I am using the Airweights vacuum table spoil board and I have my projects set to zero the Z axis on the spoil board to help prevent any damage to the spoil board. I have been playing around with trying to leave an ‘onion skin’ on the project when zeroing off the spoil board but have not had any luck. I am using Vectric Aspire for designing and am running the Redline controller. Does anyone have any advice on how to consistently leave an ‘onion skin’ when cutting a profile? I have tried zeroing the Z axis on the table with the touch plate and then adjusting the Z up .03 and then setting that as the zero but that did not seem to work.
When you say it did not work, what exactly do you mean? With your approach, a profile cut at your material thickness should be .03 above your spoiler board. However, all your other toolpaths will also be .03 shallower. A better way is to set your profile depth of cut to Z - .03, and zero off your spoiler board.
I should have been clearer on that…by ‘it did not work’, I mean the cut was still too the spoil board, there was no material left. I had not thought about the other cuts being shallower as well. It would not matter with this particular project but it definitely would with others. I will try the DOC setting that you suggested. Thanks!
You need to play around to figure out how thick your “onion skin” should be. Start with a thicker onion skin and work your way down to the thickness you’re comfortable with.
Another thought is to make sure your material is the exact thickness your put down. Ive had issues with the thickness being off.
One last thought, if its for the cut out, maybe make it the last toolpath. And instead of doing the full depth, only go down to maybe .125 left.
I have issues with thickness being off as well, which is a big reason I zero from the spoil board. If I zero from the spoil board, I can be off on the thickness a little bit and it won’t affect anything with the project. I use a lot of pine from the big box stores and it is not always the same thickness. I did have the last toolpath set up to be shallow to both relieve the amount of torque and offset the bit slightly to clean up the toolmarks.
I do the same thing. When I’m doing through cuts (ie cutting sheet goods) I like to zero from the spoiler board. Even when doing carvings, I will zero from material surface when generating toolpaths for pockets and carvings, but zero from spoiler board for the profile toolpath. When cutting out small parts, I always zero from spoiler board and leave the onion skin so the parts don’t come loose and get ruined (or get jammed and break the bit.)
When I first used my AirWeights I discovered it wasn’t perfectly flat. After a lot of measuring I learned that the biggest problem was around the perimeter. I solved the problem by putting a few strips of tape on the outer edges. When I was all done the entire surface was flat to within 0.003 inches. So with that, you could leave a skin of 0.008 inches and you should be OK.
However, AirWeights also sells a separate sheet that you place on top of the vacuum table and then you can mill that perfectly flat without cutting into the AirWeights. So I think that is the best option. You will just have to make sure you always place it on exactly the same way each time.