CNC: CNC machining – is scrap getting you money ?
Do you ever include the scrap cost in your calculations of machining cost ? Sometimes the money that you make from selling scrap can be more than the machining cost, typically for expensive metals. I’ve heard of a weird situation where a job shop paid the customer to turn parts, instead of being paid.
This picture is a screen shot from Cadem CAPSturn, showing actual machining costs for a part being machined in a job shop that uses CAPSturn. The negative machining cost indicates that more money is made from selling scrap than has been spent on machining. If you’re a job shop and are quoting for a part with a lot of material to be removed, your quote MUST take into account how much money you’ll be making by selling the scrap. Else your quote will be higher than it can be, which means you might lose out to a competitor.
Calculating the machining time, machining cost and scrap cost can be a challenge, but a lot of people do this using spreadsheets and formulae. You can do this, or you can depend on a shop floor programming software like CAPSturn CNC lathe programming software that does this for you – it is a very easy to use and affordable CAD/CAM software. Either way, please do consider this important element of machining cost.
Mumbai – Monsoon Blues
This monsoon I happened to see Mumbai from the air, and saw a sea of blue. The colour is from the blue tarpaulin used to protect homes from Mumbai’s heavy rains.
It’s not only ordinary homes. It appears that the rains do not even spare the world’s costliest home, Mukesh Ambani’s Antilla – (27 stories, 4 Lakh sq ft, 3 helipads, parking for 160 cars, 50-seater movie theatre, requires 600 staff for maintenance and running). This picture is from a couple of years ago, when (reportedly) the newly-built home was found to be leaking in numerous places.
Staying in a hotel in Powai, I also happened to see a very green side of Mumbai that I’ve never seen before.
Powai – sunny gap in a monsoon day
I only recently learnt that the colour of tarpaulin indicates its grade – e.g., blue indicates a lightweight tarp while silver is a heavy-duty tarp. The colors, their grades and approx. thicknesses are : Blue – light-duty – 0.14 mm, Yellow/Orange – medium-duty – 0.19 mm, Green – medium-duty – 0.24 mm, Silver – heavy-duty – 0.29 mm, Brown – super-heavy-duty – 0.41 mm.