3 pt backhoe

[BSims66173]

I was wondering if anyone out there has built their own 3 pt backhoe. I have seen the post about the caddigger and looked at the websites. I think I would rather have the 3 pt type over the cad type. I have read all the post on these types and mulled over the idea for a while. I have a Mahindra 4110 with a FEL and 4x4. It weighs in around 4000#. I am confident it can handle a hoe of this size. This is a project I would like to try in the near future so if anyone has any pics I would be interested in seeing them. Also any plans and specs would be great. I would like to build one that would dig around 8 feet in depth. I have looked at the LandPride and Woods series of hoes and would like to pattern mine after the LandPride kind of. I have never attempted to build anything of this nature and my knowledge of hydraulics is limited but I am a very skillfull person, can weld and use a torch pretty good. I also plan on getting a plasma cutter before I start this project to make things a bit easier. Any ideas on metal thickness at stress point and things of this nature will be a big help. I am certain that when I start this I will be asking for a lot of advice from all the great minds here on TBN. Thanks in advance. Barry

 

[sleepyhollow]

Barry,

You are embarking on quite a project... A great starting point and I think a good overall guide will be an existing commercial hoe of your choice. Sounds like the Land Pride is your favorite.

Pay close attention to material types, dimensions and tolerances. Remember to design for failure mode. If something has to give, it should be the hydrualic rods, bending.

Don't build out the faliure mode because if something fails catestophically you want it to happen gracefully, safely! Better you bend a hydraulic rod than snap a piece of steel.

You mentioned buying a plasma cutter, make sure you get one that is up to cutting 1/4" or greater plate steel. If you are handy with your torch, you might save some money and just cut with the torch (you'll spend more time in cleanup finishing though). Seam welds are good. Make sure you spot weld only where the commerial product you are basing your design on uses spot welds. There shouldn't be too many of them.

Learn some more about hydrualic systems before you start. There are some threads here and there on TBN that offer some good resources.

Hydraulic components are expensive so you want to get what you need, nothing more, nothing less. There will be 7 cylinders (2 for stabilizers, 2 for swing, 1 each for boom, dipperstick and bucket curl) if you choose to go with hydraulic swing instead of chain (chain is lower quality). Pressure relief valves and protective sleaves (safety) for hydrualic lines are things you you want to keep in mind. If cost becomes a factor then build a safer backhoe with less performance instead of skimping on safety in favor of performance.

Remember to build stabilizers (pods). You won't be able to use your backhoe effectively or safely without them. I say this only because someone a few weeks ago was considering a backhoe without them.

You might want to add rubber shock absorbers to cushion the end of swing on components. I can't think of anything else of the top of my head, but I'll add more if I think of it. Research specs of current commercial equipment recommended for your size tractor, ask lots of specific questions here on TBN and always make safety your number one consideration. I'm sure your well thought out plans will yeild a fine piece of work. Keep us posted, I'm sure other TBN folks will have some good advice.
Sleepyhollow

 

[sleepyhollow]

Barry,

One other thing occured to me, make sure your tractors hydrualic system is up to the task. Check on GPM, PSI etc. Will you need an hydraulic fluid cooler?

Also, is your tractor's 3 point hitch strong enough for the weight you intentd to put on it? Do you have a loader for ballast? You need one. Wish I thought of these before... These are primary considerations! These questions should be addressed before anything in my previous email.
Sleepyhollow

 

[blackd]

Having just completed a CadPlans FEL I would recommend that you start with one of the kits. The problem is getting the mounts, pin holes, and other machining done exactly right. This is not for the novice unless you have good tools and some machining knowledge. Getting a hole in EXACTLY the right place and of EXACTLY right size is not all that easy.

Do you have a heavy duty drill press? You will need one to machine some of the holes. Do you have a good grnder with LOTS of wheels? You will also need these. If your current valve does not have power beyond then cut into the high pressure line just after it leaves the pump. Compression fittings work just fine. Loop to the new set of valves, and then from the output loop back to where you cut the high pressure line. Obviously you need to cut a small section out of the line.

 

[ebeacham]

Just a note,
I believe your tractor weighs just under 4000 lbs without the FEL. I tried to find out what the weight of the loader was but no success.

 

[BSims66173]

thanks for the advice blackd. I have most of the tools to do the job and what I don't have my uncle owns a large machine shop nearby and can get him to help. I have read alot about hydraulics here. I have a loader on my tractor and it has power beyond. I just don't understand what power beyond is yet but I am still reading and will figure it out. Thanks again for the advice.

 

[htiek126]

Power beyond is setup on open center systems that the cylinder discharge fluid returns directly to the sump. Without power beyond, the cylinder discharge fluid is mixed with the valve's high pressure fluid return line that connects to the next valve in the circuit.

Power beyond is useful for large systems to prevent overheating of the fluid, and some claim it is useful for small systems to prevent ghosting in implements connected to valves downstream.

With many valves, the closed center, open center, and power beyond setups are simply the changing of a plug in the end of the valve that controls the flow of fluid between two output ports.