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Re: Performance or lack of...

Posted: Tue Nov 08, 2011 11:13 am
by PhillyDee
And this is why these do not cost £15K+ :lol: .

I know how you feel. As a CNC machinist and seeing the lens assembly, it really makes me shudder. It actually makes me want to do themall again, and make them out of decent aluminium. The stuff they use is shocking. No edges broken, torn finish (usually too much silicon in the alu) poor quality in general. However, I just do not have the time! (Or a lathe).

Re: Performance or lack of...

Posted: Tue Nov 08, 2011 11:29 am
by WyeModels
PhillyDee wrote:And this is why these do not cost £15K+ :lol: .

I know how you feel. As a CNC machinist and seeing the lens assembly, it really makes me shudder. It actually makes me want to do themall again, and make them out of decent aluminium. The stuff they use is shocking. No edges broken, torn finish (usually too much silicon in the alu) poor quality in general. However, I just do not have the time! (Or a lathe).
I have the lathe :D I made a delrin adaptor to hold a cheap maplins laser pointer, just to help with the alignment.
As you say it is just poor machining and nothing that couldnt be fixed with a bit of work, this has really made me think about doing something better with the mirror mounting as it is all a bit Heath Robinson

Re: Performance or lack of...

Posted: Tue Nov 08, 2011 2:25 pm
by PhillyDee
I have been meaning to replace the whole mount on there, but the aftermarket solutions, no one wants to give me a technical drawing! Without that, I cannot see if it will fit together with minimal modding.

I certainly want a mirror mount on my LS3020 for the final assembly, but a direct replacement is not available. I do not have the time to design one, and without access to decent machine tools, millign amchine and lathe, I cannot really redesign on the fly.

I work in engineering, but its the wrong sort! The only machines we have are larger machines. I work on a machine with a 650mm chuck, and am about to move to a much larger vertical borer with an approx 1.5m chuck (temporary I hope, I find them boring compared to my normal 5-axis machine!)

Re: Performance or lack of...

Posted: Tue Nov 08, 2011 5:35 pm
by WyeModels
!.5 M :shock: thats huge ! I did skin the bottom of the mount so at least it is sitting a bit better. In fairness, I know what the Chinese stuff is like as we did masses of work on my small lathe and you cant expect miracles for what they cost.
Chasing this problem down has made the difference between ok cutting and really good cutting.

Re: Performance or lack of...

Posted: Tue Nov 08, 2011 6:03 pm
by Spooky
I'll get you one Phil, dxf be ok?

Re: Performance or lack of...

Posted: Tue Nov 08, 2011 6:32 pm
by PhillyDee
Huge it is a bit big :D.
They have one of these
http://www.machinetools.com/us/listings ... g-vtc-2000
2m chuck, and an old webster bennet with a 3m chuck aswell (but thats getting sold or stored).

The one I am looking at buying is one found on eBay,
Something like that:
http://www.ebay.co.uk/itm/Pro-Co2-Laser ... 1c1f598376

Re: Performance or lack of...

Posted: Wed Nov 09, 2011 7:51 am
by robburge@sky.com
I'm very confused...not difficult I know!

My 3060 has been losing power. Whilst its never been cutting at optimum, I suspect, for a while I have been successfully cutting 2mm medite at 9/75 and 1mm MDF at 25/75. Recently performance has tailed off. Files have failed to cut through and much has been scrapped. The time and effort involved in getting parts out has been worryingly high. I have tried a variety of cleaning/alignment sessions with patchy results.

I got so fed up I decided to test it. I drew some some rectangles and set up Lasercut to cut them at 9/75, 8/75, 7/75, 6/75, 8/98 & 7/98

The 6/75 and 7/75 cut through but surprisingly 8/98 and 7/98 did not penetrate anywhere.

I then tried a constant speed but variable power: 8/50, 8/60, 8/70, 8/80, 8/90 & 8/100

Surprisingly, the lower power three just dropped out while the higher three did not cut through. I'm now runnijng all my files at 50% power and its like having a new laser! The machine itself is always set on 100%. Can anyone explain why I get much better performance at lower power, using Lasercut 3.5?

Re: Performance or lack of...

Posted: Wed Nov 09, 2011 9:52 am
by Daven
Spooky may have a better way of explaining but my take on it is that on materials such as MDF you get a carbon deposit - the carbon acts as a shield so if the power is too high there is more burning and a build up of carbon.

Dave

Re: Performance or lack of...

Posted: Wed Nov 09, 2011 11:41 am
by Spooky
Daves pretty much bang on, if you want to use higher power settings you need more air to keep the carbon out of the kerf.

best wishes

Dave

Re: Performance or lack of...

Posted: Wed Nov 09, 2011 10:43 pm
by WyeModels
PhillyDee wrote:Huge it is a bit big :D.
They have one of these
http://www.machinetools.com/us/listings ... g-vtc-2000
2m chuck, and an old webster bennet with a 3m chuck aswell (but thats getting sold or stored).

The one I am looking at buying is one found on eBay,
Something like that:
http://www.ebay.co.uk/itm/Pro-Co2-Laser ... 1c1f598376
That looks pretty good and not a bad price.
Today I levelled the whole machine up with a precision level and that has yielded further improvements im now getting 25/70 on 2mm medite, which is a huge improvement. so the moral of the story is that lots of small adjustments really do add up.