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Old 12-24-2019, 02:52 PM
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heinke heinke is offline
MetalShaper of the Month Jan 2018
Join Date: Nov 2009
Location: Livermore, CA
Posts: 449
Post Grill Opening Hammer Form

The front clip station buck is now all done with the completion of the grill opening hammer form. Like I predicted, this hammer form took a lot of work and thus time to finish. Its composed of 12 layers of MDF that are glued together to make up the form.

I want to give my friend, Michael Bonadio, a very sincere thank you for doing all the CNC work on his DIY home assembled CNC router. Given his router bed is shorter than the width of this hammer form (48 versus 63), he had to build an indexed sled to do 2 pass cuts by shifting the piece of MDF so the router head could reach the far edge for the 2nd pass. In addition, the hammer form is taller than the Z axis so he cut each of the 12 layers individually. The longer sections took about 2 hours of CNC router time each to cut.

Prior to gluing the layers together, I cut the middle out of each layer to get rid of excess MDF and thus a lot of weight. After all the layers were glued together, I cut the grill opening area out with a reciprocating Sawsall.

I plan to do flow forming of aluminum over this hammer form so I needed to make sure all the body lines and grill edge is continuous and smooth. I used bondo to fill in some imperfections where the MDF became too thin at the edge of a layer and thus the post glued edge was not smooth. After surface filing to smooth over layers, some hand sculpting/chiseling to deepen lower vent openings, and sanding, I applied urethane varnish to waterproof and ready the surface for the flow forming.

Here is the station buck with all hammer forms in place. In spite of all the weight reduction I had done, the front hammer form is still fairly heavy. I had to add a support leg just behind it to keep the station buck from tipping forward.

Im really happy with the result on this hammer form. I can foresee it as a good piece of garage wall art somewhere down the road.
Joel Heinke
Be original; don't be afraid of being bold!
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