PROJECTS: SHEET ME TAL RACING CAR
2e. Cut and drill brass hinges following pattern B7. The sides of
the hinges to cut are the ones with 2 loops around the pin, not
the ones with 3. Slide the uncut sides of the hinges under the
sides of the frame about ½" from the front. Tape and clamp
everything back down without blocking the holes on 2A and 3A,
then re-drill those holes, going through the frame and the hinges.
Unclamp everything, and then pop-rivet the hinges to the frame,
using washers underneath for added strength.
3. MAKE THE FRONT SUSPENSION
This is the most difficult part of the project — everything must be adjusted just right. Old tether cars had
leaf springs, but I wanted a buggy-style independent spring suspension.
3a. Cut out sheet metal parts B3 and B4, the suspension arms
that connect the hinges to the shocks and caster blocks. Drill 1"
holes where indicated, and shape using pliers. Pop-rivet them to
the hinges. Cut the front shock towers (B1 and B2) out of something strong. These parts take a lot of stress, so don’t use thin
steel or aluminum. I used stainless, cutting the parts with a rotary
tool and then filing them down. Use a vise and a hammer to bend
the shock towers following the patterns. Bend them to only about
80° and make sure the 2 angles are the same. These towers
connect the frame to the tops of the shock absorbers.
3b. Drill towers B1 and B2 with the 1" holes indicated by arrows on the blueprint. Pop-rivet to the car
frame, over the hinges. Gauging with a drafting triangle, pivot each tower to lean slightly forward so that its
top edge lies 2" from vertical. Clamp them in position, then drill and rivet the 2 holes next to the existing
rivet to secure the towers to the frame.
3c. Cut and bend shock tower brackets B5 and B6 out of the
same metal as B1 and B2. Clamp them into place on the front of
the frame so that the flat sides sit parallel to the back of 2A and
the side tabs sit flush against the tower. Drill and rivet the bracket
tabs to the towers and the frame. Don’t drill all the way through
the wood; just go far enough to accommodate the rivet, which
serves as a nail here.
3d. Use machine screws and bolts to attach each front shock
between the top of its tower and the front of its suspension arm.
Bolt the bottom of each caster block into its arm. Assemble the
car’s turnbuckles, substituting shorter ¾" rods for the originals,
then connect one end to the top of the caster block and bolt the
other to the back of the shock tower at about the same horizontal level. Connect the steering blocks to the caster blocks using
100 Make: Volume 11