WAM: Put it on my Tab

What is a tab? Is it just a never ending collection of debt at the local tavern? Or is it something more?

Of course everyone has different workflows and needs, so a tab can be disregarded in some events. I know what you’re thinking - Tabs are the worst because they require post-process clean up. This is true… However, they are so much more than just a nuisance to file down at the end of the cut!

Without a tab, you can lose quite a few features. In order to achieve the following, a tab is necessary!

  • Starting point.

If a tab is not used, WAM does not know where to start the pierce and begin moving along the path. Instead, the pierce is placed randomly along the path.

  • Lead-in.

This goes hand in hand with the starting point - if a tab is not used, WAM cannot determine the pierce location. In order to place the larger than kerf pierce hole, it will need to be offset from the path accordingly. Use a tab to tell WAM that a pierce point will take place here - and WAM will automatically lead the pierce point away from the path using the lead-in length determined in the material setting.

*It is important to note that if the Centerline Cut Path option is chosen, a lead-in is not possible. WAM does not know which side of the line to offset, so a lead-in is not possible. If using a lead-in, the Outisde or Inside Cut paths are required.

  • Hold-downs.

During longer cuts or multiple pieces cut, it is important to keep the cut out pieces held down. If a piece comes loose, it can get lost. Fishing for the lost piece under the cut bed can lead to longer time needed to clean a tab off in post-processing! Additionally, if the loose piece sandwiches itself between the cutting head and material, the material can get damaged while it is dragged around (glass can shatter, tile or metals can remove the clean/shiny coat, etc.). Additionally, a loose cut-out can lead to a backflow of high pressure water - causing a clog in the abrasive hose and/or hopper. In some cases, a loose cut-out can even knock the cutting head out of position, causing distortion/inaccurate cutting along the rest of the file.

Ultimately, a tab is always worth the necessary post-process cleaning. I have begun to incorporate them in all my cut files - it’s not worth the headache of potential backflow/failing a cut or damage to my material. Do you use tabs? Perhaps you have a quick way of post-process cleaning? Please share below, I always love to learn more!

How big should a tab be?

A tab should be big enough to hold the part down throughout the entire cut but able to break away when pulling the part away from the material sheet.

For a look at the default tab widths, they can be found in the Material step of WAM. Click the add/edit material button and find the material you are referencing. The tab width is found there and will always default to the material setting.

If you would like to manually adjust tab widths for one specific cut file, adjust the tab size in step 5 of WAM.

If you would like to manually adjust tab widths for a specific material setting, copy the reference material setting found in WAM and create a new/custom material with a tab width you prefer - this way it will always default to this width when using the custom material.

Finally, for a quick visualization of tabs along the paths I recommend plotting the gcode file on the website ncviewer. For a guide on visualizing gcode, give this article a read!