GR Manufacturing was founded in 2014 by Mike Smith and Peter Blundell.

Mike Smith has worked extensively in developing and improving Minitrencher in New Zealand with the Terrasaw® product lines. Terrasaw trenchers were developed, designed and manufactured in New Zealand as a kit that transformed chainsaws into hand-held trenchers. The product had a 15-year history in New Zealand. The two main advantages of the product were the construction of a chain reduction system that slowed down the chain speed to one third of a standard chain saw. This had the advantage that the digging chain lasted much longer and the position of the digging bar gave a more comfortable and less tiring working posture.

The kits were designed to work with specific models of Stihl® chainsaws. Stihl® did not support the structural change. In June 2014, Peter Blundell became TerasTradech USA, Inc.’s distributor for Terrasaw in the United States. Mr. Blundell was the pioneer in the marketing and distribution of portable Minitrencher in the North American market.

Mr. Blundell turned to Makita®, who saw it as a great opportunity to expand their product line in the US market. Makita® offered the Dolmar® PS6100 and PS7910 chainsaws as a viable alternative to the Stihl® units.Within the first year of the US market, more units were sold than in the last 15 years in New Zealand.Peter received a lot of positive and bad feedback about the product. The most important points were:

  • Premature engine damage
  • Insufficient air filtration
  • Extensive maintenance requirements

The problems led to the development of the GeoRipper® Minitrencher in 2015 after Mike and Peter worked together to improve the minitrenchers. The main improvement was to replace the chainsaw-type engine with petrol engine disc cutters.

This change was the solution to many of the earlier problems users faced with chainsaw models. A comparison of these two engines shows that chainsaw chains were designed to periodically run at around 14,000 RPM, and disc cutters were designed to run uninterrupted at 9,500 RPM. The cutters run cooler and lasted longer because of this lower speed.The air filter system of the disc cutters is far superior to the chainsaw, as it was developed to filter out concrete dust instead of wood dust. Digging in the ground creates a dust that resembles the physical properties (abrasiveness) of concrete dust.The drive speed reduction system in disc cutter machines eliminates the use of a reduction system used in the TerraTrencher®, eliminating a major maintenance problem.

The development and testing of the new GeoRipper® Minitrencher continued in 2015, before it was launched in early 2016 in the US market.

The first introduction of the GeoRipper® Minitrencher was with the following Makita® engines: the EK6101 two-stroke engine (Dolmar® PC6114), the EK7651H four-stroke engine and the EK8100 two-stroke engine (Dolmar® PC8216).

GeoRipper® is the brand name of equipment distributed by GR Manufacturing and its dealers.

A short time later, GeoRipper® conversion kits for Stihl® and Husqvarna® disc cutters followed. The kits for Stihl® are offered for the TS700 models. Smaller Stihl® concrete saws can not be converted due to ergonomic and safety requirements. The Husqvarna® kits are compatible with the K760 / K770 and K970 cutters.

Since January 2018 the GeoRipper Minitrenchers are exclusively imported, marketed and distributed in the UK by Four Ashes Machinery Ltd.

GeoRipper Minitrenchers won the Innovative Product of the Year 2019 at the Executive Hire Show in Coventry. This provided a platform to enter the UK hire market.