In this article, we’ll cover:
- What is gang drilling and why this type of drilling is different from a single drill press.
- The 4 steps to upgrading your single drill into a gang drill, including how to choose the right equipment.
- Workshop safety and how to make sure your machine can handle the workload.
In the world of high-volume manufacturing and busy shops, the single-spindle drill press is often the most significant bottleneck on the floor. While reliable, the manual process of drilling one hole, repositioning the part, and drilling again—or worse, changing tools for a secondary tapping operation—wastes valuable time and introduces the potential for human error.
If you are looking to scale your production without the massive capital expenditure of a fully custom automated machine, the solution lies in gang drilling. By integrating high-performance components, you can transform a standard machine into a multi-hole powerhouse.
What is 'gang drilling'?
Industry terminology defines gang drilling as multiple drilling operations performed in sequence or in a specific pattern. This can be achieved through two primary configurations:
- Sequential stations: Multiple separate drilling units (like the AutoDrill 2000 Series) positioned in a line, each with its own motor.
- Simultaneous patterns: A single machine spindle driving a Multi-Spindle Head to drill several holes at once.
While a standard multi-spindle head drills identical holes in a fixed pattern, true gang drilling often involves moving a part from station to station to perform progressive operations like drilling, reaming, and tapping.
Step 1: Choosing your multi-spindle setup
The fastest way to upgrade your drill press or mill is by adding a multi-spindle head. These heads attach to your machine’s spindle through standard interfaces like Morse Taper (MT), Jacobs Taper (JT), or R8 Taper adapters.
Adjustable spindle heads for versatility
If your shop handles varied jobs with different hole patterns, Adjustable Heads (such as the MS2, MS3, or MS4 models) are the ideal choice.
- Capacity: They can support 2 to 4 spindles.
- Constraint: They are limited to equally spaced holes, such as bolt circles or straight lines.
- Adjustment: Spacing is adjusted by loosening hex acorn nuts and sliding the spindles to the desired center-to-center distance.
Fixed spindle heads for dedicated production
For high-volume repeat production where the pattern never changes, Fixed Heads are superior.
- Custom patterns: They can handle any irregular pattern you require.
- Density: Spindles can be placed as close as 0.532 inches center-to-center (or closer depending on your pattern).
- Scale: While 4 spindles are common, these heads can be engineered for 300+ spindles if the machine's thrust allows.
Step 2: Selecting the right drilling unit
If your drill press isn't up to the task, or if you want to build a dedicated gang drilling line, you need independent drilling units. AutoDrill offers three primary series based on the material and hole size:
1000 Series: The fast and consistent choice
This is the standard recommendation for most manufacturing applications.
- Thrust: Up to 100 lbs.
- Materials: Excellent for wood, plastic, aluminum, and and brass.
- Speed: Two Electric Motor options, 1800 or 3600 RPM (vertical use only).
2000 Series: The general purpose workhorse
This is the standard recommendation for most manufacturing applications.
- Thrust: Up to 500 lbs.
- Materials: Excellent for wood, plastic, aluminum, and mild steel.
- Speed: Capable of up to 6000 RPM (single spindle).
5000 Series: Heavy-duty operations
When you are working with structural steel, cast iron, or holes larger than 1 inch, you need the 5000 Series.
- Thrust: Up to 1500 lbs.
- Customization: Features a Morse Taper 2 (MT2) female spindle that can be adapted to almost any tooling requirement.
Step 3: Mastering feed control and precision
A "gang drill" is only as good as its hole quality. Standard pneumatic feeding can be "jumpy," especially during breakthroughs. This is where HydroSpeed technology becomes essential.
HydroSpeed is a hydraulic feed control cylinder that provides:
- Cleaner breakthroughs: Prevents the drill from lunging through the material, which reduces burrs.
- Extended tool life: Maintains a consistent feed rate, reducing shock to the drill bit.
- Specialty cycles: You can add SkipFeed to fast-traverse through air gaps in multi-wall tubes, or PeckFeed to clear chips in deep-hole applications.
Step 4: Adding tapping capabilities
To truly turn your press into a turn-key station, you should incorporate tapping. AutoTap units utilize a Tapmatic-style self-reversing mechanism.
- How it works: The axial motion of the machine triggers the reversal. When you push down, it cuts the thread; when you pull up, it automatically reverses at a 1.75:1 or 2:1 speed ratio to back out quickly.
- Drill press conversion: This requires a torque bar installation to prevent the tapping head housing from rotating.
Engineering check: Can your machine handle it?
Before you install a 4-spindle head on your existing drill press, you must calculate the Total Thrust Required.
- The formula: Total Thrust = Single Hole Thrust × Number of Spindles.
- Example: Drilling four 1/2" holes in Aluminum requires 180 lbs of thrust per hole. 180 × 4 = 720 lbs total.
- Limit: If your machine or drilling unit (like the 2000 Series) is only rated for 500 lbs, this operation is not feasible without upgrading to a 5000 Series unit (1500 lbs).
Critical speed limits
When using multi-spindle heads, there is one "no exceptions" rule: Maximum 4000 RPM. Because these heads use internal hardened steel helical gearing, speeds above 4000 RPM create excessive heat that will cause premature bearing and gear failure in most cases.
If your application requires higher speeds (like 6000+ RPM for small holes in aluminum), AutoDrill recommends a Dual-Drive or Triple-Drive configuration. This custom setup uses one motor to drive multiple separate 2000 Series units, allowing each to run at its maximum rated speed.
Build your production line today
Transitioning from a single drill press to a gang drilling system doesn't require a factory overhaul. By selecting the right series of drilling units, adding precision HydroSpeed control, and utilizing multi-spindle heads, you can multiply your output overnight.
Whether you need a simple 2-spindle adjustable head for a drill press or a custom 20-spindle fixed head for a dedicated fixture, the components are available to make it happen and AutoDrill can help. Contact us today!