Cura and incrementing fan speed

[profepaco 0]

I have just realized that when Cura increments the percentage of fan speed when leaving the bottom layer the fans does not respond.

Let me explain it better. Fans 5%. Fans stopped. Fans 10%. Stopped. Fans 35% the fans work.

However, if I blow on the fans, they begin to work if the speed is, i. e., 10%. So the problem are the fans, that they cannot begin to rotate if the percentage of speed is too low.

Therefore, there is not incremental fan speed until about 30%, unless you blow on the fans to help them to rotate.

I think there are two solutions:

1.- Better fans. Can be find better fans with less resistance to rotation?

2.- Cura sends a 50% command to the fans to begin the rotation and then reduce the speed to the required one, for example, 10%.

 

[Dim3nsioneer 557]

I think there are two solutions:

1.- Better fans. Can be find better fans with less resistance to rotation?

2.- Cura sends a 50% command to the fans to begin the rotation and then reduce the speed to the required one, for example, 10%.

 

1. Hardly. A fan which runs at around half of the voltage level it is specified for (35% of 19V compared to 12V) is quite well performing. There are high end fans on the market which do not start until 60-70% of nominal voltage.

2. What if Cura would take the minimum fan setting for a start? In addition to the 'full at layer' setting there should be a 'start at layer' setting. @Daid: This is certainly something for pink unicorn, what do you think?

 

[Daid 306]

The firmware has a FAN_KICKSTART setting to help in this case.

 

[Dim3nsioneer 557]

The firmware has a FAN_KICKSTART setting to help in this case.

 

Are you referring to the default UM firmware or to Marlin in general?

 

[eldrick 65]

I've seen this same behavior with 14.03 on UM2. At low levels the fans are not getting enough of a jump-start to get them moving.

 

[Daid 306]

Are you referring to the default UM firmware or to Marlin in general?

 

Both are based on Marlin and Marlin has this feature. But I think it's only enabled in the UM2.

 

[Dim3nsioneer 557]

Thanks for specifying it. So, a bit of bad luck for all UM1 default firmware users.

However, I found the setting in configuration_adv.h and will test it on my UM1.

 

[profepaco 0]

Ok...so...for newbies...what can we do?

I do not know what Marlin is... is this easy to enable the quick start?

 

[Dim3nsioneer 557]

Ok...so...for newbies...what can we do?

I do not know what Marlin is... is this easy to enable the quick start?

 

Newbies should wait until UM decides to activate the option in the default firmware.

Marlin is the name of the firmware. You find the source code at http://github.com/Ultimaker/Marlin (the latter is the default UM firmware). If you're able to compile the firmware by yourself, you are not a newby anymore...

 

[gr5 2,192]

Having the fan off for the first 3 or 5 layers is usually not a problem. So I find that having the fan come on at 30 to 35% is okay.

 

[Dim3nsioneer 557]

There is maybe one thing to consider: Some axial fans (I don't know about the fan used in the UM) don't like to be low-powered as their motor overheats quite fast if there's no cooling by the impeller.