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New PR530, spacing for focus

Posted: Fri Jan 19, 2018 9:33 pm
by JimRiehl
Got my new PR530 set up and running and it works great. Makes me want to ditch the Leetro controller in my other machine and upgrade it to one of the LO ones.

Does anyone know what the focal distance is from the nozzle to the material? I know that the lens has a focal length of 50.8mm and based on my measurements I made a 20mm spacer to focus from the nozzle and that seems to work just right, but if there was a more exact number I would like to know. I could not find any documentation on the machine hardware beyond the controller docs on this forum and the machine didn't come with any hard copy documents.

Re: New PR530, spacing for focus

Posted: Sat Jan 20, 2018 2:03 am
by Techgraphix
Lenses do vary a bit.
There is a way to find out the exact focal point, but you need to make a simple tool:
Make a block with a ramp on one side, about 100mm in length and with the ramp sloping from -5 to +5mm. Next to it a part that is at 0 level.
stick a paper on the ramp. Focus, like you did before, on the 0 level. And let the laser draw a line over the ramp with a length of 100mm (low power, just enough to see the marking)
You will see that this line widens at the ends. Somewhere, you see, the line is the thinnest. That is where your focalpoint is.
If this is exact in the middle, than it's OK.
When it is about 2cm in the direction of the lower end of the ramp, your focolpoint is 2mm lower than what you set.

FocusBlock.JPG
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Re: New PR530, spacing for focus

Posted: Sat Jan 20, 2018 9:25 am
by JimRiehl
This makes so much sense, I will give it a shot this weekend, thank you!

Re: New PR530, spacing for focus

Posted: Tue Jan 23, 2018 10:44 am
by JimRiehl
Worked like a charm, I was pretty much right on. Thanks again!

Re: New PR530, spacing for focus

Posted: Thu Jan 25, 2018 1:12 pm
by Techgraphix
Good to read it worked for you (too)..
Kees