A question of materials

qa

#1

I wonder will there ever be a database of GF safe materials ? and perhaps a market place to acquire them ?? Because i am sure that would be a wonderful place for GF to make a handy profit allowing companies to list their materials there. just a thought. Also i am a bit freaked about putting something in the GF and having it burst in to flames.


#2

We have been having a LOT of discussions around materials, both from the safety perspective as well as just “will it laser?”.

Glowforge has said they will be selling materials, so one assumes those will be tested as safe. Beyond that there is common sense and google searching. :smile:

I am doing a lot of google searching these days…


#3

Once the Glowforge catalog goes live, that will give us a pretty good idea of what is safe since the company itself will be marketing. I am looking forward to that. In the meanwhile: www.laserbits.com will give you an excellent preview of possible and safe materials.


#4

Google i do love it, I mean honestly all the information in the world at your finger tips. Only problem is that thrre are many jerks like to put false information out there, that is my concern…Honestly I did not think you could laser glass but BAM Eva Kloiber does it… So yea while google is truly amazing it is only as good as the content that humans place there

and @ marmak3261 thank you for the useful information you sir are the Governor


#5

The propensity for false information is why you should always look for at least two people saying something before you believe it, and trace their information sources to make sure you are getting two independent verifications, not two re-postings of a single verification.

And always look for the counter-point. Never should anyone look only to confirm what they want, always see why someone speaks against what you would like to be true (and due to the internet trolls, you can always find someone on the counter point)


#6

OK, all true, but…
if you pick your sources carefully then the odds of getting good information increase dramatically. For instance, I almost never believe forum posts from random people on the internet unless I do a little background checking for reliability. On the other hand I generally trust Wikipedia for basic information (if not for subtlety) and I love google book search! The amount of scholarly research available is just immense as long as you are willing to put a little work into it.

Look to special purpose forums ( http://www.sawmillcreek.org/forum.php comes to mind) and trust but verify. I personally avoid the assumption that manufacturers and store are offering reliable data, since I distrust the commercial impulse to exaggerate claims and gloss over dangers. Glowforge excluded of course. :wink:


#7

I certainly have not been led astray by following @jacobturner and @jkopel and @rpegg, among others. You all temper my impulsive enthusiasm. The whole materials question is crucial for me. I have been trying to understand the physics and chemistry involved to get a better read on what to attempt. I spent a couple hours reading the Synrad newsletter last night and that sure helped. I am most concerned with materials hazards for health and safety reasons, but just as much don’t want to damage the Glowforge. Since I want to have a minimum investment in materials costs, I am loath to purchase from a supplier. Right now I am aiming for wood and leather projects out of the gate. I will purchase Delrin for the stamp, embossing projects.


#8

What you said here is so true and goes so far beyond laser, or STEM, it is pretty much a universal truth of the interwebs.


#9

Or… i could ask the maker of the device what works and what does not… all this other stuff seams like way 2 much effort… just saying.


#10

Generally we’re not going to opine on any material that we haven’t tested and provided ourselves. The whole reason we decided we had to get into the materials business was that we didn’t want to make Glowforge owners have to worry about the chemistry of their materials. We also recommend laserbits and inventables, who sell materials designed for lasers.


#11

It’s great that you plan a materials store. I looked at Laserbits but selection there is not actually that great (unless you are making signs).

One material I want to vote for you to carry is Delrin sheets. Delrin is relatively hard to find in thin (eg 3mm to 5mm) thicknesses, at least if you want smallish pieces, but much better than acrylic for structural projects (eg robot mechanisms and frames).

Unlike acyrlic it’s feasible to do snap fits etc with it. It’s about equivalent to acrylic for cutting safely (unlike PVC or Polycarbonate…). Generic acetal sheets would be fine too, as long as of good quality.


#12

@michael_mccool

This is where we get our delrin sheets for our CNC.

There are various thickness available. My husband uses 6~10mm thick sheets for 3D Printer parts.


#13

McMaster-Carr also sells Delrin in a wide variety of thicknesses:

They are not always the cheapest, but they are fast, have almost everything in stock, and their shipping prices are pretty reasonable. They also sell a wide variety of other plastics.


#14

https://docs.google.com/a/onearmedgraphics.com/spreadsheets/d/1EzgQNpSEMGb8ghoB8XEu1dyD6y6Wng317DLMvEE9PfI/edit?usp=docslist_api

This is a spreadsheet i made for mostly Australian suppliers of materials suitable for laser and cnc projects


#15

Thanks Robbie - that list will help me greatly


#16

I will have to collect a list of Japanese sources as well. I even found a site that sells colored Acetel, not just black and white.

US sites only seem to sell thicknesses in Imperial units… will have to look at Australian sites.


#17

Tripp Plastics in Sparks, NV sell acrylic in metric thicknesses:

https://www.trippplastics.com/products/products.asp?catID=127

Googling on “acrylic 3mm” turns up a bunch of other interesting links. Looks like Ebay and Amazon sell it as well.


#18

US sites may list thickness in Imperial units, but the material is not always manufactured to Imperial units. Material sold as 1/4 or 0.25 inches may be a quarter-inch or it may be 6mm or even 5mm. If they list it to a thousandth of an inch it’s more likely to be accurate and at that point some simple math will convert it to international units.


#19

I figured as much but I like to have some idea what I’m ordering. I may just take a chance with a supplier, measure what I get, and hope they don’t randomly change it later.

But really… is it so hard to list both measurements, and give tolerances?

On the other hand, I use OpenSCAD a lot which allows for parametric design. So in theory I could measure what I get, type in that number to my design, and customize the cutfile to the actual thickness of the sheet. This is a good idea anyhow because sheets do tend to vary (and if you are especially lucky, they vary across a single sheet…)