Giant 20' x 3' x 2' router build

[Blackrat]

when i started with mach3 i also found this rather unusual , that the machine wouldnt return to the point where i stopped it

but when you start to read G code and start to understand what i means, then it all starts to make sense

for example , when cutting an arc ( as mentioned ) and you stop the machine lets say 1/4 of the way thru the arc , when you restart , it will not resume from that 1/4 point thru the arc ... it will either start at the beginning of the arc , or the next line of G-code

the same with height, z - axis ... if im doing a cut , stop mid way thru and then RAISE the machine ... when i restart , the machine doesnt know that it been raised , and will only change the height when a line of gcode tells it to , so you may do an air cut for a few lines of code depending on what you cutting ....

if i stop and want to continue , i rewind a couple lines of code ...

and yes , you need to start the spindle manually ( again g code tells spindle to start right at the beginning of the code )

keep at it and it all starts to make sense .... :)

[JAZZCNC]

for example , when cutting an arc ( as mentioned ) and you stop the machine lets say 1/4 of the way thru the arc , when you restart , it will not resume from that 1/4 point thru the arc ... it will either start at the beginning of the arc , or the next line of G-code

If machine is moving and you hit STOP then you really should presume the machine as lost position and Re-home. If you want to pause the machine and resume then you should use FEEDHOLD.
If machined is STOPPED and you want to resume from point in the G-code then use the RUN from HERE command. This will do a move back into position then pause with message asking for CYCLE START it will also give you option to start the spindle.
If using RUN from HERE then it's best done from the begining of Cycle or some position move in the code rather than half way thru canned drill cycle for instance.
RUN form HERE as saved my arse so many times I've lost count and use it all the time.

[charlieuk]

If machine is moving and you hit STOP then you really should presume the machine as lost position and Re-home. If you want to pause the machine and resume then you should use FEEDHOLD.
If machined is STOPPED and you want to resume from point in the G-code then use the RUN from HERE command. This will do a move back into position then pause with message asking for CYCLE START it will also give you option to start the spindle.
If using RUN from HERE then it's best done from the begining of Cycle or some position move in the code rather than half way thru canned drill cycle for instance.
RUN form HERE as saved my arse so many times I've lost count and use it all the time.

Cheers guys yes blackrat sounds like the same thing I will re read this and try and process it.

are there any other learning tutorials that would help me learn this stuff? Cheers

[charlieuk]

Just cut my first board and im really happy with how it went. A few things need to be worked on like a vacuum system which I have found does not need much power atall to pick up the light weight foam and also a way to hold the foam down at the corners and also allow some sort of accurate registration so when you flip the block it lines up perfect to cut the other side
( im looking for ideas here) I am also wondering if the motor on the x axis is way over kill as it is spinning quite slow even when at full speed and gearing it more will just produce more torque than I would need.

[Blackrat]

gotta say that looks pretty good !

to locate the board ....

you have to have references cut into the foam block from the top side ... this is because the block is not accurate enough to flip over and carry on cutting

so instead of cutting the whole of the top of the block, id cut 6-8-10 (as many as you need to support the foam block) square patches into the block ... then when you flip the foam block over these machined patches locate onto the table by mean of MDF pieces that are the same size as the patch that was cut

hope it sorta makes sense :D

what software you designing the board in ?

[charlieuk]

That does make sence and is a good idea I have been thinking along similar lines but drilling some large say 1" dia holes in the table then using the cnc to drill some matching holes in the blank and using a large dowl to locate. Like you say it would be nice not to have to worry about the block being perfect. I guess I should try both and see

[Blackrat]

yup, thats exactly what im getting on at .... dowels in a blank that locate on the table sound good ... maybe machine round patches into the foam , and have the blank circular in shape

[Blackrat]

summing like that ?