Extruders, motors and material

This is for general discussions. Also FAQ can be found here.

Moderator: speedake95

Post Reply
twicx
Posts: 105
Joined: Fri Jan 11, 2013 1:26 pm

Extruders, motors and material

Post by twicx »

Hey folks,

I've been doing some digging around lately, mainly planning for a few mods to my own 1.5. I'm going to definitely upgrade the Z axis, but I'm just holding out to see what the 3.0 upgrades are like, before i decide on that one.

I'm looking at ideas for the extruder/motors at the moment. Looking at the new extruder from Micron (http://www.3ders.org//articles/20131231 ... icron.html) I was thinking of ways that a direct-drive dual extruder system could be made similar to this, but with an all-metal hot end, like the E3D-v5 one, or something similar (magma one looks interesting too).

There's a few considerations I have at the moment with all this though:
1. Motor selection
The new Micron extruder uses a NEMA 11 motor for the hot end, which is really neat and tidy. I would imagine that the extruders need the lightest motors out of everything on the printer, but would a NEMA 11 suffice here really?

2. Material Selection
If I was going to be designing a carriage for this, one which I'd be eventually printing, what would be a good heat-resistant material to print it in? Would ABS be better than PLA for it?

3. Electronics
I know I'm probably going to have to look at a different electronics board for this too, but how difficult is it to adapt the firmware to work with this kind of a venture? Especially considering my programming knowledge is pretty much non-existant.

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

Hi twicx,

The Micron extuder looks really nice but the pricing is breath taking :)

1. geared NEMA 11 stepper motors should be sufficient for direct drive extrusion - but it might limit the top extrusion speed (?)

2. ABS would be preferrable due to higher temperature tolerance when extruding with an all metal hotend (with high temperature filaments)

3. the firmware is quite simple to adapt when you know the specifications/pinout of your setup. When I added dual extrusion, LCD and SD reader I only needed to change a few settings in the firmware. I hadn't dealt with programming in many years and I would dare to say that you don't need programming experience to do the minor modifications that is most likely needed - but you need to know what is connected to what pin on the electronics board and be able to understand which variables needs to be changed based on the pinout/components on the board. You could either read through the source code or look into (video)instructions on the net.

Good luck with your experimentations and keep us updated.

twicx
Posts: 105
Joined: Fri Jan 11, 2013 1:26 pm

Post by twicx »

Hi Kjetilei,

Thanks for the response. Yeah that Micron would be excellent if it was a bit cheaper! Although I can't say I'm not very intruiged! I'm using it as a bit of an inspiration, although I'm planning on changing around a few things like the fan placement etc.

1. I was looking on ZappAutomation's site, and they seem to have a few interesting NEMA 11s. Including a few with higher torque. I wonder how fast the top speed would be though. It might be worth a go, considering that I don't plan on going beyond 200mm/s. Also, the nema 11s are about 200g, so I'm now thinking about the Bowden option here. I'd prefer direct drive I think, because of the whole thing with flexible filaments, but would the carriage be too heavy and create lots of backlash at higher speeds I wonder...

2. I thought as much with the ABS, although it also looks like some of the all-metal hot end designs/extruders make an effort to separate the hottest part, around the nozzle, from the carrage, which is something I'm taking into account with the design of this.

3. satoer suggested looking at the RUMBA board, as it allows for up to 3 extruders, and tonnes of fans. I think it's just a more advanced version of the RAMPS board, so it might be the one to look at. Also, i think it's around $150, which doesn't seem excessive at all.

I'm now looking at going NEMA 11 for the 2 x Extruder Motors, and NEMA 15 for the others, so I can still make it a bit quicker.

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

1. I've been thinking a long time about a marriage of a direct drive extruder and Bowden style extruder but never taken the time to design and print the needed parts and look into the needed firmware updates. What I have in mind is a traditional Bowden extruder, but with a lightweight motor/stepper placed near the hotend. The Boden style extruder would provide the torque needed to drive through the filament and the lightweight motor would take out the backlash introduced by the Bodwen cable. I looked into tiny stepper motors but never got around to order one (but I have a couple of PG35L steppers laying around - although they are heavier than I plan for).
2. ABS is the "safest" choice but PLA should work with some/many of the hotends (with proper termal control)
3. When selecting the electronics I think it would be wise to choose a board that has proper support - both in the firmware and from the seller/in the community. Especially if one does not have programming and/or electronics experience

twicx
Posts: 105
Joined: Fri Jan 11, 2013 1:26 pm

Post by twicx »

1. See, I think there must be some way of doing something similar. My plan is to get the parts, and design a chassis/carriage for it very simply in Sketchup or Rhino or something like that. I've been doing a tonne of sketches, and I think i've it figured out:
This is for one "module" i.e., one print head, it will then be mirrored for the 2nd print head. Looking at the side of it, you have the hot end, closest to the main steel frame. Beside it, low down on it, will be a small fan to cool it, on the opposite side of the main steel frame. Above the fan will be the NEMA 11 motor. The idea is then to mount the fan on a door hinge, similar to the way the Felix is done, and use the idea of the spring/arm to tighten it, but with an actual spring instead of a washer array.

2. ABS seems to be the wisest choice then really.

3. The RUMBA board seems suitable. It's got repeteir/marlin support, and it's gotten great reviews. http://reprap.org/wiki/RUMBA

twicx
Posts: 105
Joined: Fri Jan 11, 2013 1:26 pm

Post by twicx »

Ok, so I have a little update. I'm going to be doing this in stages, and I'm about to crack into the first part.

Stage 1: Motors/Z-Axis Upgrade
Stage 2: Upgrade to Single E3D direct-drive extruder with NEMA 11 Motor
Stage 3: Upgrade to Dual E3D direct-drive extruders, with RUMBA Board.

So for Stage 1, I'm looking at ordering the following motors, some for preparation of later stages:
Extruders: 2 x NEMA 11 Motors
X + Y Axis: 2 x NEMA 17 Motors
Z Axis: 1 x NEMA 17 Linear Bearing Motor with Trapezoidal Support

The difficulty I'm having is picking out the motors themselves. I've been looking on Zapp Automation, but how do I decide on things like voltages etc etc?

Ideally, I'd like to go with something from these:
X+Y: http://www.zappautomation.co.uk/en/43-n ... per-motors
Z: http://www.zappautomation.co.uk/en/line ... otors.html
Extruder(s): http://www.zappautomation.co.uk/en/41-n ... per-motors

Also, going to have to get a linear rail bearing to replace the Z too, any suggestions?

Post Reply