Laser Induction & HDPE suitability

Hi all (and also @lasertechs)

When might the next laser Induction happen? Also - @Calum_Nicoll, how did the HDPE cutting go? 3mm Ok to use on the cutter?

Rob

Laser inductions occur at the discretion of the laser techs and are dependant also on the volume of people waiting. As a laser tech myself I will be away till te end of April but I will tag @naxxfish and @nico.dejong.nz to see if they can help. With regards to HDPE see the following post: https://sawmillcreek.org/showthread.php?193717-Is-it-safe-to-laser-HDPE
Do you need to use HDPE? Acetal in 3mm sheets is easily possible… any thick acetal up to 6mm can be cut but the result will be less than perfect in the edges…

I remember someone tried this a while back, it didn’t go terribly well. Extremely melty.

I’ll see if I can run a session soon.

Not easily measurable as we don’t have a laser waiting list anymore

I’ve tried it before - it does cut ok but it is melty so edge will be not super accurate.

Acetal is a bit too brittle for my project unfortunately. I had planned to use polycarb until I saw it on the banned materials list, HDPE seemed like the better option.

So, oversize and sand?

I shall eagerly await the induction! I’d also like to write up the project on my blog - more than happy to post it on the Makerspace one as well.

http://arc-robotics.org.uk

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Maybe the laser cutter isn’t the right solution? A CNC night be though.

Yeah…but that involves phase 3…let’s not even go there! :wink:

Yeah probably - its still prob ok ±1mm - if the parts are small/needs better precision could put them on my cnc?

How about a community built 6040?

All of the precise sections of the HDPE I was hoping to do on the mill - the laser was to rough out an outline and put a couple of holes in vaugely correct places

I wouldn’t describe acetal as brittle. Aka delrin? Are you sure?

It laser cuts pretty well in 3mm at least.

I am sure that Acetal (or Delrin) at anything under about 15mm thickness is a bit too brittle for my combat robot application, which is somewhat strange. My last robot had 8mm and we shattered that just by being flipped a couple meters into the air and landing hard. We swapped out to 5mm HDPE that we had and were fine for about 12 fights before it needed replacing.

Well, our laser isn’t going to cut 15mm thick anything - so you’d have to cut it in layers (I’m guessing that was the plan anyway).

Definitely sounds like it would benefit being CNCd rather than lasered…

You could laser cut (or even print depending on precision) on paper and then use an adhesive, then face that part off. Or use conventional tracing methods. If you don’t have any curves then you can do just about anything on the conventional mill and drill press.