Branded Coasters & stepping into the unknown

woodworking
non-proofgrade
coasters

#1

I work for a local church helping them out part time with graphics and communication, and wanted to take the church logo and make some simple coasters for each person in the office. During the shopping frenzy that occurred in our house in the days between shipping and arrival, I found some 4" round cork circles and some 4"x4" wood squares at Hobby Lobby that I figured wouldn’t melt my lungs when the :glowforge: arrived.

Earlier this week I decided it was time to quit procrastinating and try my hand at some non-proofgrade material. Again, I knew nothing about lasers before “Emmet” arrived, so leaving the safe waters of :proofgrade: materials and auto settings are a pretty big obstacle for me. I realized the only way to overcome my trepidation was simply dive in, as so many of you have encouraged on these forums.

Crosses fingers & prays I don’t end up in a hospital or burning my house down.

The Plan: engrave the logo mark on the wood, cut it into a circle and simply glue the cork to the bottom. I set-up the logo in Illustrator and put a circle on a separate layer to cut and saved out the svg.

Going through the interface, I set the material to “Unknown” and it immediately asked for the height of the material. Easy enough: 0.25in. Automatically the “Focus Height” option on each of my settings was set to that same measurement. Sweet! All I need now is power, speed, lines per inch and number of passes. Well I’m guessing to start I only want 1 pass on everything, since that’s what all the proofgrade material has done. Man, this is cake!

Power. Uhhh… I don’t know. Maybe I better start at 50% just to be safe and see how deep that ends up. If it’s not right, hopefully it won’t be too deep and I can adjust after.

Speed… hmmm… speed… I don’t even know what kind of number they’re looking for. I’ll come back to it.

Lines per inch. It’s set to 225 by default, so I guess that’s probably good.

Back to the Speed thing. After digging around on the forums a bit, I came up with the magic number 335 from seeing some test sheet results from others.

Awesome. I’m all set… Oh wait, settings for the cut layer. Uhhh, 100% because I’m pretty sure that’s what I need to make sure it gets all the way through… Speed… Again with the speed. Dang, I don’t know…

I checked the forums again, and looking back I have no idea now where I found this number, but I saw it in more than one place so I thought, “Hey that must be an okay start… but wow that seems like it would cut really fast.” I set it to 197. Mistake #1.

Still unsure, I looked around and found some test cuts from @jamesdhatch which he started at 190 and worked through to slower speeds and it didn’t cut through 'til about 50%. I knew something wasn’t right, and I should’ve gone off what I saw here but for whatever stupid reason I decided to try 197 and if that was too fast to cut I could just do it again.

I put some masking tape over the wood so it wouldn’t get smoke burn & I didn’t want any of the wood exposed so I overlapped it a bit—even while I was doing this I was thinking, “Hmm, won’t this make it thicker here and not cut as deep?” Just remember, anytime your brain starts asking questions like this, it’s probably for a good reason. So naturally, I shrugged it off and kept going like an idiot. Mistake #2.

I crossed my fingers, said a prayer, and pushed the button.

I start smelling and breathing something a little different from the proofgrade wood & hope it’s just the masking tape which I SWEAR I read was safe. Suddenly, I realize that I’m an idiot and could very well be killing myself and nobody is even home to help. If I pass out who’s going to call 911? Guessing it’s probably a good idea in the future not to try something new with a laser when nobody else is around. Friends don’t let friends laser hazardous materials alone. Luckily there really wasn’t a problem, the masking just had a different smell and my greatest fear (the unexpected) just kicked in for a minute there.

Overall the first engrave wasn’t as deep or dark as I was hoping, and bonus, there were these raised streaks where I had the masking tape overlap. Crud. when it came time to cut, I went to look. I heard it but never saw it because I didn’t look up in time. It was fast! 197 was a stupid number for wood. Come to think of it, I don’t have a clue what material they were even talking about at that speed. Probably paper. Friends don’t let friends find their own answers on forums without fact checking.

Did I mention I’m an idiot? Well, at least I can cut it again right? But maybe it went through and I just don’t know it yet. I should pick it up and see. Cue brain warning, "But then you can’t just tell it to cut again, you’ll have to realign everything, and that’s not gonna be easy in the UI without some sort of helpful align tools or input for xy coordinates cough, cough HOPPER cough, cough. Cue me once again ignoring my brain. Mistake #3. Picked it up, and sure enough it cut nothing. Tried to realign the wood in the interface (which the camera showing the bed actually was a HUGE help here), and set the cut this time to 50. It barely cut through in a few random spots. Mistake #4. I was done with this piece.

Fail. I shouldn’t have been surprised having never done this before, but now I was frustrated and short a coaster. Oh well. Time to learn from this one. I want it deeper and if 50 is barely scratching the surface, lets just go 100% power. If it burns through, who cares—I still have 8 more tries remaining and I have to go back to the store anyway. Engrave Speed? 335. That worked. Lines per inch? Let’s go 270 this time since it was so light the last. Cut speed? I’m going 30. And I’m just gonna try to get the masking tape as close to each other as I can without overlapping.

This coaster actually turned out well, but I started to worry I really had gone too deep. Also, I didn’t notice it until right at the very end of engraving when it started the final cut, but all of a sudden there was moisture all over it. Not sure why it did that but assumed it was just because it engraved so deep. I just hoped it was no big deal, ignored it and moved on.

Based off what I learned here, I kept all the settings the same but engraved at 80% for all the rest. The last few didn’t cut all the way through very well, so I bumped the cut speed to 20. In the end, I had most come out decent. A few had some rough edges where they didn’t cut so well but I figured I could sand those down. I was surprised to find the 80% power was so inconsistent. I had at least one coaster that came out as light as the first engrave and one that was as dark as the second, with a random assortment of everything between.

Having never touched a woodworking project since 7th grade shop class more than 20 years ago, I ran to Menards and bought some sanding blocks, wood stain, wood finish, and disposable brushes for the wood glue I’d already purchased. My son was eager to help, so we stood in the garage together and sanded down all of the coasters. I managed to salvage the first bad one, especially since we were going to glue cork to the bottom of it. Whoever got it would just have to deal with the stripes where the masking tape overlapped. We then painted them all with wood stain and let it dry, sanded gently again (per instructions) and added a layer of finish, let it dry, and then painted the backs with wood glue and stuck the cork on. I was really impressed with how they turned out.

Until we went to get them. They had all warped, some of them pretty badly.

Not sure if it was the humidity or what, but they were fine until we put the wood glue on. I was pissed. All that hard work down the tubes on the last step. I was ready to trash them all but my wonderful wife, being much more patient than I, simply suggested we put some heavy books on them for the night and see what happened in the morning.

It worked. I left them under the books for another day and this morning, proudly handed each person at the office a branded coaster. They loved them! Couldn’t believe I made them myself.

And to be honest? I can’t believe I did either.


Input appreciated: Engraving a cello bridge
Random jobs & 1st time with clear acrylic
#2

They look just great! :grinning:


#3

They turned out great!! Welcome to the “unknown settings but figure it out” club!! You did good…loved your play by play…lol. Now make sure you write down your settings lest you forget the next tme around…lol


#4

And pick up extras of an unknown material. :slight_smile:


#5

It might be worth your while to choose one of the ProofGrade plywoods for this and then let the settings populate. Then change the setting to manual engrave or manual cut. Then you will be left with the numbers in the settings fields. Now you can get an idea of what is going on. Then you can start from there.


#6

They really look great! I love the beautiful grain coming through the etched part. Sounds like it was a good learning tool too.

One thing to keep in mind with plywood material is the glue used to make it can have a dramatic effect on how well it lasers. The denser knots found in plywood can make a difference too. I don’t know if it came into play with your project, thought I’d mention it just in case. :slight_smile:


#7

@smcgathyfay Good call. Definitely going to write those down for the future.

@jbmanning5 Seriously! I have no idea how I didn’t even think about it when I picked-up my material. I knew I would need to test some, but it never once crossed my mind when I was buying those. Will from now on for sure.

@marmak3261 I wondered what the proofgrade settings actually were—knowing probably would’ve made this job a little easier. Thanks for the tip!

@kittski Yeah, I don’t think that caused any of the issues on this project 'cause the material was a single piece of wood, not plywood. I’d heard the glue in plywoods could be a problem but not knowing if the wood in front of me at the store is gonna cause trouble is annoying. I have tried to check and make sure there’s no knots or anything in what I buy though—I feel so spoiled with the proofgrade.


#8

Well done. :slight_smile:


#9

Good write-up - I have a feeling I’ll be going through those same steps when I get mine! :grinning:


#10

Great that you pulled it off at the end and learned stuff along the way. That’s what makes it fun!


#11

nice job.

yeah you had some dry wood there; white and yellow wood glued contain a fair amount of water. often on small items like this, the warping is (surprisingly!) totally reversible.

also you’re practically never going to pass out from cutting something on a laser, barring starting a giant fire.


#12

Another thing to try when using PVA glue is to dampen the top (unglued) side of the wood. The moisture on top sort of “balances” that in the glue - causing offsetting swelling of the wood and helping to minimize curling and warping while the glue dries.


#13

I’ve been saying this since the beginning. It’s so important in so many situations, this being one of them. A physical 0,0 and numeric positioning will allow you to salvage that incomplete cut that would be wasted material otherwise.

It’s even worse when you do a 4 hour engrave beforehand and the cut fails.

There were only a couple of people who could relate at the time this was originally brought up, but as more and more people try stuff like this it will become more and more apparent. That being said… well done on the coasters! They look great.

@dan - you guys had been asking for examples of situations where this functionality would be important. Here is the most common one…


#14

Well done! This was really fun to read, by the way. Your style of writing is humorous and engaging. Not going to lie, I often just look through the pictures of project posts. But the explanation was even more delightful than the photos.


#15

Grab a copy of my current calibration template. Then you can run it on new materials to see what the cut power will be. You can shrink the size if you want to just get speed and not waste too much material. But as you’ve seen guessing wastes material too :slight_smile:️ The full size template is good for checking kerf size too.


#16

I totally agree. I have a stack of wasted material that i screwed up the numbers on and didn’t realize it till i pulled the material out. This could totally be solved by a physical 0,0.


#17

A fun read! They turned out great!


#18

Good job. Your stories are always fun to read. I’m guessing the warping was just because the material was so thin. 1/4" plywood is notorious for it.


#19

I’ve never heard of this, but makes sense. Interesting.


#20

oooh, that’s on my list o’ things to laser onto a sign to hang above the 'forge once she arrives
wonderful story, well written - glad there were happy endings