Please use this thread for general discussion, chit-chat and shooting the breeze about face shields. Other topics will be managed more strictly to ensure new users can find the info they need quickly without a long thread.
When we (Smoke & Mirrors, Nottingham Hackspace & Kitronik) started working up plans and designs for face shields we started from the idea we’d use PETG sheet from Amari plastics and follow something the same as or similar to the “Fast Face Shield” design we’d seen on the PRUSA site.
We quickly learned that PET and PETG sheet or anything else suitable for laser cutting the whole design, wasn’t available. The choices we made with the polypropylene design come from the materials readily at hand AND the design we’d been requested to make locally, that being the 3D printed PRUSA RC3 design. So we combined the essence of what we’d been asked to make, with the materials at hand.
Greeting from New Jersey… Have joined your group in the last 12 hours. I obtained layouts etc… obtain info on metric and inch conversions… Not sure if I can cut polypropylene as I have always used plexiglass. Have a CO2 laser at 60 watts size about 700 x 500 MM made by Epilog Laser. Wonder if anyone has info or help. I have no problems setting machine on metric but the poly/plex is confusing.
Hi Jerry, welcome!
Cutting PP is fine, I had not cut pp before.
I’m sure others will give you more accurate information than me.
Just stick a bit of pp on your machine and optimise the speed and power settings.
For the pp you need between 0.5 and 0.8mm (sorry I don’t do ‘old money’, ie imperial measurements!)
For the acetate/pvc we think 100 micron is a little flimsy and prefer 240 micron.
Make sure you stock up, its getting difficult to source material here!
Spread the word over there, there must be hundreds of people who can chip in.
Good luck, stay healthy and keep us informed of your efforts!
Just wanted to thank you again. PP is not available in thin dimensions within 100 miles… but I found a firm that makes and stocks material. I am getting a few sample sheets in the mail on Wednesday with idea of driving about 1 1/2 hours to the manufacturer on Friday in Delaware. They stocked flat sheets black 940 x 1829 with thickness .787 to .889 MM.
Please to cut them down to 508 x 914 MM and pick up bulk on Friday even thought my machine will take up to 508 x 914.
Found a 5 up set which fits onto the 508 x 914 sheet. Not sure if going to a larger sheet 460 x 460 would be any help… so decided to keep first order.
Will decide after running in a few days if I desire the larger sheets and layout additional multiples. thanks again
Morning / afternoon / evening jemdur! (We should be keeping general discussion on this thread!)
your dxf did not upload, I will email you in a bit, you can send it to me that way.
I have not used CorelDraw so I can’t really help you with that.
I am very, very new to all of this software so I will give you my view, but maybe someone more savvy on the forum could help you out with this.
Not sure how different software is, we use Techsoft 2d design for the drawing editing and LaserCut 5.3 for the lasering.
On out 2d design we simply change the colour of the parts to cut first. So, for example I set all of the internal pieces to RED and all of the outers to BLACK.
When the DXF file is uploaded to LaserCut it recognises the different colours as 2 different laser jobs, you can specify which one to do first and set speed / power etc for each job.
I’d assume your software will do similar.
As for jumping around, this I have not really properly got to the bottom of, I think it is something to do with drawing order and grouping (anyone else… I’m flailing here!).
I am currently at school cutting on sheets of 650x550mm… hence this reply is taking so long… every 20 mins it needs me!
Here are the files I am using (can’t give you CorelDraw versions yet as my evaluation copy is on my machine at home):
There is also the LaserCut manual, page 26 on, may be similar to what you are using.
Our laser bed had vertical slats so I have had to optimise for cutting everything horizontally so parts do not slump between the slots while in the middle of cutting.
These files have little jumping around (certainly not enough to warrant me spending hours trying to figure it when I should be burning) so you may be able to modify / adapt to suit your needs)
A word of caution, I have probably done some ‘odd’ grouping, particularly on the adjuster strap, so check carefully when editing!
If I get the chance between burning I will see what I can work up onto a 500x300 sheet for you
I believe you’re right. With our setup, I’m pretty sure it cuts the lines you drew first first, if you see what I mean. 2D Design keeps an order - each new thing is drawn ‘in front of’ the last one. You can modify this with ‘bring forward’, ‘bring to front’ etc on the ‘edit’ menu.
My school is possibly eventually creaking into action and allowing me to access the DT workshops. We have a potential local order for a couple of hundred, but if I can do more than that is there a supply channel I can feed into?
I find I’m getting some issues with some of my headbands.
the adjustable bit often has little blobs left on the back where the holes are cut which can be quite sharp. I’m just knocking off as much as I can with my fingers, but was wondering if there is a better solution
some of the cuts on the edges sometimes have a bit of residue from hitting my honeycomb I assume, that can leave a bit of serrated edge to some pieces. Any suggestions for post processing?
Would slowing down the laser speed help? The laser might then vapourise the offending bits. Might be worth running it slower, I had similar to #2 when I wass cutting too fast, slowing down made all the difference.
Is it possible to strategically place something under the sheet so the ‘blobs’ drop off, probably not!
can you turn the strip over and drag a blunt flat edge among the surface? (steel rule of such like)