Support for the mirror, necessary for the proper positioning of the same during another test is not that any device able to keep it in a safe and in a vertical position.
The support can be seen as the assembly of 5 distinct elements:
- Panel or carrier rear structure
- lower supports for the support of the mirror
- Basement
- Adjustable feet
- Fermo higher to avoid the tilting mirror
The rear supporting structure has been realized by crossing of rectangular wooden profiles so that they form a figure "A", whose maximum size you can see in the figure placed in the bottom of the article.
To support this structure, It has been realized a base, always in wood, quite robust and attached with glue and self-tapping screws. To ensure the structural integrity, It is a good thing to add a reinforcing element which joint the base with the structure “A”. This base must have a size such as to ensure stability to the structure and it must absolutely avoid the overturning once the mirror is mounted, for this reason, to ensure a further security, you can support the additional weight over the same base.
And the more 2 lower supports also made of wood, They were modeled in a crescent shape with radius of curvature equal to the radius of the mirror and positioned at 120 ° relative to one another. As you can see from these components have a step that allows to insert the mirror between it and the rear carrier structure so as to position the assicurane.
The upper stopper instead was made with a piece of threaded rod bent at 90 ° on the ends of which, which will be in contact with the mirror, is a rubber sheath pezzeto been inserted that will serve to prevent the occurrence of marks on the mirror. The bar was then fixed to the rear support via a threaded hole. It was used a threaded rod and not a smooth bar, as well as having the ability to rotate the latch bringing it closer to and away from the rear support, It will be able to turn the latch so as to provide easy insertion and removal of the mirror from the support.
To make fine tilt adjustment forward / back of the mirror required in order to put well in all the axis of the test apparatus are needed on the leveling feet, these are 4, 2 fixed ahead of, realized with the simplest of wooden blocks fixed under the base and 2 mobile rear, made with the hex-head screws that thread on the holes made on the basis. Acting on the heads of the screws are unable to change the inclination of the entire support making it easy for the orientation of the return light cone towards the Ronchi grating.
Once assembled all, the mounting of the mirror will take place in the following way:
disassembly will be proceeding in exactly the reverse manner with respect to that reported.
The dimensions of course depend on the diameter of the mirror that you are working, and then every one adapt the dimensions of the individual components depending on the own needs. In this regard will hereinafter be inserted a picture showing the maximum size of the structure as a function of the diameter of the mirror:
As you can see from the figure, you can build a single support capable of supporting different diameter mirrors, just make more holes in the structure to “A”, which will serve for the passage of screws and bolts required for fixing the lower supports. By changing the positions of the latter it is possible to support different sized mirrors and therefore the measures listed above in the drawing will be referred to the mirror with a maximum diameter which is intended to be mounted on such a structure.