Question of the day:
How do you square your piece to the CNC?
I THOUGHT I had squared mine. But when the piece was done it was off by 1/8" in 14".
I have 2 methods, first being I created a corner jig for rapid repeats basically an L on the lower left hand corner. For set up I used the jog menu and lightly scored my spoil board to ensure my L bracket was square to machine x and y. Second method is if I have to remove my bracket I will lightly clamp my piece place longer bit in router and use the jog menu ro run the bit next to piece with a .25 bit of course router off it will spin lightly twist along the piece and allows me to see if the bit runs true down x and y.
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Second method definitely helps to see run-out over the 14in your talking about.
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My primary is the first method and a lot of ppl have different fixtures you can search the forum for. This method is a once you do it once never have to again in my opinion even with scoring yhe spoilboard and removing the fixture i can easy set right back up.
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Awesome! Thanks for the great quick reply!!
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@gdon_2003 has a file for his bracket and in this topic is a lot of discussion.
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What material did you use for your Long L Bracket? It seems an odd thickness (.852"). Did you plane a piece of lumber down? Just curious.
I have a system of basically two spoilboards. The underlying one consists of 1/2" planks with 6mm threaded inserts placed in a matrix every 25mm. The top spoilboard is a piece of 3/4" MDF with the same matrix with 8.15mm holes that accept 8mm stainless dowels. At the intersection of the 3rd horizontal and vertical dowel holes I have a Quick Action User X-Y coordinate saved so I can always revert to it. Then I simply slide in two horizontal and two vertical dowels into that 3rd row and I know my X-Y will be perfect every single time with the two sides exactly square to the origin. Then once the board is placed I use the essential clamps with 6mm button head screws. Since the threaded inserts are every 25mm I can clamp most anything. I use different length screws for different board thicknesses. After clamping I remove the dowels with a pair of pliers. It’s very fast and gives me perfect references every single time. The added bonus is if the board isn’t perfectly square on the left and bottom sides you will instantly know it because all the dowels won’t touch.
99% of the time I use the 3rd set of holes as a reference because it allows me to place clamps on the left and bottom sides. If I need the extra space I can set the first row as a reference, but this usually means I’m doing the double tape, super glue method for clamping.
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Thanks for the reply! Seems like a fantastic system. The user quick actions seems especially nice (I LOVE shortcuts!! Probably most people know about it but I’m still fairly green here).
Definitely something I will seriously consider as I continue to develop my CNC setup.
Thanks again!!
I’ve been using this setup for the past two years and it works perfectly. It was a bit of a pain to setup, mostly because I was making it up as I went along. I replaced my original MDF slats with plastic, but I don’t think I’d go that route again because the plastic warped when I started installing the inserts. I was able to get them flat again once I screwed them down to the supports. Basically you just create the matrix for the inserts first with the CNC, then CNC the mounting holes in your spoilboard. Once you mount the spoilboard, just create the 8.15mm matrix in the same location as your inserts. That way every hole is both a reference for a dowel and a location for clamping. You can use wooden dowels, but I found them to be less precise. The trick is to make the holes just the right size so the dowels slip in easily with no slop. I think I used 8.15, but might have used 8.2mm. .2mm is roughly 8 thousands so you should be at least that accurate.
Another advantage to this system is the inserts aren’t threaded into your spoilboard. So when it comes time to replace the spoilboard, you don’t have to worry about reinstalling all the inserts.
This system is much more accurate than creating a bracket that’s screwed down, because screw holes are going to be less repeatable as a reference. You also don’t have to fiddle with screwing down and removing a bracket. The references are always there when you need them and don’t get in the way when you don’t.
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Setting up a quick action for your X-Y reference is a big time saver. I never have to find my X-Y reference because it never changes. The only thing I have to set is my Z reference. Another trick I had to learn the hard way is I always zero off the spoil board, then I set the final zero to my material height. The difference is your material thickness you set in CC, Vcarve, or whatever. That way you never cut through your spoilboard and you get perfect through cuts every single time.
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The material was cherry. The thickness was random. I use a lot of rough lumber and mill it to suit my needs. Likely this was a half of a thicker board that I used the other half for a project and the .852 was left over.
I had a large water oak tree die in the yard last year. I waited until spring to see if it would leaf out but it did not. I had to have a tree cutter take it down with a crane because it was too close to the house, electric lines, fence etc. After getting it on the ground I got a friend to bring a tractor over and load it into my trailer. Another friend has a saw mill and I had him cut it into 2" slabs. I like 2" slabs because I can make tables etc but if I want .75" I can resaw the 2" down and by the time it is planned/jointed there is not too much waste.
Here is about a third of the lumber from the tree.
When I buy lumber I generally buy rough lumber because it is cheaper and then mill it to whatever I need. I have a 16" SCM bandsaw, a 20" Grizzly planner, Delta jointer, Jet 1632 drum sander and Powermatic table saw. So I am equipped to handle rough lumber.
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I figured as much. I grew up on a 275 acre farm. We harvested 100’s of trees over the years (heat source and lumber). We would haul them a mile away to an old circular saw sawmill and dad and the old timer would load the logs, discussing the size lumber wanted while my brother and I would tail it, stacking the lumber onto the trailer to take home. It was always like Christmas waiting to see what the grain would be! Oak, Maple, Pine, Butternut, Cherry, Birch. There’s still some up at the farm place that I will bring the 1000 miles to where I live once in a while (LOW moisture content!)
Anyway, that ol’ sawmill wasn’t the most precise and we would end up with a variety of thickness. Because we had so much, I could just grab a 12"x8’ oak board, go mill it smooth out in the barn on the 16" planer, try out something, and throw it in the fire.
I’m guessing a lot of the lumber I used was .852" or some other random size! 