Proper Waste Board Cutting Tool

[Lookin4help (Mark Roberts)]

I’m in the process of making a waste board and there are number of circular holds 3/4 deep, and .2347 inches in diameter. What I’d like to know is can I cut these as a “pocket” with a 1/8 down cut end mill with no problem or am I just looking to start a fire? I’m asking because the 1/8 down cut is the only bit I have. However, if I’m just going to start a fire I will buy a new bit.

[WillAdams (William Adams (Carbide 3D))]

Yes, with good chip evacuation and suitable feeds and speeds that should be fine.

[Lookin4help (Mark Roberts)]

Will: Thanks. I appreciate all of the expertise help you give us.

Mark

[Lookin4help (Mark Roberts)]

Will: I just discovered a problem with my waste board design and I’m hoping you can help me with it. The sheet of MDF I am using is 36 X 36 inches which is centered in my machine. There is about an 1.5 inches from either side of the MDF to the edge the existing base that came with the machine. The design of my project is 33 X 33 inches (centered to the 36 X 36 MDF sheet). I want to use my bit zero on this project, but I find that my XXL will not go far enough to the left to reach the bit zero.

If there is not a workaround to this (?) then I presume that if do not use my bit zero, and rather move the machine as far to the lower left as it will go, use a piece of paper to manually set X, Y, and Z = 0, will my project cut centered on the MDF?

If there are any other suggestion you have I’d appreciate hearing from you.

Thanks so much for your help,
Mark

[WillAdams (William Adams (Carbide 3D))]

Correct. The BitZero has to be inset from the edges sufficiently that the machine can probe it w/o losing steps.

For such fixtures though, my approach when working up to the limits is to inset a pocket to secure/align the stock by endmill diameter plus 10% and then secure the stock after machining the pocket so that the origin is maintained.

[Lookin4help (Mark Roberts)]

Will: Thinking about this a bit further, I guess in order to get this to center on the 36 X 36 I would also have to change the stock size to 36 X 36 and manually set the X, Y and Z = 0. Correct?

I apologize for piecemealing you with this.

Mark

[WillAdams (William Adams (Carbide 3D))]

yes, that would be one approach to make that work.

[Lookin4help (Mark Roberts)]

Will: I’m still worried about centering this. If I am going to center it should I use the rapid position SW and my X, Y, Z, zero point or should I move the router as far to the west as it will go?

[WillAdams (William Adams (Carbide 3D))]

If you are worried about a cut, source a piece of scrap or an inexpensive testing material such as foam and do a test cut in that to prove things out.

[Lookin4help (Mark Roberts)]

Will: One last question and I promise not to bother with this issue again. Is the distance between the south west rapid position and south east rapid position 33 inches?

[WillAdams (William Adams (Carbide 3D))]

This will vary depending on whether or no one has calibrated for belt stretch (which I recommend doing):

Calibrating the machines over long distances

The typical technique for machine calibration: https://my.carbide3d.com/faq/belt-stretch/ depends on precision measuring tools, and is limited by the reach of the tools in question. EDIT: It also depends on access to the MDI — if using Carbide Motion v6 it will be necessary to enable this in Settings | Options: [image] It should be possible to cut strips from a suitable blank of material, one along each axis — so we set up a square file which matches an available blank of material: [ima…

and what the Travel Dimensions are set to.

For more on this see:

Notes on rapid positions and wasteboard leveling

Wrote up a bit on this here: Filled in the numbers for an XL — if someone has an SO3 or XXL and is using CM4, I’d be glad of confirmation of the other values for it there (they were made by halving the steps on my XL and configuring it to be an XXL and if you have an XL, a comparison to how things map on your machine would be welcome). Based on the above, I created a wasteboard level program for the XL: Updated file based on further numbers/commentary: SO3_XL_810x350.c2d (19.5 KB) (please …

I think drawing up the physical structure of the machine and measuring things (after calibration as noted above) is a good exercise for familiarity w/ the machine and how it moves.

[Lookin4help (Mark Roberts)]

Will: Thanks again for your help.

I have a different issue I’d like ask for help on. My XXL has bit setter and since adding it to my machine I’ve never gone back to manually setting my zero points. Now I find I have a project that will require me to manually set all three zero points and it’s been so long I am not sure I know how to do that. When I get all three of those points set, in the Jog/Position screen of Carbide Motion, there is “set zero” button. If you select that button you then go a “set current position” screen where you either select the “zero all” button" or the “done” button. Which of those two option is it that I need to select?

Thanks,
Mark

[WillAdams (William Adams (Carbide 3D))]

Please see:

Carbide Motion User Guide

If you’re still stuck, let us know the specifics at support@carbide3d.com and we will do our best to assist.

[Tod1d (Tod (with 1 'd'))]

Couple things to note: There are also individual “Set Zero” buttons next to each axis.
And you don’t have to set them to zero. You can type in any value you want.

If, for example, I’m using the 1/4" probe (dowel / drill blank), I will touch the left side of the part & type in -0.125 in the X field. Then touch the front & enter -0.125 in the Y field. Touch off the top & click “Set Zero” for Z.