Heavy Equipment Repair

This project involved the repair/reinforcement of a piece of heavy equipment. These sorts of projects are expensive – we were brought a cardboard template and asked to produce parts in 48 hours. It required us to generate the CAD on an unusual piece of geometry, allow for weld prep, and to iterate on that design using physical prototypes. But, as you will see, the equipment in use is also quite costly to sit idle. So the customer had budget and incentive to help us expedite this challenging project to completion.

PMC Equipment Rentals

Our customer for this project was Power Motive Corporation, in particular the facility located just outside of Milliken, Colorado.

Heavy Equipment Modification

PMC had supplied a Komatsu PC1250 Excavator to a project. The project realized they need a long stick on the excavator to allow them to trench deeper.

A Komatsu PC1250 Excavator supplied by PMC.

Modified Stick – Structural Questions

There was an extra-long stick available for PMC to use, but it required the holes for the pin to be relocated. The stick was sent off-site for that modification and returned.

It was discovered that the eyelet on the hydraulic piston flared out at the base of the eyelet. The original modification had material in the plates created to relocated the holes for the pin that was going to block the eyelet from full travel.

So to accommodate that flare out at the base of the eyelet, material was removed in the field. This left the support team for PMC concerned about the structural integrity of the holes for the pin, particularly since there was a weld joint that went right thru the holes.

PMC calls Colorado WaterJet

At this point, PMC called us and brought in a cardboard template. They felt if we could cut the part they designed out of 2″ steel, and we made a mirrored part for the other side of the “hinge”, they could weld it all together and get the structural integrity they needed.

We made a best effort at measuring the cardboard template, entered into our CAD system, and cut a sample prototype from masonite. PMC took that first pass prototype back to the excavator to evaluate fit.

Masonite prototype for PMC Excavator modification.

Minor changes were made to the CAD after checking the masonite prototype against the actual machinery and then Colorado Waterjet cut a prototype from 2″ foam to mimic the 2″ steel that would eventually be used. Note the bevels on the edges for weld prep. Once this piece was shown to PMC, it was pointed out the bevels went the wrong way. This kind of error is not uncommon when one person is just verbally describing a part to another person.

Five axis waterjet cutting

With the foam prototype approved, we began the cutting process. The five axis part of this to form the chamfer on the edge meant those edges had to be cut twice – once perfectly vertical and the second at the desired angle for the chamfer.

Plate of 2″ steel on the waterjet table.

Chamfer as weld prep in a 2″ piece of steel.

Removing part from waterjet table using magnet and forklift.

Both parts secured to a pallet and loaded into customer’s truck bed.

Field welding tent with hinge point of stick inside.

As preparation for welding, the hinge pin was used to line up the existing hinge holes with the ones in the new steel plates. The new plates were tack welded into place and the pin removed to save it from heat distortion.

Weld in progress around entire perimeter of new parts.

End view of weld in progress. Shows how chamfer for weld prep is being used.

Successful Heavy Equipment Repair

Click on the video below to see the waterjet cut plates in action.