I understand this about the spoilboard, but I’m confused about the process of making my spoilboard to some degree.
I had 2 sheets of MDF clamped on my table. I have my counterbores and slots milled out. But wouldn’t it be best after doing this step, is to mount this spoilboard to the frame to create all the other features, such as surfacing, drilling for jig locator holes? The one feature I need to create in my SB are .375 deep dovetail grooves for using MICROJIG components. (I definitely want single layer MDF for my spoilboard and not 2-layers using metal t-tracks).
Even if I uncheck the DIG-IN feature in the Wizard, how can I Z-Zero the top of the SB to accomplish this task of milling deeper than zero without it doing an air-cut?
I’ve calculated my WCS to be maxed out at 6.72" when I was milling out the pocket and slots. So with a maximum of 8" Z travel, that would leave me 1.200 - .750 = .53 to mill out .375" below Z-Zero.
Is my thinking on track here correct or is there another method of achieving this task?
I think attempting to do all this milling on top of another MDF just allows for too much flexing and unevenness. (I’m using (6) 4" wide strips as my underlayment, not a solid half sheet.)
Very simple: You’d set your Z offset in your Set Part Zeros>WCS CSR Table to ZERO.
Setting it that way means that you have zeroed to the top of your spoilbard.
In your CAM software set your Z zero to the the top of the material (Since the material is your spoilboard, not something that’s on top of it) and you’ll be good to.
I thought this was the case but wanted to be sure! The video demo I saw, did this for a part that was on top of the spoilboard but I wanted to be absolutely positive before this was the right method before I did something stupid to cause an accident.
In doing so, would I need to disable the DIG-IN feature and reset it when I’m done? Or would the Zero in the WCS over-ride this automatically?
Thank you Eric for your quick response! You’re the best!
I got my SP milled flat. But now I’m having troubles milling the dovetail channels because I’m getting a “Z-axis work envelope exceeded” error. I have my SB set to Z-Zero in WCS #2. My SB IS 41” long in Y-axis because I have a vertical SB that is offset from the front legs. (After I flattened, I unbolted the SB and moved it approx [Y -7”] to allow the bit to exit the back to create a full length channel.)
You can see the limit for Z +7.59”
My finish depth will be .375 below the surface. Therefore 7.59 + .375 =7.965
8.0 - 7.965 = 0.035 left out of my total Z limit.
As you can see on line 42 I’m only milling down .3438 total for my roughing pass before tool change. Even at this step, it’s not allow me to run the program.
Any clue what I need to do to overcome this error?
Perhaps this is a problem best solved with hardware? You can buy a collet extension or such to make your machine temporarily reach further than normal, or a longer router bit…
It’s hard to tell from that screeshot but my guess is that if you already have “spoilboard dig-in” turned off you’re actually exceeding the physical travel limit of your Z axis.
If you have an 8" Z axis that travel is going to be -8.6
You can test this manually by jogging down to the depth you want to cut and looking at the “machind coords” on the bottom left corner of the readout.
If you hit 8.6 and you’re not at the depth you want to be than that’s the reason. You can either use a longer tool or re-mount your Z axis a little lower.
I did as you suggested before you replied and if the total Z-axis travel is -8.6 then I should be good to go.
I will reply later with a photo or video of the router bit below the top surface to the depth I need to achieve and show you what the machine coordinates are.
Are you sure the tool you’re showing in the picture has been measured against the fixed too height setter?
There are really only two possibilities here:
You’re exceeding the physical travel limit of the machine
You have spoilboard dig-in on
Number 1 can happen if you have a tool that’s not long enough (or not properly measured) or if your spindle is mounted too heigh
To really rule out number one do this:
Jog down to Z zero (in a place where you won’t smash up your spoilboard with that bit installed)
Go to MDI and type in Z-.3438. (this is the max depth of cut in your G code file you provided) If the machine can get there without tripping a travel limit than the issue is with the spoilboard dig-in setting.
If it does trip a limit it’s a tool length/spindle mounting issue.
I had an issue on CNC v 5.22 where no matter what I did, and whether the spoil board dig-in setting was on or off, on a tool change the work envelope was setting the Z minimum to the wrong value. In my case it was a little bit above the spoil board.
The value was set on a tool change. IIRC, even if the tool change called for the same tool that was already in use and measured.
I went through everything to resolve it – recalibrated the spoil board, measured tools, toggled the spoil board dig-in option. Nothing would change the behavior. It was like the M6 macro was using old or incorrect values for spoil board height and dig-in option and always setting the work envelope Z value.
This happened to occur right when 5.24 was released. I created a new profile using 5.24 and have never seen the issue since.
TL;DR: Check the Z value in work envelope (in set part zeros) to see what is happening during the M6 macro.
[quote=“Eric, post:13, topic:4850”]
Are you sure the tool you’re showing in the picture has been measured against the fixed too height setter?
[/quote] Yes! UTILS>2: Calibrate Tool Height Setter Location followed by Yes to set Z-Zero of SB with tip of bit.
It has been turned off since our earlier discussion. I rebooted the software afterwards.
I have the bit in front of the SB (see pics) matching my Z-Zero. The Machine Coordinate shows Z= -7.59 , which has been constant each time I do this.
MDI says “BLOCK?” but does nothing after I enter Z-.3438 and return. Can you be a little more explicit with a G-code newbie like me? Sorry!
press cycle start after you enter that z coordinate. If the machine can move down, it will. If you’ve reached your travel limits you’ll see an error in the message box
See that G23 down there? That means spoilboard dig-in is OFF. When you run your job, after the spindle has started if that switches to G22 that means spoilboard dig-in is on and will need to be disabled.
I noticed when I load the file, it jumps to line 35, see image. The spindle speed was set by default. Is that the problem? Do I need to reduce this down from 20,000?
