Illumination doesn’t line up w/6.1.5 w/hi-res optics

Downloaded the 6.1.5 package for hi-res optics (40x Plan objective), built it and found that the illumination axis is several mm off the optical axis (see picture) This is my first build, but I can’t see any way to assemble it differently, please lmk if I’m missing something!

Thanks so much to anyone who reads this, I’m looking forward to a lot more builds and supporting this community in the future!


There is some adjustment laterally because the screws for the illumination mount are in slots. It is quite fiddly to get the position right, but there should be sufficient adjustment to line up with the objective. In your photo it is a little hard to see, but the screw does seem to be at the end of the slot with space to move the illumination back. I hope this will work for you.

In the photo the objective sticks up through the translation stage. For a v6.1.5 with high resolution optics you will need the sample riser on top of the stage - I think you will also need to move the objective down a little, but you will see when you have the riser fitted.
I also see that the optics module is printed in white. It is recommended to print that in black to reduce stray light in your images.

Thanks, I was able to move the illuminator as you described, look good now!

The sample riser that prints with the 6.1.5 STLs isn’t high enough for this objective, even with it lowered as far as it will go. No worries, I’ll print a taller one.

And yes, I know white is the worst possible color for this, will fix next time!

Thanks again,

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I’m glad that you got the illumination sorted.

What objective is it that you are using? The 10mm riser should be right for the usual 45mm par-focal distance.

Here’s the objective, it’s $[70 on Amazon](AmScope PA40X 40X (Spring) Plan Achromatic Microscope Objective

  • 40X Plan Achromatic microscope objective lens fits common size (DIN/JIS standard) compound microscopes
  • 40X Magnification Power
  • 40/0.65 Spring
  • 160/0.17

Why would it stick up so high? Am I missing something? The 10mm riser is not high enough, I would need a 16mm riser. I was planning to print one, but now I wonder if this is not an appropriate objective?

Thanks again for your help!

The listing in your link does not give the par-focal distance, but looks normal. Is the actual length of the objective more than 45mm from the shoulder of the thread to the top of the lens (the length of the part that you can see when it is screwed in)?
What is the stl filename of the optics module that you have printed?

It is ~45mm. I figured out how to lower the objective so that the 10mm riser works.

I really appreciate your help & will try to pay it forward!


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