Tips for using the Pro Passthrough

The lid camera is pretty accurate right in the center, so what I have been doing is putting a cross centered on my artwork every 10 inches, Then draw the crosses on my board and line them up that way.

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I’m thinking about engraving tick marks at the beginning and end of each scooch, so after the first scooch, the next set of tick marks is in the center of the Glowforge, since alignment at the far corners is not working at all right now.

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This seems to depend on the unit. Mine is off in the center. Not by a huge amount, but around an 1/8" or so, while it hits a little over a 1/4" in some areas on the edges.

I’ll try to look for the post when I have a little more time, but one way I’ve seen people work around this problem and not rely at all on the visual alignment (since it’s till getting sorted out) Is to make a jig that registers the maximum cutting width on the bed and then create your artwork in chunks exactly that size. it still requires you to register your piece of material ( 10" increments, or whatever) but some people have pulled off some pretty amazing alignment jobs.

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My size boards are always 16 inches wide, so I think i cam make a wooden clap system that is adjustable and make something that goes around the Forge to lock it into place and have it always flat against the opening.

Thanks for the ideas. All are helpful. Keep them coming.

I don’t have mine yet, but I think this will work and not depend on camera [in]accuracy:

Place a guide inside along one side of the bed inside. Hold it down with magnets. Assuming you have masking on the piece being cut, and also have a layer of masking on the guide.

Your source image would be aligned on a 12x20 art board in the SVG file as a series of layers.

Each layer would be aligned such that when the material is pushed through the right amount, the next layer is correctly positioned.

Now, for the pushing through the right amount… at the very top edge of the design, have a low-power score that will only mark the masking. Make it a line that marks both the edge of the material and the edge of the guide. This is your top registration mark.

Next, at the bottom of each panel, including the top one, again have a bottom registration mark. This one doesn’t need to go out to the guide.

After the first panel is processed, slide the material in until the bottom registration mark on the material exactly aligns with the top registration mark on the guide.

Since both registration marks were marked by the laser, there is no guessing on camera alignment.

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This has some great tips, so I’m moving it to “Tips & Tricks” and updating the title.

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If the camera is used each time to register on a + marked in the same reference area on the workpiece for each section, then the camera offset would be the same in each case and alignment correct relative to each other. No?

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That is good in theory, and eventually it should work like that in practice.

However, at this time, it has been observed by multiple people that after performing a print, the magenta outline showing where things will print can be offset–we believe it may be that the camera placement part of the GFUI is forgetting the material height. Because of this bug, trying to align the next step using the camera is likely to not be accurate. However, running a subsequent operation of the print will accurately align with what has already been printed.

Therefore, until the camera accuracy work is finished, we will be better off using alignment methods that rely upon things that have been printed in the previous passes.

TL;DR In time you can use the camera for everything. That time is not now.

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Good to know. Thanks

This is one of those major things that needs to be resolved sooner, rather than later. It effectively neuters the pro model entirely.

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Unless you use established CNC indexing techniques.

But if by “neuter” you mean “it won’t do what I want automatically and I don’t want to have to spend a few minutes more in design & processing like everyone else does” then I guess you’re right until the software is finished.

Instead of having to bandaid your files and materials with alignment markers. Would it not be better that the GF folks get this alignment problem resolved once and for all. I mean this is the heart of the system and is totally unusable for my designs which exceed 30" in length. The pass through option was the entire reason why I purchased the Pro.

The other day I ran a job and did not set the power correctly being a new user. Unfortunately, the UI does not have the option to simply repeat a cut with setting changes. I had not moved the material but did open the lid to check. This caused the cam to rescan the bed image. So without moving anything in the GF or on the screen I pressed the print button. The cut was totally off and not anywhere close to the first cut. This is not acceptable after two years plus of development.!!

After reading a lot of threads. The vast majority of people seem to roll over and just accept the fact that the combination of SW/HW is not anywhere near completed for basic operations that had been spoken about in the pre and post sales a couple of years back.

It seems that many are willing to just kluge around the issues just like in this thread. Really folks this is not what we bought in to. Its time we start demanding what that base and required features are fixed and in short order. This sucker needs to work as advertised.

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Guessing I don’t understand. Should not matter if you open the lid or not. As long as you don’t touch your design placement or move the material the cuts and engraves should be exactly where the first ones were. It is on my machine. I can process a file, change the settings and process the design exactly over the first one. Something happened for you not to be able to do that.

Yes the preview image might be off but the cuts/engraves are dead on. Sounds like you are having a different issue than the one you are complaining about.

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Rpegg

After reading your response I just did a quick test. Using the three circles. Cut one… Lifted lid did not move anything
Cut two… Even though the screen alignment image shifted the material did cut bang on the first cut. Maybe they fixed something? Third none cut simply lifted lid then grabbed screen image.

Well, Im so glad you called me on this one. But based on the bed image shifting, some jobs will simply not work. Unless one leaves a 3/8" or so gap between secondary cuts. Its obvious that we can not rely at this point on the bed/material image to be used for any kind of accurate alignment.

I need to cut wing ribs which are over 36" long. These have to be exact due to high speed wing load etc. Even being 1/16" off is not acceptable. This is exactly the type of thing that the Pass through port is designed for. I guess for the general hobbyist a little drift would be acceptable?

BTW I was not complaining but stating a fact.

Thanks much

Yeah, the operator :slightly_smiling_face: It has worked that way since the first PRUs went out. Everyone who has thought it didn’t work when they went back & followed the steps you followed found out that it worked for them too.

Now it is remotely possible that it works in some folks machines but not all and when someone complains one of the GF elves fixes that machine from the cloud. That’s another explanation.

It is doable. As you noted it is not automatic as advertised but then you accepted a beta software product where it was specifically called out that the auto alignment feature has not yet been implemented.

You can do it just like all of us in the CNC and non-GF laser world have been doing for years - index your design and material. Check out YouTube for Shopbot’s video on how to do it (it’s with a CNC but the principle is the same).

Or you can continue to point out that the software does not do what it says it does not do but that it should because it’s been a long time. That doesn’t get the feature implemented any faster or your long parts made.

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Is there a tutorial for :glowforge: that shows how to index your file and material to do this? I watched a few Shopbot videos and I didn’t see the information you suggested and wasted a lot of time learning about a tool that I don’t have.

I’m guessing that you put markers in your file that print lightly on your material and align with marks that you put on your physical :glowforge: bed sides. As you move the piece up you align the next set of markers. I would like to think that you could align the piece with the camera, but that doesn’t seem ready. I had suggested putting + marks and aligning those to previews in the GFUI and whoever responded said that this isn’t accurate enough.

No. The Pro is jut out there so I don’t think anyone has done one. Once I get mine I’ll do one if no one else has done one earlier (my ship date is the end of the month :slight_smile: so sometime in Dec maybe for the video). It’s doable with a Basic but if you need to ask how you shouldn’t do it :slight_smile:

One technique that will work is using indexing pins. See this Shopbot video for the process.

There are other ways that use markings/scorings with similar markings on the bed or methods to use a fixed bed or machine position for the index so you don’t even need pins (that’s what I do on the Redsail - indexed off the back edge of the bed). Methods using marks on the bed/frame might be off a bit which probably wouldn’t matter for lots of things, but if you want real precision you’ll want to go with some pinning method. (There are other techniques with staggered locking jigs but the pin method will work fine.)

But for a quick and easy method the tiling with pins method will work for us. Since (I presume) the bed is at the same height as the bottom of the slot on the Pro, we can’t use a sacrificial base board so you’ll need to measure for your material pins based on where the holes lie in the crumb tray and then drop your pin thru your material and into a couple of holes in the tray. Get pins that fit snugly in the honeycomb cells. You can make those using acrylic or wood too. I think @takitus had a pin design he made from acrylic for hold-offs from the bed that could be modified (make the shaft longer) if you don’t want to make your own pin design.

For high precision work using the GF crumb tray as the base you’ll want to lock the tray in place so it doesn’t move as you move the material. That’s simple enough to create a piece of wood that will butt against the side and front/back of the machine that you then pin into the honeycomb. Your project material will butt against that piece so don’t make it more than an inch overlap onto the bed. The primary purpose is to keep the tray from moving so the pins in the tray and the material are going to be in the same relative position for the duration of the job. Your actual project material would now need to be 19x12. (Since it’s your own machine, you could also just make the locking butt piece only come to the inside edge of the black plastic housing on the tray and use a couple of finishing nails drilled into the edge to lock it in and then you’d have the full 20x12 bed to use. I don’t think that would void the warranty of your machine as it’s just a modification to the tray.)

You want to create a tiled set of 20x12 artboards so that your project pieces don’t need to be moved in the GFUI. You’d start by creating the project on something that is say 20x30". Then you’d break that into 3 20x10" sections that you put on your 20x12 artboards with the pin alignment as you measured. You’ll need to use your design software to break it up. They all have different methods of breaking a larger drawing into pieces. I think there’s a tutorial out there in the GF tutorial matrix because people are using that technique to break up very high res engraves into pieces that can be processed by the GF without running out of memory. If your bed locking piece overlaps the bed then you want to make sure your design is placed with that as a margin on the side.

Alternatively you can make your own bed for this work. I’d do it with 2 pieces of material - one to be used as the bed base and the second that would go on top and act as a sacrificial board where I’m going to drill my index pin holes as I switch out projects. The two pieces should be 1.4" tall (or whatever it is that your machine has for a bed height off the machine floor). You can also do this with a stack of 1/8 and 1/4" ply. If you use this method then you can use standard dowels or finishing nails for your pins. I like finishing nails because they don’t take much room diameter-wise on my material. (With the Redsail I can drop the bed to give it room for a sacrificial board on top of the bed in the machine that will be under the project material.) Since the GF is limited to 1/4" material, 8p finishing nails will provide more than enough strength to keep the material locked in place.

Does that help? It may take you a bit to puzzle it out but once you’ve done it the first time the light bulb goes off and it’s only an extra minute or two to modify the project and then to run the two (or more) drawing files into the machine moving the project to align with the pins each time.

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This helps a lot. Of course, I have to work through it live to fully understand what works. My Pro should be here in the next few weeks, if shipping continues to be roughly 10 days from :proofgrade: material delivery. I’ll give it a try. Thanks

I can help walk you through it when it comes. I’m waiting on mine - I’d do a write-up with sample files and a video with the Basic because except for the rear slot, the process is the same but it would involve an unapproved use of magnets :slight_smile:

Grab a design that will go on a 20x12 and spin it around - you don’t need to have a 20x20 or something to test the concepts on. Like the one TJ did in the video. Grab a piece of 24x12 plywood and go at it. Once you’ve got it figured out you can graduate to the PG expensive stuff.

The other resource that’s good in the CNC world is the cnccookbook.com & its forum. You’re doing the same thing they are except the laser’s “mill” is way tinier :smile:

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