Digga Tips - Auger Bits for Drilling in Different Ground Conditions

When drilling in different ground conditions you need the right speed and the right cutting system on the auger bit to suit the different ground conditions. So which auger bit should you choose for your application? For efficient drilling on any machine requires power (torque) and down pressure.

Digga auger bits perform better at an optimal RPM against the ground conditions they are against. Similarly the auger diameter will perform better at certain speeds. For example: the larger the hole and harder the ground conditions, the slower you will need to drill. The smaller the hole and softer the ground conditions, then more speed is required. 

As a general rule we recommend the following RPM/speeds:

55-65 RPM for general earth conditions.

45-55 RPM when drilling in heavy earth, clay or shale. 

20-45 RPM when drilling in rock.

Results will depend on rock hardness, type of auger being used and machine down force.

Digga recommends the following attachments for the different ground conditions:

• When ‘general purpose’ earth drilling you can drill faster. The Digga A range of auger bits will be ideal here. These auger bits are also better for clay as the bladed teeth ‘shaves’ the spoil a layer at a time. Like scraping butter with a knife.

• In heavy earth, clay*, soft chalky rocks you want an auger bit with tapered teeth. The Digga RC range of auger bits is the ultimate all performance auger bit and will cut cleanly into earth and chalky rocks. The teeth are tapered to be able to rip the fracturable rocky/earthy ground. *Please note, this range is not ideal for drilling in clay with smaller machines 4 tonne and under.

• When drilling into rock you are going to be most effective at a slower speed with a greater amount of power. Too much speed creates too much heat and will actually ‘polish’ the rock smooth rather than chipping away at it. Too much speed will also cause the teeth to skip across the top of the rock and it will not be able to pick and rip into the rock to break it out.

For more information on our auger bits visit www.diggausa.com/auger-bits or contact us at (563) 875 7915. Stay up to date with the latest tips & trick by Digga on our Social Media channels.

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How do I avoid damage to the drive bale?

In order to avoid damage to your drilling drive, it is important to follow the correct drilling procedure. We recently saw a damaged bale with the lid peeled back as a result of incorrect operation.

Drilling with the cradle resting against the drive unit coupled with side load can create enough force to bend the bale or peel the lid off.

Therefore, it is essential to perform the drilling operation without resting the drive cradle against the drive unit, as shown in the picture above.

The drive unit is a pendulum hung attachment designed to swing freely left right, forward and back, which is why, when drilling correctly, the cradle should be positioned up and away from the drive unit allowing the drive and auger bit to swing freely, as shown below.

To find out more about the correct drilling procedure, consult your user manual. If you are having trouble, need replacement or service to your Digga products, please contact us at infous@digga.com or under 563 875 7915

Why choose a 2-speed drive over a single speed drive?

If you’re working with multiple sized auger bits or often in different ground conditions you’ll understand the expense and time wasted that comes with needing multiple drive units for the different applications. When the ground is soft you want a higher speed to get the hole drilled quickly and then move onto the next one. When the ground is hard or you’re using a large auger bit you need torque to get the job done efficiently. Speed and torque are always a trade-off; when you increase your speed you lose power and when you increase your power, you lose speed. Similar to a manual car, fourth gear allows speed but struggles with the power required to get the vehicle up the hill Standard, single speed drives are typically manufactured as a cost effective solution to provide a speed and torque to suit most applications but will give you one or the other. 2 speed drilling drives have grown in popularity over the last few years and, as leading manufacturers, we can understand why. We understand that for our customers time is money and so, our range of 2 speed drive units have been designed to help you work more efficiently - providing you one drive to operate in all conditions. The two speed drive is ideal for anyone who drills in a variety of different ground conditions and with a range of different diameter auger bits. As the name suggests, two speed drives have two speeds in one unit:

• Low-speed high-torque setting and,
• High-speed low-torque setting

The Digga 2 speed drive units give operators the option to switch between power and speed. Rather than needing 2 drives (1 for smaller diameter auger bits and softer grounds and 1 for larger diameter auger bits and harder grounds), the Digga 2 speed drive unit gives operators both functionalities in one drive.

Features and benefits of the Digga 2 speed drive range

There are a number of key features and benefits of a 2 speed drive over the standard single speed, such as:

• Save time and money by eliminating the need for multiple drive units
• 2 speed drillling drives are made with Eaton motors and Digga made gearboxes. The electrical plugs are high quality waterproof "Deutsch" connectors offer superior corrosion protection and waterproof properties.
• 2 speed drives allow for quicker drilling with a small auger bit and in soft grounds, and more torque for drilling with a large auger bit or in hard ground.
• Switch to high speed for faster spinoff of spoil on a high torque drive
• The low speed / high torque setting is ideal for drilling in fracturable rock; higher RPMs in rock cause the teeth to “skate” over the rock making it glaze over and become harder.
• The host machine can run at a lower engine RPM on certain drilling jobs therefore burning less fuel
• With the same gearbox as a single speed drilling drive, it is the same cost to service as a single speed drive unit.
• By drilling quicker, the job is finished faster so you can move onto the next job

It’s important to remember that single speed drive units have suited the market for over 30 years and unless you are working with multiple-sized auger bits, in different ground conditions regularly a single speed drive unit remains a very adequate option.

For more information on our range of drive units, click here.