Having size issues, size is double

[Kajeti]

hi recently i ve been working with a guy who gave me job offering for a side job to run his table. i can get the table to everything i need the only issue is from the computer to the table the sizes are off.. example if i make a 1x1 square it cuts it at 2x2 so on an so forth. i dont wanna spend all my time halving my measurements for it to cut the pieces out.. using myplasma cnc and the mini cad for my drawings and even tried to import stuff from inkscape still doubles the size.. changed the sizes of the files % and still nothing works is it on the computer end or what? his setup is a hypertherm and sparta robotics

[Plasma-art]

Welcome on the forum.

If you jog the table over 1 inch does it move 1 or 2 inch?
First thing that comes to mind is the steps per inch are calibrated incorrectly.

[Kajeti]

Welcome on the forum.

If you jog the table over 1 inch does it move 1 or 2 inch?
First thing that comes to mind is the steps per inch are calibrated incorrectly.

That i do not know i ll have to get back with you at the end of the week i farm as my main job and do this as a side gig on downtime. Say if was calibrated wrong how would i go about fixing it. I ve never ran one of these i m a youtube learner and know how program things for games and program tractors. Is it a basic set one a to point be or something different?

[acourtjester]

If it is running Mach 3 to recalibrate is very easy, there are many YouTube videos on recalibrating a CNC table. Call the guy and ask which software is used to run the table is the first step. There should be indicators on the screen as to positions and as Plasma-art said you move one axis and look at the indicator to see how much it moved. And measure what it actually moved and you have an answer about if it need to recalibrated.

[adbuch]

It sounds like you simply need to adjust the turns ratios for you motors.
David

[Kajeti]

It sounds like you simply need to adjust the turns ratios for you motors.
David

If it is running Mach 3 to recalibrate is very easy, there are many YouTube videos on recalibrating a CNC table. Call the guy and ask which software is used to run the table is the first step. There should be indicators on the screen as to positions and as Plasma-art said you move one axis and look at the indicator to see how much it moved. And measure what it actually moved and you have an answer about if it need to recalibrated.

okay thanks! i ll gives those a try

[adbuch]

It sounds like you simply need to adjust the turns ratios for you motors.
David

If it is running Mach 3 to recalibrate is very easy, there are many YouTube videos on recalibrating a CNC table. Call the guy and ask which software is used to run the table is the first step. There should be indicators on the screen as to positions and as Plasma-art said you move one axis and look at the indicator to see how much it moved. And measure what it actually moved and you have an answer about if it need to recalibrated.

okay thanks! i ll gives those a try

Let us know now you make out.
Thanks,
David

[Kajeti]

So there is no mach program and where can i get one?

[Plasma-art]

What software are you running exactly?

[acourtjester]

If you know where the step per number is stored in the program you can do a simple calculation to correct them. This formula can be used for inch or MM. You mark the rail and tell the axis to move so far then measure it, that is the actual travel number. The current is what is noted in the software as the original steps per value. And the Expected is the measured distance. Do the calculations and change/save the number in the software and repeat the activity about 3 to 4 times until the expected and actual travel distance is the same (equal). It helps if you extend the travel distance to a greater distance each new time to get a more accurate number.

steps per calulations.JPG

[Kajeti]

hes running mycnc plasma by spark robotics finally just called them and they had his info all saved and told me what to do.. what happen was instead of 1/32 it was set on 1/16 so it was doubling the size

[Kajeti]

Now my next problem is i have all these tap files that are g codes that were saved by sheetcam but wont work with his current setup how do i go about saving a g code in sheet cam as a dxf file

[adbuch]

hes running mycnc plasma by spark robotics finally just called them and they had his info all saved and told me what to do.. what happen was instead of 1/32 it was set on 1/16 so it was doubling the size

Thanks for the update! Glad to hear you've got it sorted out.
David

[adbuch]

Now my next problem is i have all these tap files that are g codes that were saved by sheetcam but wont work with his current setup how do i go about saving a g code in sheet cam as a dxf file

Are you looking to convert tap files to dxf?
David

[adbuch]

Here is some information that may help you.

viewtopic.php?t=18226

tap to dxf.jpg

[Kajeti]

Here is some information that may help you.

viewtopic.php?t=18226
tap to dxf.jpg

Thats what i m aiming for but i do not know how to reverse it or what the offset was

[adbuch]

Here is some information that may help you.

viewtopic.php?t=18226
tap to dxf.jpg

Thats what i m aiming for but i do not know how to reverse it or what the offset was

I think the offset would be 1/2 the kerf width used when the cut file was created. So maybe 0.025" to 0.040" (1/2 kerf width) depending on the original cutter/consumables used. Do you have an example tap file for us to play with? I'm not sure if this forum allows the .tap format for attachments. Let me see.

David

[adbuch]

Here is a file I created with Aspire and saved the toolpath as a .tap file. Then I compressed it to save as a .zip file.

TAP FILE.zip

When opened the code will look like this.

tap file image.jpg

So if you would like to take one of your tap files and compress using bitzipper or equivalent and post the zip file,
then we can take a look.

David