Totally missed this! So clever.
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I was wondering when someone else would figure this out. well done.
I made one of these a few years back that was similar, and was hoping to publish it in the catalog, but it never arrived before I got a bigger laser.
There are retaining bolt holes used to hold the gantry in place during shipping that you can attach to your carriage, which it looks like was done here. I personally used two pieces of acrylic down the sides with rubber rollers that spanned the distance between the two that would hold the object to be engraved, that were height and gap adjustable. It helped prevent the object from skidding on the bottom and ensured rotation.
This is cool. Im glad to see someone else putting this idea out there.
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Fixed video links. Apparently Dropbox blocked the links, because traffic was too high. I switched to YouTube. Enjoy!
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Nice! Yes, I am utilizing the retaining bolt holes in the gantry. I had initially considered rollers also, but due to my tight deadline, I couldn’t wait to source some. Rollers have definite advantages, and some disadvantages. The primary advantages are that rollers will provide a more consistent engrave, and they don’t require you to reverse the engraving image. I’d love to see your setup.
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sadly it was discarded in the move last year, and never rebuilt because I have a larger format laser with rotary built in (I dont even use that rotary). Ill see if I have any photos in my camera roll from around the time I built it. It was when I still had a pre-release unit I think.
I also uploaded a video on the forums right around the time I was building it with the inspiration I used to build that one. Ill see if that video is still here.
As for build details, I was using thin .5" gray conduit from home depot with plasti-dip sprayed over it. Those ran the length of the bed, along with a couple hollow metal rods to keep things in place. The sides were acrylic and slide adjustable to allow for different sized objects.
I was also looking into a version that disconnected the belts from the gantry and just left the head in place for larger objects, because I was concerned about it hitting the front. However, I never spent enough time doing rotary past the prototype stage to see if any large objects would ever get that far. Just thought id throw that out there as a possibility. Its also a bit more of a pain to attach/detach the belts though.
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here it is, way back from 2016:
I did NOT use big acrylic discs on the bars though.
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What size machine screws/bolts fit in the threaded holes on the gantry? Thanks for design idea, so awesome!
Thanks! You will need two M8x1.25 by 10-15mm long.
It’s listed on the SVG file here: Rotary Engraving a Yoyo on my Glowforge
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Oh, there we go, the file I had downloaded was Fixture_3 or something and it wasn’t in there, I didn’t know about this file, thank you!
Awesome design. I sent you $10 for providing it. Really Glowforge should look into this for a future add on
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Awesome! Thank you so much!
That is some great engineering!
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I finally got a chance to try this today on a 2 oz. clear boston round bottle. Rather curiously, the engraving was backwards, literally, on the bottle I tested. When I mirrored the engraving and tried again it came out in the correct orientation. Such an odd thing to happen! I am still trying to figure out why the machine did that. I only had luck with it once actually rolling on the tape. After that it was really sketchy, even on new tape, and was not rolling consistently. Ended up cracking the bottle from the heat buildup in the one spot. Sacrifice to the testing gods… I may have to widen my position guides a hair, even though the math worked out correctly. Just means I have to empty the other one so I can test again! Anyone have ideas on why it would have mirrored my logo?
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I’m glad you got to try this out! It has to be mirrored, because as the object rolls the top surface of the object, which is being engraved, is moving in the opposite direction relative to the normal direction of travel.
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I have had a lot of difficulty with getting glass to roll consistently, because it’s so slick. What I finally settled on that is working for me is this:
1: Beyond each end of the object, I lay a strip, three layers thick, of masking tap sticky side down, along the full length of travel.
2. Between those strips, I place single layer strips of tape sticky side up. I tape each end down with a piece of tape, making sure to stretch each strip taught.
3. I then install the fixture so that it slides over the tape. The reason for three layers face down, is so the fixture doesn’t stick to the face up layers.
I hope this helps!
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Thanks! I hadn’t gotten to three layers on the face down yet, though that’s pretty much how I was laying out my tape. After the last crack I figured I might need to do some adjusting before it blew up on the next try. lol I’ll have to try the heavier layers tomorrow.
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Ingenious! Thank you for sharing.
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This is an absolutely brilliant design. I was thinking (clearly over-thinking after this video) of all sorts of complicated things that I needed to do. Most of the times the most beautiful solutions are the simplest.
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Just downloaded the design and will be sending some money your way soon as I finish this post. I have an idea that may work to help ensure consistent rolling of the objects. Instead of using tape, what about stretching a rubber band or two around the board. Should provide some decent traction. Anyone tried it by chance?
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Thank you very much! I have not tried rubber bands. Let us know how it works.
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