I’m making parts that are being cut out of Acrylic. Parts and holes cut first.
The piece then has to be removed and painted.
The piece then needs to go back and be engraved.
I’m trying to work out the best way to re-align the piece exactly for the engraving, and came across this (timestamped for your convenience) video. The guy is using Estlcam (like me) and it appears there is a function there to do exactly this within Estlcam.
But, I am using the SKR PRO V1.2, and I’ve been led to believe it can’t be connected directly to Estlcam and commands send to it like that. Is that right?
If so, is there a way to be able to do this with the SKR PRO V1.2 and Estlcam?
This seems to be exactly the solution I need. Unless someone can point me to a different way of doing this?
EstlCam only works with p328 based controllers, either Arduino (and clones) or actual Estlcam hardware. You can use EstlCam to produce the gcode and then use a different CAM program to send that to your SKR. This is a popular route.
Rather than having the machine compensate for you having moved the workpiece origin (with the edge finder) perhaps you could relocate the workpiece in the same position it was in to do the cutting out?That way, the workpiece origin is in the same location and the engraving gcode can just be run. Include a couple of reference holes in the cutout gcode and use two ‘pins’ to locate the workpiece for the engraving,
Yeah, I’ve been using Estlcam as you’ve described already.
And yes, ideally I’d like to put the work piece back to where it originally was, but was worried about not being able to put it back exactly. Some of the engraving I need to do is quite mm precise. Hence why I was hoping to use an edge finder if possible.
Maybe I’ll have to use the piece cut outline in the spoilboard and hope I can get it square by eye!
I’ve got quite a few arduinos laying around, may even look into that side just for the engraving.
Foam works really well for making a holding jig. I made a mitre guide for my table saw, where I had a bar that fit in the table slide already, and I wanted to put 2 holes in it, where they were absolutely parallel to an edge.
I used the CNC to cut a hole the correct size in a piece of scrap, then fit the part into the hole. Then, when I ran the job to drill the holes, they were exactly parallel to the edges, so I know that my mitre guide will be correct. Well, at least as correct as my Primo is.
I’ve used foam to cut out shapes for aligning jobs, too. I use the same drawing as the part, and do the CAM to cut the outside as a pocket hole. This also means that for an engraving job, the bottom will be flat compared to the gantry, too.
There isn’t that feature in Marlin, that I know of.
Just drilling holes for three pins and putting some dowels in those holes would get it lined up too. You just need to be careful to clamp it where the pins are, and don’t clamp into the pins, or it will flex. But that kind of depends on how much accuracy you need.
@SupraGuy - Foam is actually a good idea I hadn’t thought of. I have a few sheets of HDF laying around actually. Might play around with that idea. Thanks!
@jeffeb3 - Thanks for clarifying. I was hoping that it might be as simple as a sequence of gcodes, but obviously not lol!
I’m using 2mm and 3mm acrylic for this project, and there are some holes as part of the design which I could use. I’ve been using blue tape on the spoil board, blue tape on the acrylic and supergluing them together for my test cuts/engraves. That seems to hold really well, and so I’m hoping if I can outline the piece into the spoilboard at a small depth, then I can use that to align the piece and tape/glue it down.
It’ll all be some experimentation, but was hoping I could find a way to implement the automatic touch off before doing all that haha!
That should work, but it is over constrained. You don’t need it to be a good fit 360* around your workpiece. Just the right X Y and orientation.
In that video, there were three probe points. If each of those was a dowel, then you could align the piece on those dowels and have the same amount of alignment.
Sorry, I didn’t mean cut the whole piece out of of the spoil board. I meant just like a 0.1mm outline of the piece to align the X & Y.
I think I originally misunderstood what you mean, now you’ve said that, I get it. It’s a really good idea actually. The only thing I don’t fully understand is how I would position the holes for the dowels when cutting the piece first from the larger sheet of acrylic.
There are a few ways that you can do this. Assuming 2 sided cutting, but all these work for repeat cutting on the same piece
If the holes are such that the piece can just be flipped over and the same holes used, ie: they are 2 holes in the same plane of X or Y (For example a symmetrical part) then you simply cut the holes a little extra deep, and use that depth for your locator pins.
If they are not symmetrical, cut 2 sets of pins into the spoilboard. One set for each side. In your large sheet, cut the holes for the locator pins first, then put the sheet on those pins and cut the rest of the first side. Flip the sheet over, putting the second set of pins in place, and cut the second side. Since everything is now cut relative to the pins, it all works out.
Cut the sheet with arbitrary locating pins outside of the desired shape. Cut those holes extra deep on the first side so that you can put the pins in. When you cut the outside of the shape, leave holding tabs to the outside area. Flip the whole sheet over and the work area will be between the locating pins.
Same as #3, but drill for the pin locations first, and use them to hold the sheet down in the first place.
I have a grid pattern of T nuts in my spoilboard. I’ve prepared some pieces with groups of holes that will line up very neatly with the pre-defined grid on the spoilboard. For those, I have cone shaped washers that will center bolts in the grid on the spoilboard. I have to arrange the CAM to keep the cutting bit away from the hold-downs, but it is very convenient to keep pieces in place with no possibility of them moving, and can allow some very accurate double sided jobs.
