Backhoe Build A Backhoe For PT425... It Could Happen

MossRoad · Feb 18, 2006

Well, I've always wanted a backhoe, but could never afford one for my old IH tractor. New ones were close to $8000 and used ones were over $2500 and junk. I started looking at the Cadplans units and found that the model 821 looked to be a nice kit to build. It has good specs and will do the work I would like to do. It is also towable behind a car and self powered. I found I could build one for under $4000 after all is said and done.

Then I bought the Power Trac PT425 in 2001. I had no more money in my budget, so the backhoe had to wait. We sold the IH last fall and that gave me some cash in the tractor budget again, so I re-started research.

I confirmed that the PT425 will run the Cadplans unit with no problems. The kit calls for an 8HP engine and the pump puts out about 6GPM at 2000PSI. The PT puts out 8GPM at 2500PSI, so if anything, it will overpower the unit.

I will not have to by an engine, hydraulic pump, reservoir tank and a couple other items, as the PT will provide the power and hydraulics for the unit. That should knock off at least $600. /forums/images/graemlins/smile.gif

As designed, the unit is able to operate by itself with a couple hundred pounds of counter weight. If I put a quick attach plate at the rear of the unit the PT should act as a larger counter weight. It should be very stable.

At work last week they were scrapping huge machines. I was able to score four pieces of square steel tubing that are 4" X 4" by 72" and a tad over 1/4" thick. Closer to 3/8" thick. Plus, both ends of the tubes are reinforced with an additional 1/4" of steel all the way around! I was also able to get 6 pieces of very thick C shaped channel about 72" long as well. On top of that, I got about a dozen 1/4" steel triangles that are about 18" at the base and a foot tall, plus a couple of 2" X 4" X 3/16" thick tubes of various lengths. So I believe I have enough steel to make 95% of the unit FREE! The only steel I will need to buy is some 1" ID X 1.5" OD DOM tubing and some 1" rod. That is used to make the pins and bushings. That stuff is expensive and will run around $250-$300. I will also need about 8' of 1/2" X 3" plate steel and possibly some 12" X 12" pieces of 1/2" plate.

Then I will need three hydraulic cylinders for lift, dump and curl and an additional cylinder for swing. I will also need the hydraulic valves, hoses and connectors. I'm hoping to keep that under $1200. If the budget holds, I will add a hydraulic thumb as well.

The Cadplans units call for manual stabilizers, but again at work, I scored four 18" hydraulic cylinders. They are not large enough in diameter for the backhoe, but will be fine for the stabilizer legs, I think. I will use one for each leg.

Yesterday I was surfing some welding and machine forums and found several free plans for backhoes. They were very complete and well thought out. So I will skip the Cadplans and go with the free ones. That saves a few $$$.

Hopefully, when the entire thing is done, I will get away with less than $2500 and it should be a very beefy unit. I am not planning on starting it soon, so this will be long term project, but I wanted some input from anyone with any thoughts, concerns, suggestions well before I start the project. Over the next year I will post progress and, of course, pictures. Looking forward to any and all comments regarding this project and how it relates to our PTs. /forums/images/graemlins/tongue.gif

J_J · Feb 18, 2006

David, I too went through the same thought process about the small backhoe project. Although you can find a used add on units, they usually run anywhere from $2500 to $5000, but they are just to heavy for the PT. I found a guy in Canada that laser cuts the small parts, and ships them to you in several boxes. I had to buy the 4X6, and 4X4 box stock locally. Steel has gone up about 30 % since then. The one I started is almost finished. I have built three different buckets for the unit. I'm guessing that the whole unit weighs around 650 lbs. I purchased all my cylinders and valves from Ebay.
I'm debating about using joystick or electric valves for the control. I adapted the unit for the three point setup.

MossRoad · Feb 18, 2006

From what I've seen, it looks like the hardest part of the fabrication will be the box-like structure that the boom and pivot point attaches to, and the bucket assembly with its linkage. The boom and dipper stick don't look too hard, with the excption of welding those round tube sections in for the bushings. Another part of the plan calls for making some brackets out of 1/2" plate and then welding them together to make a 1" thick bracket. What would be the advantage of that over just making them out of 1" plate to start with?

I need to get a band saw, as well. Never had the need for one but it sure beats torching and hand grinding. /forums/images/graemlins/smile.gif

SnowRidge · Feb 18, 2006

<font color="blue"> I need to get a band saw, as well. </font>

Harbor Freight is your friend if you can't find a good used one at a reasonable price. They put them on sale all the time.

MossRoad · Feb 18, 2006

I agree. For ocassional use, they are hard to beat for price. For nice stuff that will last a lifetime, there are better choices. So I have to decide what I need. In reality, I will probably be making less than 6' of cuts for this entire project if the triangles that I mentioned work out. If not, it will still be less than 20' of cuts. Then the saw will sit until another project comes up. Most likely, I will go with a cheap unit. If I start more fabrications I can justify a nicer saw down the line.

SnowRidge · Feb 18, 2006

This is the one I bought a couple of years ago. I think I got it for slightly under $150. It does the job.

Mine says made in Taiwan on it. Not sure where they are made anymore.

smartguyz · Feb 18, 2006

Hi David,

That sounds like an agressive project. I have a few projects in mind as well. You know, when I first was looking at all this, I remember that I thought Ed DiMaria's backhoe was really cool. Remember - it's this one...

Just curious, why didn't you go that route?

-Rob /forums/images/graemlins/smile.gif

BobRip · Feb 18, 2006

What is wrong with using the minihoe?

Bob Rip

Taylortractornut · Feb 19, 2006

Moss Road you still have your bucket that was intended for your Mini hoe ive never gotten around to completing. just pm me an address and ill get it to you. It works good I had it temporarily attached to a hommade version of an Addahoe for my excavator.

Rick_Taylor · Feb 19, 2006

Moss, I have no doubt in your ability to construct a small backhoe under a strict budget. I do have doubts about it's usefulness. A few years ago I purchased one of THESE from Northern. It's called a Trencherman and is a double for the hoes designed by CadPlans. It is very strong and can really dig, when I can get it to stay put. Using the arms in the front is a waste of time. If soil is dry, they scoot along. If soil is moist, they bury themselves. Giving up on the arms I have evolved into hooking it to the front hitch on my RTV. One person runs digger, other person sits in RTV pressing tightly on brakes. In hard soil it still manages to move the 2000 lb+ RTV around. What I'm leading up to is doubting the 425 will have enough weight and/or braking to hold the backhoe while digging. I sure wouldn't want to put the pressure the Trencherman is capable of against the lift arms on the PT. The PT WOULD break. Just my $0.02 worth.