The Chopper Compendium

I've recently been talking with a few new, but experienced, builders and it's come to my attention that when I talk about 'Mockups' they think I'm trying to send them back to Kindergarten. I have a hard time understanding why anybody in the fabrication business can't understand the importance of doing mockups before committing to the steel but I guess it's a 'new' thing with the 'digital' generation that expect immediate gratification. If you're got a proven design then go straight to it and weld everything up but if you're prototyping a design a wooden mockup will save you in wasted material and wasted labor. Years ago when I was involved with the Indian historical group we had plans for the Scout 640B frame but there were a few dimensions missing that none of us could figure out. I built an entire frame from wood and the missing dimensions were easily found and verified to work. It took two days to build the mockup which was nothing compared to the days and weeks we had all invested in trying to do Cad drawings and 3D renderings to find the missing 'offsets' in some of the tubing runs. Sometimes the old ways are faster and more accurate than modern methods when you're dealing with minor differences in a particular design. To my way of thinking if you can't build a wood mockup of a frame or a fork design then you probably can't build the same design in steel to begin with so in some ways it's a test of a persons skill set and a good way for them to test their own capabilities before they get into a project to far.
If you look through this site in detail you'll see dozens of examples of using mockups, some of them are rudimentary, made from cardboard, and some are pretty sophisticated being executed in wood but they all serve the same purpose and that is to perfect and verify a design prior to final fabrication. Let a word to wise be sufficient.

When I could not come up with the money to have the Leafer I wanted machined from 6061, I had some nice white pine laying around and being 2" x 8", was perfect for the legs. So I roughed them out with a jigsaw and stacked them to get the holes drilled and installed brass bushing. I wanted to work out the rockers and to remake the trees to change the trail. The rocker in the plans created neg trail, when the axle was placed in the forward hole. By moving the stem hole forward and using the same hole for axle and link, I can get the look I am after.
I have decided to use my router to finish the legs in the I-beam style they where designed to be machined in. Finished and painted HOK Chrome, they will look like the real thing. Mocking them up in 3/4 ply would have been easier, but I take the road less traveled, but again maybe that is why I stay lost most of the time... ; )

gary, you taught me the importance and i think i have shown that i took it to heart. just look at my mock ups used for the 90* rule. wooden rockers, trees spring perch...look at greg's wooden springer mock ups. i preach cut cheap material and make one set of expensive metal ones.

Years ago I was asked if I do mock-ups. I said, "Hell no! Why waste time doming something twice." The truth was I do mock-ups where I'm not sure it will work the 1st time. I've done a template for my primary to verify hole alignment and interference with the frame. I did a full size wooden mock-up for my seat spring perch for many reasons including wether or not I can weld it properly. Cardboard for the frame bends, gussets, axle plates etc...

IMO People do more mocking up than they admit. It's just not the 1st tool they pick out of the box. Unfortunately, it seams to be the last tool they pick.

I do a ton of mockups lots of cardboard but I have lots of junk metal lying around at work and sometimes I like the mockup so much it becomes permanent . when I did the triumph frame I had no real measurements to go from must have put the motor in and out 50 times till I got everything where it looked good to my eye