One decision that comes up in shops with multiple deep hole drilling machines is whether to use individual coolant systems or a central system. I’ve worked in shops with both setups, and each approach has trade-offs that depend on the number of machines, the type of work, and the shop layout.
Individual Systems
Each machine has its own coolant pump, tank, filter, and chiller. This is the standard configuration that most machine builders ship.
| Pros | Cons |
|---|---|
| Simple installation — no infrastructure planning | More equipment to maintain |
| Independent operation — one machine down does not affect others | Higher total equipment cost for multiple machines |
| Dedicated coolant for each machine — different mixes possible | More floor space required |
| Easy to isolate a machine for maintenance | More power connections and electrical infrastructure |
Individual systems are the standard configuration for most machines. They are simple and do not require infrastructure planning beyond a power connection and a drain line. I’ve found that individual systems also give you the flexibility to run different coolant mixes for different jobs — a water-based emulsion for steel work on one machine and oil-based coolant for aluminum on another.
The downside is the equipment cost adds up. A complete coolant system for a gun drilling machine — pump, tank, filter, chiller — costs $15,000-$25,000 per machine. For four machines, that is $60,000-$100,000 in coolant equipment alone.
Central Systems
A single coolant system serves multiple machines through a network of supply and return pipes. One large pump, one big tank, one chiller, and one filtration system handle all machines.
| Pros | Cons |
|---|---|
| Fewer total components to maintain | Complex installation with piping layout |
| Better filtration — larger system handles finer filtration | All machines affected if the system goes down |
| Lower total cost per machine at scale | Needs backup pump for reliability |
| Less floor space per machine — equipment is in one location | Coolant temperature harder to control across machines |
| Consistent coolant quality across all machines | Cannot run different coolant types on different machines |
Central systems are common in production environments with multiple identical machines running the same parts. I’ve seen a shop with six identical BTA machines running off one central system for years with no issues. The coolant was always at the right concentration, temperature, and cleanliness because the central system had better filtration and more consistent maintenance.
The main risk is a single point of failure. If the central pump fails, all six machines stop. That shop had a backup pump that switched on automatically — a necessity that added $8,000 to the system cost.
Hybrid Systems
Some shops use a hybrid approach: a central coolant supply with individual chillers at each machine. The central system handles filtration and concentration control. Each machine has its own chiller for temperature control.
I’ve seen this work well in shops where machines run different materials but the same coolant type. The central filtration system maintains consistent cleanliness. The individual chillers let each machine run at the optimal temperature for its specific job.
The hybrid approach adds complexity but solves the temperature control problem that pure central systems have. The cost is about midway between individual and central systems.
Installation Considerations
Individual system installation: Place the machine, connect power, connect water for coolant mixing, and start using it. The installation cost is minimal — typically $2,000-$4,000 per machine for electrical and plumbing connections.
Central system installation: Requires planning the piping layout, sizing the pump for the longest supply run, installing isolation valves at each machine, and commissioning the system. The installation cost is $20,000-$50,000 depending on the number of machines and the piping distance.
I installed a central system in a shop with five machines spaced 15 meters apart. The piping run required 100 meters of schedule 80 steel pipe, 22 isolation valves, and three weeks of installation time. The system worked well, but the installation was more involved than I had anticipated.
Cost Comparison
For a shop with four machines:
| Cost Factor | Individual Systems | Central System |
|---|---|---|
| Equipment cost | $80,000 ($20,000 x 4) | $50,000 (one large system) |
| Installation cost | $10,000 ($2,500 x 4) | $30,000 (piping, pumps) |
| Annual maintenance | $8,000 ($2,000 x 4) | $5,000 (one system) |
| Annual energy cost | $24,000 ($6,000 x 4) | $18,000 (more efficient pump) |
| 5-year total | $290,000 | $205,000 |
The central system costs about $85,000 less over five years for four machines. The savings come from lower equipment cost (one large pump vs four) and lower maintenance.
What I Recommend
For most job shops with fewer than five machines running different types of work, individual systems are simpler and more flexible. The cost premium is worth the independence.
For production shops with five or more identical machines running similar work, a central system offers significant cost savings and better coolant quality.
The most important factor is machine utilization. If the machines run at different times or on different parts, individual systems provide more flexibility. If all machines run the same parts on overlapping shifts, a central system makes more sense.
Key Takeaways
- Individual systems cost more per machine but offer flexibility and independence
- Central systems save money at scale but create a single point of failure
- Hybrid systems combine central filtration with individual chillers for temperature control
- Central system installation requires significant planning and $20,000-$50,000 in infrastructure
- A central system saves about $85,000 over five years compared to four individual systems