You have recently started a new job as a manufacturing engineer for a machining company. As part of your new job, you have been asked to provide a recommendation on how to improve one of the existing turning operations. Specifically, you have been asked to recommend which type of turning inserts should be used in an external turning operation where the part is $400mm$ in length and $88mm$ in diameter. Based on the desired part geometry, you know you have a choice between either a brazed insert tool that the company already uses or a more 'disposable' insert tool, both of which are made from cemented carbide.

From your online research$/$shopping you have determined that each of the brazed insert topls will cost the company $$42\mathrm{.}00,$ while the disposable inserts $($which have four cutting edges per insert$)$ will only cost $$7\mathrm{.}00$ per insert. You also know that the Taylor tool$-$life parameters for this grade of cemented carbide are $n=0\mathrm{.}25$ and $C=300(\frac{m}{m}in).$

By talking with the machine operators in the shop, you learned that they typically use a feed of $0\mathrm{.}26m\frac{m}{r}ev$ for cemented carbide inserts. Based on their experience, they also said that it would probably take $2$ minutes to load and unload the work, $2\mathrm{.}7$ minutes to change out one of the re$-$grindable tooling, but only $1$ minute to change out one of the disposable inserts. For the brazed tool, they shared that it could make around $16$ parts before it needed to be scrapped. If you wanted to regrind the brazed tool cutting edge, they also warned you that you should probably allot $6$ minutes for the operation to be performed.

You also asked your supervisor for operational costs. They shared that occupying$/$using the lathe for this turning operation costs the company $$\frac{21\mathrm{.}00}{h}r$ and the tool re$-$grinding cost the company $$\frac{19\mathrm{.}00}{h}r.$

$(6$ pts$)$ First, using the above information, $($a$)$ you should list all of the variables$/$parameters that you use in evaluating the different tool types.

$(40$ pts$)$ Next, for each tool type you should report the $($b$)$ cutting speed for the minimum production cost, $($c$)$ expected tool life that minimizes production cost, and $($d$)$ cycle times and costs per unit of production.

$(40$ pts$)$ For each tool type, you should also report the $($e$)$ cutting speed for the minimum production time, $($f$)$ expected tool life that minimizes production time, and $(g)$ cycle times and costs per unit of production.

$(14$ pts$)$ This information will help you provide a thorough recommendation of which tool should be used to your impress your supervisor. Which tool would you recommend when trying to minimize cost and why? Which tool would you recommend when trying to minimize production time and why? What is your final tool recommendation for the shop and why?