If holes are drilled with large diameter in solid wood, the best results are achieved in a stationary application. We at FAMAG mean by large diameters holes which are larger than 60mm.
A classic tool for freehand application is the Forstner bit. If you look at the delivery programme of various manufacturers you will notice that the traditional length is 90mm and the largest diameter is 50mm. Why is that so?
With increasing bore diameter grow also the advancing forces. Must be a applied a very large advancing force, the human muscle power is often no sufficient. By Classic Forstner drills is the feed force by diameter 50 mm already so high –especially by hardwood- that the manufacturer decided: more is not possible! In practice, this constitutes so that the Forstner Bit just will not really drill into the wood. In this application, undesired friction forces caused the heat and let the tool wear out at an early stage.
The feed forces by our Bormax and the TCT-Bormax³ are significantly lower, we manufacture these tools up to 60mm and with a length of 90mm. Try it out you will be amazed, because that really works freehand still very good.
But if you want make really big holes freehand: we recommend this „little „trick:
By the way the FAMAG counterbores are available from 85 mm with a hexagonal shank of 13mm.
This means that these tools can extend well with the FAMAG extensions of the series in 1639. WE produce them in a total length of 125,250 and 400mm.
All extensions have 4 clamping screws (offset by 120° mounted) and the shaft of the extension 3 clamping surfaces. This means that these extensions can be combined well and have very good concentricity properties in these combinations.
With this application, holes can be made up to a diameter of 100mm freehand in softwood and laminated plates comfortable. Please note, however, that larger forces occur here on the machine and your wrists. Please use a powerfull machine which should also have a solid handle.
