The Openflexure Microscope Version 7.0.0-beta1 was released last week. This is now the recommended version for the Microscope in the build instructions on the project web site. Version 7 was built on a huge effort over a couple of years by @j.stirling doing most of the work (including developing the software to automate the instructions) with @r.w.bowman and contributions from a number of others.
If you have not already built a V7 from the Alpha releases, now would be great time to try it! Please post here to say how you get on.
All the files and instructions for the last full release Version 6.1.5 are still linked directly from the project webpages as well. The beta release of V7 already more robust, has better instructions, and has fewer issues than 6.1.5 so we feel that it is now time to point to that as the recommended build.
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Known bugs and bug fixes:
We have identified a couple of bugs in the V7.0.0-beta1:
Pi Camera lens spacer:
V7.0.0-Alpha3 introduced a bug that was not noticed, the lens holder is incorrect and will not hold the Pi camera lens in the right place. This can cause strange problems in the image quality as the lens is not held firmly flat to the mount, or may make it impossible to focus because the lens is recessed too far into the spacer.
(Gitlab issue #287 for details)
SOLUTION: use the PiCamera lens spacer from version V7.0.0-Alpha1
Condenser 5mm LED work-around:
The illumination module was substantially changed for V7.0.0-Alpha3, to accommodate a custom PCB. It was designed to allow a 5MM LED to be used as an alternative, but a bug causes the 5mm LED to be in slightly the wrong position so that a diffuser cannot be fitted.
(Gitlab issue #286 for details)
SOLUTION: Use PTFE tape as a diffuser, as the optional suggestion in the LED workaround instructions
added 18/01/2023: (There is also a hidden explanation https://build.openflexure.org/openflexure-microscope/v7.0.0-beta1/info_pages/illumination_optics_explanation that is not linked in the instructions, but may be useful here)
added 27/09/2023: Gitlab merge request !321 addressed this. The new lid STL is condenser_lid (MR321).stl (350.0 KB) which allows the 5mm LED to fit with a diffuser as in the v7.0.0-beta1 instructions.
Condenser for Upright version
The condenser module for the upright microscope has no access for putting the nut into the nut-trap.
(Discussed in Gitlab merge requests !315 and !316)
SOLUTION: There is no static solution at present. !316 is close to completion to address the issue. There is a ‘View App’ button on that page that will take you to the latest build of this modification with the new parts and instructions this will change whenever we try something new and may may become broken
Edit 27/09/2023: The new parts and instructions are now merged, which makes it harder to link to the solution. The image below of the new upright optics assembly should show how it is now basically the same assembly as the normal illumination using the illumination PCB or 5mm LED work-around. There is a new condenser upright_condenser(MR316).stl (500.0 KB), and a platform upright_condenser_platform (MR316).stl (91.8 KB). The platform takes the place of the lid in the standard illumination assembly.
Another bug and bugfix for V7.0.0-Beta1:
Nano-Workaround LED power:
As noted in the Forum thread Questions on Mounting Nano Conversion Plate, it is not possible to connect the LED to the power pins on the Pi when using the nano converter plate in the motor electronics workaround.
SOLUTION: Power the LED from the 5V and GND pins of the Arduino Nano.
This is not quite a bug, but is is a large modification to the stand and electronics drawer
The electronics drawer in the released v7.0.0-beta1 does not fit the prototype Sangaboard v0.5. This was attended to in Gitlab merge request !319. There is a discussion of Sangaboard v0.5 on another thread, where new parts to fit that are also posted Sangaboard v0.5 now available - General - OpenFlexure Forum.
