[Millsy]

Hi all I`m Back'
I have a new problem Roadrunner size To small

First of all this is what I`ve got , I have an x3 mill with fusion deluxe kit with 5 mm pitch screws, and a G540 control ,X&Y have a Nema 23/387 oz motors & the z has a Nema 34/600 oz motor I have tuned the motors as per video and book ( I maybe wrong ). In mach 3 on the settings page I have fine tuned the motors to move a pre selected distance metric and mach has changed the settings to suit the distance, and they move that said distance , and when I jog the axis around they move at a good pace . I loaded road runner file and changed the F## code to a G21 for metric and moved my axis to were i want to start, regen the dro`s and pressed cycle start . starts ok but the motors barley move and at the end I have little tiny patch that is supposed to be the Road Runner.I did go into the midi screen and program x10 and y10 to see what happens the motors do go the distance but it takes a long time to get there.
Does any one have any ideas as to what my steps per revolution should be on these motors ? or Have I done something so simple that i cant see it.

Thanks in advance . Brian

[TOTALLYRC]

Try cutting it in G20 instead

Mike
P.S. I typed out a much longer reply but I erased it by accident.

[Millsy]

Hi Mike Thanks for the reply
I tried G20 seems to work but ( but I`m not shure ) because my axis move so slow I was not going to sit there for hours watching it drag out, my problem is when i load road runner Change F## to G20 move my axis to where i want to start, regen the dro`s and hit cycle start the x axis takes about 2 minutes to get to the cutting depth and the x and y axis move just as slow. there is a lot of tiching from the motors you can see the dro`s move but very slow.
I am at a lost to as what is the problem.

Any more suggestions ?

Regards Brian

[Trotline]

You say you're changing the F## to a G21/20. Why are you changing the F command? Are you aware that F in gcode is the "Feedrate" command, and controls how fast the axes move?

G-code - Wikipedia, the free encyclopedia

Luke

[Millsy]

Hi Luke ,

No I was not aware that changing F command is the feed rate , I had read in a post somewhere that because I use metric only, that you had to change the F at the top of roadrunner code to G20/21 because it is in inches not metric . Thanks for that information I`m still learning . Now that road runner is in inches what is it I have to change so I can mill it in metric .

regards Brian

[Millsy]

Hi Luke ( you are good ) :-)

I put the feed rate back into roadrunner F60.000000 and it works great but my reason for changing it was Road runner is very small a tiny little patch this is my first run since building my cnc
so now what do i do to make road runner larger . I do use metric.

Thanks again Brian

[Trotline]

The problem you're most likely hitting is that the roadrunner file is drawn in Imperial. You'll need to convert it to metric in whatever CAD software you're using, or set Mach3 to run in Imperial for this particular cut. The difference is just a mode, really. The drawing is done in "units" which are then expressed as either inches or milimeters, with the obvious 25.4x difference in size. Depending on the size of your machine's working area, you may need to scale the drawing anyway. I don't recall the original size of the drawing.

Luke

[Millsy]

Hi Luke

Thanks for the help I have got cad software called Punch via cad V8 I will see if i can get the G code into this and give that a try :-)

Cheers Brian

[ger21]

The problem you're most likely hitting is that the roadrunner file is drawn in Imperial. You'll need to convert it to metric in whatever CAD software you're using, or set Mach3 to run in Imperial for this particular cut.

Adding G20 at the start will tell Mach3 to run it in imperial (inch) mode. You don't need to convert it in a CAD program.
Just make the first line G20, and the second line F60 for the feedrate. You can adjust the F number to increase or decrease the feedrate.

The roadrunner file runs at about 7" in Y by 7-1/2" in X. If that's too large for your machine, you can adjust the size with the axis scale dro's.

[Millsy]

Hi Gerry,

Thanks for the info it works a treat ( I`m that excited you just don`t want to know )

Now to try some aluminium chips .

Cheers Brian