All four of the Porsche G935s have had their wheel wells marked, drilled and shaped and I've started adding the sill boxes.
To get the stance right, the position and shape of the wheel wells is critical. The bodies are now almost at full width and the main profile shapes have been refined. It’s time to do the drilling and shaping.
This was achieved using a fixture (middle) to hold the jig plate (left) in a vertical position with screws into the edge and through the face of the plate. The jig plate is reversible so both sides could be done.
A heavy machinist's v-block (right) sits in the pocket between the plate (when installed) and the rib on the rear of the fixture to hold the fixture steady during drilling and removed to allow finer motion during shaping.
To allow the full diameter of the Forstner bit to clear the jig plate, a spacer plate was thickness sanded to position the G935 farther away from the jig plate whilst still allowing dowel pin engagement.
Templates were used to position and mark the wheel well outline and axle centers on both sides of each body. Previously marked feature lines and measurements were used to match side-to-side positioning.
The spacer plate is in position and the fixture was ready to assemble.
The fixture is set up for the driver side wheel wells. Four screws allow the jig plate to be reversed to do the passenger side wheel wells.
Before drilling, the spacer plate was relieved for the front wheel wells on both sides. The vertical pencil lines indicate what needs to be removed to allow the Forstner bit tip to engage with the axle center punch mark.
The drill stop was set for the correct depth and the main bulk of the wheel well was removed with a Forstner bit. The clamp and heavy v-block behind the plate help keep the body aligned during drilling.
A separate, thicker spacer plate was used to move the body even farther away from the plate to leave space for the sanding drum for shaping the wheel wells to their precise outlines.
To make fine motions easier, final shaping was done without the heavy v-block.
After careful sanding, there is a slight offset from the marked lines to allow for future final adjustments.
Bonus shot since you came this far - first shot with prototype maple wheel/tires in nominal position to start final zeroing in on the stance. The sill boxes have been added and shaping of the door profiles has been started.
Next up - 010 – Intercoolers-Sills – The side and plan view profiles are closer to final with the addition of two more key components: the intercooler boxes and sills.
For more of the story click on any of the following links:
012 - 2nd Skins Layer-Splitters
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