Maximum Volumetric Flow Rate

[FriedPCB]

Printer Model

Voron 2.4

Extruder Type

Galileo

Cooling Type

AB-BN

I've been following Andrew Ellis' print tuning guide. When it comes to the maximum volumetric flow rate I'm getting around 15-16 mm3/sec. I am no one near the 24 mm3/sec described in his guide for a Rapido HF (not UHF). I'm using a 0.4 copper plated nozzle, Galileo clockwork, 260F hotend with ASA filament. Did I miss something or doing something wrong? Is anyone getting the higher flow rates? Thanks.

 

[LoadMaster7]

I've been following Andrew Ellis' print tuning guide. When it comes to the maximum volumetric flow rate I'm getting around 15-16 mm3/sec. I am no one near the 24 mm3/sec described in his guide for a Rapido HF (not UHF). I'm using a 0.4 copper plated nozzle, Galileo clockwork, 260F hotend with ASA filament. Did I miss something or doing something wrong? Is anyone getting the higher flow rates? Thanks.

Sorry, I have no answer for your question. I am in the process of building one, once my Formbot 2.4 R2 kit arrives.

I wanted to thank you for posting this question. I was unaware of Andrew's tuning guide. I am now and I believe it will help me with my build. It is much appreciated.

 

[jovdvyver]

I've been following Andrew Ellis' print tuning guide. When it comes to the maximum volumetric flow rate I'm getting around 15-16 mm3/sec. I am no one near the 24 mm3/sec described in his guide for a Rapido HF (not UHF). I'm using a 0.4 copper plated nozzle, Galileo clockwork, 260F hotend with ASA filament. Did I miss something or doing something wrong? Is anyone getting the higher flow rates? Thanks.

Unless I'm mistaken, at the time of this writing, the difference between the profiles is the limit configured for "Volumetric Speed" in Print Settings.
They are otherwise identical, far as I can tell.
I actually appreciate that it is a really good starting off point profile for decent speed with great quality.
You can always go to the "Speed" menu in print settings and just start increasing numbers there.
I'd start with bumping up infill speed and see how that treats you.

 

[FriedPCB]

Unless I'm mistaken, at the time of this writing, the difference between the profiles is the limit configured for "Volumetric Speed" in Print Settings.
They are otherwise identical, far as I can tell.
I actually appreciate that it is a really good starting off point profile for decent speed with great quality.
You can always go to the "Speed" menu in print settings and just start increasing numbers there.
I'd start with bumping up infill speed and see how that treats you.

Thanks, I'll try that. There is a simple method for estimating volumetric flow rates describe in Ellis's tuning guide. This test approximates how much plastic you can push through the hot end before it starts to under extrude. It's this particular test where the Rapido HF that I have only delivers approximately 15-16 mm3/sec instead of the expected 24 mm3/sec. Are there other factors that I need to understand or consider? Why do I not get a value closer to the 24 mm3/sec that is expected with the Rapido? I understand that it does not have to be exactly 24 mm3/sec but I'm currently off by approximately 30-33%.

 

[Oberon]

I'm no expert in rapido hotend so I can't say if that's the expected flowrate but 15-16 sure seems low for any HF hotend. Temperature seems high enough that it shouldn't be a factor, maybe you've got yourself a case of filament slip or extruder motor skip. I'd start by tightening the extruder a bit more, and if no change then back up and increase motor current.

 

[eridum]

I don't know the galileo clockwork or the Rapido. You'll get decent feedback from people who are actually using it. The only easy check (I'm sure you've already done that) is to ensure filament comes in easy with no friction or pinch point prior to entering the extruder.

 

[NoGuru]

Sorry, I have no answer for your question. I am in the process of building one, once my Formbot 2.4 R2 kit arrives.

I wanted to thank you for posting this question. I was unaware of Andrew's tuning guide. I am now and I believe it will help me with my build. It is much appreciated.

He has some good profiles to use as a start to get you dialed in.

 

[FriedPCB]

I'm no expert in rapido hotend so I can't say if that's the expected flowrate but 15-16 sure seems low for any HF hotend. Temperature seems high enough that it shouldn't be a factor, maybe you've got yourself a case of filament slip or extruder motor skip. I'd start by tightening the extruder a bit more, and if no change then back up and increase motor current.

I tightened the extruder a little and increased the extruder motor current from 0.53 to 0.67. That definitely helps (motor current). I'm now getting 20 mm3/sec. I'm not sure if I should push the motor current any further. The is from the LDO Galileo kit. LDO recommended 0.53. I'll do a little more research to see if I can the motor current. I read somewhere that you shouldn't exceed 0.7. Thanks for your help.

 

[Andreas]

Thanks for that question;

I also have a rapido hotend and was surprised about the low flow numbers. Still not sure if I did sth wrong.

I‘m using a bondtech CHT 0.6 nozzle. With ASA and low heat I only made it to 14… When heated up more around 17.

Next step was to increase extruder amperage from 0.3V to 0.5V and tighten the screw which adjusts the strength from gears to filament. With that I managed to go to 21 on the lower heat settings and around 23 with higher heat.

At a last try I went up to 0.7V (max for my LDO 1A motor) and managed to get to 33 with high heat settings.

I still expected it to be more with the rapido HF hotend and the bondtech nozzle.

I will continue to run my extruder motor on 0.7V and see if that causes any issues on the long run.

Would be happy to hear other flow rates if you tested that yourself.

If you havent seen the tool I can recommend this for easy and fast testing (I had to adjust my printer cfg though for this)

Hotend Flow Test Gcode Generator

Generate Gcode to test your 3D printer's maximum hotend flow rate at different temperatures.

hotend-flow-tester.netlify.app

and yes: I know this thread is old but I wont do a new one for the same question

 

[FriedPCB]

Thanks for that question;

I also have a rapido hotend and was surprised about the low flow numbers. Still not sure if I did sth wrong.

I‘m using a bondtech CHT 0.6 nozzle. With ASA and low heat I only made it to 14… When heated up more around 17.

Next step was to increase extruder amperage from 0.3V to 0.5V and tighten the screw which adjusts the strength from gears to filament. With that I managed to go to 21 on the lower heat settings and around 23 with higher heat.

At a last try I went up to 0.7V (max for my LDO 1A motor) and managed to get to 33 with high heat settings.

I still expected it to be more with the rapido HF hotend and the bondtech nozzle.

I will continue to run my extruder motor on 0.7V and see if that causes any issues on the long run.

Would be happy to hear other flow rates if you tested that yourself.

If you havent seen the tool I can recommend this for easy and fast testing (I had to adjust my printer cfg though for this)

Hotend Flow Test Gcode Generator

Generate Gcode to test your 3D printer's maximum hotend flow rate at different temperatures.

hotend-flow-tester.netlify.app

and yes: I know this thread is old but I wont do a new one for the same question

Hi Andreas,
Sorry for not replying sooner. I put my 3d printing activities on the back burner for a while but I am getting around to them again. I will check out the app and will push the extruder voltage to 0.7. I will let you know if the results improve. Again thanks for the feedback and information.

 

[Andreas]

Don't worry, I'm sure it will be useful for others.

And btw: when running on 0.7V the motor got too hot for my taste (around 70C if I remember correctly) when running longer prints.

So I went back to 0.5V and reduced my slicer settings...

I'm also currently not active and will try other hotends during winter time

 

[Sanity Agathion]

70 degrees should not be as problematic for motor, as long as it does not melt plastic parts it's mounted to, you are OK.