How to adjust flow rate in firmware due to small nozzle diameter variations

Hello,

I have machines that are all pretty much set up the same. I need to be able to program in the firmware, the flow rate of each machine due to the small differences in the nozzle diameters. I dont want to have to use the setting in the slicer because then I wont be able to interchange gcode from one machine to another since the flow rate adjustment is different for each. I would like to set this in the firmware so I never have to make the adjustment manually in the FLOW menu before a print.

Do you guys know where I can do this in config.h? I was thinking of using E steps/mm to get the same effect but it hasnt been working successfully for me. If I want to reduce flow I would rather not do it using that method.

Thanks

It cannot be done like that. The whole Gcode is geared to the amount that is extruded at any instant, it has to be in the Gcode as far as I can see anyway.

Fit the same size nozzles to all the machines.

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Originally Posted by Mjolinor

It cannot be done like that. The whole Gcode is geared to the amount that is extruded at any instant, it has to be in the Gcode as far as I can see anyway.

Fit the same size nozzles to all the machines.

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I tried, the nozzles are different by such a small amount that I can visually tell the difference. I get a 5 pack of 0.5mm nozzles from china and some of them overextrude badly. I need to get 0.4mm and drill them out with my 0.5mm drill bit but even then its not exact.

Use a "dental file" they are small reamers that dentists use for root fillings, very accurate and can be either tapered or parallel. You can make your nozzles exactly the size you want and all exactly the same.

I cant quite find a file that is 0.5mm in diameter. There are dental files I see on google but nothing about specific diameter or diameter tolerance. Maybe the keywords im using are wrong. Do you have a link?

No, I bought abox full of them off ebay 10 years ago, enough to last 10 lifetimes.

They are labelled, for example: L21mm RSS 15/40
or: No 30 25mm.

I think there is an ISO table dictating sizes like SWG for wire.
Here is the full label from a box

Thomas
superflex hand
files hedstroem
L25mm ISO35

A picture, if you copy link location and paste in the URL it will be much bigger.

http://imgur.com/TIkFL2L
http://homepage.ntlworld.com/dknpowe...017_131019.jpg

Seems like you should be able to just use Esteps. Or, after each print starts, use the LCD menu to adjust flow.