Damped boring bar in CNC turning – how does it help ?

Damped boring bar – what is it, and how does it help in boring ?

Damped boring bar - on the machine
Pic. source: Kennametal

A damped (also called tuned) boring bar has a hollow body with an inertia mass suspended between rubber bushes one at each end. The inertia mass is surrounded by a special oily liquid. When vibration starts, the dampening system absorbs the energy of the vibrations and minimizes it. Damped boring bars are used for high L/D ratios. This post talks about L/D ratios and reducing vibrations in boring.

Damped boring bar - internals
Pic. source: Sandvik

Damped boring bar - how damping works
Pic. source: Kennametal

Pre-tuned boring bars are adjusted to a particular L/D ratio (e.g., 10). If you want to use such a bar at a different L/D ratio, you have to re-tune the bar. Re-tuning basically means moving the internal inertial mass axially, done by rotating screws on the outside of the bar. You do this by actually taking trial cuts and rotating the screws by amounts specified by the manufacturer of the tool. Text source: Cadem NCyclopedia multimedia CNC training software. Machine monitoring system on Industry 4.0,CAD/CAM software,CNC Program Simulation,CNC Training Software


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Aloo Tikki and Aloo chaat on Delhi’s streets


One the ‘must do’ activities when I’m in Delhi is eating Aloo chaat and Aloo tikki on the footpath. These are some of the most popular items in Delhi’s repertoire of street food. Very tasty, and very easy to make. The Chaat and the Tikki are different things, but always go together because of the common raw material – potato.

The Tikki is a flat patty of mashed potato and onion (with spices like jeera, pepper and ginger), fried in a shallow pan. Served with tamarind and pudina (mint) chutney. The Aloo chaat is large pieces of potato, marinated in spices salted and fried on the same shallow pan as the tikki. It has a crisp outside and a soft inside. Served with a sprinkling of masalas, coriander leaves and lemon. You get a couple of toothpicks on the plate, and you skewer each piece of Aloo, pop it into your mouth, and attain heaven with each bite. I prefer the Chaat to the Tikki.

FAQs, and Answers:
1. Is this hygenic ? Answer: This is the street, remember ?
2. Is this healthy ? Answer: Ha, Ha, Ha !

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