Video of Tractor and Frame assembly in William's second month Dedicated Project Visits report:

Cut List

Square tube:

4 × 7'8"×4"×4" tubes for base
3 × 5'×4"×4" under base tubes
2 × 52"×4"×4" vertical chassis centre tubes
2 × 55"×4"×4" vertical chassis tubes for front corners
2 × 59"×4"×4" vertical chassis tubes for rear corners (PC mounting area)
2 × 84"×4"×4" top chassis tubes
3 × 44"×4"×4" top chassis tubes

Rounds:

4 × 28"×1-7/8" axle shafts
4 × 54"1-7/8" loader shafts
2 × 100"×6"×2" front loader arm tubes
2 × 84"×6"×2" rear loader arm tubes
12 × 8" dom to mount loader shafts to loader arms.
1-7/8"bore bushing tubing to mount loader arm shafts to frame
1"bore tubing for 8 bushings to connect h/cylinders to loaders
plate to mount bushings to loader arms

Plate:

12 × 10"×8"×0.5" steel plates to mount flange bearings and hydraulic motors to
2 × 12"×12"×1/2" plate to mount h/cylinders to base
4 × 32"diameter × 9" wheels
1/2"plate & 1-15/16"tubing to make wheel mounts

Other

[16] thrust bearings - in the form of large washers with 1-7/8" hole.
[8] double-split shaft collars, 1-7/8"

Bolts

Functionality list:

[40] 3/4x5-1/2", with [40] washers for one side and [40] metal lock nuts for the other side. For wheel plates & cylinder plates.
[42] 3/4"x9" bolts, [80] washers, and [40] metal lock nuts. This is for the assembly of the main frame.
[16] 1/2"x2" bolts + [16] nylon lock nuts + [16] lock washers to suit. Motor attachment to motor interface plate. These could be 2" studs, as these are welded to the motor interface plate.
[8] 3/4"x2" bolts for motor; [8] nuts to weld; [8] lock washers. Attachment of motor interface plate to frame.
[32] 5/8"x2"bolts + [32] metal lock nuts, [32] lock washers to suit. Mounting of bearings to frame.
[32] 9/16"x2" fine thread bolts, [32] washers, [32] nylon lock nuts. Attachment of wheel to wheel hub. Includes studs, nuts, and washers.
[4] 3/4"x4.5" bolts; [8] nuts; [4] nylon lock nuts. Mounting of wheel bushings to wheel shafts.

TOTALS:

[40] 3/4"x5.5" bolts
[42] 3/4"x9" bolts
[4] 3/4"x4.5" bolts
[8] 3/4"x2" bolts
[120] 3/4" washers
[80] 3/4" metal lock nuts
[16] 3/4" nuts
[4] 3/4" nylon lock nuts
[8] 3/4" lock washers

[16] 1/2"x2" bolts
[16] 1/2" nylon lock nuts
[16] 1/2" lock washers

[32] 5/8"x2" bolts
[32] 5/8" metal lock nuts
[32] 5/8" lock washers

[32] 9/16"x2" bolts
[32] 9/16" washers
[32] 9/16" nylon lock nuts

Hydraulics

Note that the following list involves 2 loaders. For a simpler version, a single front loader is sufficient. Two loaders are used for extreme flexibility.

(download Blender file here)

Main

Parts from Surplus Center:

Functionality list:

Note: Green indicates finalized shopping list from Surplus Center. Blue indicates list from McMaster Carr. Red is Dalton Hydralics. See Parts Sourcing for contact information.

[8] flange Bearings - [1]
[2] Front Loader cylinders - 36" - $174 - 48 5/8" retracted length - [2]
[4] 3/8 NPTM x 1/2 NPTF 90 SWIVEL [3] for Front Loader Cylinders up to hose
1. 4.9 square inch area at 2500 PSI implies 12000 lb of force for each cylinder
~~[0] Rear loader cylinders - [4]~~
~~[0] SAE 8M x 1/2 NPTF 90 SWIVEL [5] for Rear Loader Cylinders~~
[4] QA plate hydraulic cylinders ~~& 2 Rear Loader~~ [6]
~~[0] 3/8 NPTM x 1/2 NPTF 90 SWIVEL [7] for Q.A. Plate Cylinders~~
[4] Motors - [8]
1. [8] SAE M 10 to NPT M 1/2" for Ports [9]
2. [4] SAE 4M TO 1/4" NPTM CONNECTOR for Case Drains [10]
3. [8] 1/2" QC for Motors [11]
4. [4] 1/4" QC for motors [12]
[4] 1-1/4" shaft couplers - [13]
[1] 1-3/8" 6T fully splined shafting - [14]
[2] Female 1-3/8" 6T spline coupling - [15], $30 each
[12] 1.875" double split shaft collars - [16]
1. got 10 double split
2. got 2 single split - [17]

Valves

[1] 3-spool motor valve, 25 gpm - [18], $288
[4] 1/2" Quick Couplers [19] - for motor valve work ports
[4] 1/2" NPT M to NPT M 90deg Elbow for Motor Valve working ports [20] - for 2 sets of work ports to wheel motors
[4] 3/4" NPT quick couplers - Dalton Hydraulics - 2 for in/out, 2 for auxiliary work ports
[2] 1/2 NPT hex nipples [21]-for auxiliary pair of motor valve work ports
[2] 3/4 NPT hex nips [22] - in and out of valve
[2] 3/4 NPT to 1/2 NPT bushing [23] - auxiliary work ports

OSE Danfoss Black 2 Spool

[4] SAE 8M TO 1/2" NPTM CONNECTOR for working ports [24]
[6] 1/2" NPT QUICK COUPLER F/F S20-4 [25]
[1] SAE 10 PLUG for OSE BLACK 2 Spool [26]
[2] SAE 10M TO 1/2" NPT CONNECTOR [27]

3 Spool Husco

[1] 3/4" NPT quick couplers - Dalton Hydraulics - 1 pair for inlet
[1] 3/4" NPT nip - [28] - for inlet
[3] 1/2" nip for return cross [29]
[1] 1/2"-1/4" bushing - to accept case drain return [30]
[2] quick coupler pairs for return line - [31]
Pipe cross fitting on the return line to accommodate case drain return - [32]
~~[1] SAE 12 M to NPT 3/4 M Connector [33]~~
~~[1] SAE 10M TO 1/2" NPT CONNECTOR [34]~~
~~[1] 1/2 X 1/2 X 1/2 NPTF TEE [35]~~

2 Spool Prince Valve

~~[1] 3/4" Quick Coupler for outlet (already included in central 3-spool motor valve)~~
[2] 3/4" NPT nip for inlet/outlet - [36]
[1] 3/4" NPT tee (already have these) for inlet
[2] 3/4" to 1/2" bushings - [37]
[1] 1/2" NPT male elbow - [38]
[2] 1/2" quick coupler pairs - [39]

Cushion Valves

[2] 1/2 NPT 30 GPM 1500-3000 PSI HYD CUSHION VALVES - [40]
[4] 1/2" male QC tips to plug into valves, which already have female QCs [41]
[2] 1/2 NPTM x 1/2 NPTF swivel [42] for cushion valve to mount tees, for separating to right and left cylinders; only one swivel needed per cushion valve
[4] 1/2" nip - [43] - going from between swivel and tee.
[4] NPTF Tee [44]- 4 for loaders only, not QA plates

Power Cube

[1] Coupler half, 5/8" - $10
[1] Coupler half, 1" - $10
[1] Solid spider - $14
[1] Breather cap - [45] - $8
- [1] 3/4 NPT coupling - found at big box hardware stores
[1] Suction strainer, 2" tp 1-1/4" - [46] - $23
- Use for dual Power Cubes
- [1] Use 2" coupler from bix box store to thread into Power Cube frame
[1] Pressure relief for power cube bypass- [47]

Hoses

Between Motor Valves & Motors

[4] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for in/out of the valves [48]
[4] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for in/out of front motors [49]
[4] 1/2 X 1/2 X 1/2 NPTF TEE [50]
[4] 1/2" X 48" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for rear motors [51]

Motor Case Drains

[2] 1/4" X 72" NPTM 2750 PSI HYD HOSE to run parallel with tractor sides [52]
[1] 1/4" X 30" NPTM 2750 PSI HYD HOSE from Tee to Tee in return hose [53]
[1] 1/4" X 36" NPTM 2750 PSI HYD HOSE to Rear Motors [54]
[3] 1/4 X 1/4 X 1/4 NPTF TEE [55]
[3] 1/4 NPT hex nipples [56]
[4] 1/4" NPT quick couplers are already with the motors

Front Loader

[2] 1/2" X 12" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE from Valves to Cushion [57]
[2] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for left front loader cylinder [58]
[1] 1/2" X 48" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for right front loader cylinder [59]
[1] 1/2" X 60" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for right front loader cylinder [60]
[2] 1/2" NPT COUPLER MALE TIP S71-4 [61]