Edge finish on laser cutting.

[Chris123Participant @chris123]

[Chris123Participant @chris123]

I need some parts cutting from aluminum sheet and am considering laser cutting.

Does anyone have any pictures of what the edge finish would be like?

I have had parts water jet cut before and the finish was terrible.

Thanks,

[JasonBModerator @jasonb]

The water jet cut stuff I have had (steel) in the past has had as good or better than lazer cutting. You can get several qualities of cut on a waterjet, if you just went with fast and cheap then the finish will not be as fine as a slower cut.

J

[John Stevenson 1Participant @johnstevenson1]

What thickness ?

I think I have some 3mm bits here. Must admit that as you go thicker in alloy the cut does degrade compared to steel.

[Ian PParticipant @ianp]

Thickest I have had cut in Ali is 4mm and I could describe the edge as 'very high precision' or 'very poor' depending on what the job was for. Realistically its not the same as a machined finish but it only takes a few seconds work drawfiling the edges to remove all traces of how the edge was cut,

All the waterjet cutting I have had done (on 10mm Ali), or I have seen on other customers jobs, has been almost close to a machined finish so either your expectation was very high or whoever it was did a poor job. I have certainly never seen a terrible water (or laser) cut job.

Ian P

[Speedy Builder5Participant @speedybuilder5]

Its not Ali, but I have just been working with some laser cut discs in 3/8 mild steel with some 9mm dia holes cut in it. I can't believe how clean the holes were. I just stuck a reamer thro to clean them up, but there was little to remove sufficient for bolt holes.

[Chris123Participant @chris123]

Interesting.

I wasn't given a choice of what type of finish.

This the part:

 

Edited By Chris123 on 09/02/2014 04:21:41

[JasonBModerator @jasonb]

This is watrjet cut steel, the top and bottom plates are Q3 and the 8mm thick toothed plate Q2. Q1 is a fine satin finish through to Q5 which is just the most economical basic cut out, you can also have different qualities of cut on the same part.

I was able to paint straight onto the two finishes with no further work required and no sign of any texture.

J

Edited By JasonB on 09/02/2014 07:42:40

[Brian WarwickParticipant @brianwarwick88192]

is it not like everything else you get what you pay for, the faster machine runs the cheaper the job but the lower the quality

everything i have had cut (6mm steel) has been ready to go and in my opinion very reasonably priced

[KWILParticipant @kwil]

Your photo clearly shows that the cut has been too fast, if properly done the jet is slowed at any change of direction to avoid the curved tail effect clearly shown on your sample. I have seen waterjet cut parts in aluminium, anodised and put together like a fine jigsaw, so it can be done.

[John McNamaraParticipant @johnmcnamara74883]

Hi Chris 123

I have a sample of 10mm aluminium cut on a Techni water jet of their name and a star, it was at the AIEEE Engineering exhibition in Melbourne The star part is cut at an acute angle. The edge finish looks like a fine sandblast the points and edge are sharp enough to cut you. They were giving the samples out as they cut them, So I know it can be done. It also enabled the angled kerf you sometimes see on thicker water jet parts greatly reduced or eliminated. However not all water jets have the ability to angle the head.

You have to ask the contractor to show you examples of the work they can do, Some have pretty old machinery.

Regards
John

.

[Chris123Participant @chris123]

Thanks for the answers, looks like mine were cut too fast then.

The bottom of the part is 0.5mm wider than the top, so they have a taper of 0.25mm on each edge.

The time I spent designing these parts and making prototypes I was pretty upset/disappointed when they arrived.

 

I will will try water jet cutting again I think, but use a local company I can visit and talk to.

 

Thanks for for your help!

Edited By Chris123 on 09/02/2014 16:30:03

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