The FRASTE ML MAX and FRASTE FS 250, two of the most capable geothermal drilling rigs on the market today. Both are built to perform. But which one belongs on your next job site?
Meet the Little Brother: FRASTE ML MAX
The FRASTE ML MAX is the Swiss Army knife of geothermal drill rigs. At just 7 feet wide and weighing in at approximately 19,000–19,500 lbs, this compact crawler rig punches well above its weight class. Powered by a Caterpillar C4.4 engine producing 148 HP at 2,200 RPM (EPA Tier 4 Final), the ML MAX was built for flexibility, accessibility, and speed.
What makes the ML MAX stand out in the geothermal drilling world is its 360° hydraulic slewing ring rotation. When you’re drilling a residential geothermal loop field in a tight suburban backyard, fenced in on three sides, with landscaping you can’t tear up, the ability to rotate the entire mast assembly a full 360° without repositioning the crawler is a game changer. Drillers working on subdivision geothermal systems know this scenario intimately. You’ve got ten bore holes to hit in a yard the size of a tennis court. The ML MAX lets you work efficiently without repeatedly breaking down and repositioning.
The rotary head delivers up to 5,232 ft-lbs of torque at 115 RPM, more than enough to push through unconsolidated soils, clay, and soft rock formations common in residential and light commercial geothermal bore fields. The mast handles 10-foot drill pipe and stores 40 rods on the rig’s automatic rod manipulator, keeping the operator safe and handling rod changes with precision. Pull-up force reaches 13,488 lbf and pull-down hits 10,790 lbf, solid numbers for a rig this compact.
Real-world ML MAX scenario: A geothermal contractor is installing a closed-loop ground source heat pump system for a 15-unit residential development. Each unit needs two 250-foot vertical bore holes through sandy loam and weathered limestone. The lots are small, access is tight, and the project manager wants minimal lawn disturbance. The ML MAX rolls in, plants its four independent hydraulic stabilizers, and rotates from bore to bore without ever needing to reposition the crawler on the trailer. Fast, efficient, and minimally invasive, exactly what the job calls for.
Meet the Big Brother: FRASTE FS 250
If the ML MAX is precision and agility, the FRASTE FS 250 is raw power and depth capacity. This is the geothermal drilling equipment you call when the project is large, the formation is hard, and you need to go deep. Powered by a Caterpillar C-7.1 ACERT 6-cylinder bi-turbo engine producing 275 HP at 2,200 RPM (Stage IV / Tier 4 Final), the FS 250 is in a completely different weight class.
The FS 250’s rotary head (Model R16D055) delivers up to 13,718 ft-lbs of maximum torque, more than double that of the ML MAX. The mast handles 20-foot drill pipe with a stroke of 25 feet 3 inches, and the pull-up force is a massive 31,500 lbs. The crawler carrier alone carries a rated load of 58,500 lbs and spans 8 feet wide. The rig features a Jib Boom with 180° hydraulic slewing and a telescopic arm, a thread-saving system to protect your drill string, and an angle drilling capability of up to 20° with memory positioning, critical for directional geothermal installations.
The mud system on the FS 250 is equally serious: a Bean/FMC E04 Quadruplex pump (21 GPM, 580 PSI) combines with a Tibban 3×4 centrifugal mud pump capable of delivering 238 GPM. This dual-pump setup is designed for the volume and pressure demands of large-diameter, deep geothermal drilling in challenging formations. The oil tank alone holds 144 gallons.
Real-world FS 250 scenario: A geothermal energy developer needs to drill a series of deep production wells, 600 to 900 feet through hard granite and basalt for a district geothermal heating system serving a university campus. The formations require significant rotary torque to penetrate, the project timeline is aggressive, and the contractor needs a rig that won’t flinch drilling large-diameter holes to serious depth. The FS 250 is on-site the next morning. With its 984-foot rated drilling capacity, high-torque rotary head, and dual mud pump system, it chews through hard rock that would stall a lesser machine.
What They Share: FRASTE Quality Across the Line
Despite their differences in scale, both rigs share the engineering philosophy and core features that make FRASTE geothermal drilling equipment world-class. Both feature the FRASTE Automatic Rod Manipulator, the proven all-hydraulic pipe handling system that keeps operators away from the pinch points and dramatically reduces fatigue on multi-hole projects. Both are equipped with double hydraulic clamps, block valves on all hydraulic cylinders for enhanced safety, four independent hydraulic stabilizers, integrated Caterpillar compressor units, and 12,400-lumen LED lighting systems for night drilling. Both comply with the latest EPA emissions standards. And both come finished to Bore Logic’s professional specifications, ready to work the day they arrive on your job site.
So Which Geothermal Drill Rig Is Right for You?
The answer comes down to depth, diameter, formation, and access.
If you’re drilling residential or light commercial geothermal loop fields, working in tight urban or suburban environments, need 360° positioning flexibility, and your formations are moderate, the FRASTE ML MAX is your rig. It’s the most agile, site-friendly geothermal drill rig in its class.
If you’re tackling large commercial or industrial geothermal projects, drilling deep in hard rock formations, need maximum torque and pull capacity, or managing multi-well production fields, the FRASTE FS 250 is built for you. It’s the workhorse that doesn’t back down from the toughest geothermal drilling jobs on the planet.
Both rigs are available through Bore Logic. Contact us today to discuss which geothermal drilling equipment is the right fit for your next project.
