As a new CNC user, I have a quick question. I am coming from the laser community and those machines have a crosshair laser pointer for project alignment. Is there anything like this for CNC or do you just have to visually line up your bit? Thanks.
You can use bit zero to align the X, Y, and Z zeros.
2 Likes
There are laser alignment methods available if that’s your preference.
I think the usefulness of these methods comes down to the material you plan on cutting most and the accuracy that entails.
There’s the cheap and easy x beam method where you mount two lasers on your Z carriage and configure the cross of the x under your tool.
I’d guess this is the most common DIY laser alignment method but it’s not good enough for high precision work IMO.
Then there’s the laser offset method which can be much more accurate but that’s entirely dependent on the precision of your setup.
Basically hard mount a single laser a known distance from your spindle bore. Then line up with the single laser dot and offset by your known distance.
This method seems more useful but considerably harder to get right. (A cheat might be to use a collet based laser to ensure alignment with your spindle bore but at that point you’re doing a tool change regardless…)
Then there’s vision! Which seems much more common in the laser realm than the CNC world for some reason.
Same idea as the offset laser pointer, put a camera somewhere on your Z carriage. Configure a bunch of offsets and corrections to your camera image, then you can just “look” at a spot with your camera and apply the relevant offset.
It seems surprisingly approachable to set up and has the potential to be absurdly accurate. Cool stuff.
So there’s a long list of things you could do, none of which are actually worth doing from the start.
But once you get a good feel for how you work with your CNC, a method mentioned might stand out as useful to you 
(But honestly…just get some kind of bitsetter like @Woodcrafter mentioned. Quickest and easiest way to save time and avoid silly mistakes while you learn the ropes 
)
1 Like
I have seen people talk about using something like this but like you say the offsets need to be dealt with but that could be done through a quick action
Would be cool if it measured Z as well like the one one in my laser.
1 Like
Another quick trick is to chuck a Vee bit in you spindle / router, jog over to where you want your zeros set, using the tool as a pointer, and set zeros.
5 Likes
For an example of doing this see:
1 Like
I have a large L bracket on my spoilboard. I use that about 90% of the time. Once you set your X Y and Z zeros they are remembered over power cycles. The X and Y are always remembered but the Z is remembered after the router/spindle goes to the BitSetter. That was a change made a couple of versions back. Although remembered it has to have its memory jogged to remember the Z.
The advantage of the large L bracket is you place your material in the same place. The cross hair method could work but the L bracket makes your life simplier. If you place the material in the same place then you only have to set Z if your material thickness is different from a previous project.
I use the bottom of material about 90% of the time so I dont even have to set the Z zero. An advantage of using bottom of material is you dont leave onion skin at the bottom of your cutouts or scar up your spoilboard. It is a change in routine but it is worth it. The only thing to be aware of is in Jog Rapid Positions is the X and Y work fine but to do the Z+6MM you have to jog off your material before issuing the command or your bit will crash into your material if it is less than 6MM thick. So just remember to jog off the material to do the Rapid Position of Z+6mm to avoid crashing into your material.
Here is my CC file for a large L bracket. I have 2" threaded spacing for my spoilboard so just modify for your particular spacing on your spoilboard. When I remove the L bracket and place it back on loosely bolt it down and use the jog function of the router by jogging back and forth and push the L bracket against the bit to make sure it is aligned to the X movement.
long_L_bracket.c2d (296 KB)
I saved this in v7 of CC so it should work in v8 because it is not a 3d project. There are also some cam clamps included in the file. If you dont use cam clamps then you can just disable their tool paths.
1 Like
Just as a final note, if you do have a fence or some other way of setting your stock accurately in the same place, once you set your X-Y zeros for that position, you can remember those zeros in a Quick Action.
One of the options for creating a Quick Action is ‘Set zero to the current location’. Jog the machine to the desired location, and create a Quick Action there.
In the future, you can invoke that Quick Action to set the X-Y zero to that specific location. I use this all the time to zero out to my fence.
The accuracy is basically ‘how much error there is in the limit switches’. On my machine it is small enough that I ignore it.
The one caveat is that for belt drive machines, if you re-calibrate for belt stretch, then that will likely shift the position, and you would need to re-create or edit the the zeros.
4 Likes