Danobat MTG XLD

The Danobat MTG XLD is the large-diameter MikroTurnGrind, a horizontal hybrid that hard turns parts up to 680 mm (26.8 in) and fine grinds within Ø260 x 350 mm (10.2 x 13.8 in). Danobat's summary of the horizontal hybrid, parts up to Ø260x350 mm in size, quotes this model's grinding envelope.

Two figures are surprising for a machine with that swing. Floor space is 7 m² (75 sqft), barely more than the 6.5 m² (70 sqft) of the MTG-100. And the spindle speed is 4,000 rpm, the same as the small model, where the comparable turning-only Mikroturn 100 XLD is listed at 2,000 rpm. Both figures are printed consistently in the metric and imperial tables. A chuck sized for a 680 mm (26.8 in) part will not in practice run at the full speed, so the usable speed for a given workholding set-up is worth asking about.

The table also carries a positioning row for this model: zero point clamping system. Danobat does not expand on it, but a zero point interface is the usual way to make a removable unit repeat its location, and the page says the grinding spindle can be assembled and disassembled in two minutes.

As on every MikroTurnGrind, turning does the bulk of the work and grinding finishes the surfaces that need it, in one clamping. Stated workpiece results are dimensional accuracies of ≤ 2 µm, roundness of ≤ 0.5 µm and 0.1 – 0.2 µm (Ra). The hydrostatic main spindle is guaranteed to a runout error of ≤ 0.1 µm and the guideways hold 1 µm positioning and 0.2 µm repeatability. Base and spindle housing are natural granite with an integrated vibration-dampening system.