1.75 mm vs 3.00 mm I've only used 3.00 mm filament. However, there seem to be a lot of good reason to use 1.75 mm filament: Then, would there be any reasons to use 3.00 mm filament (or not to 1.75 mm filament)? I think I read it somewhere that 1.75 mm are a bit more expensive (because it's easier/faster for manufacturers to extrude 3.00 mm filaments), but all the suppliers I have seen either had the same price for both or had a very little difference in price between them. Another possible disadvantage with 1.75 mm I can think of is that inconsistency in filament thickness/diameter may have bigger impact on it. For example, if the diameter varies by +/- 0.5 mm (in the same spool), it's difference of 28.6% vs 16.7% variation. Well, obviously my assumption is that this variation in diameter is nominal and constant regardless of the filament size, rather than being proportional to the size of the filament. Also, to move the same volume of filament, the extruder will have to push more (longer) filament with 1.75 mm, and faster (to extruder the same amount at the same rate). This may cause the extruder motor to work harder and run hotter? Or, will that be compensated by the fact the motor now needs to use smaller force (therefore we may be able to reduce the driver current)? I'm pretty sure this topic of filament size has been discussed before, probably many times. So, I apologize for asking it again - it may have been my poor search skill, but I couldn't find any thread about it... or, maybe I didn't search hard enough :p If it's more convenient for you, you can just give an URL for those previous discussions (as long as they still relevant and not too out of date). Thanks! https://reprap.org/forum/read.php?1,248179,248179#msg-248179 Sun, 08 Mar 2026 23:10:03 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,248179,269704#msg-269704 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,269704#msg-269704 Dale Dunn General Wed, 20 Nov 2013 11:23:41 -0500 https://reprap.org/forum/read.php?1,248179,269514#msg-269514 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,269514#msg-269514
I've got goin on whatever the producer gave me on the spool. Nothing more and nothing less. Is filament tangled on the spool? Sometimes. You betcha. The more I can reduce my margin of error the better.]]> Dorian General Tue, 19 Nov 2013 21:51:25 -0500 https://reprap.org/forum/read.php?1,248179,268827#msg-268827 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,268827#msg-268827
Quote
destroyer2012
...
Just for the record that is a terrible reason to do anything. Companies don't actively try to make their machine work better.
...

They do when they're competing. Still, it's not a good reason to make a choice when you can try to understand the design criteria yourself.

Linear filament required changes with the square of the diameter. All your doubling examples should have factors of 4.

Spool movement and tangles on the spool are a non-issue for my spool. I don't know what you've got going on. I don't think mine is remarkable in any way.]]> Dale Dunn General Mon, 18 Nov 2013 12:51:56 -0500 https://reprap.org/forum/read.php?1,248179,268740#msg-268740 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,268740#msg-268740
Here's my reasoning; if the filament is roughly twice the diameter the machine will have to pull half the length of filament for any given print. I'm cutting down the spool movement by half. I'm cutting the changes of the filament jamming on the spool in half. Less mechanical movement for the same job is always better.

From what I understand the only cost is that 3mm is stiffer. I imagine if I were printing in a detached building in a cold environment that would be a factor but I think printing in those conditions would be less than ideal in the first place.

A lot of commercial machines are using direct drive extruders that can only handle 1.75mm. Cost is a factor for the company producing the machine. Think about what goes into a wades extruder; 3 bearings, two gears, and a drive pulley (hobbed bolt). What goes into a direct drive extruder; one bearing and a drive pulley. When you produce a million units those bearings and gears add up.

If the trend continues eventually 1.75mm filament will win the day. Even if it isn't the practical choice commercial demand will increase the supply of 1.75mm and 3mm will be more expensive as suppliers re-tool.]]> Dorian General Mon, 18 Nov 2013 09:34:05 -0500 https://reprap.org/forum/read.php?1,248179,268622#msg-268622 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,268622#msg-268622
Quote
N314
Professional FDM machines (Stratsys/3D systems) use 1.75, so i figure they probably have pretty good reasons for doing so...

Just for the record that is a terrible reason to do anything. Companies don't actively try to make their machine work better. Their only motivation is to design something so they can make more money. Maybe in some cases a better machine equals making more money, but usually not.

I would guess the reason they use 1.75 is so you have to buy their filament, since if they used 3mm then you could use plastic welding rod (which is 3mm in diameter and much, much cheaper than the stock stratasys filament). Of course I am talking about a time before reprap 1.75 mm filament existed.]]> destroyer2012 General Mon, 18 Nov 2013 02:52:51 -0500 https://reprap.org/forum/read.php?1,248179,268565#msg-268565 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,268565#msg-268565
Professional FDM machines (Stratsys/3D systems) use 1.75, so i figure they probably have pretty good reasons for doing so...


-Nick]]> N314 General Sun, 17 Nov 2013 21:47:51 -0500 https://reprap.org/forum/read.php?1,248179,268529#msg-268529 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,268529#msg-268529 nechaus General Sun, 17 Nov 2013 19:12:05 -0500 https://reprap.org/forum/read.php?1,248179,267784#msg-267784 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,267784#msg-267784 destroyer2012 General Fri, 15 Nov 2013 21:30:50 -0500 https://reprap.org/forum/read.php?1,248179,267228#msg-267228 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,267228#msg-267228
[attachment 21200 bulldog_open.JPG]]]> Reprapdiscount General Thu, 14 Nov 2013 23:37:07 -0500 https://reprap.org/forum/read.php?1,248179,267186#msg-267186 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,267186#msg-267186 aduy General Thu, 14 Nov 2013 19:11:21 -0500 https://reprap.org/forum/read.php?1,248179,267185#msg-267185 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,267185#msg-267185 I once had some glow in the dark PLA, it was totally different, It would simply break easy, for example,
It would break by bending it once to far in my hand,
It would break from the extruder pressure bolt, also from the bend in the bowden tube.
Dropped the spool and ended up with an unusable spool as it had breaks through out the whole thing

It was very old and never kept in air tight container, I had it when i first got my printer, went out and stocked up on plastic but could not use it, layed around for 6 maybe 8 months.
When the stuff was brand new, it was fine, but never used much, it was ultra low temp,
All my PLA i get now gets is pretty good, i never have it long enough to go bad, i can use a spool easily within a week.
Never had this kind of issue with abs or nylon]]> nechaus General Thu, 14 Nov 2013 18:59:32 -0500 https://reprap.org/forum/read.php?1,248179,267154#msg-267154 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,267154#msg-267154
Thanks]]> Anonymous User General Thu, 14 Nov 2013 17:31:50 -0500 https://reprap.org/forum/read.php?1,248179,266815#msg-266815 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,266815#msg-266815 nechaus General Thu, 14 Nov 2013 05:33:10 -0500 https://reprap.org/forum/read.php?1,248179,266681#msg-266681 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,266681#msg-266681 nechaus General Wed, 13 Nov 2013 21:04:02 -0500 https://reprap.org/forum/read.php?1,248179,266009#msg-266009 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,266009#msg-266009
btw the wheel would only be for a bowden setup.

also i have zero interest in printing pla, I live in arizona, pla melts in my car haha, its really useless. abs polycarb and nylon are all fairly flexible, the polycarb isnt as flexible but it doesnt mind being bent at all.]]> aduy General Tue, 12 Nov 2013 16:37:19 -0500 https://reprap.org/forum/read.php?1,248179,266002#msg-266002 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,266002#msg-266002 When im getting to the end of a 3mm reel the printer is practically climbing up the filament.
Perhaps my workshop is a bit too cold.]]> Vince General Tue, 12 Nov 2013 16:07:52 -0500 https://reprap.org/forum/read.php?1,248179,265707#msg-265707 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,265707#msg-265707
1457554_684747278215986_1232347079_n.jpg


why? because im tired of having to fiddle with the extruder during prints that can take upwards of 24 hours, and because then they can take less time because i can push more plastic through.
]]> aduy General Tue, 12 Nov 2013 04:14:31 -0500 https://reprap.org/forum/read.php?1,248179,265689#msg-265689 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,265689#msg-265689 thejollygrimreaper General Tue, 12 Nov 2013 03:29:57 -0500 https://reprap.org/forum/read.php?1,248179,265672#msg-265672 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,265672#msg-265672 aduy General Tue, 12 Nov 2013 02:18:41 -0500 https://reprap.org/forum/read.php?1,248179,250303#msg-250303 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,250303#msg-250303 Yvan General Mon, 30 Sep 2013 23:02:12 -0400 https://reprap.org/forum/read.php?1,248179,250264#msg-250264 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,250264#msg-250264 destroyer2012 General Mon, 30 Sep 2013 18:33:22 -0400 https://reprap.org/forum/read.php?1,248179,250200#msg-250200 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,250200#msg-250200 Yvan General Mon, 30 Sep 2013 16:00:42 -0400 https://reprap.org/forum/read.php?1,248179,250161#msg-250161 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,250161#msg-250161
Thanks for the tips.]]> cobrageek General Mon, 30 Sep 2013 14:56:04 -0400 https://reprap.org/forum/read.php?1,248179,249452#msg-249452 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,249452#msg-249452 -------------------------------------------------------
> Thanks Yvan. I'll try the cut-off wheel option
> and probably add some resistance to the bearing to
> keep it from "just spinning".
>
> Mihai, I've thought about the MK7, but I wasn't
> sure how it would work in the current extruder.
> Isn't it larger than the bolt? How do you put
> this in without changing the layout in the
> extruder?


Instead of adding friction you can offset the cutting disk such that its axis is tilted about 20 to 30 degrees from that of the bearing. This will also give the groove a rounded profile which will better match the filament.

Even if the bearing rotates freely the wheel will still cut into it because the two are not rotating in exactly the same direction.

I attached a drawing to clarify what I mean:
[attachment 19213 x.jpg]]]> lister6520 General Sat, 28 Sep 2013 05:17:01 -0400 https://reprap.org/forum/read.php?1,248179,248609#msg-248609 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248609#msg-248609
Yvan Wrote:
-------------------------------------------------------
> So far I've used variations of letting the bearing
> spin on an 8 mm shaft while I cut a grove with a
> Dremel tool and abrasive/cutoff disk.
>
> Last time, I used a small nylon brush as a
> friction brake to control the spin of the bearing.
> It can rotate way to fast as it tried to follow
> the high rpm cutoff disk.
>
> iquiz, I'm not a big fan of bowden setups because
> they add another layer of play or slack in the
> chain. I should try one though, just to see how it
> all works out.]]> iquizzle General Wed, 25 Sep 2013 15:04:23 -0400 https://reprap.org/forum/read.php?1,248179,248598#msg-248598 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248598#msg-248598
Mihai, I've thought about the MK7, but I wasn't sure how it would work in the current extruder. Isn't it larger than the bolt? How do you put this in without changing the layout in the extruder?]]> cobrageek General Wed, 25 Sep 2013 14:22:26 -0400 https://reprap.org/forum/read.php?1,248179,248422#msg-248422 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248422#msg-248422
What I know for sure is that using 1.75mm filament does allow your extruder to more more precisely control the filament. I'm going with 1.75mm plastic for my first personal printer because other than physical differences, I think that it's getting harder to find wide varieties of 3mm filament in more stores. It's also going to be my first experience using 1.75, might as well jump into new territory and experiment.]]> Coin3 General Wed, 25 Sep 2013 01:24:12 -0400 https://reprap.org/forum/read.php?1,248179,248419#msg-248419 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248419#msg-248419 -------------------------------------------------------
> I've found a few reports that indicated that they
> have made bolts intended for 3mm and they worked
> fine for 1.75mm.

MK7 is made that way ... and it works very well.

regards,
mihai]]> mihai General Wed, 25 Sep 2013 00:47:05 -0400 https://reprap.org/forum/read.php?1,248179,248407#msg-248407 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248407#msg-248407
Last time, I used a small nylon brush as a friction brake to control the spin of the bearing. It can rotate way to fast as it tried to follow the high rpm cutoff disk.

iquiz, I'm not a big fan of bowden setups because they add another layer of play or slack in the chain. I should try one though, just to see how it all works out.]]> Yvan General Tue, 24 Sep 2013 22:03:54 -0400 https://reprap.org/forum/read.php?1,248179,248404#msg-248404 Re: 1.75 mm vs 3.00 mm https://reprap.org/forum/read.php?1,248179,248404#msg-248404 iquizzle General Tue, 24 Sep 2013 21:37:18 -0400