zx81
1
I’ve been printing for a while now originally had a prusa i3 aluminium kit which has since now been retired for a ps3steel with much better components (trapezoidal lead screws, bulldog xl extruder, smoothieboard controller etc) I’ve always used 3mm filament because that’s what I started with … However my buldog xl is huge and heavy (I did try a Bowden setup but I really dislike it) now I was thinking of dropping down to 1.75mm filament this will allow me to fit 2 direct drive all metal extruders in the same space occupied by the bulldog xl this should allow me to extruder faster and therefore up my printing speed. Is this a sound idea or do I stick with my 3mm filament
pakman
3
If you use extruder motors and hot ends scaled for one size or the other, on most frames you can get identical print quality. But as u noted, switching to equipment scaled for 1.75mm will allow for either lighter weight for your carriages to move, or dual setup. Alao, you may revisit bowden and find it is easier.
I don’t think it’s likely that the volumetric speed of a small 1.75mm extruder will be significantly higher than for a 3mm extruder.
The 1.75mm extruder will have to push (linearly) nearly 2 times the speed of the 3mm extruder in order to match it in volumetric speed.
This doesn’t mean a smaller/lighter extruder doesn’t have it’s advantages, a lighter extruder allows you to move your carriage faster.
Are you sure that you are bound on the E axis?
Just asking, because my I3 (3mm with wades geared extruder) is almost always bound on Y.
Also, I personally wouldn’t do a dual extruder setup, unless they are exactly aligned (in Z) and you have very good ooze prevention, it will end up with a mess.
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curve
5
The world seems to be going to 1.75 so it seems a sound idea, I am using 1.75mm on a Prusa i3 plus with a E3D-V6 and get good results. I have just designed a deal extruder setup that I shall implement over the next few days.
Ken
Noah
6
3mm filament definitely has its advantages, namely thicker filaments are less likely to buckle, giving you better printing results with filaments like ninjaflex. That being said, I get great results with my 1.75mm e3d v6. Having a thinner filament means you can extrude faster, but at the same time, less filament is going through the nozzle, essentially, either way you end up with more or less the same extrusion speed. The one advantage 1.75 has over 3 is that 1.75 filament is much more widely available, as well as 1.75 extruders and for that reason I’d recommend you make the switch to 1.75.
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Why should 1.75mm filament lead to smaller and lighter extruder? It’s all the same. Shure you can save some space and weight by replacing the Bulldog XL with a smaller directdrive extruder, but I would not do that. The Bulldog XL with it’s 5:1 gear is ways better than all directdrives I know. Just change your Bulldog XL to 1.75mm filament and hotend.
Yes this is a good idea 1.75 made a huge difference for me If you go dual you might not get the extra speed as you moving extra mass around But with a single you will a lighter faster extruder for sure that will allow you to move quicker
yyc3d
9
i think being able to do both would make you more flexible!
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I am in the process of doing this too. My first printer is a Prusa i3 with a 3mm Wade extruder and hexagon all metal hotend that I do love because it accepts any kind of filament and never chokes.
Yet I think 1.75 is the future. So I have built a new generation Prusa i3 with the same extruder and hotend, only newer design and 1.75mm.
I will finish the 30+ 3mm spools I have in stock, and renew only with 1.75. Within a few months I will have no more 3mm filament left and will replace the original extruder on my first i3 by a double or triple -whatever will work in a year from now- 1.75 direct drive extruder.
Before you switch to the double direct drives, I would buy a roll of PETg and print out one of these Gunstruder : Belt friction extruder Cold-end by andreasL - Thingiverse. If you do that I think there is a strong possibility that you will like using 1.75 mm. Also I would think about getting the Prusa I3 aluminum back out and adding ABL, I know you will eliminate alot of the frustrations that you likely had with the aluminum. Finally I would switch to 1.75 as a default because of the breakage and 1.75 is sold in ALOT of places 3 mm not as much.
zx81
12
I’ve luckily never had an issue with oozing on the direct drive setup this is why I prefer it to the Bowden setups, the filament is constantly under pressure in the PTFE tube with a Bowden I think it gives inconsistent results. Y axis? Z axis is the slowest axis on my printer. Volumetrically speaking if move from 3mm to 1.75mm I can remove the gearbox on the extruder and go from 495 steps per mm to 107mm steps per mm that’s 4.6x quicker.
Yeah, I dislike bowden too for that reason. But dual extruder is more finicky because you can ooze (even a little) from one nozzle while printing with the other one, and especially if you have different colours, that’s pretty notable. And that’s not even speaking about tiny misalignments where one (potentially cold) nozzle hits the printed part repeatedly while printing.
Ofc. Z is the slowest of them all, but it’s not the binding factor, Z needs to do very little work. If you were to double your Z speed, would it speed up your print significantly? at least in my prints not. the Y on the other hand. is moving nearly constantly at pretty high speeds, speeding it up would speed up the whole print, but my Y is hitting the limit of my steppers/drivers, so I am limited in overall speed by the maximum speed of my Y axis, so there is no point in speeding up any other axis (even not E or Z) If I don’t speed up my Y.
If you remove the gearbox you are also reducing your steps/mm³, so you have to also account for the fact that you loose accuracy on your E. (And I think accuracy in E is important for good printing results, but might be wrong here)
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