The back of the machine is locked in place. The front has the potential for a bit of movement due to the door so I wasn’t going to register off of that. I think the rear is safe. I think @Dan mentioned that as an alternative when I was musing on using something attached to the rear of the crumb tray frame as a backstop.
I like a lot of what youre saying. Goes along with the fiducial ruler/homing corner thats been discussed. I think the real key here to accuracy is having the head camera have the final say on whats 0,0. The lid cam can shift in respect the rest of the unit. Ive had a lot of issues with this already but some of those were pre-release issues.
If there was a registration point somewhere in the machine (top back left would be great) that the head cam could doubly home to, then we would always have a solid, repeatable 0,0. We could always reliably position relative to that.
The lid cam is great and has its place in making use of those weird pieces of scrap and a few other things, but I dont think its an acceptable solution for the true amount of accuracy we should be able to be getting from these machines.
OK, I think that can accept a STEP file if I get it modeled. I do use it occasionally but normally use OnShape.
Yes but I think since the lid camera is use to position the artwork on the work piece it is only important to register the head to the camera. The head camera is presumable already registered to the head. The only thing missing is auto alignment instead of having to do it manually. But when it can do double sided it should be able to do this.
Yes but the head camera should be able to find the material corners accurately. It has to for double sided cuts to work.
This was my first thought as well. Maybe some sort of block that we can push up against.
There is a little play left-to-right as well. Ive been considering filling in those slides with a solidifying plastic and just leaving a single dimple. In the end, once I get my machine, I might just drill some holes through the bottom and run a bolt right down through the feet of the bed so I know its always in the same place
Good points. I suppose the bounding box of the artwork should be aligned with the bounding box of the blank. That would handle circles. As for odd shaped pieces of scrap then I think manual alignment is fine. After all you can’t put odd shapes in jigs anyway.
If you make a universal corner 0,0 locator (what I will try and do with CAD later) then you could make circular jigs or whatever and use the locator as the corner to place your jig that holds the odd shapes rigidly
Exactly. One jig to rule them all
It’d be cool if glowforge allowed us to use the visible laser on the head assembly as visible marker. Then when you create your jig you can have a light ‘dot’ or hole what was created when the jig was created to line up too.
What palmercr said in his post is how I always expected the glowforge to work (eventually.) Yes, a circle has its issues (until you cut a hole in it), but the glowforge wasn’t sold to me as a better CNC. I’d rather it locate and orientate the artwork to ten dog tags tossed in the bed, than be expected to make a precision jig and precisely overlay my artwork. I’m willing to accept there will be corner cases where a 0,0 point is the only or very superior solution, but that just goes to the right tool for the right job argument.
What are the grid legs made out of? Can a couple of spacers attached to the side/back have magnets on them?
Seems backwards to me. The head camera should be able to locate the jig, not shine a spot for you to manually line up the jig.
It’s a tray with 4 bulges more than feet. Those fit into dimples on the floor of the GF housing.
The tray is made of steel but the issue with registering to the tray is that it’s not locked to anything in the machine or relative to the head/rails. That’s what I had originally suggested and @dan suggested keying off the back wall instead.
Huh Okay. I’ll keep my idea’s to myself. Sorry.
Sorry, I didn’t mean to be dismissive. I just think Glowforge should use its cameras to their full potential rather than us having to work around them.
Good question. The unfortunate reality is that there simply is no shape that will work for every scenario. Currently the Glowforge has nothing though, and that isn’t a good starting point, no matter what shape you’re working with.
Rant follows… I’m moderately sorry.
Yes! Another “the Glowforge doesn’t work like a CNC machine (even though it’s totally a CNC machine)” thread. My favorite.
Geometrically, you only need three points of reference to align any two shapes together. Once you have three points of your workpiece fixed in known locations, you can calculate the locations of all the other points in a design. The beauty of working with a CNC machine is that we can allow the computer to do all that calculation. Once we get our three fixed points the machine can handle the rest.
It’s no mistake that material tends to have 90° corners. Sheets, slabs, and blocks with 90° corners have been used by humans for thousands and thousands of years. Once we, as a species, started working on flat surfaces, 90° corners in our building materials was almost a certainty (in my opinion). Rectangles have many properties that make them objectively better/simpler to work with than other shapes (I’d list some, but this post is nerdy and preachy enough already).
So, since human-made materials are typically rectangles, it makes the most sense to have stops built into our manufacturing equipment that are designed to work with rectangles. I wish the Glowforge was designed to work with rectangles.
Once you start using it, you’ll see why you need the 0,0 =P. It’s designed to be a precision machine, but then the controls that would allow us to use it as such aren’t there. There’s really no reason for them not to be. It won’t take away anything from the product. Leaving them out does however.