Fascinating Ideas, Tried and True

Harbor Freight Backhoe
HF Backhoe
The Harbor Freight backhoe/trencher is a great technology that has evolved over time. It doesn't have the weight that traditional backhoes have, so the force the bucket exerts on the ground depends on it's two front black stabilizers.  Once these are planted firmly with the teeth planted in the ground as shown below, the backhoe works amazingly well. The basic modifications discussed here further improve its performance.

Basic HF Backhoe
Towing this baby backhoe requires removing the front stabilizers and moving the back wheels to the front. Unfortunately there is no good place to store the four somewhat heavy components of the stabilizers on the backhoe. Alternatively, one can move the backhoe with the stabilizers in place by using the bucket and boom to lift the stabilizers off the ground and inching the backhoe forward or backward. While this does work, the distance of the stabilizers to the ground requires short steps and the sharp points at the ends of the stabilizers can damage parking lots and garage floors. One solution is to flip the stabilizers so that the points face upward. Retracting the stabilizers backwards through the square tubes also allows bigger steps to be made.

Another solution is to add wheels as shown below. This has the additional advantages of being able to move the baby backhoe by hand in a garage or parking lot, and allows it to be loaded easily onto a trailer for transport on public roads. Although the backhoe has a towing hitch, it is not adequate for towing the backhoe on public roadways since the wheels are not rated for high speed roads. So a trailer is needed along with some way of loading and unloading the backhoe.

HF Backhoe on Boat Trailer
So I added two 2X10 ramps to my Glastron Boat trailer as shown above. I also added four front wheels. Each wheel is rated at 300 lbs for a total allowable load of 1200 lbs. The backhoe without stabilizers weighs about 1000 pounds.The wheels are spaced to match the distance between the ramps on my trailer. Note the upper part of the stabilizers remains in place and are used to support the wheels. The  wheels are mounted on short 4X4 pressure treated post wood and attached with four threaded rods and brackets.  For this prototype no permanent changes like welded joints were made or needed. If the prototype didn't work, I wanted to be able to revert the backhoe back to its original condition. The wheel height is just enough to allow the stabilizers to ride above ground when fully retracted and with the points facing upward. That way the stabilizers can be moved with the backhoe. To minimize the weight and due to clearance issues, I did remove the stabilizers in the above picture and placed them in the back of my SUV for towing. I also removed the seat and placed it in the SUV.

Note the added ramps on this trailer have no effect on using the trailer for loading, unloading and towing my boat. My boat sits in the middle of the trailer without touching the ramps. Note also that the wheel distance on the backhoe might have to be adjusted to match the distance between the ramps. This is not a major issue because both the front and back wheels can slide in or out on their square steel tubes.

The above picture also shows the thumb, the two long steel shank teeth near the bucket, I added to the backhoe. I've used this thumb to pick up timbers and logs, stumps and even medium size rocks. It has almost no effect on the backhoe's ability to dig, so I just leave it in place. It is made with two pieces of 3/4" plywood, a short piece of a 4X4 post, four large bolts, two half-inch steel brackets, two turnbuckles, and two 18" box blade shanks. The total cost was about $65. For this prototype no permanent changes like welded joints were made or needed.

Securing the backhoe to the trailer:
Securing backhoe to trailer
A unique design advantage of this approach is the center of gravity of the backhoe on the trailer is low and slightly in front of the trailer wheels. It rides very smoothly since the boom is low and nothing is bouncing. I sometimes forget it is there when I am towing it with my Ford Escape. I would take this backhoe on this trailer to California and back to Maine if needed.  By the way, don't forget to turn off the gas to the carburetor when towing the backhoe or any tractor on a trailer. The float valve in the carburetor will bounce on the road and could flood the engine. I learned that the hard way.

The bucket above rests nicely on the winch post. I also tie the bucket down with a rope as a safety precaution. I drilled two 3/4" holes straight through the two 4X4 posts used for the front wheels, and directly through the bottom ramp. I pass two long bolts through these holes to tightly anchor down the backhoe. I also use two tie-downs straps as shown to secure the back of the backhoe.
You can see the 4X4 with a bolt in it in the above picture, just to the right of the left trailer wheel.

Unloading the backhoe:
HF backhoe
The center of gravity of the backhoe is controllable by moving the boom and bucket forward or backward. At the right position, the four front wheels are holding all of the weight of the backhoe. This allows the backhoe to be tipped easily forward or backward, and allows it to be moved on a flat surface like that of a garage floor or a parking lot. The back of the 4X4 acts as a brake on the ramps as can be seen in the picture above. To move the backhoe on the trailer, the back of the backhoe has to lifted slightly so that the 4X4 does not touch the ramp. The boat winch strap is used to safely control the position of the backhoe.

Harbor Freight Backhoe 
A simple 2X10 board in the center of the trailer placed in the middle of the trailer is used for pushing the front wheels off the trailer and inching them off of the trailer with the bucket. You can see the 2X10 tied down to two boat struts with a white rope in the third picture on this page. The above picture shows the bucket resting on this board, and pushing down so that the front wheels are off of the ramps. Extending the boom and bucket slides the backhoe backwards on its two back wheels. When the front wheels are completely off the trailer, raising the boom and bucket will lower the front wheels onto the ground. Loading the backhoe onto the trailer is basically the reverse of these unloading steps.