Kubota b7100 FEL build on a budget

Lil Foot

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1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,259
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Peoria, AZ
Don't have the tractor here to measure, but I tried to find picsthat show th spacing between the uprights/arms:
IMG_20140504_124624.jpg
IMG_20181118_135246378_HDR copy.jpg
IMG_0166.jpg
 
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trial and error

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B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Lil Foot if anything mine are actually tighter to the tractor hood based on the mounting points/front wheels in ur pictures, I would say the distance on my posts is very similar if not a little narrower
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Don't have the tractor here to measure, but I tried to find picsthat show th spacing between the uprights/arms:
View attachment 98196 View attachment 98197 View attachment 98198
It seems I misspoke, as another member has specified the distance on tower/arm width on a b219 loader to be 30" and 35" inside and outside respectively

I dont think the extra two inches which translates to 1" on each side on my build is a critical difference, especially when the material I am using for the bracing to the front of the tractor is 2x2" square tube (overkill im sure, but what I planned for and have) and it clears wirh comforatble tolerances, the exhaust and intake when welded to the inside of the towers. Also the "belly brackets I fabbed up to support the crossmember to the trans case don't allow me to go much thinner even if the braces I Lan to use did.
That is one shiny tractor and plow in your pictures, looks like it gets the job done and looks good doin it
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
I adapted a B219 to my B5100; if you need any measurements, just ask.

- Bart View attachment 98224
Thanks I've seen your build on here and I'm pretty sure on YouTube as well, I may have some questions down the line but my measurements are likely a little varied from both the actual b219 loaderas well as the 5100 I'm using tidbits from others builds and adapting them to my build as I go and also learning a ton from other members on here as well as a lot of what not to do from my own mistakes others are graciously pointing out. It may take me a little bit if trial and error but I'm determined to have this thing whipped, it may not being the most attractive peice of machinery and certainly won't rival most of the members on here builds but as long as it functions when I'm done ill be happy
 
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Lil Foot

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Lifetime Member

Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,259
2,203
113
Peoria, AZ
That is one shiny tractor and plow in your pictures, looks like it gets the job done and looks good doin it
Thanks!
Tractor is original paint, but the plow is shown right after a fresh coat of paint, but before it got used.
It used to be a badly faded med blue, with some surface rust. :)
IMG_20140504_124634.jpg
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Thanks!
Tractor is original paint, but the plow is shown right after a fresh coat of paint, but before it got used.
It used to be a badly faded med blue, with some surface rust. :)
View attachment 98247
I like those large skid shoes, do they work well on unfrozen gravel? 🤔
 

Lil Foot

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Lifetime Member

Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
May 19, 2011
7,259
2,203
113
Peoria, AZ
I like those large skid shoes, do they work well on unfrozen gravel? 🤔
I've only used the blade once, scraping the cinders off my driveway for reuse after I raised it to put in a culvert.
They worked great on that, but the driveway was hard packed & dry.
IMG_0026.JPG
IMG_0027.JPG
 
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Vigo

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B6100, B8200
Jan 9, 2022
595
339
63
San Antonio Texas
Coming along huh!

If you want more than 60" lift height you would probably move the tower/upright end of the lift cylinders upwards, but in doing so you lose a bit of lift force. The factory hydraulics have a relief valve in the 3pt assembly which i believe is set at something like 1700psi already. What i mean by that is if you were designing towards a lower pressure but end up not having the lift force you wanted, you can always go up on pressure and until you pass the 3pt relief pressure you're not doing anything Kubota didn't design it to handle. So my personal opinion would be get the lift height you want and then tune pressure to suit your desired lift force and you will likely still end up way below 1700psi anyway.

For reference, here is a B219 with cranked pressure picking up WAY more than 500lbs. Possibly 1000lbs.
Craigsb6100.JPG
craigsb6100a.JPG

There is a pressure gauge mounted on the tractor in these pics and even picking up MUCH more than at factory pressure, it still stayed under 1400psi for most of this lift, until it got up near the very top at which point it took about 1800psi.

I'm not sharing this to recommend you ever try to pick up 1000lbs to 6ft high with a b7100 (this is a silly anecdotal showoff pic, not something practical or useful) but it just goes to show you that if you have 2" cylinders you're going to run out of rear counterweight to keep the back wheels down, before you run out of 'headroom' to make pressure on the factory hydraulics. If you have 1.5" cylinders then yeah, you probably can't replicate this dumb idea picture on factory hydraulics without taking some risks with your engine driven pump, but can you still lift over 500lbs to full height basically no matter what? Yes. So i would adjust the lift cylinder placement on the uprights to get your desired lift height, and then adjust your loader relief valve to get it to lift whatever you want it to based on your normal/available counterweight.
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Coming along huh!

If you want more than 60" lift height you would probably move the tower/upright end of the lift cylinders upwards, but in doing so you lose a bit of lift force. The factory hydraulics have a relief valve in the 3pt assembly which i believe is set at something like 1700psi already. What i mean by that is if you were designing towards a lower pressure but end up not having the lift force you wanted, you can always go up on pressure and until you pass the 3pt relief pressure you're not doing anything Kubota didn't design it to handle. So my personal opinion would be get the lift height you want and then tune pressure to suit your desired lift force and you will likely still end up way below 1700psi anyway.

For reference, here is a B219 with cranked pressure picking up WAY more than 500lbs. Possibly 1000lbs.
View attachment 98472 View attachment 98473
There is a pressure gauge mounted on the tractor in these pics and even picking up MUCH more than at factory pressure, it still stayed under 1400psi for most of this lift, until it got up near the very top at which point it took about 1800psi.

I'm not sharing this to recommend you ever try to pick up 1000lbs to 6ft high with a b7100 (this is a silly anecdotal showoff pic, not something practical or useful) but it just goes to show you that if you have 2" cylinders you're going to run out of rear counterweight to keep the back wheels down, before you run out of 'headroom' to make pressure on the factory hydraulics. If you have 1.5" cylinders then yeah, you probably can't replicate this dumb idea picture on factory hydraulics without taking some risks with your engine driven pump, but can you still lift over 500lbs to full height basically no matter what? Yes. So i would adjust the lift cylinder placement on the uprights to get your desired lift height, and then adjust your loader relief valve to get it to lift whatever you want it to based on your normal/available counterweight.
I like it lol nor saying I want to try it but those pictures are pretty impressive.

Based on my calculations 1, 1 inch rod 1.5 inch bore cylinder set at 15 degrees and 1500 psi will lift 686lbs per cylinder, being that im not sure I can get a much of a shallower angle based on my current arm/ tower configuration I'm not sure how much my lift height will be affected, I'm going to mess around with all this hopefully Saturday afternoon to see if I can get a little more lift height by sliding the arms forward a little bit, yes this will put my fulcrum a little more forward of the front wheels (we are talking 2-3 inches at the most not 6) thus reducing my lift capacity but it might gain me some crucial lift height I would rather have a nice happy median of both capacity and height, I plan on keeping the under 400lb concrete counterweight on the 3ph that I use for plowing. That will be my limit to keeping the rear wheels on the ground, if I end up lifting the rear wheels off the ground with that counterweight, that will be my sign that I did ok on that median. I have no desire to add more weight to the back on a regular basis to counteract any extra lifting capacity. Special circumstances may apply once in a while My end goal is to do more, faster then I could before with a wheelbarrow and a Shovel but also not risk breaking things on a 30+ year old tractor that is hard to find parts for lol
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
595
339
63
San Antonio Texas
Based on my calculations 1, 1 inch rod 1.5 inch bore cylinder set at 15 degrees and 1500 psi will lift 686lbs per cylinder, being that im not sure I can get a much of a shallower angle based on my current arm/ tower configuration
Well you're using the calculators and doing the actual math so you're probably way ahead of me already. But im thinking that 686/ea or ~1370 total is at the pins right in the crook of the loader arms, so i believe you would take the distance from the upright/tower pin to the pin there at the base end of the lift cylinder in the crook of the loader arm, and the distance from there out to the bucket pin. And whatever proportion those two distances are, is the proportion of 1370 you will get at the bucket pins?! Im getting confused already. Something like, if you cylinders end at 1/2 the distance to the bucket, then half of 1370 is what you will get at the bucket. Or something like that. I should have researched before posting this one!!
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Well you're using the calculators and doing the actual math so you're probably way ahead of me already. But im thinking that 686/ea or ~1370 total is at the pins right in the crook of the loader arms, so i believe you would take the distance from the upright/tower pin to the pin there at the base end of the lift cylinder in the crook of the loader arm, and the distance from there out to the bucket pin. And whatever proportion those two distances are, is the proportion of 1370 you will get at the bucket pins?! Im getting confused already. Something like, if you cylinders end at 1/2 the distance to the bucket, then half of 1370 is what you will get at the bucket. Or something like that. I should have researched before posting this one!!
That's basically my understanding, I haven't crunched those exact calculations as far as distance from cylinder pin to bucket pin but I've used 2/3 as a rough guess which I think is fairly conservative based off of actual loader weight as well as, distances. But ill have to get some real #'s before final assembly
Edt , who knows it may be half
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
595
339
63
San Antonio Texas
Yeah, if you assume 1/2 is the worst case scenario its still over 500 lbs off the ground. But usually as the loader lifts the leverage gets worse.. even though the cylinder ends up pointing near vertical, it ends up being more lateral distance out past the cylinder than behind it. Generally loaders lift something like 50-60% of what they can lift 'off the ground', to their full height. So here's hoping you have more like 900lbs off the ground so you can get 500 all the way up.
 
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trial and error

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Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Vigo, all sounds good, that's kinda the #'s I am aiming for
 

barts

Member

Equipment
4wd B5100, FEL with Piranaha bar, box blade, log arch, 3 point hitch adaptor
For what it's worth, the stock pressure relief valve on my B219 cracks open at about 800 ps; this appears to be about 500 lbs at the bucket based on guessed weight of rockets. By the way, for a quick calculation of lift through all the linkage, etc, just measure the travel of the cylinder at the position that is interesting, and measure the corresponding lift or drop of the bucket. If the bucket travels twice as far as the cylinder moved at that point, the lifting force on the bucket will be half the force of both cylinders.

Needless to say, a pressure gauge is a very handy thing to have on a hydraulic system; I have no idea why mine didn't have one when I got the tractor + loader.
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
Spent about 4 hours this evening drilling a bunch of holes at my father's house/shop with a much sturdier and true running drill press. Got the brackets for the lift cylinders drilled and the boom arms drilled oversized for my "budget bushings" should be able to get a fair amount of work done Saturday with a lot of the prep work done today, lots of welding and fitting planned for Saturday and with any luck I'll have some forward progress to show for it. No pics of the hole drilling process sorry guys just didn't have time to stop and snap pics between changing bits and finegalling things in the shop that is setup up more for woodworking then it is for machining metal, we made a ton of metal shavings and punched a bunch of holes . fingers crossed they are all within close enough tolerances to the right places
 

barts

Member

Equipment
4wd B5100, FEL with Piranaha bar, box blade, log arch, 3 point hitch adaptor
If you have the time, drill & tap (1/4-28 works) for some Zerks so you can grease the thing easily... if that's a bridge too far, pack the joints w/ a nice sticky waterproof EP grease when you put it together.
 
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trial and error

Well-known member

Equipment
B7100dt manual trans. homemade FEL, 4 way hydraulic dozer blade
Feb 16, 2023
392
369
63
NY
If you have the time, drill & tap (1/4-28 works) for some Zerks so you can grease the thing easily... if that's a bridge too far, pack the joints w/ a nice sticky waterproof EP grease when you put it together.
Unfortunately I think drilling and tapping the "bushings" is beyond my skillset, also they are going to be recessed in the loader arms to the point that inserting a grease gun will be nearly impossible and that would require an extension of the zerk (not totally impossible but a pain). I would love to have zerks in all moving parts but I think it isn't going to be feasible. The cylinders I'm using do have zerks which is a major bonus. However for the pivot pins I'm likely going to have to resort to "option B" remove and heavily grease them at regular intervals. If this proves to be too much of a pain I will attempt to do what "Torch" did and cross drill and bore a zerk into the pins, but again that is probably out of my wheelhouse. I really do appreciate the advice and have been putting serious thought into how to maintain the pivot points. Is there a particular grease that you reccomend or will any marine/offroad washout resistant type #2 grease suffice?