By necessity I began with the floor frame as the mechanics of each subsequent upward addition had to be worked out as I progressed toward a workable system. Even with the measured drawings completed, it still seems the logical beginning point.
Considerable variation is possible in the base as long as the upper structure can be securely attached. The length of the front and back rails will determine the width of the machine. The 17” width was chosen so that I could lay the machine on it’s side in my pickup bed and close the cover. However, the machine transports quite nicely in the assembled upright position secured with ratchet straps. There is plenty of mass in the Bridge/Flywheel assembly to keep the center of gravity low without an especially heavy base frame. I wanted to be able to close the bed to keep other equipment protected.
Cut/Purchase List: Refer to drawing Base Frame Top View.
AP1. Anvil Post (1), 37” of 4.5” i.d. SC40 Standard Black Welded Pipe.
AP1. a Torch cut a parabolic shape Drift Drop Window, if desired, and fold in on the bottom hinge and weld the perimeter. This also prevents things from falling to the bottom inside the anvil post.
AP2. Anvil Foot-Post Braces (2), 1” x 1.5 x 12”, square tube.
AP3. Seat Bracket Sleeve, (1), 5 “ of 2” Square tube.
AP3a. Locking Bolt/Nut, 1/2”-13 x 1.5”. This can be added at a later stage.
AP4. Front Flywheel Stop, (1), 5.5” x 1.5” square tube. This can be added at a later stage.
AP5. Anvil Back Post Brace, 16” of 1.5” Square Tube.
AP7. Anvil Foot Spacers, 1.5” square tube (2)
AP8. Anvil Foot, 1/4” x 4” x 15” (2)
AP9. Center Anvil Post Base Plate, 1/4” x 4” x 15” (1)
BF1. Front Rail, 16” of 1.5” x 1.5” Square Tube
BF2. Back Rail, 16” of 1.5” x 1.5” Square Tube
BF3 Side Rail, R, 40” of 1.5” x 1.5” Square Tube
BF4 Side Rail, L, 40” of 1.5” x 1.5” Square Tube
BF5 Anvil Post Base Plate, 1/4” x 15.5” x 17” Plate
BF6 Bridge Post Base Plate, 3/8” x 4” x 5” Flat Bar
BF7 Transverse Base Rail, 16” of 1.5” x 1.5” Square Tube
BF8 Spring Axle of 3/4” SC40, 19”
Standard Black Welded Pipe, o.d 1.050”.
BF9 Spring Axle Bearing, (2) L & R, 1.5” of 1.25” SC40 Standard Black Welded pipe, i.d. 1.38”.
My Assembly Sequence:
1. Weld the Side Rails (BF3 & BF4) and End Rails (BF1 & BF2) into a rectangle (square carefully). Note that the end rails fit between the ends of the side rails. Weight or clamp so the weld beads do not warp the base and it remains flat. Consider points to place holes for concrete anchors if secure floor fixation is planned. My primary machine sits on a stall mat which prevents “walking” and there are no floor bolts.
2. Weld the Center Anvil Post Base Plate (AP9) to the center of BF1. Tack the anvil post in place but plan for easy removal after the position of the braces has been established.
3. Tack weld the Lateral Anvil Post Feet AP8 to AP9 at about 45º angles and weld the AP7 foot spacers.
4. Weld the Transverse Brace Rail (BF7) 5” inside of each end of the base frame.
5. Weld the Bridge Post Base Plates (BF6R & BF6L) in 16.5” from the end back. They are not essential, as the post can be placed directly on the floor. They do provide extra welding line length.
6. Weld the Spring Axle Bearings (BF8) on top of the Back Rail on each side.
With a solid base it is now possible to start building upward. The Bridge-Tower is next.