Plans for Mendel90 to use 1.75mm filament?

Hi, the subject says it all...

Are there any plans to upgrade the Mendel90 to use 1.75mm filament? From what I've heard, it's the only way to get finer prints and details...

Thanks, Netsrac

Not sure about that. The nozzle diameter ultimately determines the minimum line width and that is independent of filament diameter.

I can see the advantage of 1.75mm filament for Bowden-fed Delta printers where the lighter weight of the filament feed would assist the agility of the hot-end movement. The extruder parts could also be smaller and lighter.

The Mendel90 was designed to use 3mm filament, how is changing to 1.75mm an upgrade?

Regards,
Neil Darlow

Edited 1 time(s). Last edit at 12/11/2013 05:55AM by neildarlow.

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

But why do all the newer devices like the new Makerbot's use 1.75mm.

There could be many reasons. A product that is lighter in weight. Smaller filament spool sizes. Some models may use direct-drive extruders for which 1.75mm is the best choice. Lower production cost for machines.

Also, I believe a lot of commercial machines are encased or feature an enclosing chassis. Routing 3mm filament around confined spaces would be more difficult than 1.75mm. The Mendel90, being open-plan, does not have this impediment.

In a lot of countries 3mm filament is also cheaper to buy than 1.75mm so it makes a good choice for the home market. Nophead can probably explain better his reasons for going the 3mm route.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

1.75mm is usually more expensive than 3mm and I don't see any advantage on a machine with a moving table Y axis.

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[www.hydraraptor.blogspot.com]

I've been using 1.75mm from the get go.

I just inserted a sleeve to convert the 3mm hole to 1.75mm and got a 1.75mm hotend.
Wahla! Printing with 1.75mm filament.
prices are generally the same here.

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Custom all metal CoreXY
- Duet 2 Wifi w/ PanelDue 7i
- 330mm x 360mm x 500mm
- 750w Silicon heater

Custom Mendel90
(Backup printer - Old reliable!) - Sold

I use a 1.75mm bowden drives on the Dual extruder Lasercut Mendel90 with 1.75mm filament. I only changed to 1.75mm in order to do to a bowden system though - 3mm works fine for single extruders.

Tony

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[blog.think3dprint3d.com]

Perhaps UltiMaker is the gold standard for print resolution and layer height (now 0.02mm) and they use 2.85mm filament. So I would say there would be little need to move to 1.75mm filament to get better print quality.

UltiMaker Filament

Quote
netsrac
Hi, the subject says it all...

Are there any plans to upgrade the Mendel90 to use 1.75mm filament? From what I've heard, it's the only way to get finer prints and details...

Thanks, Netsrac

I'm planning on switching to 1.75mm, but it's not because of print quality. The filament size has no direct connection with it. Instead i'm thinking of switching because I like the simpler setup of direct drives. The stepper motor is directly driving the plastic into the extruder hot end. It's smaller with less moving parts. Google "EZstruder" and compare it to the Wades extruder we're using.

I have an option for 1.75mm on a mendel90 using the Ezstruder here:

[www.thingiverse.com]

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goopyplastic
I have an option for 1.75mm on a mendel90 using the Ezstruder here:

[www.thingiverse.com]

Your designs look very nice. I would like to try this option. I'm wondering what changes I need to make to the M90 firmware to use the EZStruder? Also, the EZStruder works with 3mm or 1.75mm filament. Do you have experience with both sizes? Does it work equally well with both? Thanks a lot. Garry

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Garry Bartsch
Your designs look very nice. I would like to try this option. I'm wondering what changes I need to make to the M90 firmware to use the EZStruder? Also, the EZStruder works with 3mm or 1.75mm filament. Do you have experience with both sizes? Does it work equally well with both? Thanks a lot. Garry

technically it works with 3mm but I don't think the standard stepper motor has enough power to drive it. That's why everyone uses the a geared system like Wades for 3mm.

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lions3

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Garry Bartsch
Your designs look very nice. I would like to try this option. I'm wondering what changes I need to make to the M90 firmware to use the EZStruder? Also, the EZStruder works with 3mm or 1.75mm filament. Do you have experience with both sizes? Does it work equally well with both? Thanks a lot. Garry

technically it works with 3mm but I don't think the standard stepper motor has enough power to drive it. That's why everyone uses the a geared system like Wades for 3mm.

Then I will try to convert a J-Head to 1.75mm as Mogal describes above. So far the closest PTFE tube I can find on eBay is 3mm O.D. and 2mm I.D. Would this be the correct size to use?

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Garry Bartsch
Then I will try to convert a J-Head to 1.75mm as Mogal describes above. So far the closest PTFE tube I can find on eBay is 3mm O.D. and 2mm I.D. Would this be the correct size to use?

check the Jhead website. He normally sells the different PTFE liner sizes. [www.hotends.com]

I would imagine the main reason that makerbot is using 1.75mm is that direct drive extruders aren't strong enough for 3mm. On a bot where the extruder moves in both X and Y the weight / size of the extruder is important so 1.75 is important.

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lions3

Quote
Garry Bartsch
Then I will try to convert a J-Head to 1.75mm as Mogal describes above. So far the closest PTFE tube I can find on eBay is 3mm O.D. and 2mm I.D. Would this be the correct size to use?

check the Jhead website. He normally sells the different PTFE liner sizes. [www.hotends.com]

Thanks.

I'm not sure why I got the idea that I have to convert a 3mm J Head to .75mm when he sells 1.75mm J Heads ready made! I can just buy the 1.75mm J Head. Will I just be able to assemble it the way the M90 J Head is done (muffler cement holding the thermistor in, PTFE tubing on the wires, wrapped with silicone tape, etc.) and it will work fine with the M90 straight away? Or will I need to alter the firmware for it's possibly different thermistor?

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goopyplastic
I would imagine the main reason that makerbot is using 1.75mm is that direct drive extruders aren't strong enough for 3mm. On a bot where the extruder moves in both X and Y the weight / size of the extruder is important so 1.75 is important.

Hi Goopyplastic,

I received the EZStruder I ordered and it looks very nice. I'm wondering what alterations you made to the firmware to make it work with your M90? Did you make any other changes to software related aspects of the M90? I have seen your extruder mounting solution on Thingiverse and it looks very nice.

Thank you and best regards,

Garry

Quote
Garry Bartsch

Quote
goopyplastic
I would imagine the main reason that makerbot is using 1.75mm is that direct drive extruders aren't strong enough for 3mm. On a bot where the extruder moves in both X and Y the weight / size of the extruder is important so 1.75 is important.

Hi Goopyplastic,

I received the EZStruder I ordered and it looks very nice. I'm wondering what alterations you made to the firmware to make it work with your M90? Did you make any other changes to software related aspects of the M90? I have seen your extruder mounting solution on Thingiverse and it looks very nice.

Thank you and best regards,

Garry

Gary,

I'm in the same boat. Just finished wiring up mine with a EZstruder... BUT one of my linear bearing is bad. So i'm in limbo for a couple days before I can start testing.

As to firmware, I did a bunch of research the other week and I "think" there's 2 things i'm planning to switch. First, the extruder motor needs to switch directions. Second, E_STEPS_PER_MM has to change for the direct drive. PLEASE PLEASE take this with a grain of salt as these 2 items are NOT confirmed yet. As I'm waiting for that part to arrive before I do real testing.

My guess at the EZstruder formula for E_STEPS_PER_MM:

#define E_STEPS_PER_MM ((3200 * 1.0)/(1.0 * 10.56 * 3.142))

I honestly don't remember if I needed to switch directions or not, I want to say I didn't.

As for esteps, I was using a value of 95 for E_STEPS_PER_MM

Just thought I would update with a pic of my Mendel90 running with the EZstruder

Like Mogal, I have been printing 1.75mm filament since day dot simply by slipping a piece of 1.75mm ptfe into the 3mm hole leading down to the hotend. Then just callibrate as per nophead's instructions, set the appropriate values in slic3r and good to go.
Using a Mk5 J-Head and a 0.3mm nozzle.

Never had a jam, and I don't use the fan either. Since I'm printing PLA directly to the glass (no glue/tape/juice/hairspray, etc) the fan makes the glass contract slightly when it comes on, and it pops the print off the glass. I simply leave the heat bed at the default 60deg (Marlin default config) for the entire duration of the print. When it has finished, I have added the custom g-code under slic3r to home the axees (axii?..axises?) and turn the heaters off. I can actually hear the print releasing from the glass as it contracts, but I've not had a print let go during a print. Oddly enough, if I leave the heatbed on, pop the print off then put it back on the bed..it seems to reattach itself to the point where I can drag the X axis along by pulling the printed item.

For the bed prep, I scrape it with a box cutter blade, and give it a good wipe with some isopropyl. I don't fully remove the glass from the build platform either...just scrape and wipe and I'm good to go for the next print.

One thing that has improved the reliability of getting that first layer down and not skip steps if it does hit a zit is set the z-lift height in slic3r. I was having real problems with the nozzle hitting the edges of perimeter lines, and being so well stuck to the glass, would cause the steppers to jump. Since setting a z-lift of 0.2mm, not had a first layer fail on me. It's just enough lift to clear any zits, which only seem to occur on solid layers. Infill layers are really clean.