Material removal rate tells you how much material is being removed per unit of time. It is useful for comparing tool performance, estimating cycle times, and spotting process problems. I calculate MRR on every new job to establish a baseline. I track MRR for each job and compare it to the baseline over time. A 20% decrease in MRR indicates tool wear or a process problem. A sudden drop often catches issues before the tool breaks. ...
Tool change time on a deep hole drilling machine gets overlooked because the drilling cycle itself is long. A typical BTA drilling cycle might run five to fifteen minutes, so a three-minute tool change seems insignificant. But add up thirty tool changes per shift across three shifts and suddenly you are losing 4.5 hours of spindle time per day. Quick-change tooling addresses exactly this hidden productivity drain. The Cost of Conventional Tool Changes On a standard machine, changing a gun drill or BTA drill head involves stopping the spindle, retracting the tool past the guide bushing, loosening set screws or a drawbar mechanism, pulling the tool, inserting the new one, tightening, resetting coolant pressure, and restarting. I have timed this at 4.5 to 8 minutes for a competent operator on a typical machine. ...
Choosing between a dedicated deep hole drilling machine and using a standard CNC machine depends on the volume and depth requirements. I have worked with both configurations across multiple shops and the answer is rarely a simple one-size-fits-all. Over the years I have developed a framework for making this decision based on production volume, depth-to-diameter ratio, and tolerance requirements. Cost Breakdown: Dedicated vs Standard Machine A dedicated deep hole drilling machine costs $150,000 to $400,000 new, but the purchase price is only the beginning. When I put together a full cost comparison for a shop considering this investment, I look at several categories beyond the machine itself. ...
I calculate cost per hole on every job, even quick quotes. Knowing the true cost keeps my pricing accurate and highlights where to improve. Here is my complete method for calculating deep hole drilling costs. The Five Cost Components Every hole cost breaks down into five components. The percentages vary by job, but the structure is the same. Component Typical Range What It Includes Machine time 50-60% Cycle time x machine hourly rate Tooling 15-25% Drill cost per edge + regrind cost Labor 10-20% Load/unload time x hourly rate Coolant 5-10% Coolant purchase + filtration + disposal Overhead 5-10% Facility, management, quality, utilities Machine time is always the largest component. Reducing cycle time has the biggest impact on cost per hole. I focus on machine time first when optimizing a job. ...
Estimating cycle time for deep hole drilling is straightforward if you break it into parts. I have been quoting jobs for over a decade, and the formula below has served me well across gun drilling, BTA, and ejector drilling. The total cycle time determines whether a job is profitable. Miss it by 20% and you either lose the quote or lose money on every part. Here is how I calculate it. ...