PCB Coasters - Page 1
Forum section: electronics / projects

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 04:59:12 pm
content: So I've been using reject PCB's as drink coasters, and had an idea: Why not see about making PCB's that are MEANT to be drink coasters?I've been working on designing one, and so far it looks like this:I'm not quite sure if I want to make them to sell, or just make them for myself, or create other designs that people might want.So I've created a survey to gauge people's interest in them. Feel free to take the survey, or leave feedback here! At the end of the survey is a field to leave your email address if you'd like to receive a discount code if I decide to sell these or coasters like them in the future. This is entirely optional.Survey link here!

author: German_EE
author_rank: Super Contributor
timestamp: June 30, 2019, 05:15:58 pm
content: I see a small problem here. A bar coaster is normally made of paper or card which a) absorbs spills and b) isn't slippery. How do you deal with this?

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:20:50 pm
content: Quote from: German_EE on June 30, 2019, 05:15:58 pmThere are coasters available that are made of hard/non-absorbent material.I could do something like use a non-smooth self-adhesive material and attach that to the bottom side.But I've used PCBs as coasters before and generally for my own in-home use I've never had a problem using them as they are.

author: djacobow
author_rank: Super Contributor
timestamp: June 30, 2019, 05:28:44 pm
content: Typically, coasters that are made of a non-absorbent material have a bit of a rim so as to contain the sweat from the glass. That would be hard to arrange for a PCB, but not entirely impossible. You could put a wire around the edge as people often do for a high-current trace.However, I see more and more coasters that are pretty much just decorative, so why not.Of course, even cooler would be a PCB coaster that actually did something. Maybe light up your drink and change color with the temperature or something. :-)

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:30:22 pm
content: Quote from: djacobow on June 30, 2019, 05:28:44 pmThat would be interesting too! I'm hoping to keep these quite cheap for now, so they'll just be bare boards, but add some electronics would be a lot of fun!

author: Gyro
author_rank: Super Contributor
timestamp: June 30, 2019, 05:37:45 pm
content: I'd loose the vias!The last thing you want is something that lets liquid through and then sandwiches it between the mat and table top.

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:38:24 pm
content: Quote from: Gyro on June 30, 2019, 05:37:45 pmThat's part of the logo I use. Would you prefer just pads, or another design element?

author: Gyro
author_rank: Super Contributor
timestamp: June 30, 2019, 05:40:09 pm
content: (see edit above)

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:41:00 pm
content: Quote from: Gyro on June 30, 2019, 05:40:09 pmQuote from: Gyro on June 30, 2019, 05:37:45 pmAh yes, that's fair. Pads would probably be a better idea then. Keeps the design element but is more functional.

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:44:11 pm
content: Quote from: mdszy on June 30, 2019, 05:41:00 pmHere's an updated image. The view is a little misleading, the pads would be the same color as the traces, of course. They're all exposed and gold immersion plated.

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2019, 05:50:47 pm
content: I have pcb coasters and rulers from various companies.The coaster does not work, it just slides all over the desk and is annoying. Too lightweight, it needs thin feet like a real coaster, they have felt. Cork on top. Vias would soon be plugged with coffee.

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 05:53:59 pm
content: Quote from: floobydust on June 30, 2019, 05:50:47 pmHm, I see.Small self-adhesive rubber feet would probably be useful for keeping it from sliding around.

author: Cloud
author_rank: Regular Contributor
timestamp: June 30, 2019, 06:00:14 pm
content: I have stopped using PCBs as coasters and replaced them with 4" trays. Since they have cavities which trap the liquid from glass

author: tooki
author_rank: Super Contributor
timestamp: June 30, 2019, 06:01:26 pm
content: Quote from: mdszy on June 30, 2019, 04:59:12 pmBigclive did a video on this 2 months ago:

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 06:03:06 pm
content: Quote from: tooki on June 30, 2019, 06:01:26 pmOh yeah, forgot about that!

author: DaJMasta
author_rank: Super Contributor
timestamp: June 30, 2019, 07:26:29 pm
content: May screw with your logo, but you could use some ring shaped traces covered in solder mask with holes in the solder mask between them as little grooves that could catch the edge of glasses that aren't just flat-bottomed - the little bit of thickness could probably make a noticeable difference. Maybe some sort of crosshatching of the traces or solder mask or both on the bottom could increase traction a smidge. Not going to be as stable as a paper one, but a little less slippery than just a bare PCB.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 30, 2019, 07:40:16 pm
content: try a cold/iced drink and see what happen when it sweats and you want to drink and lift the glass... i have sort of coaster here 3d printed pla pastics that keeps the ants out, surely it can contains spills/sweat just fine but i have to put tissue as sweat absorbent and "non-stickiness" on top. as sweet as it sounds, logos and leds and all but... it can be a wall decoration as well... ymmv.

author: mdszy
author_rank: Unknown
timestamp: June 30, 2019, 07:41:26 pm
content: Quote from: Mechatrommer on June 30, 2019, 07:40:16 pmI've been using PCBs as coasters for a while now and they always seem to work just fine in that regard.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 30, 2019, 07:44:21 pm
content: maybe your pcb is too big, heavy or just the way you lift the glass. i tend to lift a glass straight up and...

author: rcbuck
author_rank: Frequent Contributor
timestamp: June 30, 2019, 11:20:38 pm
content: I bought a set of these about 10 years ago.https://www.amazon.com/TerraCycle-Circuit-Board-Coasters-set/dp/B0045EJT5ENot sure if you can still buy them.They have a silicone rubber gasket around the outside edge that keeps them from sliding. Each side has a thin plastic coating laminated onto the board so the liquid does not go through the holes.If the iced drink sweats, the glass does stick to the coaster. When you lift the glass the coaster stays stuck to the glass. My solution for that is to let one edge of the glass sit on the silicone ring. Then it doesn't stick to the coaster.If you spill something onto the coaster you have to remove the outer silicone ring, rinse it with water, and rinse the coaster with water. After the rubber ring has dried, just put it back on the coaster.I have had two of them sitting on the sofa end coffee tables for the last 10 years and use them daily.

author: thinkfat
author_rank: Unknown
timestamp: July 01, 2019, 11:46:41 am
content: Now, if you could use the spilled liquid together with special coating on the pads, forming a 'beer cell battery', that would then light a LED...Gesendet von meinem Nokia 6.1 mit Tapatalk

author: ptricks
author_rank: Frequent Contributor
timestamp: July 01, 2019, 11:57:13 am
content: I have coasters with cork on top of them , suppose to absorb the moisture I guess. The problem remains that when it is humid if I lift my glass the coaster comes with it and then drops off with a thud onto the table . I would think a PCB or smooth surface +water + bottom of glass would be even worse.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 01, 2019, 12:26:50 pm
content: Quote from: ptricks on July 01, 2019, 11:57:13 amI always thought of this as some kind of feature, as long as the coaster isn't too wet and sprinkles everything with beer after landing.

author: thinkfat
author_rank: Unknown
timestamp: July 01, 2019, 12:44:46 pm
content: Quote from: Ysjoelfir on July 01, 2019, 12:26:50 pmThen, mill some slots into the pcb and line the bottom with cork. This will break the surface tension, stop liquid leaking through and provide some friction on the table.Gesendet von meinem Nokia 6.1 mit Tapatalk

author: Gyro
author_rank: Super Contributor
timestamp: July 01, 2019, 08:58:26 pm
content: You're better just using a Pringles lid - it provides thermal insulation from the desk. Put another one over the top of a hot drink and it prevents heat loss from evaporation.