Hello All,
I've been looking into improving the quality of my cuts for perspex jewellery. Sure, I can get a nice cut quality, with a 60W tube on 75% power, at about 20mm/sec, but on light coloured perspex there's staining on interior angles where a hole is cut out. There's no staining on the convex side of a cut - the stain only sits on the interior acute angle.
This is a very, very picky thing - on most perspex you just won't notice - but look at a white, cream or yellow, and you can see slight discolouration. This doesn't really matter, except with jewellery, where it has to be PERFECT.
I have tested a huge array of chemicals, including acids and bases, solvents and soaps to try to remove this discolouration, to no avail. It does seem that the perspex is chemically changed and the stain is embedded.
I've also fitted a bigger air pump (with double the flow rate). More air equals less stain? While it may make the issue a little better, it doesn't definitively solve it.
Other strategies I've tried include thoroughly cleaning the bed before cutting perspex. This doesn't seem to help. (How about soaking in a bath of 10% sodium metasilicate cleaner overnight, then pressure washing for 10 minutes, then repeating the whole soak, wait, pressure wash process with new cleaner. Did I say clean?)
And how about this - suspending the perspex to be cut 30mm above the bed by balancing it on spacers. Surely, that'll help? Maybe a bit - but not enough.
There's only one strategy I've found that works, and I don't like it. Slow the cut RIGHT DOWN (1mm/sec) and turn the power down as low as I can get away with to get a convincing cut (35%?). This produces beautiful results, but far too slowly for my liking.
Any advice? I was wondering whether there are other settings (tube frequency perhaps?) that might avoid this problem. Or perhaps sodium metasilicate is EXACTLY the wrong choice of cleaner. Or maybe... I don't know! Double cutting perhaps? First time to cut, second time to clean?
All the best,
James
Suppressing Stains on Light coloured Perspex
Re: Suppressing Stains on Light coloured Perspex
Hi James,
Are you using Perspex branded acrylic? I find the cheaper acrylics tend to do this but the Perspex or Amari brands are better (not sure if as good as you need though).
On a 60w tube I would say 75% is a bit high - I tend to cut about 20mm/s at 62 so wroth making sure your focus and mirrors are spot on.
Do not change the frequency - at least not before talking to HPC - I have heard this in the past but to be honest I would not like to advise and changing may do more harm than good.
Best
Dave
Are you using Perspex branded acrylic? I find the cheaper acrylics tend to do this but the Perspex or Amari brands are better (not sure if as good as you need though).
On a 60w tube I would say 75% is a bit high - I tend to cut about 20mm/s at 62 so wroth making sure your focus and mirrors are spot on.
Do not change the frequency - at least not before talking to HPC - I have heard this in the past but to be honest I would not like to advise and changing may do more harm than good.
Best
Dave
Using two LS3060's and an ex 3020 user
Please note I am not employed by HPC, any advice or recomendations I give are based on my own experience and are not necessarily the same as HPC's. First point of contact on any hardware issues should be with HPC
Please note I am not employed by HPC, any advice or recomendations I give are based on my own experience and are not necessarily the same as HPC's. First point of contact on any hardware issues should be with HPC
Re: Suppressing Stains on Light coloured Perspex
Thanks Dave!
I've messed around with intermediate powers, and yes, I can get a good cut at 60-odd percent, but not every single time with every single colour. Branded perspex is exactly what I'm using, but I've been a smidge generous with the power just because a few colours really don't like to cut. Dark purple and dark red are particularly resistant. It's also worth noting that the thickness of cast perspex can be all over the place! They say +/- 10 % plus 0.4mm, which means that a nominally 3mm piece of perspex can be 3.7mm thick and still in spec!
Either way, turning the power down a smidge (which I generally approve of for other reasons (like overheating and fire!) doesn't avoid the stain problem.
Maybe I'll have a chat to the technical people at HPC about frequency. I'm aware that messing with it may spell bad news for the PSU, so I'm not minded to experiment without advisory parameters from people who know.
Key here is working out the method to produce perfect jewellery at maximum speed. 1mm/sec just won't (pardon the pun) cut it.
Maybe it's time for a new lens. I've used the same one quite heavily for 3 years, so maybe it's getting tired and emotional.
Cheers!
James
I've messed around with intermediate powers, and yes, I can get a good cut at 60-odd percent, but not every single time with every single colour. Branded perspex is exactly what I'm using, but I've been a smidge generous with the power just because a few colours really don't like to cut. Dark purple and dark red are particularly resistant. It's also worth noting that the thickness of cast perspex can be all over the place! They say +/- 10 % plus 0.4mm, which means that a nominally 3mm piece of perspex can be 3.7mm thick and still in spec!
Either way, turning the power down a smidge (which I generally approve of for other reasons (like overheating and fire!) doesn't avoid the stain problem.
Maybe I'll have a chat to the technical people at HPC about frequency. I'm aware that messing with it may spell bad news for the PSU, so I'm not minded to experiment without advisory parameters from people who know.
Key here is working out the method to produce perfect jewellery at maximum speed. 1mm/sec just won't (pardon the pun) cut it.
Maybe it's time for a new lens. I've used the same one quite heavily for 3 years, so maybe it's getting tired and emotional.
Cheers!
James
Re: Suppressing Stains on Light coloured Perspex
No problems.
Yes fire is a big risk on small cuts!
Do you take the covering off the material - wonder if that contaminates the cut? I can't say I've noticed much of a difference in colour. Can try it on mine using Amari stock (Perspex don't seem to like smaller companies so gave up using them!). I have cut thousands of small bits and no one has mentioned it but maybe it is not so important for their needs
Best
Dave
Yes fire is a big risk on small cuts!
Do you take the covering off the material - wonder if that contaminates the cut? I can't say I've noticed much of a difference in colour. Can try it on mine using Amari stock (Perspex don't seem to like smaller companies so gave up using them!). I have cut thousands of small bits and no one has mentioned it but maybe it is not so important for their needs
Best
Dave
Using two LS3060's and an ex 3020 user
Please note I am not employed by HPC, any advice or recomendations I give are based on my own experience and are not necessarily the same as HPC's. First point of contact on any hardware issues should be with HPC
Please note I am not employed by HPC, any advice or recomendations I give are based on my own experience and are not necessarily the same as HPC's. First point of contact on any hardware issues should be with HPC
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