He started as a Universe Inferno (awesome figure) I started by replacing the hands with Alternator hands. Next up was finding a proper crane. I used Mudflap (awesome for parts and ratcheting joints) The crane attaches to his back with a small clip and back up rare earth magnets. It attached the same fashion to the alt mode. I made the gun for his left arm more easily removable.
The fun started getting out of control when I added the LED lights. I removed the interior of the cabin to accommodate the power supply, wiring, etc. Then removed the lights up top, drilling small holes where the 3mm LED bulbs stick up out of. There's a button on his side window which controls these lights. There are 3 settings, independent flashing, in sync flashing, and always on.
The bulbs are red, and I painted the interior of the light fixtures with translucent red also.
I painted Grapple with an enamel yellow/orange. 2 thin air brushed coats, not as difficult as I thought. I wanted Grapple to be more modern looking so I steered away from the 'over the edge' orange of his original. I top coated the yellow/orange with a thin coat of metallic "Amber yellow" (awesome color) then final coated with "tequila sunrise" lacquer from House of Kolors. This color actully is pearl/iridescent. In person, if you were to look at this paint close up, you can see a slight alteration of the hue from certain angles.
A video demonstrating the lights in action can be seen here:
I suck at creating videos, and unsure how to change the dark gray to black on his borders, also, the compression seemed to make him very orange
http://www.youtube.com/watch?v=zZJIJ6Hv8fA
or here:
grapple on Flickr - Photo Sharing!