Are you sure it's only 40 liters/min? What is the diameter of hoses on the backhoe? 3/8 or 1/2? There should be some specs or a plate on the backhoe that shows these values...
Tractor backhoe - homemade
- Thread starter BFreaky
- Start date
Are you sure it's only 40 liters/min? What is the diameter of hoses on the backhoe? 3/8 or 1/2? There should be some specs or a plate on the backhoe that shows these values...
rScotty
Super Member
- Joined
- Apr 21, 2001
- Messages
- 8,345
- Location
- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
No, I'm not 100% sure of the flow values..... But close. ....I'm extrapolating because the OEM specs are at max flow and max pressure - and I prefer to run at about half that. My main assumption is that my gear pump system is approx. linear with RPM being the main var. Then I sort of "nudged" the calculated answers because of experience with the way the various viscous losses change at my lower flow rates. Yes, it's a guess.
Bottom line, mine could run at your optimal figures but I don't. If I was doing an original design I would most probably do it the same way you have. Your values seem correct. Kubota's design will handle the higher flow at full RPM.
I wish I did know the hose ID, but don't. Just from measuring the most common OD of the hoses on this hoe, they are roughly 5/8" OD (21 MPa rated). My guess is that means my hoses are 3/8" ID...not exactly because they are metric of course. The thumb circuit is a step larger hose diam.
Interestingly, the swing relief pressure valves are specified to be set at about 17 MPa and the main circuit at 20 MPa.
Luck, rScotty
Kyle_in_Tex
Super Star Member
Late to the party as usual (I am). You have great talent and at such a young age. I love watching great craftsmen at work. Your drawings are really good. Thank you for sharing and posting pictures. This will look good on your resume. 
How did you measure rear of tractor to incorporate the fitment of your frame? Did you get it close, bolt some things up and weld it in place? I am lost without cad program. SolidWorks is good and they sell it cheap to college students. But a bit higher $$$ if you are a business, but worth it if you are in the design business.
I am sitting on the edge of my chair waiting for more pictures.
How did you measure rear of tractor to incorporate the fitment of your frame? Did you get it close, bolt some things up and weld it in place? I am lost without cad program. SolidWorks is good and they sell it cheap to college students. But a bit higher $$$ if you are a business, but worth it if you are in the design business.
I am sitting on the edge of my chair waiting for more pictures.
Kyle_in_Tex
Super Star Member
Late to the party as usual (I am). You have great talent and at such a young age. I love watching great craftsmen at work. Your drawings are really good. Thank you for sharing and posting pictures. This will look good on your resume.
How did you measure rear of tractor to incorporate the fitment of your frame? Did you get it close, bolt some things up and weld it in place? I am lost without cad program. SolidWorks is good and they sell it cheap to college students. But a bit higher $$$ if you are a business, but worth it if you are in the design business.
I am sitting on the edge of my chair waiting for more pictures.
How did you measure rear of tractor to incorporate the fitment of your frame? Did you get it close, bolt some things up and weld it in place? I am lost without cad program. SolidWorks is good and they sell it cheap to college students. But a bit higher $$$ if you are a business, but worth it if you are in the design business.
I am sitting on the edge of my chair waiting for more pictures.
First I examined the whole tractor, from top to bottom and of course I went under it (several times
). Then I used my imagination and made about 20 drawnings of various solutions for the frame. After I was satisfied with the idea, I used pieces of cardboard to copy critical points (holes etc) and made precise cardboard models with every detail. When that was done, all I had to do was to get the material and draw these pieces in CAD for CNC cutting. The rest of the procedure is described and shown with pictures on the 1. page of this topic . The whole project requires alot of thinking and prediction because it's a prototype. That's why I'm building it in stages (1. tractor underframe, 2. coupling, 3. main frame, 4. stabilizers, 5. seat and controls, 6. boom swing, 7. boom and dipperstick, 8. buckets, 9. hydraulic installation, 10. painting and testing, 11. PARTYYY )Indeed :-D
Renze
Elite Member
I design wheel loaders for a job, and your craftsmanship and design exceeds most factory made construction machinery...
Will you make a SERIOUS subframe under that MTZ, in order not to rip the bolts right out of the rear axle castings, or worse, rip the backend casting ??
Will you make a SERIOUS subframe under that MTZ, in order not to rip the bolts right out of the rear axle castings, or worse, rip the backend casting ??