What is it about?

Calibrex combines in a single module 42 mm thick, a calibration system and a slot tracking system compatible with UVEX 3, all in 3D printing.

3D model of the Calibrex case here in red assembled with the UVEX 3 in gray.

UVEX claims to be an easy to build instrument. It uses 3D printing for mechanical production and uses standard components that can be purchased from companies like ThorLabs (for mirrors, the network, the lens). At the origin of the project, UVEX is perfectly integrated into the Shelyak Instrument system, the slot, the guide cube and the calibration box are those proposed by the company for the ALPY 600 spectroscope. UVEX being a low cost DIY project (Do it Yourself), it was natural to offer a Guidance and Calibration system in 3D printing, only the remaining slot to order from the company Shelyak.

In situation, UVEX 3 + Calibrex, installation on a C11, Zwo Asi 178MM guide camera.

Thus was born the Calibrex project which offers a single compact box which combines the functions of slit guidance and calibration with Argon / Neon lamp (lamp present in choke blocks for fluorescent tube) and a Tungsten lamp.

Model n ° 2 which equips the ALPY600 spectroscope in Basic version, installed on the 3D printing support of the UVEX 3.
Neon / Argon lamp present in the ignition choke of fluorescent tubes. These starters for a few euros provide a good light source necessary for the calibration of the spectra.

L’attribut alt de cette image est vide, son nom de fichier est guidage_fente_atlas-C2019y4.jpg.
Image of the guidance, Comet field C / 2019 ATLAS Y4 April 04, 2020 – C11 + Calibrex – Camera ASI ZWO 178MM 2s of 4×4 bin pose.
Spectrum of the internal neon calibration lamp in the caliber, 30s of installation UVEX 300 rpm + ATIK 314L + bining 1×1

The electronics are based on Arduino Nano which contains a microcontroller for flash memory and a mini USB port. The lamp control program is therefore saved in the arduino. The control of the lamps and the tilting of the reflector is carried out either by direct control via a switch on the side of the box, or by software via a dedicated ASCOM driver, filter wheel type driver.

Under the hood, on the left the Arduino Nano, the transformer, the connectors, on the right the servo motor with the paddle before mounting as well as the Relco lamp. Note the white circular arc mounted on the servo motor allows to obscure the telescope field during calibration. Here you have to paint it black and keep white a central area of ​​a few millimeters in the center. This simulates the opening of the field at F8. Thus the lines of the lamp of the calibration lamp are thinner which gives a more precise calibration.

A switch on the side of the box selects the remote mode, and the manual mode. In remote mode the switch is deactivated, the command is made exclusively via the CALIBREX USB port. The clear position allows to realize the spectra of the targets as well as the autoguiding, in neon position the ArNeon calibration lamp is on and the palette obscures the beam of the telescope, for the flat position the tungsten lamp is on, and finally in closed position no lamp is lit but the palette obscures the field of the telescope.

Ascom filter wheel driver – ASCOM.Spectro for controlling calibration lamps

From the Ascom driver, you can control the Calibrex box remotely, making it compatible with Remote mode. The advantage of diverting a filter wheel driver and being able to automate the alternation between object spectrum and calibration sequence acquisition in the same way as a three-color imaging sequence via the software automation interface. acquisition of the Prism or MaximDL type.

Boite de dialogue sous Prism qui permet de contrôler l’activation des lampes de calibration du CALIBREX.
A team effort, the Nice people, from left to right, Stéphane Ubaud, Alain Lopez, Jean Luc Martin, and Pierre Dubreuil.

This Post Has 2 Comments

  1. Willie Buning

    Hello, Bonjour.

    Is there a forum or Q&A part, for building the Calibrex Unit.
    I think I was reading somewhere , that the source code for the ASCOM controller is available is this true?

    with kind regards.

    Willie Buning.

    1. Stephane Ubaud

      Non le code source du driver n’est pas disponible actuellement, il est possible qu’on le diffuse plus tard 😉

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