I am starting a new thread on the new site for my Tracked Backhoe. I am hoping to finish this fall so things are moving along fairly quickly at times. This will be an introduction to the project for some of you and a progress report for others.

For people who haven't seen the original posts on the old site, this project is a remote controlled backhoe based on a Kubota rice harvester chassis. It has a 15 horsepower 3 cylinder diesel. It will be about 40" tall so it can go under my house and dig.

Here are pictures as of today.



Front view

The twin uprights in the center are framing to mount the hydraulic cylinder to control the blade. Since the diesel is well out to the right (left in this view) and can't be relocated without using a hydraulic link, I'm trying to put weight on the other side to balance the machine. I will probably still have to add weight to the other side in addition to the pump unit and the batteries.

The air tanks are for the air system which controls the track brakes and clutches and the main clutch and shifter.

Looking down the left side



I'm working on mounting the backhoe. The hoses are from the slew cylinder. I bought a small 3 point hitch backhoe to try to save some time. There is still lots to build. I think I can get the two batteries around the back of the pump unit. One to the outside just behind the primary pump and under the air compressor pulley.


Right side




The hydraulic oil reservoir goes here but I also have to get a fuel tank in there somewhere. I added a fuel pump to the engine so I have flexibility in positioning the fuel tank. It was originally gravity feed.


The back




Note the trailer hitch receiver. This is for the hydraulic dump trailer that goes with the backhoe. There is an extra pivot point and hydraulic cylinder to lift the hoe so it doesn't hit the trailer when the machine starts to climb a hill and the trailer is still on flat ground.

The next few days are going to be spent trying to fit all the major components on the chassis and putting in cross bars and brackets to mount them. I think at some point I will have to tack the tracks off and turn it over to finish welding everything.

Chris

I thought I would work on the bucket and blade today. I'm trying to get this project to be fewer pieces and even tacking things together gives me a sense of progress and the result takes up less space.

First I tacked the various parts for the blade together so I can layout the shape for the end plates.






I finally decided that the wear bar could be welded on. I'm not likely to ever wear it out. I have a box of hardsurfacing rod for when the final welding is done.

Then I tackled the smoothing bucket. I did the weld on the inside of the pipe with a stick welder (DC) and tacked one side on.



I used a piece of wear bar for a front edge on this bucket too. This also had to have the inside weld done before the other side plate goes on and blocks the view and restricts access. The wind was coming up a bit and I was having trouble with shielding gas so I stopped for the day.






It was no great surprise that the plate warped a bit with welding the pipe in place but it comes back nicely with a little pull from the pipe clamp.

Chris

That sure would have been nice to have had when I dug out from under my house. The plant had thrown out several conveyor belts complete except for the side frames. The gearmotors were 575volts so I removed the windings and turned the armatures off in the lathe. Both had brakes out on the end so I had a drive end for input. Had 15ft scrap sections of 1X3 tubing for the frames. The door under the house is about 3X3ft, the conveyor stuck out just far enough to empty into a custom built dump trailer. The axle was made from 2 inch solid stock with hubs made from old rollers and utility trailer wheels. The boys and I hauled countless tons of dirt out from under there so we could redo the plumbing, take out the old heating system and fix the bathroom floor. It all was done by hand, the trailer was towed by a golf cart. Yep that little digger would have been nice....
T

Hi Terry,

What you did with your house is exactly the back breaking labor I'm trying to avoid. I would rather put in the hours building the machine than spend the time under the house with a shovel.

Here is the link to it on the old site.


Tracked Backhoe on old site

If you scroll down you will find the little hydraulic dump trailer I built. I still have to weld up the box.


Chris

Here are the cut out plates to build the aluminum box for the little trailer. Welding them together is fairly high on my to do list but I need to get some 6" x 1/4" Flat for the fenders first and I'm waiting until I have more metal to order,




Today I worked on the winch which is attached to the backhoe frame. It was raining so I needed an inside task.





Here is mounting the modified air starter/hydraulic drive unit to one of the winch side plates.

The inner circle of holes is to provide clearance for some socket heads bolts that hold the front bearing retainer in place.


The 3 x 1 1/4" bars are spacers to hold everything in alignment while I weld it in place. I will probably leave them in place afterward. They are 1/2" bolts. I used the holes for these spacers to bolt the two side plates together while the holes were drilled and tapped. The holes for the flange bearings are threaded 7/16". There is no room for bolt heads or nuts on the inside of the plates.






The drum is show here so you get an idea of what it will look like.





Chris

Chris: The only thing that saved my back was my then teenage sons. One likes to dig, the other likes to drive. It would have been a real pain in the.....body.....to have weeged myself in and out from under the house when the trailer was full. We even hotrodded the golf cart a bit to give it some more go. I still need to get under there and do the footings and knee walls. I'd also like to put in a walk in door where the crawl in is now. Now I have all this time and no money plus a totally screwed up body, things go a bit slower than they used to. Keep on building and posting, you do fine work!
T

More progress on the winch.

I milled the straight sections of the plate to clean them up a bit and cut the hole (with hole saw) for the DOM tubing for where the hydraulic cylinder attaches. Then it put some parts together to see how everything fit.I will weld in a continuous piece of DOM and when all welding is finished I will cut the tube in the middle so the end of the cylinder fits in. This way everything stays aligned and you know the pin will go in.



I have to get shorter bolts for the flange bearings and flat head bolts for the motor assembly (air starter thing). The bolts interfere with the chain.



The cable is also visible in the pictures.



Any way so far so good. I ordered a new hydraulic motor this morning. Basically a bolt in replacement for the one that is there ( a few little mods) but it will have about twice the torque and the ports are on the side instead of the end so the hoses won't stick out as far.

Chris

I've been piecing together a mount for the "dozer" blade on the tracked backhoe. Tying it to the existing frame so it handles all the loads without having to do any serious or overhead welding. I'm also hoping to not have to take off the tracks. The design is coming together pretty well and I've got a lot of the metal cut. It will be two welded sections which bolt together and bolt and clamp to the existing frame. Instead of pacing when I take a break from this I've been welding on the bucket and blade. Today I got a quick coat of primer on the blade (except where the brackets weld on). The primer is still wet in the pictures.





I still may do some trimming on the end pieces but I can do that with the primer on.




It weighs 95 pounds. I am weighing things as they get finished and will soon be working out the weight distribution for the machine. I have some extra steel to put on the non engine side if I need more weight to have it balance.

Chris

neat idea.

i dug out half of my basement about 5 years ago. i rented a bobcat mini-excavator, and took the cab off. luckly, i have a level rear entrance, and could fit our skid steer in the door (just barely). we cut the rops off the skid steer and wheeled the dirt out with that.

i'm now sitting at my computer, were there used to be 6' of dirt

It look like you making some good progress, and nice work too.

Great build man. I am looking forward to seein yer winch in action.

Continuing with mounting the blade,

The frame of the rice harvester chassis is basically a 4 x 4 tube down the center and two pairs of struts doing down to the track bogie rails. The struts are formed from plate and are open at the bottom so I can't put compressive force across them. Also, this (original) machine was built by a human not a robot so I have unfortunately found things not straight or symmetrical.

First is a bracket to transfer the load from the blade across the front strut. The a diagonal piece of channel carries the force up to where the rear strut meets the 4 x 4 frame member.








Front view with it in place.



Two 5/8" x 2 1/2" flat bars attach to the front face and come forward about to ahead of the tracks, 1/2"-3/4" inside the tracks. This is where the blade pivots from. There will be additional structure to vertically support these bars.




Top view bracket in place. Notice that the struts don't line up on each side of the 4x4 tube. This caused a problem with my carefully laid plan. (fixed by adding washers)



The brace that goes to the back (painted with primer). Again something didn't line up as it was expected to. Not a major problem just another delay. I probably should have measured the angle of each of those struts instead of measuring one and assuming the rest were the same. I will weld a piece of 1/4" x 1 1/2" fb to the end of the channel and tuck it under the big clamp (at the back end. The flatbar and the clamp will transfer the force to the top of the back strut where it is welded to the 4x4.


Cutting holes for DOM tubing in the end of the flat bars.

This was easy. Dealing with the vertical force, which is the weight of the machine, will be a little messy because the engine and gearbox are in the way. At least it will be easy to test. Just clamp a strong bar to a point at the back of the machine and have it cantilever forward, hang a dial indicator on it and lift the machine with the blade. I will be able to measure how much the frame deflects.

Chris

An update on the winch part.

I've gone to quite a bit of effect with this thing to make it serviceable. In the case of the winch, you have to take the drum out to change the cable. Since those two big side plates will be welded in place, the only way to get the drum out is to pull the axle out. I've already got it stuck twice and nothing is rusty. It is easy to press out in the shop but when it is finished I expect problems. Usually (well, sometimes) when you are trying to get a stuck shaft out and use a brass drift and even a light hammer it is easy to mushroom the end of the shaft (especially stainless)and get it stuck worse. This is not really a problem with hardened shafts, but is with steel and SS. The shaft has to be a tight fit on the shaft (so the shaft spins on the bearings not the drum spins on the shaft) and I can't get a keyway or pin in there.

What I'm hoping is a solution is to make a slide hammer to take the shaft out in the future. It goes together with a rubber mallet now and if ti is serviced in the future I will clean things up before it goes back together so the main challenger is getting it apart.




The shaft is in the picture. I threaded one end (5/8 NC) and made a threaded coupling to match. I drilled a 5/8" hole through the big piece of steel and the smallest piece is threaded 5/8" as a nut for the other end. I will probably just get a piece of 5/8" reddy rod to finish it up for now. When I have nothing to do someday I can put threads on both ends of a 5/8" rod and replace the reddy rod. The main thing is having the threads on the end of the winch shaft so I can go ahead with the winch and have a plan to get it apart again in the future.

Chris

Update on mounting the blade.



The framing as it extends to the back of the machine.



Reaming the bores for the pins. I know the reamer is a few bucks but if you are doing something like this it is probably worth it. It was sure nice to just slide in the pins. (They are not the final pins, just whatever I grabbed for now)






Then I clamped a piece of tubing on to see if they would pivot together. Everything was smooth.

My stash of steel that I collected for this project is starting to get low. The piece of tubing I used to check out the hinges, looks like it could do it permanently.




The fixed piece of this frame still needs to be supported (mainly tension) from the top. If I ever need to get to the brakes and clutches in the transmission, this piece has to be removable. Hence the two 1/2" bolt holes in the 5/8" flat bars. I need to have this all bolted in place before I can may the struts which will support the front of this frame.



The reason for notching the crosstube is to get the correct height for the pin attaching the hydraulic cylinder that controls the blade.



The open ends are where the piece of 4" channel built into the back of the blade will weld on. To make sure they are in the right place, I will wait until it is on the machine before I weld on those lugs for the hydraulic cylinder. I welded pieces in place between the ears so the entire enclosed space will be sealed from water when it is welded to the blade.

Chris

Working on the backhoe end of the machine today.



I made up the mount for the as yet "unnamed cylinder". I'm thinking of calling it the "DRAW" cylinder because in some conditions it can pull straight back on the bucket. It is mainly there to get more clearance while the machine is on uneven ground with the trailer. This ram lifts the entire hoe including the slew mechanism and winch. If the boom is centered and you use this cylinder and the boom or stick you can pull straight back.



This picture shows the three points where the hoe assembly will mount. The red markers are pointing to the two pivot points to the right and left and the mount for the end of the cylinder. The top of the cylinder attaches to the top of the winch frame. I still have to cut the DOM tubing out of the center of the bracket so the cylinder can go in.



With the tubing cut and the remainder reamed to fit the cylinder was snug and the pin slide in. No tapping anything with a mallet, just pushing by hand. I used one of the pins from the rearward mounts, for now. Once it has been moved around a few times it probably won't stand up on it's own like it does for the picture.

Here is the winch frame just sitting on the slewing frame.



I'm thinking about adding some bracing. The DOM tubing sitting at the top is where that cylinder will go. The piece of tubing pretending to be a brace is a brace for somewhere else.



I have to contend with the "airstarter/winch drive" on the other side so the bracing may not be symmetrical.




I will play around with bracing tomorrow. I have to cut that piece of DOM tubing that runs across the bottom so there are two pins (look at picture 2 above), so it would be nice to get some more support in that area.

The Hall Effect sensors for the winch drive came today but that will wait until it rains again.


Chris

Continuing on...

I still have some plate left so I cut a couple of pieces with the bandsaw and cleaned up the cut with a mill.



I will wait until the subframe is farther along before I weld these plate on. This piece is getting heavy.





Continuing with the subframe I welded in more bracing at the front and cut out the piece of DOM tubing. The brace with the hole in it is to allow access to the pin for the slew cylinder.

The whole thing will get a boost in rigidity when the side of the winch and those brace plates are welded on.

My welding is getting better.

Here it is with the pins in at the forward pivots. I will weld those lugs on soon. Then I can start welding the winch to the frame.



I will mount one of the hydraulic manifolds on each side of the winch on brackets made from 2" x 2" angle at about the same angle as the outside of the brace plates.


While the welds were cooling I was also trying to mount the blade frame.

Here is a side view through the tracks.



It was a bit of a wrestling match at times and I had to put in a shim but it finally went together.



I guess I have to paint the transmission.



There is more framing to come. Something down from above to the bolt holes (you can see one). If I ever need to service the gearbox (brakes, clutch ETC) I need to be able to remove this frame. You can see where the strut shadows one of the transmission bolts. The brakes are the other side of that bolt.






I decided to hang the blade strut on to see how it looked. The pins went right in and it pivots smoothly. The top of the cylinder will go into the cutout in the DOM tube the strap runs over at the top. Again I will leave it as one piece until all the local structural welding is done. This seems to be working well at maintaining alignment.





I use the ratchet wrench to turn the gearbox and move the machine around. The small pulley there is an auxiliary output. The input pulley is larger and is on the other side of the transmission.

Tomorrow it is back in the garage and off with the engine so I can weld framing in near the engine.

Chris

Well, I didn't get the engine off but I did some welding on the subframe for the backhoe.





The welding was going well. E7018 rod. I did my first overhead weld with 7018 today, It actually looked OK. It was where the back crossbar meets the center 4 X 4.



Time to weld on those mounts for the pins. The line of the pins has to be right angle to the hydraulic cylinder. I lined the aluminum flatbar up with the pins with a small square. The the big square checks it against the side of the cylinder tube. Then a few tack welds to hold it in place.

And see if it still moves. Yup




Then some careful welding to try to not warp anything. I kept tapping the pins back and forth as I welded to get an idea how tight they might be getting. One started to tighten up but I think it was mostly heat expansion because it eased a little when I let it cool down. They are tight clearances. At the end of it all they both came out with a light tap with a rubber mallet.

I put a bit of primer on and ran the reamer through to clear out the paint and touch up for any warping. It when through very easily and made a few slivers of metal.







This frame is still not attached to the machine. Now that the pins are welded in place I can weld the winch onto the movable backhoe sub frame. Not this piece above, but the one with the slew cylinder in it. It's getting hard to name all the stuff. Once the winch is welded on it will be too heavy for me to move around much and of course it could be a challenge to get those pins in, but with it detached I can roll it over on its side to do some of the welds. When I make the final pins for this I will put a little taper on one end to help line things up.

Chris

It's still not raining so I'm still working outside.

I took the motor off and in doing so caught the oil drain hose on a piece of framing during the lift. In the long run it is a good thing because to hose was tired and readily parted at the hoseclamp at the oil pan. On the down side I had better things to do than spend an hour cleaning up oil in the garage.

I welded the side brackets onto the winch frame.


And notched the bottoms of the plate to fit the supporting frame.





I still need to figure out a good way to do a final alignment before I weld those two pieces together.

I cutout some triangles and welded in pieces of flat bar to make braces for the tube across the back. They are 1/4" thick. the large one is for the back of the tube and the smaller one is for the forward edge of the tube.






I cut some spacers out of 1 1/8" plate (because I had it) to put between the upper and lower tubes. This will to some extent form a truss (at least at the ends). The stabilizers can be mounted on the upper or lower tubes depending on the terrain. The center section has to stay partially open at the top for the slew cylinder. This is why the new piece is being welded on underneath, to make the center more rigid. I may be able to fit in straps from the top of the channel down to the lower tube when I have the slew cylinder in place and can see what space is left.



My plan is to weld the spacers to the bottom of the top tube while I can still turn it over. Then there is room to weld to the lower tube with a flat horizontal weld. Just looking at the picture and thinking about it now I could also just weld in 1" x 1/4" flat bar. I don't think I have any but it could go in later.


Chris

Mostly welding today.



The brackets at the back.



And then the winch to the sub frame. I reamed the top DOM tube and stuck 1" bars in both holes so I could line things up. That's a 24" caliper in the picture, measuring the distance between the two rods.



Then I put in a bracket to hold one of the hydraulic manifolds. I use the existing brace plate to hold up one end. It wasn't a perfect idea.



It sticks out a bit too far for me to do the same on the other side and I will have to use 45's on the pressure and return lines to clear the winch motor gearcase. I will have to tuck it in more on the other side so it clears the side of the hydraulic reservoir.




I still have to find a place to mount the third one of those manifolds. The two on either side of the winch (which is where the hoe attaches) control the hoe and the thumb. The other 4 valves are the stabilizers, the winch and the blade. For now anyway the winch and the trailer (dump cylinder) will share one circuit. I will write about that when I get there.


Chris

Today I cut more metal, did more planning and welded the backhoe subframe onto the chassis. I didn't want to weld to the 4 x 4 tube close to the transmission so I built a clamp using 5/8" threaded rod.





This structure reinforces the existing frame.


I also made progress on the slide hammer for removing the winch axle. It used the rest of the 5/8" rod. The winch axle is attached in this picture. When this is threaded onto the end of the axle it can be used to put it in or take it out. It has to come out to change the cable.




Chris