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DAVCO KB-45 Vertical Band Saw
- InvoiceĚý
- MaintenanceĚý
- User's ManualĚý
Oil Change
The reducer (model TKV60Ěý, p. 2 in the user’s manualĚý) needs an occasional oil change. Say, yearly. We use an extreme pressure (EP) gear oil SAE grade 85W-140, despite the user manual specifying “Shell Tellus oil 69” (see p. 11). The rational for our oil selection is provided below.
The reducer requires 660 mL of oil which, according to the reducer manufacturer, Ěý
, fills the gear box to about 3/4 of the fluid level sight. (Note that when you turn on the machine the oil level rises in the sight considerably and remains at the new level.)
Rational for choice of oil
Following a communication with the reducer manufacturer, we learned that the components are shipped pre-filled with oil. A sticker on the reducer indicates that “MOBIL GEAR 632” oil was used, which has the consistency of molasses. Often, machining equipment manufacturers alter the reducer oil specification in the user’s manual based on the actual load on the component; hence the specification of Shell Tellus 69. (Incidentally, Tellus 69 does not seem to exist and may be a typographical error.) Assuming that Shell Tellus 68 is the bandsaw manufacturer’s intended specification one sees that the oil type for the reducer has a wide range: Tellus 68 (ISO 68) is a much thinner oil than the Mobilgear 632 (6EP, ISO 320) originally in the reducer, not to mention that Tellus oil is a hydraulic oil and not even a gear oil!
Furthermore, the technician at Raymond Robert Ltd. mentioned that he typically uses the following worm gear oil “Industrial Gear Oil EP-7 ISO 460” for all gear boxes containing a worm gear. This shows a margin on viscosity.
According to Shell technical support, the EP additives in oil can attack certain metals when the oils reach temperatures of 90-deg Celsius. However, since the reducer initially was filled with an EP type oil this issue is not a concern.
As for our choice in oil: ISO grade 320 oil appears to be equivalent to SAE grade 140. Given that one could go as low as ISO 68 (SAE 20) the choice of EP 85W-140 gear oil seems to be a comfortable compromise. The chosen oil can also be purchased locally in several hardware stores.