DIY Mini Digger

[Colcreate]

Rose jointed?? You mean like the "eyes"

Yes the eyes in the joints are spherical (sometimes called spherical joints) and are free to revolve in any direction allowing quite a few degrees of movement.
I used two of these on the ends of the steering ram.

 

[farm boy00]

Yes the eyes in the joints are spherical (sometimes called spherical joints) and are free to revolve in any direction allowing quite a few degrees of movement.
I used two of these on the ends of the steering ram.
<img src="http://www.tractorbynet.com/forums/files/build-yourself/438251-diy-mini-digger-image-jpg"/>

Yup i catch what you mean

 

[Colcreate]

Backhoe

I hadn't managed to do anything on the backhoe over the last couple of weeks, but I did find a few hours over the weekend to figure out the bucket ram.
The hydraulic ram used on the main boom was the best one of a matched pair that I bought, the other which I'm now using for the bucket has a few pits in the chrome at the eye end. It still has 400mm 16" of clean travel though which is just enough to give me the bucket curl. I thought about shortening the cylinder to suit the stroke but it seemed better to use its full length as it adds strength to the beam.
I've welded the top ram mounts on to the beam and bored them out ready to have bushes welded in place.
The bucket was a rusty Ebay bargain and has cleaned up well using electrolysis. I chucked it in a plastic barrel full of water & washing soda and left it connected to a battery charger for 24hrs. The worn out bushes were cut off and new ones tacked in place. They will be fully welded and reinforced once all the linkages are made.

The backhoe folds up quite well and at full lock the bucket sits just clear of the curve of the tyre without sticking out at the side.
Height is a bit of a problem and I have to remember to lower the boom when driving it in and out of the doorway.

 

[farm boy00]

Anything new? ?

 

[mickeyw]

Just found this, and will certainly be following your progress. I like what I see.
You have struck two big areas of interest for me - diggers and Landrovers

 

[arkydog]

nice build! the blade idea would be good but the bad point of the is the is too much surface area of blade to really dig in as opposed to an stabilizer arm each side to not only have a smaller surface on the ground to bite in better but so you can level the machine. also you will be able to tilt machine at an uphill or down hill and have machine level.

years ago i built a small digger an wished i had that ability. now i have a kubota b3200 with loader and bh77 backhoe and also an old alis chalmers backhoe 816 that will dig 17' deep and wouldn't be without the independent stabilizers.

 

[Colonel Monk]

Cool Project. Nice work!

 

[Colcreate]

It's been a while since I have worked on this but here's what I managed to do the other day.

The bucket linkage here is a bit too long and ideally needs shortening by about 2 inches but it works ok for now.
I picked up a couple of ram seal kits recently so had a go at stripping the bucket ram down. What a Job! The cylinder has a locking wire which needs to be wound out but the piston rod housing was stuck solid. I had to cut out a wrench from 3/8" plate to fit the housing then heat up the cylinder end with oxy/acet while battering the wrench with a sledge hammer to get it to shift.

Once it started to move and I found the end of the locking wire it all wound out quite easily. The new seals are fitted and the outside of the ram has been paint stripped. It works well and just needs painting up.
The other matching ram was even more stubborn and took over half a day to strip, it just didn't want to move! It's still in bits now as I want to shorten it before reassembly. It will replace the stick ram when finished.
The main boom ram is also being replaced for one with a slightly larger diameter cylinder to give more lift capacity and to smooth out the jerky action that was becoming apparent.
The whole boom, stick and bucket assembly has ended up a lot bigger and heavier than I ever intended.
This was meant to be a small backhoe project but has somehow grown in size.

That's all for now!

 

[Colcreate]

Still working...

 

[KubotainNH]

Nice!

 

[Stomper]

Good to see, thats a cool build. Great job

 

[mickeyw]

Well done getting on with this project.
I'd love to see more photos of the build if you have any, oh and how about a video of it working ?

 

[farm boy00]

Any more info how you did the hydraulics ??

 

[Colcreate]

Any more info how you did the hydraulics ??

The whole thing runs off a single pump driven by a 15hp engine.
The pump feeds directly to the steering priority valve and then on to the front 6 way spool block which has a carry over port that feeds the rear backhoe spool block which is also a 6 way.
One of the front spools operates the hydraulic motor which drives the transfer gearbox and the front & rear axles. This gives me fingertip control of forward and reverse and the box has 2wd, 4 wd and 4wd low.
Another spool is used for the single front loader lift ram, and a third spool controls the tilt ram. I salvaged the forks and forklift backplate of an old truck which gives me side shift with the 4th spool. The front bucket hooks over the fork backplate and is secured with a towing pin, it can easily be removed and the forks fitted for moving pallets.

Later this year I want to pipe up a small hydraulic motor to a hedge cutter blade and mount it on a quick release to the front loader arm. So the remaining two spools will be used for operating the blade and a small ram for positioning.

The backhoe works very well although I never really finished the stabiliser legs. The leg rams are in place and work I just didn’t get around to making the extending feet to give it a wider stance. I am digging mostly on level ground and find that if I drop the front loader bucket down hard it mostly is enough to keep me steady.

The hydraulic tank is way too small and was only ever meant as a temporary test tank. After and hour or more of backhoe work it does get hot but not too bad.
So that is the hydraulic side of things, I can move around at a reasonable working speed and lift the front loader bucket or forks at the same time providing there is not too much of a load. The priority valve always makes sure I can steer. When stationary or crawling though the single loader ram will lift a full bucket of dirt but struggles with much over a couple of hundred kg and will stall the engine if I dont back off the relief valve. I have one more identical lift ram in the shop so might twin up with that this year and increase the lift capacity for handling pallets of paving flags etc.
I will be stripping it all down soon anyway, fabricating a much bigger oil tank as well as some body panels and a possibly an open cab frame then a basic paint job before reassembly.

 

[texasranger556]

Impressive work! Another purpose of outriggers on a backhoe besides stability is to reduce the stress on your rear axles while digging, and remove the bounciness of your rear tires.

 

[Colcreate]

Impressive work! Another purpose of outriggers on a backhoe besides stability is to reduce the stress on your rear axles while digging, and remove the bounciness of your rear tires.

Yes it surprising, the tyres (OK tires) seem quite tough until the back hoe gets pulling under a big root.

Unfortunately I didnt plan the layout very well and ran out of room by the time I got to thinking about the outriggers. The leg rams sit within the two vertical channels and really should have been spaced as wide as the wheels but it would be a major job to start again. So the plan is now to have horizontal extending legs each side mounted on pivots behind the rear differential and spanning out diagonal as wide as the wheels with the rams bearing down on them at mid point. The rams move in a fixed plane up and down so the legs will have to extend (telescope) between the fixed pivot end and the ram mounting point. That is a job for the summer when I strip it down for fettling & paint.
Here is a photo of what it looks like at the moment, the rams are over kill but I picked them up cheap!

 

[davedavies]

i enjoyed reading about your back hoe loader build....I have a similar project to do later this year...at least similar in the choice of drivetrain....I am planning on building a digger loader...not quite like a skid steer but similar to one...using Land Rover Series 2 or 3 axles...with rear steering and because i want it to have lots of digging power and lifting capacity...I am looking at using a 4 cylinder motor with a decent size hydraulic pump to drive a hydraulic motor for the transmission....am looking at either a Land Rover transfer case or some other 4wd transfer case....it will all depend on what I can find...the thing is I have built garden tractor many years ago when i had a biggish section and now I have another property...1.75 acres...and I want to move a lot of soil around...got a big house to build with a basement...and other stuff to do as well..so instead of buying a existing skid steer....I would rather build my own...being a fabrication engineer and mechanical designer does give em an edge....will post what I do when it happens ok....mean while good luck with your beast...Colcreate..

 

[farm boy00]

i enjoyed reading about your back hoe loader build....I have a similar project to do later this year...at least similar in the choice of drivetrain....I am planning on building a digger loader...not quite like a skid steer but similar to one...using Land Rover Series 2 or 3 axles...with rear steering and because i want it to have lots of digging power and lifting capacity...I am looking at using a 4 cylinder motor with a decent size hydraulic pump to drive a hydraulic motor for the transmission....am looking at either a Land Rover transfer case or some other 4wd transfer case....it will all depend on what I can find...the thing is I have built garden tractor many years ago when i had a biggish section and now I have another property...1.75 acres...and I want to move a lot of soil around...got a big house to build with a basement...and other stuff to do as well..so instead of buying a existing skid steer....I would rather build my own...being a fabrication engineer and mechanical designer does give em an edge....will post what I do when it happens ok....mean while good luck with your beast...Colcreate..

Why not build something like a toolcat?? I like the toolcats but couldn't afford one so I want to build one but that won't be for many years. Did a lot of designs on Google draw

 

[Colcreate]

i enjoyed reading about your back hoe loader build....I have a similar project to do later this year...at least similar in the choice of drivetrain....I am planning on building a digger loader...not quite like a skid steer but similar to one...using Land Rover Series 2 or 3 axles...with rear steering and because i want it to have lots of digging power and lifting capacity...I am looking at using a 4 cylinder motor with a decent size hydraulic pump to drive a hydraulic motor for the transmission....am looking at either a Land Rover transfer case or some other 4wd transfer case....it will all depend on what I can find...the thing is I have built garden tractor many years ago when i had a biggish section and now I have another property...1.75 acres...and I want to move a lot of soil around...got a big house to build with a basement...and other stuff to do as well..so instead of buying a existing skid steer....I would rather build my own...being a fabrication engineer and mechanical designer does give em an edge....will post what I do when it happens ok....mean while good luck with your beast...Colcreate..

Thanks for the comments.

If I was to build another.....
I would go with a bigger engine, a compact Diesel engine say 40-50hp with twin hydraulic pumps. The 15hp Kohler bogs down at times as it does not have the torque at low rpm but otherwise works extremely well and is a perfect match for the pump, pure luck here as I knew nothing about hydraulics before I started!
Four wheel steering would be interesting, two front Land Rover axles which would also make crab steering possible? Not quite sure if stability would be compromised though?
The 50 inch max width that this ended up at is about right for me as l am often working in confined areas so I would still recommend narrowing your axles. If you go full width the front bucket has to match and that is a lot of weight to contend with, which is harder to drive into dirt and even harder to lift and carry. I can just about drive into a pile if freshly dug earth, take a full scoop, lift and manoeuvre safety. The power requirements soon shoot up.

Four wheel drive is a must however you end up doing it! I would like to experiment with hydraulic motors independently driving the axles through a further chain/gear reduction rather than a transfer box. Putting the engine to one side instead of in the centre at the front or back was a good move for me as it is out of the way and helped keep the overall chassis length down which improves manoeuvrability.

Anyway good luck with your project, and get used to the strange looks you get when friends tell others, oh yes that guy built his own; digger, loader, backhoe, tractor thing....

This is what I was using it to dig up yesterday...

 

[Eric Salop]

Great to see you got it all working :thumbsup: