Early Stage Researcher 1.1 Work Package 1 Claude SANZ Early Stage Researcher 1.1 Work Package 1 Magnet Nano-positioning system Manual pre-alignment system Stretcher CMM granite table Seismic sensor Wire going through the BPM and the magnet BPM

the SESHAT, the CMM & the Wire The SESHAT is the ‘Shape Evaluating Sensor: High Accuracy & Touchless’ The CMM is the Leitz Infinity Coordinate Measuring Machine The Wire is the PACMAN reference wire SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Requirements: - Hello, I am the SESHAT, I am looking for an infinite light – No, I am the Leitz Infinity, a Coordinate Measuring Machine… - wire enters: I am looking for a goddess of writing and measurements – There is only the SESHAT and me here. – yes, I am a sensor. Who are you? – I am the PACMAN reference wire, and it is indeed the Seshat I should find. You, the sensor, wear the name of the Egyptian goddess of wisdom, writing and measurement. – Well, it is rather good Where to go next? CMM: Coordinate Measuring Machine

the SESHAT, the CMM & the Wire PACMAN reference wire: CuBe, 100 µm in diameter, ~1.2 m long Form error SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Linear weight Tensile strength Reflectance Requirements: X-ray spectroscopy SEM observation 2.46 µm | 2.93 µm Micro-hardness AFM measurements Resistivity 2 µm Where to go next? SEM: Scanning Electron Microscope AFM: Atomic Force Microscope www.madrimasd.org NGK: 1.76 µm CMM: Coordinate Measuring Machine

the SESHAT, the CMM & the Wire Magnet Nano-positioning system Manual pre-alignment system Stretcher CMM granite table Seismic sensor Wire going through the BPM and the magnet BPM 700mm 1250mm SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Requirements: Requirements: -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> The requirements for the SESHAT: Maximum weight: 1.2 kg Low energy emission Maximum width: 100 mm Not disturb the wire Stand magnetic field Can be calibrated Maximum Permissible Error in positioning: MPEE[µm]=0.3 +L/1000 Where to go next? CMM: Coordinate Measuring Machine

The SESHAT’s Sensing element CMM & PACMAN requirements: Light Small Can stand strong magnetic fields Highest repeatability Measuring the form Do not disturb the wire Possible to calibrate Fitting with the CMM translation SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Sensors available on the market: Low force touch probes Eddy current probes Acoustic probes Optical sensors Interferometers Confocal chromatic (several providers) Shadow based Confocal Fringe pattern recognition Camera based Tunnel effect probes Capacitive Sensors available on the market: Low force touch probes Eddy current probes Acoustic probes Optical sensors Interferometers Confocal chromatic (several providers) Shadow based Confocal Fringe pattern recognition Camera based Tunnel effect probes Capacitive Requirements: -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> -> Stand magnetic field > 15 mT -> Can be calibrated Where to go next? CMM: Coordinate Measuring Machine

The SESHAT’s Mount for the chromatic confocal sensor The parts constituting the SESHAT: The chromatic confocal sensor A rotor A stator which can be linked to the CMM A rotary mechanical connection between the stator and the rotor Something mastering the rotor’s move Something giving information on the position with high accuracy SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning : aluminium is well modelled, cheap and easy to handle, rather light : with a three ball plate, in aluminium : a bearing : a motor : an encoder Requirements: -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> How to reach high Accuracy? Lowest random motion Highest stiffness for the assembly Low impact of the bearing surfaces Isostaticity (or reduced hyperstaticity) A well mastered move Reduced vibrations High damping effect Fitting Eigen frequencies Well known position and high accuracy positioning Reduced Abbe offset Accurate positioning of the rotor Air bearings: 12 pads, mounted on ball screws, opposite each other I just read that the bearings with lowest random motion error are the air pads – air pads? – yes, now you can find air pads made out of a porous media and they are stiffer. On top of this, they could go over the opening. – What opening? – Well, I will be stretched from both ends, so you will need to open your rotor in order to let me enter by the bottom – yes, you are right, this will not simplify our quest ! – OK, let’s take as many air pads as possible, to have a very stable and stiff motion – no, you should not, you will be hyperstatic – oh – yes, it induces stresses inside your body and you cannot know how to move properly, which frightens the accuracy. 12 pads: 4 pads with two opposite along y and z, arranged at 120° : a piezo motor High damping effect Where to go next? : the motor’s vibrations frequency should fit : the encoder is as close as possible to the sensor : the motor does nanometric steps CMM: Coordinate Measuring Machine

The SESHAT’s Mount for the chromatic confocal sensor The parts constituting the SESHAT: The chromatic confocal sensor An aluminium rotor An aluminium stator with the right plate Air bearing bringing high stiffness and high quality for the rotation A piezo motor fitting with the miscellaneous requirements A high accuracy encoder as close as possible to the sensor SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning The aluminium part of the stator should be stiff enough The air pads require very tight tolerances on form and surface quality: the form error should be less than 2.5 µm on the open rotor (due the air gap size of 5µm) The piezo motor requires a hard material to walk on: typically alumina ceramic The encoder has a minimum bending radius of 200 mm Requirements: The stator is quite large -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> The rotor must be open -> Stiffness The weight is higher -> Weight <1.2 kg -> Tight tolerances <2 µm A company must be able to reach these tolerances! I just read that the bearings with lowest random motion error are the air pads – air pads? – yes, now you can find air pads made out of a porous media and they are stiffer. On top of this, they could go over the opening. – What opening? – Well, I will be stretched from both ends, so you will need to open your rotor in order to let me enter by the bottom – yes, you are right, this will not simplify our quest ! – OK, let’s take as many air pads as possible, to have a very stable and stiff motion – no, you should not, you will be hyperstatic – oh – yes, it induces stresses inside your body and you cannot know how to move properly, which frightens the accuracy. 12 pads: 4 pads with two opposite along y and z, arranged at 120° The machine tool should make it An alumina ring must be inserted in the aluminium rotor and opened Where to go next? There is a high risk of breaking the ring with the motor Let’s have a look at the SESHAT! The rotor has a minimum radius The minimum weight is higher

The SESHAT’s Mount for the chromatic confocal sensor SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Requirements: -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> … -> Stiffness -> Width <100 mm I just read that the bearings with lowest random motion error are the air pads – air pads? – yes, now you can find air pads made out of a porous media and they are stiffer. On top of this, they could go over the opening. – What opening? – Well, I will be stretched from both ends, so you will need to open your rotor in order to let me enter by the bottom – yes, you are right, this will not simplify our quest ! – OK, let’s take as many air pads as possible, to have a very stable and stiff motion – no, you should not, you will be hyperstatic – oh – yes, it induces stresses inside your body and you cannot know how to move properly, which frightens the accuracy. 12 pads: 4 pads with two opposite along y and z, arranged at 120° Where to go next? **CMM: Coordinate Measuring Machine

The SESHAT’s Mount for the chromatic confocal sensor The parts constituting the SESHAT: The chromatic confocal sensor An aluminium rotor An aluminium stator with the right plate Air bearing bringing high stiffness and high quality for the rotation A piezo motor fitting with the miscellaneous requirements A high accuracy encoder as close as possible to the sensor SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Requirements: The weight is too high Weight optimization should be performed Stiff and light: Carbon and honey comb structure + peek The structure is larger than the maximum width allowed Peek is very unstable with temperature variations -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> … I just read that the bearings with lowest random motion error are the air pads – air pads? – yes, now you can find air pads made out of a porous media and they are stiffer. On top of this, they could go over the opening. – What opening? – Well, I will be stretched from both ends, so you will need to open your rotor in order to let me enter by the bottom – yes, you are right, this will not simplify our quest ! – OK, let’s take as many air pads as possible, to have a very stable and stiff motion – no, you should not, you will be hyperstatic – oh – yes, it induces stresses inside your body and you cannot know how to move properly, which frightens the accuracy. 12 pads: 4 pads with two opposite along y and z, arranged at 120° There is a high risk of breaking the ring with the motor The hard material should be very well bounded to the rotor For the prototype and the proof of concept, it will be plain alumina Where to go next? Optimisation is under process: 3D printed titanium or Scalmalloy with an alumina ring is being considered (Ti and Al2O3 behave similarly) CMM: Coordinate Measuring Machine

Where to go next… Check independently the parts constituting the SESHAT: The chromatic confocal sensor A rotor A stator with the right plate Air bearing bringing high stiffness and high quality for the rotation A piezo motor fitting with the miscellaneous requirements A high accuracy encoder as close as possible to the sensor Assemble the SESHAT prototype and proof the concept Measure the influence of the air pad’s air stream on the wire Find the optimal material and technique to lighten the SESHAT Adapt the sensor on the CMM Determine and apply the best method for the sensor calibration Determine and apply the integration strategy for using the sensor with Q7 Compare the results with the simulations being performed Understand the gap between the contact & non-contact from measurements SESHAT, CMM & Wire -> Shape Evaluating Sensor: High Accuracy & Touchless -> MPEE [µm]= 0.3+L/1000 -> CuBe Φ100 mm -> 3σ < 0.5 µm for the wire axis positioning Requirements: -> Stiffness -> Weight <1.2 kg -> Width <100 mm -> Tight tolerances <2 µm -> Hardness > = 1175 kg/mm2 -> Stand magnetic field > 15 mT -> Can be calibrated -> … I just read that the bearings with lowest random motion error are the air pads – air pads? – yes, now you can find air pads made out of a porous media and they are stiffer. On top of this, they could go over the opening. – What opening? – Well, I will be stretched from both ends, so you will need to open your rotor in order to let me enter by the bottom – yes, you are right, this will not simplify our quest ! – OK, let’s take as many air pads as possible, to have a very stable and stiff motion – no, you should not, you will be hyperstatic – oh – yes, it induces stresses inside your body and you cannot know how to move properly, which frightens the accuracy. 12 pads: 4 pads with two opposite along y and z, arranged at 120° Where to go next? CMM: Coordinate Measuring Machine

Thank you for your attention… Do you have questions? @ Deviant Art, Seshat drawn by Mme Kikue

PACMAN’s Reference Wire Choice of the wire provider   Good Fellow California Fine Wire company NGK Form error measurement 1 [µm] 22.47 1.37 1.44 Form error measurement 2 [µm] 1.74 2.31 2.75 Form error measurement 3 [µm] 2.88 2.39 2.10 Form error measurement 4 [µm] 3.37 2.89 1.56 Form error measurement 5 [µm] 3.79 2.00 1.85 Form error measurement 6 [µm] 8.17 2.08 1.82 Form error measurement 7 [µm] 1.26 1.47 Form error measurement 8 [µm] 0.96 1.25 Form error measurement 9 [µm] 1.88 3.50 1.38 Form error measurement 10 [µm] 1.52 5.53 1.48 Mean [µm] 2.93 2.46 1.76 Standard deviation [µm] 2.04 1.23 0.39 The environmental noise measured on the same day as these measurements had a standard deviation of 81 nm.

Choices of sensor and wire providers

The SESHAT and the Quest of the Accuracy The result of a partnership