I should do one too soon.

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Nothing fancy. Just a webcam and a YouTube live event. https://support.google.com/youtube/answer/2474026

Here's a time-lapse video of the link cup printing.

https://www.youtube.com/watch?v=Fk3TGHQeiVY

Hi

Could you put me down for a hardware kit too?

Will need shipping to Australia...

Quote:

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Originally Posted by lemming

Hi

Could you put me down for a hardware kit too?

Will need shipping to Australia...

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No problem. I'll post back here when they're ready.

clough42 Do you have a version for the NEMA 17 motors? as we already have them from our failed direct drive dual experiment. If not it should be easy for us to modify..
Thanks

Nice design!

I was wondering on the physical connection and whatever Marlin changes are necessary.

In Marlin, my guess is that we need change MOTHERBOARD from 33 to 34.

That translates to the following physical connections on the Ramps 1.4 board:

• D10 = Hot End #0 (12v)
• D09 = Hot End #1 (12v)
• D08 = Heated Bed (12v)
• D11 = Servo (5v)
• D04 = PLA Fan (12v)

My questions (assuming the above is correct):

1. What Fan Expander are you using? I see one from Makerfarm which states it exposes D4/D5 and one from Geetech which exposes D6/D11.
2. Regardless, how is the servo connected? The Geetech usurps all of the servo pins and only directly (via pin headers) exposes the 4 fan pins (D4/D5 or D6/D11) and 2 pins for an external voltage source. I cannot find any info on the Makerfarm version (other than the description supplied on the Markerfarm website), but the Geetech has schematics that clearly show a common MOSFET gate voltage. So my question is how does this thing power both the 5v servo and the 12v fan though either of these gizmos? I mean, how does either of these adapters handle both a 5v servo and 12v fan?
3. Can you supply all of the Marlin changes you have made? E.G. Any changes in pins.h? Any changes to support the belt systems?

I'm really skeptical of the Makerfarm fan expander (just due to the lack of documentation, no photo of the other side of the board and the off-hand comment implying it does not provide a buffer between the ramps and fans).