What are the fundamental differences between T4 and T5 hydraulic coring machines?
In basic terms, the T5 is the bigger heavier brother of the T4. And the T5 better suited to higher volume applications of coring work.
See video link of one of our customers iDrill using a T5, and see the notes in the video detailing all of the coring actions.
https://www.youtube.com/watch?v=DV7YO-euTfM&t=46s
T4
The Xcalibre T4 is less than 750 Kgs, when fully loaded, so in the UK it can be towed on an ordinary driving licence.
Has max 220 litres of water.
One person could easily operate a T4 alone.
Designed as the perfect sampling machine.
Core up to 350mm.
T5
The Xcalibre T5 is 1350 Kgs so needs an additional licence in the UK.
Has max 450 litres of water, so a heavier duty machine.
We would recommend two persons to operate the machine safely.
Cores up to 800mm.
Both have machines have remote handset controls.
Explain Self-contained European approved coring trailer
Self-contained diesel or petrol engine coring trailers complete with coolant tank for fast & cost-effective diamond core drilling. No additional generators or power supplies required.
European approval allows for local registration by any customer within the EU by merely providing the ‘EU homologation’ document, supplied with the machine, to their local vehicle registration office.
All Xcalibre coring trailers have a maximum approved road towing speed up to 140 KPH for travel between work sites, subject to local speed restrictions.
Overrun braking is fitted to all trailers and matched to the weight of the trailer, as this provides optimum braking performance.
Engine fuel tanks & coolant tanks have been sized to match typical duty cycles. In most cases the trailer has enough fuel & coolant for a full day’s usage.
What type of engine should I have for my machine Diesel or Petrol engines? (Why Kohler, Hatz or Honda)
Xcalibre only use approved engines, as supplied to the major construction equipment manufacturers, to ensure the reliability of our machines.
Using internationally accepted engines gives our customers the support of worldwide dealer/service networks plus the easy availability of spares & service parts.
The choice of diesel or petrol engine may depend on the customer’s existing fleet, or restrictions that may apply on site such as airports, or areas where operating noise is an issue. The choice of diesel or petrol engine does not alter the machines capability.
We fit engines optimised to our machines performance as regards the maximum drill torque & the maximum drill feed. These are matched to the correct size of hydraulic drill motor, see ‘Drill Motors’ section.
We also specify engines to run at their most efficient RPM, as this helps hydraulic performance & improves fuel consumption.
Once these parameters have been maximised for the weight, size of machine & drill diameter, you have optimum drilling performance, so there is no benefit in using larger than necessary engines.
Why offer a variety of Single/Two speed drill motors
A core barrel’s rotational speed is very important as the diamonds held within each segment have optimum cutting speeds.
If the segment’s speed over the surface material is too high, the diamonds within the segments are stripped out & the segment then becomes ‘glazed’ see below. This is a very common problem for any machines fitted with the incorrect size of hydraulic drill motor.
Core drill diameters can range from 50mm to 800mm, so it is important to understand the customer’s typical core diameter.
When coring Asphalt the ideal segment speed across the surface material should be approximately 6 metres per second.
Using the wide variety of motors available, we can specify motor size to give this optimum speed when the engine is on maximum power.
When coring Concrete the ideal segment speed across the surface material should be approximately 3 metres per second.
Using the wide variety of motors available, we can specify motor size to give this optimum speed when the engine is on maximum power.
When coring through Steel or re-bars or very hard flint concrete the ideal segment speed often needs to be reduced to 1 to 2 metres per second.
Different drill diameters rotating at the same rpm, produce different segment speeds over the surface. So when fitting an increased diameter of core drill, the drill RPM needs to be reduced to maintain the optimum cutting speed.
Two speed drill motors are easily switched, whilst drilling, between high and low speed using the twist & turn control knob.
Two speed motors are sized for a fast rpm, but when switched to low speed setting, they rotate at 50% of the high speed setting.
This allows an operator to drill through a top layer of asphalt at the higher optimum speed of 6m/s and quickly switch to the lower optimum speed 3m/s when reaching concrete material underneath.
Why hydraulic drill motors rather than electric motors?
Xcalibre use ‘orbit’ type hydraulic drill motors as they deliver a similar torque output over a wide range of RPM’s which is ideal for drilling applications.
Hydraulic motors are pressure limited by a relief valve, so even if jammed or stalled they do not suffer from electrical current surges & overheating which then leads to burn-outs or clutch failures.
Electric drill motors are usually supplied with integral 3 speed reduction gearboxes to achieve only 3 fixed RPMs. However, each selected speed through a gearbox significantly changes the torque output of the electric motor, which is not ideal for drilling.
Hydraulic motor RPMs can be varied by altering the engine rpm with very little change in torque output, plus they can also have the additional 2 speed facility, giving a very wide range of drill RPMs.
What is the Proportional drill feed control about?
Once the core barrel’s correct rotational speed has been determined, the critical issue is the accurate & easily adjustable control of the feed pressure onto the drill.
Excessive feed pressure is a very common problem, particularly with inexperienced operators.
Excessive feed pressure will quickly damage the drill face by tearing out the diamonds held within the segments before the segment material has worn down sufficiently to expose new sharp diamonds. This is called ‘Glazing’ and will basically stop the drilling process. See section 3.
T4 & T5 machines have a selection of pre-set drill feed pressures controlled from the remote handset, so the operator can start with a very low feed pressure to gently make a register into the surface material.
Once the drill is centred in the register increased feed pressures can then be applied. This feature we call ‘soft start.’
Some machines use cumbersome adjustable guides to try and centre the core barrel when starting to drill, but this can encourage the drill to be fed into the surface with too much pressure & immediately damage the segments by glazing. ‘Soft start’ feature eliminates this problem, as a carefully made register in the surface material is the best way to achieve clean accurate cores.
Once the drill is centred into the register the operator can progressively increase drill feed pressure in steps to achieve optimum feed. The sound made by drilling is often the best indicator of a good cutting performance.
If the core barrel meets a re-bar or a harder material, the change of sound alerts the operator so he can immediately switch the drill feed upwards ‘one click,’ this draws back the drill from the cutting face by 10mm and stops the actual feed process although the drill continues rotating. This action protects the drill segments from potential glazing.
The operator can then progressively start to apply lower feed pressures than previous in addition to decreasing the drill rpm.
Harder surface materials or steel re-bars are best drilled with lower feed pressures and lower drill rpm.
What height drill mast should I have and why? (Increased drill mast strokes 700mm, 1000mm or 1200mm)
A common difficulty is the extraction of the core sample from a core barrel when drilling has finished. This may require the trailer to be moved or the core barrel to be unscrewed from the drill motor allowing the core sample to be removed from the core barrel.
Taller mast stroke machines allow for the core barrel to be lifted high above the surface so the sample can be completely withdrawn without the need to move the trailer, thereby speeding up the drilling process.
Example: A 500mm or 600mm long core sample can be easily removed from the core barrel when using a 1000mm or 1200mm stroke mast.
Make note that T5 with the 1200mm drill stroke is 3 metres high!
Why have Lateral movement of drill motor?
When positioning a coring trailer to a specific marked location, the forwards or backwards movement is relatively easy to achieve, but often the drill needs to be moved laterally to match a finite position.
A lateral moving drill head option allows for this final positioning of the drill barrel.
Lateral movement also allows certain sizes of cores to be taken in parallel without re-positioning the trailer.
Maximum drilling diameter at the machines lateral extremities will be reduced slightly due to the natural of the machines.
T4 Lateral maximum diameter at its extremity would be 200mm. But ok for 350mm in the centre.
And the T1 and the T5 maximin diameter at its extremities would be 250mm and ok for larger sizes in the middle.
Is the T4 & T5 safe & easy to use with the 3 switch remote handset?
The handset has been ergonomically designed and can be operated in one hand, from a safe distance, whist keeping full control of the drilling process.
Handset provides full control of hydraulic stabilizers, drill rotation, drill feed pressures plus an ‘E’ stop.
Standing directly in front of a core drill limits an operator’s view of any oncoming traffic or similar dangers. The remote handset allows the operator to stand out of the roadway whilst keeping full control of the drilling process.
Once the handset is disconnected from the machine the engine cannot be started or operated, which acts as an additional security feature.
What are Stabilizer options available?
As standard T4 & T5 machines are supplied with stabilisers to position the trailer at 90 degrees to the surface being drilled which ensures a good sample.
However, we have an optional isolation switch that allows operation or either only front or only rear stabilizers as required.
This feature allows the trailer to be positioned on an uneven surface, such as drilling close to a raised kerb.
T1 coring trailers can be supplied with two ‘wheeled’ front stabilizers which allows the operator, on a level surface with multiple cores, to only raise the rear stabilizing foot from the surface and then reposition the trailer before lowering the rear stabilizing foot for the next core to be drilled this feature is ideal for Airport runways.
What is the ‘PTO’ Power Take Off facility?
Provides an auxiliary hydraulic supply from the coring trailer to power additional hydraulic tools for in-fill tamping or off-trailer hydraulic drilling.
