# cnc spoilboard



## shop 101 (Feb 22, 2012)

Hi, My name is Eric. I have beeen a cabinetmaker for 21 years. My employer recently starting using cabinet vision and this program wants to cut too deep into the spoilboard. Has anyone faced this issue and overcome it??


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## jw2170 (Jan 24, 2008)

Welcome to the router forum.

Thank you for joining us, Eric.


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## malb (Sep 15, 2008)

Hi Eric, I operate an 8x4 Procam CNC in an Australian cabinet shop. The Procam uses US Centroid controllers and servo motors.

In our setup, the kitchen design is done in CabinetVision, then when finally approved, is exported to Enroute to finalise sheet layout, tool selection and toolpath. 

At the router, we sense the spoilboard skimmer bit, and the three primary cutter bits on a daily basis, and the balance of the tools weekly to avoid cumulative errors. Sensing uses inbuilt routines to load a tool from the changer, move to a spring loaded sensing target, and slowly feed the non rotating tool down onto the target until contact is made, the slowly raise the bit, recording into memory the depth setting where the tool lifts off the target. As part of the sequence, the values are displayed on screen and can be edited or modified by the operator before being saved.

Once the machine has beed sensed, we skim the spoilboard using another inbuilt routine. This always skims 0.5 mm (about 0.020inch) lower than the previous skim, and when finished adjusts the stored baseline table height by the same amount. If the spoilboard is getting to thin, it is replaced and skimmed using another routine which sets baseline table height back to its initial value.

Once the board has been skimmed, we do depth test jobs for each cutting tool, aiming to achieve a slight penetration of the board to ensure complete penetration while cutting but minimise damage to the board. Typically we would aim for about 0.005in penetration. If need be, we can open the settings stored in the sensing operation (above) and tweek the depth settings for individual tools in 0.001mm increments via keyboard, or in 0.1mm steps with function buttons. Once tweaked the setting is saved and a new depth test job is run.

We generally do not have issues with minor depth errors if we set up properly each day. However we can have occasional gross errors if we set the wrong material thickness for the job in Enroute or use the wrong tool depth there. These are normally detected prior to cutting as when we load a job, we view the sheet layout on the system controller and then view the depth profile. The boss has carved through the spoilboard and into the machine base three times in the two years that I have been operating, but I have had one cut 2mm into the board and detected four or five jobs that would have been into the base had I proceeded.

Hope this outline of setup procedure helps if the problem is at the machine end.

I can't offer much help if the issue is in the way you are using CabinetVision as I don't work with that. If you go through Enroute I might be able to help a little as I can use it but are not up to configuring it.


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## maxicamuk (Feb 23, 2012)

*Origin setup or machine zero G79*

Hi there,

I don't have much experience with Cabinet Vision, however I am sure the following applies to almost all routing setups with servo drives.

Most servo systems work with a three stage homing (referencing) cycle.

The first stage the machine will seek the limit switch
The second stage it will seek the first marker pulse
The third it will apply the null offset distance, which will be set from the first marker pulse.

If your error is accumalitive then this may not work however if it's the first skim is deep but the second would be correct and assuming the tool length offsets are accurate you can adjust the Null Offset in either a positive or negative direction. The direction will depend on where your Z axis limit switch is and whether zero is in fact the table surface or the tip of the tool.

What you are trying to do is adjust the Null offset by your depth error. Then when you restart your control and re-reference the machine and then skim the depth should be correct.

Again as I don't know cabinet vision then this may be a software error, if you probe a tool and bring it in to zero is it perfectly on the top of your table? Also some machine setup use origin offsets such as G54 etc in that case you can adjust the extra depth out using the origin offset table.

If I knew more about your machine and control I could maybe help more?


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## woodman12 (Feb 12, 2012)

just start the cut over the part higher than normal ie z=0 on the surface but raise it and zero it and it will not touch your spoil board


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