Buying-Guide

Buying your first deep hole drilling machine is a significant investment and a major step for any shop. I have helped several shops make this purchase, and I have seen both good decisions and expensive mistakes. The key is matching the machine capability to the work you plan to do while leaving room for growth. Capacity Planning for Your First Machine The most common mistake I see is buying a machine that is too small. Shops focus on the first job they have lined up and buy a machine that barely handles it. Six months later, they turn down work because the machine cannot handle larger diameters or deeper holes. ...

Buying a used deep hole drilling machine is a common way to save money. I have bought and sold several used machines over the years, including a 1995 gundrill that ran for another eight years after purchase and a BTA machine that needed a full spindle rebuild within six months. The difference between those two outcomes was the inspection process. Here is the checklist I use. Spindle Inspection The first thing I check is the spindle. I listen for bearing noise during a test run at multiple RPMs. A quiet spindle with smooth operation is a good sign. A rumbling or grinding sound means bearing replacement, which costs $5,000 to $15,000 depending on the spindle size and whether the replacement includes a new bearing cartridge or requires a full rebuild. ...

Machine spec sheets list dozens of numbers. Not all of them are equally important. Here’s how I read a spec sheet and what I focus on. Critical Specs These specs determine whether the machine can do the job: Drilling diameter range. The minimum and maximum diameter the machine can drill. The effective range is narrower than the spec range because tooling availability limits the actual range. Drilling depth. The maximum depth the machine can drill in one pass. This is determined by the feed axis travel and the drill tube length. ...

Machine spec sheets for deep hole drilling machines are written by marketing departments. Some numbers are meaningful indicators of real performance. Others are chosen to make the machine look better than it is on paper. I have evaluated a dozen deep hole drilling machine brands over twenty years, and I have learned which specs predict actual drilling performance and which ones are just numbers on a page. Here is how I separate the two when I read a spec sheet for a deep hole drilling machine. ...

I get asked pretty often by shops that are thinking about buying their first deep hole drilling machine — especially after they land a job like EV motor shafts or mold cooling channels. The question is usually: what should I buy? The answer depends on the work, the volume, and the budget. But there are some patterns I’ve seen across dozens of shops. Start With the Parts The single biggest mistake I see is buying a machine first and figuring out the parts later. The machine needs to match what you’re actually going to drill. ...

When I look at a deep hole drilling machine — whether for purchase or for a specific job — I check certain features that tell me whether the machine is capable of producing good holes consistently. Here’s what I look for. Spindle Condition The spindle is the most important component. I check: Runout at the tool interface. Should be under 0.005mm TIR for a good machine, under 0.01mm for an acceptable machine. Bearing noise. A quiet spindle has good bearings. A rumbling spindle needs bearing replacement. Speed range. The spindle should reach the speeds needed for the diameters you’ll drill. A machine with a 6000 RPM max is limited to drills over about 3mm diameter. Coolant union. Check for leaks at the rotating union. A leaking union means pressure loss at the tool. Coolant System The coolant system determines whether the machine can clear chips effectively. I check: ...