Hydraulic Trimmers

    (NL7-6.5) 2.5 ton pump with 20mm pump travel. Maximum rock size is 7in x 5in. This is our smallest hydraulic trimmer. It is strong and lightweight so it can be taken in the field. The original manufacture was in China, with several important upgrades by us. A shield has been added under the lower chisel. This keeps chips out of the wiper gasket and piston assembly. New oversize set screws prevent the pump from moving during operation. This helps prevent damage to the pump piston. The pump uses standard hydraulic jack oil, and metric set screws which are easily locally available.
    Each unit comes with 2 spare chisels, safety goggles, a set of spare seals and o-rings, and 8 mm allen key.

New price $275 plus shipping  save $50

   This machine should only be used by adults who have read and understand these instructions. The high pressure and sharp chisels split rock with great force. This can cause flying rock fragments to violently break off. Safety goggles should always be worn. Hands should not be placed where they could be pinched. A shop apron is suggested.
    Begin by screwing down the compression screw on the specimen. Do not use the compression screw to break the specimen. This can break the handle! The chisel piston is raised by pumping the handle below the white dot. Lifting the handle above the white dot drops the chisel piston. Try to not allow the specimen to overhang the handle and prevent dropping the piston.
     Use cracks and the grain of the rock to your advantage. Lightly scoring the specimen can direct and aid in splitting tough material. The size of specimen that can be trimmed varies with the material. Sound judgment and starting out with smaller pieces while you slowly increase your knowledge will yield big dividends.
    By starting off slowly you will learn when a rock won't trim. Knowing when to stop and not to lean on the handle will keep the unit working with little upkeep.
     You must maintain the pump set screws tightness at all times! Inspect and tighten screws before each use. Periodically wipe down the machine with a lightly oiled rag. Cover the machine when not in use with a plastic bag.
     I don't fasten the unit down. If you set it in a box with the back high and the sides cut diagonally down to a 2 inch lip on the front, it is easier to clean.
    The plastic shield can be warmed in hot water, dried and draped over the bottom beam. The lower chisel holds it in place. The cutout is where the handle comes out of the lower beam. The purpose of the shield is to keep rock grit out of the wiper seal and to prevent damage to parts of specimens that fall on the lower beam.

Start by removing the two chisels. Raise the compression screw and position a work light directly overhead. At the bottom of the lower chisel socket is a set screw for bleeding the pump of air. Clean the area well and then loosen the set screw several turns. Pump slowly until air stops coming out and just oil comes out. Tighten the set screw. Lay the unit to one side and clean out the extra oil. Check if this solved the problem.

If bleeding the pump was not sufficient, then oil will need to be added. Begin by completely removing the compression screw. Put a cloth down and turn the unit upside down. Clean the bottom of the unit well. Remove the screw on the bottom of the pump. Using a small knife blade in the seam of the pump bottom and carefully pry the base off. Pry up up from one side and then on the other side, working slowly. A small amount of oil is added and then work the pump slowly. The piston will extend and air bubbles will come out. When the piston is out approximately 5 mm and the oil level is not too high the base can be replaced. The piston can be carefully and slowly pushed up if it extends too far. Be careful as this has potential to squirt you in the eye! Cover the screw hole in the base with a cloth and carefully replace it so as not to nick it, it using a twisting action. Replace the screw and check that the seam is tight, but not overtightened.

Turn the trimmer right side up and work the piston up and down. Get all the air bubbles in the system to the top of the reservoir in the piston. Bleed the pump, but if you can, leave the piston a few mm off of bottoming out. It can be bled later without refilling. Too much oil and the piston travel can be too much and damage can happen to the wiper seal if the piston gets out of alignment

Gallery 1 Guanajuato, Guanajuato, Mexico
Gallery 2 Ojuela Mine, Mapimí, Durango, Mexico
Gallery 3 Santa Eulalia, Chihuahua, Mexico