Feed speed support

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1

Hello. Does Maslow recognise the F command for feed speed? If yes, what are the units, and what is a good value? If no, where does one set the feed speed (and again, units and value)?

2

Yes, the maslow recognizes feed rate, it’s in either inches per min or mm per
min (depending on what unit you are in at the time)

the machine theoretically maxes out at 48 ipm, but most people find better
results under 30 ipm

David Lang

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3

Normally this is in ‘Tool’ or ‘Machine’ setup.

Fusion360 Tool setup
image

Easel Machine setup
http://fab.academany.org/2018/labs/fablabulb/ga_pcb_process.html

1805_Easel_PCB-4c.png464×652 44 KB

4

Thanks, but the second part of the question was only if the F command was not supported.

I’m using FreeCAD, and I’ve found where to set the speed. Internally (in FreeCAD) it is recorded as mm/s. I need to check that the units are converted to mm/min when I export the G-code.

5

Gcode can be in millimeters or inches and the program that creates the gcode should put a G20 (inches) or G21 (millimeters) command at the top of the file. You do not need to convert units.

6

Yes, the units of measure are specified as metric or imperial, but the F parameter requires units per minute. Internally, FreeCAD stores this as units per second.

Therefore when FreeCAD exports the speed we must multiply by 60 to get units per minute.

7

Ah OK. Normally it is the job of the ‘Post Processor’ to do unit conversion. Could not quickly find one for Malsow for FreeCAD. Did find some info about writing one using Python.
https://www.freecadweb.org/wiki/Path_scripting#Using_pre-_and_post-processing_scripts

The Malsow only supports a few Gcode commands (G0-3, G20-21, G90-91) so the post processor will be quite basic. See https://github.com/MaslowCNC/GroundControl/wiki/G-Code-and-MaslowCNC

Here is the Fusion360 Post Processor (in JavaScript) as possible reference.

8

Right. I was dealing with that in another thread:

I was suspicious of the F parameter argument so I asked about it here and put the results back there. Unfortunately @Walt_Moorhouse does not seem to be around at the moment to comment on my modification to his script.

9

Merged today.

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