Prusa i3 extrusion issues
Posted by Layerz
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Prusa i3 extrusion issues June 11, 2015 05:34PM |
Registered: 8 years ago Posts: 18 |
Hi all,
I've built and owned my prusa i3 for a couple of weeks and am struggling to fine tune everything.
It is a Sunhockey laser cut acrylic frame with a heated bed.
I have leveled the bed and am using 3m blue painters tape and first layers are adhering ok, I'm mainly wondering what's going on with my extrusion rates.
Using Repetier to test 100mm I got 80 extruded so have been increasing the extrusion rate and have had to go as high as 280% flow, I'll paste my settings below.
Also I have shown cubes printed at different extrusion and then the boat from benchy at 280%, when measuring the boat with calipers the length and widths appear to be within +1% but heights fall a little in and around +2%
Thank in advance as really hoping to resolve this.
I've built and owned my prusa i3 for a couple of weeks and am struggling to fine tune everything.
It is a Sunhockey laser cut acrylic frame with a heated bed.
I have leveled the bed and am using 3m blue painters tape and first layers are adhering ok, I'm mainly wondering what's going on with my extrusion rates.
Using Repetier to test 100mm I got 80 extruded so have been increasing the extrusion rate and have had to go as high as 280% flow, I'll paste my settings below.
Also I have shown cubes printed at different extrusion and then the boat from benchy at 280%, when measuring the boat with calipers the length and widths appear to be within +1% but heights fall a little in and around +2%
Thank in advance as really hoping to resolve this.
Attachments:
open | download - Settings1.png (135.9 KB)
open | download - Settings2.png (134.2 KB)
open | download - Settings3.png (135.3 KB)
open | download - Settings4.png (141 KB)
open | download - Settings5.png (134.8 KB)
open | download - boat1.jpg (588.9 KB)
open | download - boat2.jpg (572.9 KB)
open | download - boat3.jpg (603.6 KB)
open | download - cubes.jpg (601.2 KB)
open | download - Settings1.png (135.9 KB)
open | download - Settings2.png (134.2 KB)
open | download - Settings3.png (135.3 KB)
open | download - Settings4.png (141 KB)
open | download - Settings5.png (134.8 KB)
open | download - boat1.jpg (588.9 KB)
open | download - boat2.jpg (572.9 KB)
open | download - boat3.jpg (603.6 KB)
open | download - cubes.jpg (601.2 KB)
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Re: Prusa i3 extrusion issues June 11, 2015 06:32PM |
Registered: 10 years ago Posts: 581 |
For that great a difference between extruded and measured, you really need to set E steps per mm using the M92 gcode command. I'd also run the same test a few times. If your guidler tension isn't correct, or you are extruding your test too fast, you can get missed steps and inconsistent results. You need to get a consistently extruded length of filament first before you tune E steps per mm, or change the extrusion multiplier.
Your print width and height can be affected by over extrusion. This is particularly noticable on the top layer. If you run your finger over the top layer and it feels lumpy, chances are you're over-extruding and your print will be too high.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
Your print width and height can be affected by over extrusion. This is particularly noticable on the top layer. If you run your finger over the top layer and it feels lumpy, chances are you're over-extruding and your print will be too high.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 11, 2015 06:50PM |
Registered: 8 years ago Posts: 18 |
I'll have to get into it tomorrow night/weekend and keep testing as I have upped the tension a bit from where it was when first built.
What I found was that when I increased to 125% I got my 100mm instead of 80. Could this be lack of extra tension that would be needed to push it through the extruder?
Or in other words seems ok for testing but not for actual use so needs extra tension?
What I found was that when I increased to 125% I got my 100mm instead of 80. Could this be lack of extra tension that would be needed to push it through the extruder?
Or in other words seems ok for testing but not for actual use so needs extra tension?
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Re: Prusa i3 extrusion issues June 11, 2015 06:52PM |
Registered: 10 years ago Posts: 581 |
Increasing to 125% to get 100mm will have more to do with the correct E steps per mm setting than tension. If, with the same settings, you're getting different lengths then either your tension is off or something is causing missed steps on the extruder. The first thing to get is consistency - with the same settings, can I get the same length of filament extruded every time - even if it's too much or too little? Once that's sorted, then you move on to the correct E steps per mm.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 12, 2015 04:45PM |
Registered: 8 years ago Posts: 18 |
OK tonight I'm trying something a bit different.
If I try to extrude just from the bowden I consistently get 85mm.
With the hot end warmed up and trying to extrude I found it either wasn't gripping hard enough to pull through PLA, so I adjusted the idler and now it seems to skip/knock. Either way when all set up I'm seeing hardly anything pulled through the extruder.
If I try to extrude just from the bowden I consistently get 85mm.
With the hot end warmed up and trying to extrude I found it either wasn't gripping hard enough to pull through PLA, so I adjusted the idler and now it seems to skip/knock. Either way when all set up I'm seeing hardly anything pulled through the extruder.
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Re: Prusa i3 extrusion issues June 12, 2015 07:07PM |
Registered: 10 years ago Posts: 581 |
It now sounds like you're trying to extrude too fast. Set the hot end to 200 celsius and extrude 100mm at 100mm/minute.
M104 S200; Set extruder temp.
G91; Set relative positioning (so subsequent G1 E100 commands will dom something, rather than nothing).
G1 E100 F100; Extrude 100mm at 100mm per minute.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
M104 S200; Set extruder temp.
G91; Set relative positioning (so subsequent G1 E100 commands will dom something, rather than nothing).
G1 E100 F100; Extrude 100mm at 100mm per minute.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 13, 2015 07:33AM |
Registered: 8 years ago Posts: 18 |
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Re: Prusa i3 extrusion issues June 13, 2015 07:34AM |
Registered: 10 years ago Posts: 581 |
Sounds like the vref might be too low if you're getting skipped steps at 100mm/min. I'd try turning the pot, as you suggested - just nudge it up slightly, test the extrusion, rinse and repeat until you get it extruding without any skips.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 13, 2015 08:26AM |
Registered: 8 years ago Posts: 18 |
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Re: Prusa i3 extrusion issues June 13, 2015 09:18AM |
Registered: 10 years ago Posts: 581 |
Normally clockwise, yes (although the geeetech ones go anti-clockwise). 1/12th is a good amount to turn them.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 13, 2015 09:34AM |
Registered: 8 years ago Posts: 18 |
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Re: Prusa i3 extrusion issues June 13, 2015 09:50AM |
Registered: 10 years ago Posts: 581 |
That's great. Now you can set the E steps per mm and you'll be good to go.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 13, 2015 09:53AM |
Registered: 8 years ago Posts: 18 |
Yea I just manually upped the extrusion to 120% in cura....should of been 133% but got my best print yet.
I need to work out how to use the m500 code to store the estep value, the board came pre loaded with settings and not 100% sure on how to reflash/update yet.
Also owe ya a pint if I ever make it to a maker event and you are there. Glad to be getting to the point of nearly being there with stuff and can start projects I planned.
I need to work out how to use the m500 code to store the estep value, the board came pre loaded with settings and not 100% sure on how to reflash/update yet.
Also owe ya a pint if I ever make it to a maker event and you are there. Glad to be getting to the point of nearly being there with stuff and can start projects I planned.
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Re: Prusa i3 extrusion issues June 13, 2015 10:00AM |
Registered: 10 years ago Posts: 581 |
Do you know what the existing E steps per mm are? Up the value by 133% and send the following to the printer (replace , including the <> symbols, with the new calculated value):
M92 E
M500
Then send M503 to the printer to confirm the new value's been saved.
You really don't owe me anything. I've been helped out a lot by the people on this board; I'm sure you'll do the same. 3D printing is nothing if not a learning experience.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
M92 E
M500
Then send M503 to the printer to confirm the new value's been saved.
You really don't owe me anything. I've been helped out a lot by the people on this board; I'm sure you'll do the same. 3D printing is nothing if not a learning experience.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 13, 2015 11:04AM |
Registered: 8 years ago Posts: 18 |
Yea checked them last night and they are 0080.5
Honestly the help is really appreciated. That one tweak has brought everything together.
So with better nearly perfect 10x10x10 calibration cubes I tried the Cura robot.
Fairly happy with this first attempt but want to learn what causes the issues on small details that can be seen on the hands and antenna mainly.
What I noticed on the print it the head seems to be pushing the material down a bit, up to this point I've had a lot of fun getting prints anywhere near this so now extrusion is sorted I think the nozzle height might come up a bit, also perhaps I need a fan set up to cool the PLA.
Anything that stands out in this print at all as obvious issues if I'm off base with nozzle height and the cooling fan?
Honestly the help is really appreciated. That one tweak has brought everything together.
So with better nearly perfect 10x10x10 calibration cubes I tried the Cura robot.
Fairly happy with this first attempt but want to learn what causes the issues on small details that can be seen on the hands and antenna mainly.
What I noticed on the print it the head seems to be pushing the material down a bit, up to this point I've had a lot of fun getting prints anywhere near this so now extrusion is sorted I think the nozzle height might come up a bit, also perhaps I need a fan set up to cool the PLA.
Anything that stands out in this print at all as obvious issues if I'm off base with nozzle height and the cooling fan?
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Re: Prusa i3 extrusion issues June 14, 2015 09:06AM |
Registered: 8 years ago Posts: 18 |
OK so ran this off this morning, trying to figure out what's causing the issues around the mouth and right eye.
When I watch the print it seems the very front (of the mouth/chest area) lifts up and is pushed down by the nozzle, but that that rest is fine. Is this temp related and maybe needing a fan?
Or should I be looking at other causes too?
When I watch the print it seems the very front (of the mouth/chest area) lifts up and is pushed down by the nozzle, but that that rest is fine. Is this temp related and maybe needing a fan?
Or should I be looking at other causes too?
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Re: Prusa i3 extrusion issues June 14, 2015 09:09AM |
Registered: 10 years ago Posts: 581 |
The print might be running a little hot. A fan pointed at the business end will definitely help with the bridging, too. Have you run through the calibration steps on the reprap wiki yet? [reprap.org]
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.
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Re: Prusa i3 extrusion issues June 14, 2015 10:56AM |
Registered: 8 years ago Posts: 18 |
I'll run through now and will print off the x y calibration to tweak those steps.
Also I've noticed I still had my PLA set to 230 degrees. So think there might be some worth in dropping that down.
Looking for a fan shroud design for my print head design too. Hoping something has been already designed for my kind of prusa.
Also I've noticed I still had my PLA set to 230 degrees. So think there might be some worth in dropping that down.
Looking for a fan shroud design for my print head design too. Hoping something has been already designed for my kind of prusa.
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Re: Prusa i3 extrusion issues June 14, 2015 03:25PM |
Registered: 8 years ago Posts: 18 |
Going through the Wiki and trying the X/Y stl but I don't understand the following:
**********************************************************************************************
Basic Equation
With that knowledge, we can sum up what the extruder moves to get the size T = 10 mm exactly 10 mm wide:
movement=(intended size−2∗track offset)∗scaling
This holds true for measurements of any size, i.e. also for the 100 mm size of our calibration frame:
M10M100=(10mm−2∗TF)∗S=(100mm−2∗TF)∗S
***********************************************************************************************
I have W as 100.5 - 101 mm
T varies from 10.2 - 10.65 mm
I think these may be the result of X and Y being slightly out, but somewhat confused as how to use the measurements in the formula.
Edit: I think I will start a new thread tomorrow on this as the title issue was resolved with adjusting the extruder controller pot.
I believe now I need to fine tune all 3 axis.
Edited 1 time(s). Last edit at 06/14/2015 04:36PM by Layerz.
**********************************************************************************************
Basic Equation
With that knowledge, we can sum up what the extruder moves to get the size T = 10 mm exactly 10 mm wide:
movement=(intended size−2∗track offset)∗scaling
This holds true for measurements of any size, i.e. also for the 100 mm size of our calibration frame:
M10M100=(10mm−2∗TF)∗S=(100mm−2∗TF)∗S
***********************************************************************************************
I have W as 100.5 - 101 mm
T varies from 10.2 - 10.65 mm
I think these may be the result of X and Y being slightly out, but somewhat confused as how to use the measurements in the formula.
Edit: I think I will start a new thread tomorrow on this as the title issue was resolved with adjusting the extruder controller pot.
I believe now I need to fine tune all 3 axis.
Edited 1 time(s). Last edit at 06/14/2015 04:36PM by Layerz.
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