How to build a floor pan

a few people were asking how i built the floor pan for my attex racer so i thought i'd just post it. the same bassic idea should work for other machines.

i started with a peice of .090 aluminum 25 1/2 inches wide by 20 inches long. laid out all the cuts (first pic) and cut it out. on the inside where it goes around the laterals i punched the corners in a rotax punch with a 1" circle. the cutout for the foot brake got punched with a half inch. then use a band saw to make the cuts, and clean it up with a scotch brite on a 3" grinder. all of the outside corners were also rounded. once the pan was cut i broke the front 1" and the back 1" up at about a 45* angle. that was the easy part.

next i cut some bungs to mount the pan to the frame. they are 1 5/8" tall. some 3/8" solid stock drilled and tapped to 1/4-20 on both ends. i used 7 bungs to mount mine. 3 on the front cross member, one on each of the center rails, in front of the mount for the laterals. and one on each of the outer frame rails. other than the ones on the outer rails, i just mounted them where i could without interfering with anything else. the ones on the outer rails were mounted as close to the back of the pan as i could. i drilled a 1/4 hole in the frame for each of the bungs, and mounted them with 1/4-20 bolts. (with red loctite) i made the bungs all the same length, but the attex frame isn't the same height everywhere, so i just shimmed the bungs to height with washers between the bung and frame. i did 1 washer on the outer rails, 3 washers on the front crossmember, and 5 washers on the center rails. (bungs could be made to length so you didn't have to shim, but i was using the lathe at work, and my machine was at home so i just guessed on the length and did them all the same)

once all the bungs were in place, i made some transfer punches to locate the mounting holes in the pan. to make the punches, cut the head off a 1/4-20 bolt and chuck the threads lightly in a drill. then run the part of the bolt hanging out of the drill against a belt sander at a 45* angle untill the end is sharpened into a spike. screw these transfers into the bungs with the point up. set the floor pan in and line it up where you want it. then hit the top of the pan lightly with a soft faced hammer right on top of 1 of the transfers. (the ones on the outer rails were the easy ones to do first as you can see right where you need to hit) once you have hit 1 of the transfers, take the pan out and drill a 1/4" hole at the mark left by the transfer. put the pan back in and let the spike come through the pan in the hole you just drilled. hit 1 more of the transfers, remove the pan and drill that one. once 2 of them are done, the pan can't really move so you can go ahead and hit all of the other transfers. then drill the rest of the holes. if you want to bolt your pan down you should be done at this point. i want mine to be removable without tools, so i built some mounting studs. cut the head off some 1/4-20 x 2" bolts. screw them all the way into the mounting bungs. (i put some rubber gromets on top of mine to reduce noise/ vibration) set the pan in with the studs coming up through the holes. then put a 1/4 flat washer on top of the pan and make a mark on the stud with a sharpie. take them all back out and drill a 1/16 hole through the stud at the sharpie mark. cut the studs off just above the 1/16 hole. reinstall with red loctite. drop in the pan, washers on top and spring pins to hold it down.

hope this helps out and feel free to modify to fit your needs. (take measurements of your frame before you start as i'm not too sure how close Attex's tollerances were) don't forget to add some bling!

the hardware picture is from left to right. the spring clip, mounting stud, mounting bung, homemade transfer punch, and rubber gromett.

The remaining two pictures show the final product!