Anyone have a grid pattern or something like that on their wasteboard for lining up material? Pics request

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I swear im not OCD but not having super straight cuts along my X is driving me a little nuts. I believe my upper spill board isnt 100% square to my frame. I ended up going with the T nuts method with them countersunk underneath and I thought I was pretty square but my profile cuts as of late have proven wrong.

Im thinking of doing some kind of grid pattern with either a V bit or a endmill over maybe a painted spill board for max visibility. And using those lines to line up the edge of my material on.

I have a spill board on top of a spill board essentially lol. I also have end stops so I suppose I should enable and run from those before I do any type of grid. Any suggestions or ideas on getting the max squareness with my cuts and lining everything up?

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I usually cheat by always going with bigger material than what I need and cutting out my shape.

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i think most people get around this issue by having the CNC cut the mounting holes in the spoil board. if you do it that way the holes always line up strait with the X and Y axis of the CNC. i would imagine cutting guide lines using the CNC would have a similar result.

though i’m new to all of this CNC stuff so hopefully someone with more experience can confirm this :slight_smile:

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You need to also have a good reference point for each truck when you start the machine up. I don’t have endstops. I use hard stops (could be just clamps or some 3D printed rig, or blocks of wood). I move the gantry against the blocks before starting the machine and then I move the tool with the motors after that. If you have dual endstops, then the electronic endstops perform that service.

So one issue is that you need to be consistent. If you’re not consistent, square won’t help you. The hard stops or endstops help with that.

The next issue is that you need to be square. You can draw a rectangle, or just the corners with the CNC and see if they are square by measuring the diagonals. But trust me, it won’t matter unless you are first very consistent. If you were square when you made the T nut holes, but then have a different starting point when you went to cut the car, then it doesn’t matter how square the T nut holes are.

Once you have a reliable and square build, you can make sure the workpiece is square by:

  • Putting one corner of the workpiece against the bit, and secure that corner. Then move along the X axis and use the bit to again align the wood. This works well enough for most situations.
  • You could drill holes for dowels using the machine. These dowels would be used to align the workpiece.

I hope that makes sense. I’m not sure what procedure you have to start up a job. Keep in mind that work pieces are also not guaranteed to be square to start with.

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There are a number of possible solutions to this problem, and I’m going to suggest one approach. I’m going to assume you want to fix your current setup rather than start over, and that you drilled the holes for the inserts using your CNC. This suggestion comes in two parts. The first is a way to get your spoil board inserts better aligned to the machine. The second is to have the machine drill some holes with the spoil board mounted to use for pegs for stock alignment. The first part could be skipped.

To get your spoil board better aligned, author a cutting file that bores two holes a fraction of a mm deep. The holes should be just slightly larger than the bit you will have in the router for this test. The first hole will be at 0,0, and the second will be at 0 on the Y axis but the distance from the bottom left hole to the bottom right hole. So if your holes were 50mm apart, the second hole would be at 800,0 (16*50 = 800). Edit the .gcode file add a line at the bottom to pause…something like:

M0 Pausing now

Next remove all the screws holding your spoil board down except one in a corner. Position the router over the center of the hole in the bottom left corner. With the router turned off, run the .gcode file. The end position when the router pauses should be over the rightmost bottom hole. If it is not, adjust your spoil board and repeat the process. You can lower the bit into holes before starting and at the end to get a better visual on how centered the bit is in the hole.

Once you are happy with the alignment, screw the board down and retest one last time. If you will be removing your spoil board for reasons other than replacement, I’d insert at least two holes through the spoil board into the base board for alignment pins.

Before calling this adjustment done, I’d author the same kind of cutting file on the Y axis. So if your holes are 50 mm apart, one hole at 0,0 and a second at 0,400, and test in the Y direction also. If the holes are correct one direction but off in another, you have a skew problem of some sort that needs to be addressed.

And Jeff makes an excellent point, creating hard stops to start with a the axes aligned is very beneficial.

This process will get your spoil board close, but I’d take it one step further and have the machine bore some holes specifically for the pegs. I’d bore these holes between the current holes. To start you just need a few on the X and a few on the Y. I’d would go with pegs 3/8" or larger, and I’d bore the holes all the way through the spoil board. Using larger pegs and deeper holes will mitigate any tilt that might occur when using the pegs. Since the machine will be boring the holes, you will be assured that the pegs in these holes will align your stock with the machine.

As noted above, you could ignore the first part of this suggestion about aligning the spoil board and simply author a row of peg holes in the X and Y. I only suggest the alignment because it makes other things work a bit better like creating rules to push your stock against, or having similar clamping across the stock.

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I just over-size my stock and use the MPCNC to cut the outer perimeter when done :slight_smile:

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I used the CNC to cut holes in my spoilboard.

It’s all well and good to use the CNC to cut out your stock when you’re making a complete part, but sometimes you might want to cut something into an existing part. For example, when I made my ZenXY, I cut a hole into an Ikea tabletop. I needed it centered very well, and parallel to the existing table edges, and I was not going to cut the table down afterwards. For that, I could not have done it accurately if I couldn’t line up the part on the CNC without knowing exactly where it was. I also had to line up a cut on the opposite side so that it would center in the same place.

Even for parts that I cut entirely myself, the tablesaw is much faster for simple straight and parallel cuts, particularly in thicker material. (I still probably cut out stuff from 1/4" maybe even 1/2" material.)

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you can always use the spindle to line up the part.

Run the spindle to the bottom left corner of the part. Lower it until the bit is below the surface of the part. Push the part up to the bit. Then put a clamp on the opposite side of the board across from the bit to keep it from moving in the X direction.

Without turning the spindle on, jog it to the right until it’s close to the end of the part. Push the part up against the bit on the right side and put a clamp on the other side of the board. Jog the spindle left and right a bit to verify it’s riding along the edge of the board. Once verified, add your clamps on the near side of the workpiece to lock it in place.

Assuming your piece is ‘square’, aligning the piece on the bottom with the spindle should also align it vertically as well.

Regarding my recommendation to using the MPCNC to cut the perimeter… I agree. The table saw is a lot faster, but you can use the MPCNC to make a single pass in the wood. This gives you a template to cut to either with the table saw and a sled, or the bandsaw.

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I prefer my radial arm saw :smiley:

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My dad has one of those. They’re great.

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Not molding head fun makes me nervous with that much steel above table but doable :smiley:

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But your ok with a 1hp router 3" above a table and held in place by plastic?

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MOSTY but I’m not pushing the piece of wood with my bear fingers either but hi speed razor blades can cause a nervous twitch :sweat_smile:

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I often use pushers… getting my figures that close to any saw (above or below a table) makes my mind go to dark places XD

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Table saws give a nice false sense of security. No one willingly (or at least intentionally) puts their fingers or arms into the saw blade. But whenever I see people even grab the workpiece behind the saw I cringe. There was a really scary video where someone was trying to cause kickback. They were holding the wood behind the saw blade on a TS and trying to get it to kick back. They thought the real danger wa the board flying. But the real danger was in 1-2 frames of video the board took off, and pulled their fingers in towards the blade. They narrowly missed not being able to count to ten anymore on their fingers.

I would love to have a RAS. Mostly because it doesn’t take nearly as much space as a miter saw. But I would not use it to do rip cuts. I think if you only use them for cross cuts, and you keep the wood firmly against the fence (no free handing). You will stay pretty safe. If you need to cut something smaller than about 5", then use one of those hold down stick things.

We all probably treat everything with the wrong amount of fear. It is really hard to grasp the difference between a 0.1% chance and a 0.01% chance. Even though those are both pretty high is you are talking about losing a finger to a power tool.

I also have a healthy respect for my drill press. I think it’s probably the second most dangerous tool in my shop. I think that was cemented the one time I lost control of a cordless drill when a big hole saw bit and was thrown out of my hand. The instant power was enormous.

But I also let my kids pull the handle on the drill press with me, as long as they listen to the rules every time.

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Agreed, the RAS is a great and versatile tool, and I will admit I have ripped wood on it before (definatly the most dangerous thing you can do with it) but as long as your aware of the forces involved and use your head for better safety your fine. And I know my safety has only gone up since I have had a 3dp… why risk holding wood when I can print a rolling clamp that will do it for me?

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I wish more woodworkers had 3D printers.

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i wish i could automate my RAS, it would be nice to set up a job and be able to stand 6’ away while it did its thing. especially when ripping wood. but mine is a hand down from my father, who bought it used. its like twice as old as i am, so its not exactly worth putting that kind of time into :slight_smile:

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My dad’s RAS is about as old as I am. He’s never had a table saw, so he used his RAS for everything you’d typically do with a table saw. I remember multiple times helping him hold 4x8 sheets of plywood as we ripped them down to useable stock.

I would like to know what type of miter saw you have that a RAS would take up less space. :slight_smile: All the RAS I’ve ever seen are the size of table saws. The support for holding the material would need to be the same size no matter which one you had.

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I’ve been around carpentry shops most of my life. A table saw is a VERY dangerous piece of equipment if you are not always aware of where you are in relation to that blade all of the time.

I’ve seen a table saw take fingers. I’ve seen one launch a 2X4 through a cinder block wall. Fortunately that one missed the guy loading the truck, but not by much. My father is missing the finger nail on his ring finger and has a notch in the last joint on that finger from a table saw incident.

The only thing I’ve seen with near the rate of injury is a bandsaw… Well, and the sander, though those injuries are less severe.

I don’t have a radial arm saw, but those are very useful, within the limits of the saw’s reach. There are some jobs that it is definitely the best tool for, much better than a mitresaw. I will have one in my garage someday.

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I was doing a stupid cut on a small table saw and had it kick the piece back at me. I had a good hold on the piece, so all it did was spin it out of my hand and gut punch me. What I remember at the time was thinking that it wasn’t a smart cut right as I started it. Now, if I feel uneasy about a cut AT ALL. I stop and rethink what I’m doing.

My wife and kids also know that if the table saw is running, to wait until it’s turned off to try to get my attention. I focus 100% on what I’m doing when at that saw.

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