Useful Information » NEW MODELS

 

We have the pleasure to present you our new models, loaded with new technologies, high precision with calibrated screws and servo motors:

• ATC models:  A737R, A736R, A637R, A636R, A537R, A536R, A437R, A436R
• MTC models: A732R, AA731R, A632R, A631R, A532R, A531R, A432R, A431R.

Calibrated screws models with servo motors have the following accuracy specifications:

• Absolute accuracy:  7.5 μm @ 254 mm (0.3 mil @ 10 inch)
• Positioning repeatability: 1.5 μm (0.059 mil)
• Internal resolution: 0.1 μm (0.0039 mil)

IIn order to achieve the accuracy mentioned above, all new models are equipped with thermal compensation:

• for the screws
• for the material under machining on all models

All software and firmware components of our systems are under complete control of our updates and improvements.p>

• PhCNC™ our control and CAM software
• PhPhCNC440™, the firmware of our CNC controllerspan>
• PhACdrive™, the firmware of our AC/BLDC spindle drive
• PhSTdrive™, , the firmware of our X,Y,Z intelligent stepper drives

 

A complete list of our models: System selector

Model	Table Size	Work envelope XYZ	Tool change	Tool Calibration	Positioning system	Spindle speed [rpm]	Tool holders
A737R	Extra Large	23.0x15.0x1.3 inch 584x381x33 mm	Automatic	Automatic	Servo control	100,000	23
A736R	Extra Large	23.0x15.0x1.3 inch 584x381x33mm	Automatic	Automatic	Servo control	62,000	23
A637R	Large	16x11x1.3 inch 406x279x33 mm	Automatic	Automatic	Servo control	100,000	16
A636R	Large	16x11x1.3 inch 406x279x33mm	Automatic	Automatic	Servo control	62,000	16
A537R	Enlarged	15x9x1.3 inch 381x229x33 mm	Automatic	Automatic	Servo control	100,000	16
A536R	Enlarged	15x9x1.3 inch 381x229x33 mm	Automatic	Automatic	Servo control	62,000	16
A437R	Standard	12x9x1.3 inch 304x229x33 mm	Automatic	Automatic	Servo control	100,000	12
A436R	Standard	12x9x1.3 inch 304x229x33 mm	Automatic	Automatic	Servo control	62,000	12
A732R	Extra Large	23.0x16.2x1.3 inch 584.2x411.5x33 mm	Semi-Automatic*	Automatic	Servo control	100,000	N/A
A731R	Extra Large	23.0x16.2x1.3 inch 584.2x411.5x33 mm	Semi-Automatic*	Automatic	Servo control	62,000	N/A
A632R	Large	16x12.2x1.3 inch 406x310x33 mm	Semi-Automatic*	Automatic	Servo control	100,000	N/A
A631R	Large	16x12.2x1.3 inch 406x310x33 mm	Semi-Automatic*	Automatic	Servo control	62,000	N/A
A532R	Enlarged	15x10.2x1.3 inch 381x259x33 mm	Semi-Automatic*	Automatic	Servo control	100,000	N/A
A531R	Enlarged	15x10.2x1.3 inch 381x259x33 mm	Semi-Automatic*	Automatic	Servo control	62,000	N/A
A432R	Standard	12x10.2x1.3 inch 304x259x33 mm	Semi-Automatic*	Automatic	Servo control	100,000	N/A
A431R	Standard	12x10.2x1.3 inch 304x259x33 mm	Semi-Automatic*	Automatic	Servo control	62,000	N/A

* manual tool change, prompted and fasilitated by the software

 

All models are equipped with precision linear gauge for tool penetration control (our CAST™ control) maintaining the desired tool penetration within the resolution of 1μm (0.039mil) in reference to the material surface.

 

All of our systems are made in US, using local high quality materials and components.

 

There is no other (LPKF, MITS, T-TECH, ...) offer on the market currently that comes even close to the accuracy and precision that our models offer!

 

 

Thermal compensation, calibrated screws, linear encoders

We are showing below the typical calibration graphics of a high quality lead screw (similar lead screws are used by all manufacturers/competitors in this business).
The graphics shows the absolute positioning error along the length of the screw.
It is visible that the error consist of two components:

• error from the screw by it self, related to the production of the screw and nonlinearity of the driving motor (we will call this - screw error)
• screw thermal expansion error

Most of the screws specifications are given at 68 °F (20 °C), but actually they never work at this temperature. In fact different axes has different screw temperatures etc. all related to the particular machine design.

Absolute positioning errors at 36°C(97°F) & 20°C (68°F)

 

As it is seen on the graphics both error components affect the accuracy differently:

• The screw error affect mostly small distance movements and may reach 25 μm @ 2.54 mm (1 mil @ 100 mil). It is quite logical that it has repeat equal to one screw turn.
• The thermal expansion error is quite linear and affect the accuracy in the long distance movements. Here it reaches 110 μm @ 381 mm (4.3 mil @ 15 inch)

The material under machining also has its own thermal expansion that has to be compensated in order to achieve maximum accuracy at desired temperature.

We resolve the problem with linear encoders mounted temporary during the production cycle of the system. A calibration procedure is applied and it records the difference (the error) of the screw compare to the linear encoder. The process that we call "screw calibration" maps the differences every 0.01 inch and stores them in the flash memory of our PhSTdrive™. It is an intelligent stepper motor drive (DSP microcontroller based) that allows using servo feedback and/or dynamic real time corrections based on the screw calibration map.

This type of positioning system also shows incredibly high accuracy of less than 8 μm positioning error @ 254 mm (10 inch). It has the advantage that the cost of relatively expensive linear encoders is eliminated and the accuracy is still close to the first one.

We are taking in account all thermal expansion factors, such as screws temperature and material temperature. All factors related to the material under machining are settable by the operator.
After mapping the screw errors, we have eliminated the main sources of positioning errors and the thermal expansion appear to be the main factor to the final accuracy of the machined product.

 

Other Recommended Links:

► System selector
► Comparison table - machines with automatic tool change
► Comparison table - machines with manual tool change
► Optional equipment
► Myths and truths in PCB prototyping
► Our software versus others