Fabricating Loader Sub Frame for B7100 HST

torch

Active member

Equipment
B7100HSD, B2789, B2550, RC54-71B, 48" cultivator, homemade FEL, homemade Cab
Jun 10, 2016
1,256
2
38
Muskoka, Ont.
It appears to me that the bucket ended up about a foot forward of the ideal position -- make sure you have a healthy counterweight hanging from the 3PH to avoid overloading the front axle.

Run a 1/2" pipe tap through your return T to open up the threads so the cap will sit properly.

I would be leery of removing that top brace between the columns. It probably would not be required if the columns were made of larger steel, but presumably somebody engineered that set up and determined that the bracing was needed.

That said, I think the brace could be re-worked -- either arched to provide clearance, or (as it appears to be held by a single bolt at either end) simply hinged with a bolt and lock-nut on one end while secured with a clevis pin on the other. The tiny bit of play would still keep the columns well short of deformation.
 

Lil Foot

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Equipment
1979 B7100DT Gear
May 19, 2011
4,594
26
48
Peoria, AZ
I agree with everything torch said.

If it were me, I would be engineering a hinge/quick disconnect setup already. Or, alternately, I would fabricate a brace that moves the crossbar back over the dash, so the hood would open without having to disconnect anything.

This next point is personal preference, but every 2 stick FEL I have ever seen has the lift stick inboard, and the curl stick outboard. Not a big deal, unless an experienced operator is going to use it, or you are worried about learning "muscle memory" opposite of everyone else.
Or maybe you folks from down under do it opposite from us?:D

Finally, a word of caution about using it to back drag with the edge of the bucket.
Your loader has a single curl cylinder instead of a pair of cylinders. That means all the impact load is on one ram instead of split between two rams. Impacts, like hitting a stump or rock when back dragging with the bucket edge down, can break or pull the threads off the end of the curl ram. (a relatively common problem with inexperienced operators and single curl ram FELs)
If you keep the bucket angle shallow (not vertical) and use common sense on speed, you should never have a problem.
Great job on your fabrication & installation! Keep us updated as you fine tune the setup.
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
It appears to me that the bucket ended up about a foot forward of the ideal position -- make sure you have a healthy counterweight hanging from the 3PH to avoid overloading the front axle.

Run a 1/2" pipe tap through your return T to open up the threads so the cap will sit properly.

I would be leery of removing that top brace between the columns. It probably would not be required if the columns were made of larger steel, but presumably somebody engineered that set up and determined that the bracing was needed.

That said, I think the brace could be re-worked -- either arched to provide clearance, or (as it appears to be held by a single bolt at either end) simply hinged with a bolt and lock-nut on one end while secured with a clevis pin on the other. The tiny bit of play would still keep the columns well short of deformation.
Thanks for your advice Torch, I did some rudimentary measurements from a couple of Pics I got online to try and make sure that the bucket was in about the right position... I'd be curious if anyone had a measurement perhaps from the centre of the front hub to the tip of the bucket at ground level... Probably too late for me to do too much about it now... but at least a measurement could help me ascertain how "out" I am and what the risk is.

I haven't managed to find the right sized Tap to sort out the Oil Fill cap not seating properly, but will keep my eyes open for one... or for someone that might have one.

Have gone with the "hinged at one end option" exactly as you have suggested for that cross brace, so not too much of an issue when having to refuel.

I have rear wheel weights and a flail mower that I can attach to the tractor as a counter balance... and after my initial testing... I am definitely going to need them... spent more time lifting one of the rear wheels off the ground than lifting the bucket (Mind you I was trying to dig out a fairly large clump of Pampas Grass that was desperate to stay in the ground!)
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
I agree with everything torch said.

If it were me, I would be engineering a hinge/quick disconnect setup already. Or, alternately, I would fabricate a brace that moves the crossbar back over the dash, so the hood would open without having to disconnect anything.

This next point is personal preference, but every 2 stick FEL I have ever seen has the lift stick inboard, and the curl stick outboard. Not a big deal, unless an experienced operator is going to use it, or you are worried about learning "muscle memory" opposite of everyone else.
Or maybe you folks from down under do it opposite from us?:D

Finally, a word of caution about using it to back drag with the edge of the bucket.
Your loader has a single curl cylinder instead of a pair of cylinders. That means all the impact load is on one ram instead of split between two rams. Impacts, like hitting a stump or rock when back dragging with the bucket edge down, can break or pull the threads off the end of the curl ram. (a relatively common problem with inexperienced operators and single curl ram FELs)
If you keep the bucket angle shallow (not vertical) and use common sense on speed, you should never have a problem.
Great job on your fabrication & installation! Keep us updated as you fine tune the setup.
Thanks heaps for your advice Lil Foot, Given I have Zero experience with driving loaders... I would not have known that the Valves are reverse to normal... Our water may spiral down the plughole in the reverse direction to yours and we might drive on the opposite side of the road, but I'm guessing that loader valve position is probably universal... quite an easy fix, I can simply swap them over. Mind you, I did find that the they are currently positioned I can be raising or lowering the arms of the loader with the pad/palm of my hand while operating the tip of the bucket with my fingers... will be interesting to see how dexterous i can be with them the other way around!

Given you advice about back dragging... I have questing about the operation of the ram that drives the bucket... I found in the short period of time I was testing it out When I did try to backdrag, when the bucket cam under too much pressure (but less than I expected) the bucket rotated forward... would that indicate that there is a leak in the bucket ram?

Its interesting, because in trying to dig out the pampas grass... I was able to get the bucket slightly under the roots and put enough pressure on using the bucket that it would lift the rear wheels off the ground, so seemed that there was ample hydraulic pressure there?
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
Well It works... got a lot to learn... but fundamentally looks like it does what it should.
Now just need to figure out why I have Hydraulic Oil Leaking out of the transmission!!! not sure if it is to do with my previous episode of splitting the tractor to replace some of the PTO gears (I did replace all of the gaskets with new ones!) But wondering if I haven't torqued the Transmission back onto the rear axle housing correctly...
Or I did (Unknowingly) over fill the Transmission with hydraulic fluid when I installed the Loader... Could have this done any damage? Burst a gasket? or is there a "weep hole" somewhere to allow too much hydraulic fluid to seep out?
Any advice much appreciated.
 

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taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
Encouraged by the "Give it a go" advice that I got earlier in the thread... I decided to fabricate "Legs" for the loader so that it would stand by itself when removed from the tractor...
Just need a couple of coats of paint and should be good to go!
Please don't look too close at the welding :rolleyes:
 

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Lil Foot

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1979 B7100DT Gear
May 19, 2011
4,594
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48
Peoria, AZ
when the bucket cam under too much pressure (but less than I expected) the bucket rotated forward... would that indicate that there is a leak in the bucket ram?
It's possible for the seals to leak in one direction and not the other, but it's highly unlikely. Probably just a geometry related thing, with the loader's geometry just having more leverage in one direction.
that it would lift the rear wheels off the ground,
That highlights the need for a counterweight on the rear, such as a box blade, rear blade, or weight box.
 

dlsmith

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BX2230, LA211
Nov 15, 2018
515
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18
Goshen, IN
Looks to me like you did a fine job building the subframe and getting it all to fit together.
Good job guy!
 

torch

Active member

Equipment
B7100HSD, B2789, B2550, RC54-71B, 48" cultivator, homemade FEL, homemade Cab
Jun 10, 2016
1,256
2
38
Muskoka, Ont.
I'd be curious if anyone had a measurement perhaps from the centre of the front hub to the tip of the bucket at ground level... Probably too late for me to do too much about it now... but at least a measurement could help me ascertain how "out" I am and what the risk is.
When I built my loader, one design "rule of thumb" I came across was that the bucket on the ground should be approximately 1 front tire diameter in front of the tractor. EG: if the front tire is 20" in diameter, then the back of the bucket should be approximately 20" in front of the tractor.

Further out, and it's too easy to lift the rear wheels off the ground (as you discovered), plus it puts excessive weight on the front axle. Closer in and the bucket dumps it's load on the hood at full lift.

I haven't managed to find the right sized Tap to sort out the Oil Fill cap not seating properly, but will keep my eyes open for one... or for someone that might have one.
Ask a plumber or pipefitter. 1/2" NPT is a common size for those trades.
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
When I built my loader, one design "rule of thumb" I came across was that the bucket on the ground should be approximately 1 front tire diameter in front of the tractor. EG: if the front tire is 20" in diameter, then the back of the bucket should be approximately 20" in front of the tractor.
Thanks Again for the info Torch... I feel a bit more comfortable now armed with that info... seems that based on that rule of thumb the bucket is sitting in roughly the right place relative to the front wheel... see pics attached
20 inches by my calculations is 508mm and the back of the bucket sits approx 1050mm from the rear of the front tyre
 

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torch

Active member

Equipment
B7100HSD, B2789, B2550, RC54-71B, 48" cultivator, homemade FEL, homemade Cab
Jun 10, 2016
1,256
2
38
Muskoka, Ont.
Ok, it must have been the perspective in the pics, it just looked further forward than it was. But the tape don't lie, so you're golden there.

1/2" NPT is the standard tapered thread for 1/2" pipe (National Pipe Thread). Pipe is sized by nominal ID (tube is sized by nominal OD) so the OD is ) .804", a little over 21mm.

Since pipe thread is tapered, running the tap in a little deeper will open up the thread and let the cap wind in further.
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
Taranakiguy, that is an interesting steel tape measure. Just don't see them is these parts!

You're doing a nice job. Nothing much more satisfying then building something yourself that does what you want, the way you want and save a couple of thousand dollars!
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
20,734
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38
Sandpoint, ID
Hi again Torch




Not sure if I have a different size Hydraulic Transmission Oil filler cap??? But mine doesn't seem to be 1/2 inch. It seems to be more like 20.5mm (13/16" or am i measuring it wrong?
Yes your measuring it wrong, 1/2" is the inside pipe measurement, and yes that is a 1/2" NPT fitting. ;)
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
You're doing a nice job. Nothing much more satisfying then building something yourself that does what you want, the way you want and save a couple of thousand dollars!
Thanks D2Cat...
I really enjoy learning by doing, so this little Kubota has been a great classroom. At some point I'd love to strip her right back and freshen her up with new paint etc... but that might have to wait until I've built a decent workshop!


Taranakiguy, that is an interesting steel tape measure. Just don't see them is these parts!
Ha.. just assumed that this would be the sort of thing that lying around in every toolbox in the world?
 

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taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
1/2" NPT is the standard tapered thread for 1/2" pipe (National Pipe Thread). Pipe is sized by nominal ID (tube is sized by nominal OD) so the OD is ) .804", a little over 21mm.
Yes your measuring it wrong, 1/2" is the inside pipe measurement, and yes that is a 1/2" NPT fitting. ;)
Thanks Torch and Wolfman... I obviously have got a lot to learn... so thank you yet again for the advice...
I have ordered a 1/2" NPT tap so hopefully that will do the trick
 

taranakiguy

Member

Equipment
B7100-D HST
Apr 2, 2019
49
0
6
Hamilton, New Zealand
Well the Loader Legs seem to function as intended... just need to get some paint on them... but as you can see with the water on the bucket... it's been a bit wet to paint outside (might need to hook her back up and move it under cover)

Question...
Is it normal practice to somehow anchor the bucket when trying to back the tractor out from under the loader? I'm assuming it must be, as mine was really tightly bedded onto the subframe and wouldn't budge without the persuasion of a block of wood and a large hammer.

So I'm wondering in future if it would be worthwhile perhaps tethering the bucket to a solid post (or something similar) to anchor the loader in the hope that I can then simply reverse the tractor (once removing the locking pins) to slide the tractor out from under the loader...

(don't think the wife wife was too impressed that I asked her to stand in the bucket and act as said anchor!)
 

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D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
Maybe you just have the mounting brackets built to a real close tolerance! Maybe a bit of wear from removing the loader will make it a bit easier. The should actually be free when all the pins holding it are removed and the weight is off the loader towers.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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38
Sandpoint, ID
All my loaders have the loader stands further forward, acts as a seesaw, curl bucket down, set stands, curl bucket up and the back of the loader pops up to clear the mounts, disconnect the loader hydraulics and away ya go. ;)
The old Kubota loaders used bars / stands off the sides of the bucket, to allow it to lift the back of the loader up then there were stands like yours too hold up the back legs.
 
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