Original Mantis microscope repair after major stand failure - Page 1
Forum section: electronics / repair

author: nixxon
author_rank: Frequent Contributor
timestamp: May 29, 2024, 10:19:48 pm
content: If you have an original Mantis microscope, be aware. The aging plastic parts of the microscope stand are prone to sudden failure and following damage.A couple of months ago I heard a loud bang. I ran into my "office" and found my original Mantis microscope head on the floor. It had fallen down from my desk, but luckily it wasn't severely damaged. It turned out that the pivot pin of the microscope swivel arm (stand) had broken clean off. I guess it happened due to aging plastics and material fatigue. The material could no longer withstand the designed tension.I replaced the broken stand with a spare stand I had around, and forgot the whole incident. For a while.A few days ago I happened to notice that the replacement stand had a visible crack where it attaches to the microscope head. The crack went along just where the first stand previously hadfailed. So I decided to temporarily remove the microcope from the desk and store it until I figured out what to do next.Today I decided to have a go at fixing the first stand that failed. I will share some pictures of my repair attempt. I used a 1mm steel "wire" (single strand) to attach the broken piece to the rest of the stand. The wire has a rated strength of 78 kg, so I hope it will not break. I cut off a piece of a popsicle stick to make the base better able to withstand the wire compression force on the stand connection frame.I relocated the lower wire after noticing that pivoting part was sagging under the weight of the Mantis head.My message after this is that you better pay attention if you are still using the original Mantis microscope

author: nixxon
author_rank: Frequent Contributor
timestamp: May 29, 2024, 10:27:09 pm
content: Last pictures with the head mounted. It seems that the sagging is due to wear and tear, and not the pivot pin bending forward. Fingers crossed...

author: spostma
author_rank: Regular Contributor
timestamp: May 30, 2024, 04:38:56 pm
content: the same has happened to me, and I made a stronger joint out of two off-the-shelf steel profiles(one to join two wooden beams and a flat plate).I used a 10mm steel shaft as hinge, also supporting the lower part of the Mantis head with another bracket.This is necessary, for my Mantis is a lot heavier than normal, as I mounted big lenses onto it,for those interested, I attached pictures of my modified mantis head as well.For normal viewing two stacked achromatic macro lenses (62mm Marumi DHG Achromat Macro 200plus a 62mm Nikon 6T achromatic macro lens) with some 60mm aperture,and as my own SLWD solution a Sony VCL-HGD1658 teleconverter plus the main lensof a high power Rodenstock X-ray objective (I think it was a 90mm F1.0) as macro objective.Those bigger lenses are mounted on a rotating disc with 3 pcs. 62mm filter thread adapters glued into it.I replaced the mirrors in the mantis head by bigger ones, and the fixed lens in the head also by a 62mm Nikon 6T achromatic lens.I lined the inside of the Mantis head with black paper to reduce internal scattering, and added a sunlight shadebecause sunlight on my forehead did reduce my viewing contrast too much.The exit pupil of this modified mantis is almost twice the diameter of a normal Mantis,thus gaining a lot of freedom while working on a PCB (see picture).The optical quality is superb, and almost no distorsion is visible.My main working lens has a 36mm FOV with 115mm freedom above the PCB with a 60mm exit pupil,and my extra magnification lens has 20mm FOV with 90mm freedom above PCB with a 36mm exit pupil.I can give more information for whoever would like to upgrade theis mantis as well...

author: spostma
author_rank: Regular Contributor
timestamp: May 30, 2024, 04:40:59 pm
content: .. and some more pictures belonging to previous post...