WS39 casing tooth
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B47K22 bullet toothHunan · Site support & custom coring tools
From on-site support to a custom 1.6 m coring system
DRILLNOVA · Field report · Updated
DRILLNOVA helped replace another supplier’s roller bits on the customer’s 1,500 mm barrel, guiding positioning and welding on site. The customer later ordered a new, taller 1,600 mm barrel and a separate core-recovery tool for a different project.
See the on-site work
The starting point: problems with the customer’s existing tools
The original site used a Sany 405R, with a 1,500 mm pile diameter and nominal 1,500 mm core barrel. The site note describes grey-white granite, moderately to slightly weathered, with many piles starting at or close to rock level. It quotes an average rock-socket length of about 10 m for the project.
Rock encountered at the original site
The barrel and roller bits already on site were supplied by another manufacturer. After experiencing fractured legs and other cutter problems, the customer asked DRILLNOVA to assess the setup. We arrived with replacement roller bits and checked every existing cutter position, the barrel opening and the retained shell.
The project’s average rock-socket length describes the ground conditions; it is not the service life of a roller-bit set.
Original non-DRILLNOVA bits: twelve-position inspection
What the twelve-position inspection found
On the customer’s original, non-DRILLNOVA roller bits, we recorded fractured legs at positions 2, 5 and 11, with varying insert breakage at the other positions. Numbering the photographs kept each finding tied to the actual cutter seat. It gave the replacement discussion a defined list of damaged positions, rather than a general description of a worn barrel.
These are different cutter positions in the same survey before roller-bit replacement, not before-and-after performance photographs.
The measurements that changed the fitting plan
The existing ring measured 1,417 to 1,425 mm across the opening. This 8 mm spread describes the worn tool’s condition, not a fabrication tolerance. Replacement fitting needed those actual measurements.
The 250 mm-long ring had a recorded 40 mm wall; three spiral guides measured 18–20 mm in height. Together with the cutter survey, these dimensions defined work on the ring, cutouts, scrapers and guides as well as the replacement roller bits.
On-site support, shown step by step
The visit turned the survey into hands-on fitting support. We brought replacement roller bits and worked with the site crew on positioning, checking and welding the customer’s retained 1,500 mm barrel. The photographs and video below follow the actual work.
01 · Establish the reference and trial-fit the roller bits
The documented method used the measured maximum and minimum diameters, a straight steel bar and a marked centre reference to set the first inner and outer roller-bit positions. Checking the fit together with the welder made the intended position visible before it was fixed.
02 · Weld the mounting areas and recheck the setting
The old arrangement had a recorded embedment of 150 mm. The case-specific fitting plan proposed spacers and a 130 mm embedment, subject to the selected cutter drawing. The work combined seat preparation, the cutting path, angle and projection checks; the same references were used as fitting progressed.
0:25ORIGINAL SITE · WELDINGOn-site roller-bit welding · 25-second recordA continuous view of the welder working at the replacement mounting area. Original site footage, presented without audio.Watch video 
03 · Record the stage reached and the remaining scope
The record included the whole cutting end as well as individual positions. Cutout clearance, worn guides and the proposal for two additional scraper blocks remained part of the cutting ring assembly discussion.
View the original barrel and the end-of-day assembly record
What this support provided: a measured fitting reference, direct guidance for the crew and a documented replacement arrangement. Land clearance subsequently delayed the original project, so this barrel did not enter a follow-up drilling trial. The next stage of cooperation was the separate 1.6 m order below.
A taller barrel and a separate tool for large-core recovery
For the later project, the customer needed to recover a large-diameter core with a relatively small rig for the intended task. The question was how to plan the core length and recovery method around the available machine, rather than choosing a larger cutting diameter alone.
1. Increase the barrel height
DRILLNOVA developed a taller roller-bit core barrel to accommodate a longer core section for the proposed recovery approach. The barrel height was tailored to this application, rather than treated as a universal specification.
2. Provide a wedge-type core-recovery tool
A separate wedge-type tool formed the recovery part of the package. The workshop footage below shows the actual tool made for the later order.
0:11LATER ORDER · RECOVERY TOOLThe separate core-recovery tool · workshop viewA close view of the wedge-type tool supplied with the later order. This records the tool itself, not an on-site extraction test.Watch video For a similar requirement, the rig, intended core dimensions and recovery method need to be reviewed together. The original site record identifies a Sany 405R; the later 1.6 m order is a separate project stage.
The next project: a new 1,600 mm barrel
The customer returned to DRILLNOVA for a 1,600 mm roller-bit core barrel for a new pile diameter. The photographs show that later order during workshop welding and on the vehicle with the accompanying tool. This was a new tool for a new project, separate from the earlier 1,500 mm barrel repair.
LATER ORDER · 1,600 MM
The tooling supplied together
- Larger cutting diameter: a new 1,600 mm barrel for the new project.
- Taller shell: developed for the proposed longer-core recovery approach.
- Separate recovery tool: the wedge-type tool formed the recovery part of the package.
The photograph and workshop videos connect the agreed approach to the actual tooling made for this order.
0:21LATER ORDER · CORE BARRELThe taller 1.6 m barrel · workshop walkaroundThe cutting end, taller shell, spiral guides and connection end in one continuous workshop view.Watch video The follow-on order is the recorded commercial outcome: the customer continued working with DRILLNOVA after the site support and tooling discussion.
Measurement log: dimensions and all twelve positions
| Field | Original recorded scope |
|---|---|
| Average rock-socket length | About 10 m · project description |
| Pile-length notes | 10–20 m in the English note; 10 m to over 30 m in the Chinese note · ranges not reconciled |
| Rock description | Grey-white granite; moderately to slightly weathered in the Chinese note |
| Rock strength notation | “UCS 100 MPa+” in the site note · no laboratory test report supplied |
| Operating record | No numeric head-speed, feed-pressure or depth/time window attached to this survey |
| Item | Recorded measurement |
|---|---|
| Application / rig | G59 highway project; 1,500 mm piles; Sany 405R |
| Nominal core barrel | 1,500 mm |
| Cutting-ring measured diameter | 1,417–1,425 mm; 8 mm measured spread |
| Cutting ring length × wall thickness | 250 × 40 mm |
| Barrel shell length | 1,800 mm |
| Spirals | 3; recorded height 18–20 mm |
| Old cutter positions inspected | 12 individually numbered positions |
| Position | Recorded condition | Estimated insert breakage |
|---|---|---|
| 1 | Insert breakage | 45% |
| 2 | Fractured leg | — |
| 3 | Cone-body wear + insert breakage | 35% |
| 4 | Insert breakage | 90% |
| 5 | Fractured leg | — |
| 6 | Insert breakage | 70% |
| 7 | Insert breakage | 20% |
| 8 | Insert breakage | 90% |
| 9 | Insert breakage | 20% |
| 10 | Insert breakage | 80% |
| 11 | Fractured leg | — |
| 12 | Insert breakage | 90% |
Insert-breakage percentages are the survey’s visual estimates. The three fractured-leg positions are recorded separately. Project pile depths and rock-socket lengths are not metres drilled by this set.
Case-specific preparation and confirmation points
| Survey finding | Proposed work | Item to confirm before fitting |
|---|---|---|
| Cutting ring varies across measurements | Use maximum/minimum measurements to establish a shared centre | Reference the cutter layout to the agreed barrel centre |
| Old embedment recorded as 150 mm | Use spacers for a proposed 130 mm embedment | Check that case-specific proposal against the replacement drawing |
| Extensive broken inserts and 3 fractured legs | Review ground transitions, cutter placement and operating records | Keep position-specific findings; no single cause was established |
| Guide wear and clearing concerns | Prepare cutouts and consider 2 additional scraper blocks | Confirm cutout size, scraper clearance and welding plan |
The table preserves the original preparation and confirmation points. The team subsequently helped with positioning and welding on site; a separate final weld-acceptance record and follow-up drilling data are not included. No single cause of the damaged legs and inserts was established.