Precision linear motor tables available in aluminum
MMG Mini-Mag line of precision linear motor tables from Dover are available in aluminum-based versions with an optional single phase motor to reduce controller complexity, system footprint and cost. Technology enhancements also enable operation in a vertical orientation without requiring a counterbalance, functionality that is for precision imaging applications. Original steel-based Mini-Mag versions are also available for use in more demanding application environments.
“The Dover MMG stage combines the advantages of proprietary direct drive linear motor technology with a uniquely sized and extremely compact 81mm x 93mm footprint to deliver the ultimate motion building block for high throughput imaging applications,” says Lou Elias, Regional Manager, Dover. “Additionally, the MMG delivers excellent mechanical and servo stiffness to optimize motion for the three basic phases of automated imaging applications – sample positioning, focal plane definition, and frame capture.”
For XY sample positioning, sustained throughput of up to 2,000 moves per minute is possible. For focal plane definition, the optimum Z position of the magnifying objective is determined, and the vertical objective positioning moves (<5um) are often accomplished in <20ms, which can occur in parallel with the XY positioning motion. During frame capture, in-position stability is vital to producing quality images, and MMG provides position stability typically less than 100nm.
Four options, with 25mm, 50mm 100mm or 150mm travel, are currently available. The MMG provides accuracy ranging from 2um to 8um and resolution options ranging from 1.0um down to 5nm. Each model is capable of repeatability to ±0.4um (with 0.1um or better encoder) and is rated for 8kg load capacity.
One of the Mini-Mag’s most significant features is an Integral anti-creep linear guideway. This can increase uptime by as much as 15% in high duty cycle applications by eliminating the need for homing moves typically required to reset standard crossed roller bearing retainer cages. These stages also feature adjustable limits to reduce the time needed to make changes to stage travel, thus reducing prototype development time and system startup costs by up to 10%.
An integrated advanced feedback mechanism enables exceptional uncompensated accuracy. This encoder eliminates the need for compensation tables or slope correction factors, thus lowering software and integration complexity and implementation time. Operation of the single phase MMG in a vertical orientation is possible with loads up to 0.25kg. Higher loads can be accommodated with the standard “Z” axis counterbalance option kit.
MMG stages leverage Dover single and three-phase brushless motors to enable control with various OTS drives and controllers, and deliver up to 20% greater throughout compared with piezo-driven actuators. No specialized piezo or proprietary motor/drive technology is necessary.
The MMG stage can be used in constant velocity (CV) or high throughput point-to-point applications, allowing common units to be used. For OEMs, this lowers Bill-of-Material (BOM) costs while reducing and simplifying their unique parts count. Their precise performance, short lead times and lower cost of ownership make them ideally suited for use in life science and clinical diagnostic instruments. They are also well suited for use in OEM Metrology applications and photonics/laser machining applications.
– Edited by Gust Gianos, Control Engineering, www.controleng.com