1.75mm Filament vs 3mm Filament Sorry to ask such a basic question, but I can't find any discusion about this. I want to order a Prusa from MakerGear today. Can anyone tell me which way to go between the 1.75mm vs 3mm hot end? Is one size more common than the other? Thanks for your help! Steve https://reprap.org/forum/read.php?1,128719,128719#msg-128719 Thu, 16 Apr 2026 04:26:44 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,128719,610659#msg-610659 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,610659#msg-610659 JamesK General Sat, 16 Jan 2016 14:42:43 -0500 https://reprap.org/forum/read.php?1,128719,610628#msg-610628 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,610628#msg-610628
If only because the 1.75 is easier to handle, and runs off the spool easier and can be fed from a simpler extruder I'd pick 1.75.]]> DjDemonD General Sat, 16 Jan 2016 13:33:37 -0500 https://reprap.org/forum/read.php?1,128719,610038#msg-610038 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,610038#msg-610038
Quote
mbrembati
Quote
Sublime
It seems that everyone thinks that 1.75mm takes less force but as far as I understand this is not true. A certain volume of plastic going through a certain size hole at a certain rate takes exactly the same pressure regardless of the filament input size. Or to put it simpler, the nozzle diameter determines the pressure required to extrude not the filament.
[...]
I believe you are confusing pressure with force.
I agree that the pressure depends on the nozzle diameter, but the force you need to push the filament is Pressure x Filament Section Surface. As S = Pi x (Wire Diameter/2)^2, the force you need to apply to the wire is (3/1,75)^2= 2,94 times higher with 3mm wire.

Yes but you dont account for the speed/flow at which you need to push the filament through, ie Bernoulis equation Conservation of Energy
There is however a school of thought that it takes less time for the heat to fully melt 1.75 compared to 3mm for a given rate of flow/filament length although if this is the case, raising the hotend temp by a few degrees would counter this. In countenance to this is the amount of energy used to melt a given volume of plastic does not change.
In my experience 3mm is far less likely to tangle and is far easier to untangle when/if it does, and is less likely to snap. Also when using flexible filaments 3mm is going to be stiffer than 1.75 and so less likely to kink along the filament force path (ie the path exiting the hobb through to and inside the cold section of the hotend)]]> Mutley3D General Fri, 15 Jan 2016 09:46:42 -0500 https://reprap.org/forum/read.php?1,128719,609867#msg-609867 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,609867#msg-609867
Quote
Sublime
It seems that everyone thinks that 1.75mm takes less force but as far as I understand this is not true. A certain volume of plastic going through a certain size hole at a certain rate takes exactly the same pressure regardless of the filament input size. Or to put it simpler, the nozzle diameter determines the pressure required to extrude not the filament.
[...]
I believe you are confusing pressure with force.
I agree that the pressure depends on the nozzle diameter, but the force you need to push the filament is Pressure x Filament Section Surface. As S = Pi x (Wire Diameter/2)^2, the force you need to apply to the wire is (3/1,75)^2= 2,94 times higher with 3mm wire.]]> mbrembati General Fri, 15 Jan 2016 03:07:25 -0500 https://reprap.org/forum/read.php?1,128719,375207#msg-375207 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,375207#msg-375207
Quote

Quote
Ralph.Hilton
10% is far too high. I see no reason to use a supplier who can't guarantee 5% .
I totally agree.
Unfortunately I've seen many "guarantee it", but won't back it up when they fail to reach those specs. The company who jammed my bowden laughed and blew me off when I complained. This same company later asked me to make prints for them because they lack a printer, despite the fact that they claim to use the filament in their own printers and blame customers for all filament failures. There are some real sleezeballs out there.
I would pay with Paypal and use their dispute procedure. Also order a small quantity trying filament from a new supplier.]]> Ralph.Hilton General Fri, 27 Jun 2014 08:29:23 -0400 https://reprap.org/forum/read.php?1,128719,375189#msg-375189 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,375189#msg-375189
I have machines running both sizes of filaments and I can't find any reasonable difference between the two.]]> umdpru General Fri, 27 Jun 2014 07:38:51 -0400 https://reprap.org/forum/read.php?1,128719,375048#msg-375048 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,375048#msg-375048
Quote
andyinyakima
So sheepdog43, you think 1.75 mm jhead would be a better place to start and compare results with the one I have now?
You're welcome,
I may not always agree with the reasons, but I do agree with many of the others in what they recomend...
If you already have a good working 3mm setup with a .5mm, until you have a reason to change, don't. You aren't going to get radically better results.

Worry about changing when you have either reached the limit of the machine or your skill. Until then, save your money.


Quote
Ralph.Hilton
10% is far too high. I see no reason to use a supplier who can't guarantee 5% .
I totally agree.
Unfortunately I've seen many "guarantee it", but won't back it up when they fail to reach those specs. The company who jammed my bowden laughed and blew me off when I complained. This same company later asked me to make prints for them because they lack a printer, despite the fact that they claim to use the filament in their own printers and blame customers for all filament failures. There are some real sleezeballs out there.


As for companies... Ultimachine is great. It's similar to the older Makerbot stuff. Microcenter also carries a line by Toner Plastics (1.75mm only) that is also comparable, and well priced actually, especially since you can pick it up locally if you live near a Microcenter. I've had good luck with all 3, but given a choice, I will pick Ultimachine every time, I just wish it was cheaper. They also send samples of other colors, which is cool for trinkets.]]> sheepdog43 General Thu, 26 Jun 2014 22:37:34 -0400 https://reprap.org/forum/read.php?1,128719,375025#msg-375025 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,375025#msg-375025 I like MatterHackers, never let me down and I recommend them all the way. I've heard good things about UltiMachine. I've only tried 3DXTech's ABS/PA alloy, but it is the most pristine stuff I've ever purchased, package and filament both, so I assume their other stuff is good as well. I'll be buying some of it to see at some point.]]> MrDoctorDIV General Thu, 26 Jun 2014 20:24:16 -0400 https://reprap.org/forum/read.php?1,128719,374992#msg-374992 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374992#msg-374992
I would like to take 3d printing to a science as much as possible but because the
extruded part is changing constantly I can see where an artistic variable needs to be
allowed such as the G-code

Is there a list of Filament Suppliers to Avoid because of quality issues?]]> andyinyakima General Thu, 26 Jun 2014 18:28:38 -0400 https://reprap.org/forum/read.php?1,128719,374912#msg-374912 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374912#msg-374912
Quote
Ralph.Hilton
Quote
sheepdog43
Another problem is filament precision, anything over 10% out of spec is considered problematic. On 3mm, this is .3mm that is a HUGE deviation and very easy to stay within spec, on 1.75mm, you are allowed only .17, which is troublesome for some manufacturers. I have had some 1.75mm filament that was .24mm out of spec and jammed my bowden tube so bad I had to hammer a stiff metal rod into the tube to get it out.
10% is far too high. I see no reason to use a supplier who can't guarantee 5% .
Most agreed. If it's any more than 0.1mm I'd never again buy from them, percentage aside.]]> MrDoctorDIV General Thu, 26 Jun 2014 13:57:52 -0400 https://reprap.org/forum/read.php?1,128719,374907#msg-374907 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374907#msg-374907
Quote
sheepdog43
Another problem is filament precision, anything over 10% out of spec is considered problematic. On 3mm, this is .3mm that is a HUGE deviation and very easy to stay within spec, on 1.75mm, you are allowed only .17, which is troublesome for some manufacturers. I have had some 1.75mm filament that was .24mm out of spec and jammed my bowden tube so bad I had to hammer a stiff metal rod into the tube to get it out.
10% is far too high. I see no reason to use a supplier who can't guarantee 5% .]]> Ralph.Hilton General Thu, 26 Jun 2014 13:36:25 -0400 https://reprap.org/forum/read.php?1,128719,374874#msg-374874 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374874#msg-374874
Quote
andyinyakima

The last part of your statement is what I suspect on my hotend, not so great quality. That's why I was thinking of a metal hotend.

I have also been thinking about direct drive extruder versus gear drive; any comments appreciated.

One last question how critical is g-code? I am using Slic3r 1.0.1.
I tried both direct and geared, honestly, there isn't much of a difference most of the time. The geared ones have more power, the direct ones are faster. With 3mm filament a direct drive is usually to low powered for any kind of printing speed so those are mostly used for 1.75mm.
Currently i only use geared extruders (Wade derivates, own construction and Bulldog).
G-Code is actually very critical. Adjusting the slicing software is an important part of the over all adjustment of the system and is needed to achieve not only optimal but actually useable results.]]> Srek General Thu, 26 Jun 2014 11:04:15 -0400 https://reprap.org/forum/read.php?1,128719,374868#msg-374868 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374868#msg-374868 I'm not speaking with experience, so take it with a grain of salt, but from I can see, go geared for quality, 1:1 direct for simplicity and ease.]]> MrDoctorDIV General Thu, 26 Jun 2014 10:39:57 -0400 https://reprap.org/forum/read.php?1,128719,374861#msg-374861 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374861#msg-374861
Quote
Srek
I agree with vegasloki. You will get more out of calibrating your machine than changing the filament. In the german forum the user Hardwarekiller is using 3mm filament to print to the highest standards i have seen yet. The filament size does not make the difference in quality, the calibration of your machine and the quality of the hotend does.

The last part of your statement is what I suspect on my hotend, not so great quality. That's why I was thinking of a metal hotend.

I have also been thinking about direct drive extruder versus gear drive; any comments appreciated.

One last question how critical is g-code? I am using Slic3r 1.0.1.]]> andyinyakima General Thu, 26 Jun 2014 10:17:18 -0400 https://reprap.org/forum/read.php?1,128719,374780#msg-374780 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374780#msg-374780 Srek General Thu, 26 Jun 2014 04:46:43 -0400 https://reprap.org/forum/read.php?1,128719,374766#msg-374766 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374766#msg-374766
Quote
andyinyakima
So sheepdog43, you think 1.75 mm jhead would be a better place to start and compare results with the one I have now?

If I do decide on metal I will research it well, thanks.

At this point you'll get more out of tuning the machine you have now rather than getting another hot end. Plenty of people make good prints with a .5 nozzle and 3 mm material. It's more forgiving to learn. Once you get your machine more dialed in, print faster, use a bowden, etc you will be in a better position to judge what you need and reap the benefits of using 1.75 material. Make some prints then post the pics on the forum and ask for opinions on what could be done to improve the prints.]]> vegasloki General Thu, 26 Jun 2014 03:39:27 -0400 https://reprap.org/forum/read.php?1,128719,374728#msg-374728 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374728#msg-374728
If I do decide on metal I will research it well, thanks.]]> andyinyakima General Thu, 26 Jun 2014 00:36:13 -0400 https://reprap.org/forum/read.php?1,128719,374719#msg-374719 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374719#msg-374719 Anonymous User General Wed, 25 Jun 2014 23:40:46 -0400 https://reprap.org/forum/read.php?1,128719,374697#msg-374697 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374697#msg-374697

Prices have evened out on filament.
It also used to be that 3mm had a greater selection, today, it's pretty even.

Where 1.75mm shines is that you don't have to gear it down as far, or at all. You get the effect of a higher ratio extruder without having a higher ratio. Some users do get away without any gear reduction, however, I don't recommend trying that on any head with a nozzle smaller than .4. At .4mm, even the best motors are hard pressed at times to keep pushing it at any decent speed which is why you see lots of geared stepper motors on deltas (which almost exclusively use 1.75mm), which are actually geared even lower than a Wade's extruder. At 5:1 on 1.75mm, you get a very precise filament extrusion with lots of power behind it. This is especially important on smaller nozzle sizes. Another benefit to 1.75mm is weight and flexibility, on a bowden tube, the 1.75mm weighs less and is more flexible, which is more important in a delta.

It's not all roses.
1.75mm has a smaller contact patch and cross section, as such, you're far more likely to strip or crush the filament. Most hobbs are designed for 3mm filament, making the problem even worse. This isn't a huge issue until you start ramping speeds up. I have one hobb that slips at just 150mm/s, but most will handle 200mm/s on a .35mm J-head. Things get complicated fast beyond that speed.

Another problem is filament precision, anything over 10% out of spec is considered problematic. On 3mm, this is .3mm that is a HUGE deviation and very easy to stay within spec, on 1.75mm, you are allowed only .17, which is troublesome for some manufacturers. I have had some 1.75mm filament that was .24mm out of spec and jammed my bowden tube so bad I had to hammer a stiff metal rod into the tube to get it out.]]> sheepdog43 General Wed, 25 Jun 2014 21:46:53 -0400 https://reprap.org/forum/read.php?1,128719,374666#msg-374666 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,374666#msg-374666 and other local 3d printer fans. I have done some calibrating extrusions tweaking the firmware. The extrusions
x,y are within 1% but my details like letters, degree marks leave something to be desired, I am using 3mm
filament and my extruder end is .5mm.

I am going to try a 1.75mm filament to see if my detail will improve.
I am thinking of an all metal extruder, one that will also extrude more of the exotic
filaments!
Any pros and cons?

From this thread I noticed the dated 2012 post leaned towards 3mm mostly based on price.
Posts with dates of 2014 lean towards 1.75mm maybe because price has come closer to 3mm and
detail has improved? (I'm guessing)]]> andyinyakima General Wed, 25 Jun 2014 19:00:00 -0400 https://reprap.org/forum/read.php?1,128719,333011#msg-333011 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,333011#msg-333011
Quote
Sublime
It seems that everyone thinks that 1.75mm takes less force but as far as I understand this is not true. A certain volume of plastic going through a certain size hole at a certain rate takes exactly the same pressure regardless of the filament input size. Or to put it simpler, the nozzle diameter determines the pressure required to extrude not the filament.

Its like assuming a hydraulic system with 2" lines some how has more force than one with 1/2" lines. The only difference is the maximum volume per minute that one gives over another. The actual force is determined by the cylinder diameter which is the equivalent of the nozzle hole.

The only difference I am aware of with 1.75 over 3mm is the volume of plastic per step. 3mm puts out almost 4 times the volume of plastic per step as 1.75mm in the same extruder. The only time this matters is when printing really small layers, like 0.1 and less combined with a really complex model. If you want to try and print really tiny layers with 3mm you can make an extruder with a lower gear ratio, like 10:1 instead of the stock 3.3:1

That's true for determining the working pressure in the system, but to generate the pressure in a cylinder you need to apply force over the area of a piston. With (3/1.75)^2 times the area, you'd need about 3 times the force to generate the same pressure.]]> DaveX General Tue, 01 Apr 2014 05:26:35 -0400 https://reprap.org/forum/read.php?1,128719,332999#msg-332999 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,332999#msg-332999
Quote
Sublime
It seems that everyone thinks that 1.75mm takes less force but as far as I understand this is not true. A certain volume of plastic going through a certain size hole at a certain rate takes exactly the same pressure regardless of the filament input size. Or to put it simpler, the nozzle diameter determines the pressure required to extrude not the filament.

Its like assuming a hydraulic system with 2" lines some how has more force than one with 1/2" lines. The only difference is the maximum volume per minute that one gives over another. The actual force is determined by the cylinder diameter which is the equivalent of the nozzle hole.

The only difference I am aware of with 1.75 over 3mm is the volume of plastic per step. 3mm puts out almost 4 times the volume of plastic per step as 1.75mm in the same extruder. The only time this matters is when printing really small layers, like 0.1 and less combined with a really complex model. If you want to try and print really tiny layers with 3mm you can make an extruder with a lower gear ratio, like 10:1 instead of the stock 3.3:1

While all of that is true there's other factors at play, I believe the friction at the not-so-melted zone must be much higher for 3mm filament Vs. 1.75 since there's more surface area in contact with the extruder barrel, therefore more friction. Also the thicker filament must have a longer melt transition zone (exacerbating the first issue) because the surface area to radiate away the heat coming up from the melting zone into the barrel heatsink is proportionally smaller than the cross sectional area that is drawing heat up the filament.

Besides that one advantage of 1.75mm filament I can think of is that it is easy to use all the filament in the spool, even the last meters tightly wound around the spool hub.]]> CaptainObvious General Tue, 01 Apr 2014 05:04:45 -0400 https://reprap.org/forum/read.php?1,128719,332625#msg-332625 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,332625#msg-332625 laserboy General Mon, 31 Mar 2014 11:23:03 -0400 https://reprap.org/forum/read.php?1,128719,152107#msg-152107 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,152107#msg-152107
I wouldn't recommend that. ABS decomposes into some unfavorable things at such a high temp

Not to mention I'd think it would cause the extruder nozzle assembly to clog.]]> xiando General Mon, 03 Sep 2012 13:09:23 -0400 https://reprap.org/forum/read.php?1,128719,152051#msg-152051 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,152051#msg-152051
the 1.75 is better if you can run that, your flow control resolution is much greater, for a start, you'll get less ooze because there is less molten plastic behind the nozzle with the correct retraction settings you should be able to get some very nice prints

if you can afford to put a direct drive extruder on your machine i would highly recommend it, however if you are stuck with a wades type of geared extruder then it's worth the money on one of those hyena hobbed bolts, unless the bolt that comes with it is really good and nice and round (not all are)]]> thejollygrimreaper General Mon, 03 Sep 2012 04:34:18 -0400 https://reprap.org/forum/read.php?1,128719,152050#msg-152050 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,152050#msg-152050
Imagine how little force would be required to feed 3mm if the temperature were set to 500 degrees? Pretty much none I would think (although that is too high), so I believe that the temperature of the nozzle is really what counts.]]> Tekwizard General Mon, 03 Sep 2012 04:05:19 -0400 https://reprap.org/forum/read.php?1,128719,129351#msg-129351 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,129351#msg-129351 misan General Thu, 19 Apr 2012 02:34:55 -0400 https://reprap.org/forum/read.php?1,128719,129340#msg-129340 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,129340#msg-129340 Just think about it as a hydraulic system: In one case the driving piston is 3mm, in the other case the piston is 1.75mm.
The area is only 34% of the bigger filament so therefor the required force is also only 34% of the 3mm value.
Bertho]]> Bertho General Wed, 18 Apr 2012 23:21:21 -0400 https://reprap.org/forum/read.php?1,128719,128876#msg-128876 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,128876#msg-128876
Luckily I was able to buy 1.75mm ABS filament at the same price as 3mm. If not, I guess it may make sense to create a 3mm to 1.75mm dedicated extruder to source yourself.]]> misan General Sun, 15 Apr 2012 17:14:21 -0400 https://reprap.org/forum/read.php?1,128719,128816#msg-128816 Re: 1.75mm Filament vs 3mm Filament https://reprap.org/forum/read.php?1,128719,128816#msg-128816
Or, if you use the same gearing then a smaller motor can be used making it smaller and lighter.

A smaller lighter extruder is a benefit for small machine. For a large machine the mass of the bed dominates, so no point in having a fast X axis and a slow Y axis. But you could perhaps fit two 1.7mm extruders for dual extrusion and be the same mass as one 3mm extruder.]]> nophead General Sun, 15 Apr 2012 07:24:09 -0400