Backhoe update. I'm making progress (Video included)

[David Devuono]

I am attaching a picture of an extreme case of cylinder overlap when I converted some cylinders from a FEL project to a backhoe. You can always shorten them later or buy a bigger tractor. Good thing about making your own is fixing it. The only problems I have had are too small of a pump on my 45 year old tractor and my main boom pin dropped out when the cottor pins broken. Took five people to remount the boom. Now I weld a plug with a hole for a drift-punch on the bottom of any verticle pins.

 

[88acres]

I commend you for your interest in building this. I too am a home fabricator and love turning dreams into reality. My shop looks like a small business. Looking at your design I am feeling like you will have a few letdowns. Id love to be wrong. Not being graduated engineering professionals but instead being non trained mechanical engineers we all have our opinions based on our past knowledge accquired in various areas.
I recently bought a Bush Hog 750 backhoe. The specs show that the bucket gets the most force around 3380 lbs with the next being the dipperarm that connects to bucket at around 2244 then last and least is the crane arm closest to the tractor at around 675lbs on my unit. With the bucket rolliing at 3380 lbs I have a feeling the first rock you try to roll out that doesnt move is going to bend your bucked as if it were made of aluminum foil.
Now dont hear me wrong. I think your model is great but in my gut feeling it needs to be greatly tuned. Possibly the length of the arms is going to reduce your power enough that your ability to bend them will diminish. They might flex enough for you to stop before bending. It seems like when working with hydraulics everything always looks like it was built too strong.....well there is a reason for that. There are so many points in the design that will have stress and hopefully its those points that will be beefed up enough to distribute the stress out to wider areas reducing the danger or damage. If you dont want to do any
re-design which Im sure is the case....I would at minimun start welding extra plating onto the sides of most everything you have there. Its the sides that need it not the tops. The tops just basically hold the sides together in place. They dont see much stress. Most of these tractor style backhoes weigh in at 1000 lbs. Interested to see what yours weighs when your done. It might could use some more steel.

:thumbsup: Good luck and I hope it all works great for you and hoping Ive never been so wrong before ..... I would love to come back in here and say... Wow, was I ever off key on this one.

Take care pal, your doing great..... Vic S.

 

[chad22]

:thumbsup: Good luck and I hope it all works great for you and hoping Ive never been so wrong before ..... I would love to come back in here and say... Wow, was I ever off key on this one.

Take care pal, your doing great..... Vic S.

Thanks. I at least finally got to try out some of the hydraulics tonight. :thumbsup: At first I couldn't get no fluid to pump, after trying and trying thinking it was just air. :confused2: I decided to turn the pump around and it worked. :laughing:

All that time it was pumping from the valve side and not the tank. That used pump I bought off ebay for $25.00 really does work. It's got lots of power. I had to basically almost idle it to let the boom down.

I did have one weld break on me though. It was the bottom cylinder mount for the boom. The reason it broke is because I had the come along still attached and I was gonna raise it up a bit to release it. Me not familiar with the controls lowered the boom instead of raising it. Before I could react it snapped it off.

Not to mention, I also forgot I had only tacked welded it in a few places.

I can't hardly get to it with my welder to weld it back in place now so I figure I'll just drill a few holes there and bolt that mount back on.

The only thing I wasn't able to try out yet was the bucket. I still have to get the hoses I need for it.

But I was able to raise and lower the stick, swing it back and forth which worked out great. And of course the boom until the cylinder mount broke.

I also have to grind and re weld the bottom part of the tank. It was dripping hydraulic fluid out a bit due to a flaw in my weld.

I've drained the tank for tonight so I wouldn't lose the fluid. I'll probably go up to the shop tomorrow and fix the tank.

Chad

 

[hizoot]

I also have to grind and re weld the bottom part of the tank. It was dripping hydraulic fluid out a bit due to a flaw in my weld.

great opportunity to test the flash point of the hydraulic fluid...please be careful!!!!!!

 

[evo803]

Whatever you do do not clean up the tank with brake cleaner !!!!! It produces a deadly gas ( PHOSGENE ) that WILL kill you.

 

[chad22]

great opportunity to test the flash point of the hydraulic fluid...please be careful!!!!!!

Thanks, I'll try to be careful.

I tested the flash point last night. I tried welding it up where I thought it was leaking with the oil in the tank, and caught the oil on fire around the edge of the tank.

I got the oil out of the tank now, so once I clean the outside of the tank up it should be fine to grind and re weld.

I'm gonna grind the whole weld off on the bottom where I welded the side panel on "Over a pump mount hole" the tank had a pump mounted inside of it previously. So I just covered the hole up with a piece of sheet metal. All welds holding except around the bottom.

That's the only weld I missed up on.

I was gonna go down to the shop today and fix the tank, but it's raining out and the shop leaks, and I don't want any water finding it's way into the tank.

Chad

 

[chad22]

Whatever you do do not clean up the tank with brake cleaner !!!!! It produces a deadly gas ( PHOSGENE ) that WILL kill you.

Thanks. Did not know that. Will keep that in mind. :thumbsup:

Chad

 

[David Devuono]

I once built a longrange gas tank for a 4x4. I would fill it with water and look for the wet spots. After draining it and welding 2-3 times, I found I could weld it with water still in it. Worked great. Just boil any moisture out of the tank before it rusts or you add hydraulic fluid.

 

[KubotainNH]

I'm looking forward to seeing a video of this doing some work. As others have noted, something will probably break at some point but that's how you learn what works and what doesn't. Looks like you enjoy building the stuff and that's all that matters aside from staying safe.

 

[chad22]

I'm looking forward to seeing a video of this doing some work. As others have noted, something will probably break at some point but that's how you learn what works and what doesn't. Looks like you enjoy building the stuff and that's all that matters aside from staying safe.

:laughing: Somethings did break on it. So the backhoe is out of service until I get a new welder in a few months.

When I fired it up in the shop things were breaking. The bottom boom mount broke off, the boom cylinder mount broke off.

The mount for the stick cylinder broke. I re welded those up the best I could with my welder. "The welder is a piece of sh*t " it's not putting out the amps it has been.

It held up enough for me to drive it home and dig a little bit.

I'm gonna make it work for a bit with the riding mower so I can dig out the "water line that needs replaced badly". until I can get the parts to rebuild it totally separate from the mower.

I'm planning on building it like the backhoe in this link 2007 GO FOR DIGGER TOWABLE BACKHOE | eBay
The go for towable backhoe. I'm gonna use the axle from a trailer I bought for $10.00 the bed is rusted out on it. I'm then gonna add some chain sprockets to the hubs and make the backhoe drivable using some hydraulic motors.

I also got some swivel casters off an old dixon ztr mower frame I found in the dumpster.

Chad