Davis MFG model D100a backhoe attachmentgreenspun.com : LUSENET : Countryside : One Thread
Couple years ago I bought remains of above backhoe attachment for super cheap. It had been modified to mount uniquely on an unspecified tractor at an odd angle. I suspect maybe to dig alongside a house foundation. The outriggers are missing also. Probably also to facilitate use in tight quarters. Anyway, I am finally getting around to making it into a 3pt backhoe attachment to use with my old WD equipped with a pto hydraulic pump since native WD hydraulics are marginal to say the least.
I am having trouble finding any info on original specs for this machine. Apparently Davis MFG is either out of buisiness or absorbed into a larger manufacturer.
Would an 11 gallon per minute hydraulic pump be adequate to power this relatively small backhoe (looks to be limited to 6, maybe 8ft depth, but with a wider bucket and heftier hydraulic cylinders than many small backhoes). I have used small backhoes before that left alot to be desired in way of power and prefer to avoid that condition. A 21 gallon per minute pump is only marginally more expensive but would need at least a 21 gallon resevoir to supply it. This seems maybe a bit of an overkill, but these are the two sizes commonly available in pto driven pumps. Suggestions?
-- Hermit John (hermit@hilltop_homestead.zzn.com), September 28, 2001
Calculate your cylinders consumotion and match that to the source of fluid,any cylinder travel above the rule of thumb which is an inch per second per cylinder is desirable. To fast of a travel will make the machine too sensitive and it will jerk rather than flow through movement. Too little will make the machine feel too slow. Any larger hydraulic supply will have an engineer with tables and charts who can assist you.
-- mitch hearn (firstname.lastname@example.org), September 29, 2001.
Sorry Mitch, I didnt mention this is a very low budget makedo project with cheapest parts I can find. Figured readers might figure that out from my discription. I cant afford to go to some "large hydraulic supply" couple hundred miles away to buy my way out of problems with "expert" advice.. I just thought somebody who might have a small backhoe attachment could tell me what size their backhoe's hydraulic system is (many have a separate hydraulic system powered by pto pump) and I could scrounge something the next size bigger. Its not like I can spend big bucks on some rare oddball hydraulic pump that is perfectly sized with perfect manners. Or else somebody might know where info on my particular antique backhoe attachment could be aquired. Twitchy, I can live with, slow and no power, I cant live with.
-- Hermit John (hermit@hilltop_homestead.zzn.com), September 30, 2001.
O.K. John, lets do it the cheaper way. Measure your cylinders diameter in inches and measure the distance they expand also in inches, from fully closed to fully open. With this info phone Northern Hydraulics and ask what size pump you need. I don't have their 800 number but they do have a web site and will quickly figure it for you if they think their going to sell you something. OR
Calculate all cylinders displacement in cubic inches, add them together and then devide by 231 ( cubic inches per gallon), this will tell you how many gallons you need to open all cylinders fully and give you a hint of how big of a pump you will need. Any of you math nerds or other indoor type people are welcome to step in here.
200 miles to a hydraulic supply? Wheres home: Outer Mongolia? Do you have a 6 digit zip code?!!
-- mitch hearn (email@example.com), September 30, 2001.
Now Mitch, you said "large" hydraulic supply. There are small ones much closer. Last time I went to one of those, a small check valve was $25 and out of stock. Same was $5 from Surplus Center (out of Lincoln NB)catalog. By the way "using" stores time without intending to buy isnt real kosher do you think although to be honest, I was thinking of going to dealer of new backhoe attachments and getting some literature with no intention of buying. Whatever compromises one is comfortable with I guess.
All a mute point as I found couple sites offering build it yourself plans on net and their biggest self powered backhoe used a 6 gpm pump so imagine an eleven gpm pump should do ok for my needs. I will maybe try doing the measurements and math and see for sure.
Seeing the buildityourself plans described, I am now considering making a separate frame for my backhoe with independent power source. Can even use fixed outriggers. I have some extra small engines around and used pumps for small engines are lot more prolific and cheaper than pto pumps.
-- Hermit John (hermit@hilltop_homestead.zzn.com), October 01, 2001.
John, "using" store time is a counter attack for what they are doing, what would you call electronic menus where they waste your time? They are elimitating a persons job and money for themselves, their personal gains at your expence instead of giving service. Go look at the owners house, is it larger, fancier, better than yours? I have no guilt; they have chose the playing field, I am just playing at their level....
-- mitch hearn (firstname.lastname@example.org), October 02, 2001.