DIESELprogrammer
Veteran Member
Select FINISHED!
Several of you have emailed me with inquiries about the hitch I have designed for my 03 Golf. You all want to see the final result and many have asked the process that I used to create the design. At this moment I am waiting for the steel distributor to call and tell me my materials are ready. When they are, I expect about two weekends to get the assembly, welding and installation done. Until then, I thought I would try to answer some of your questions and give you a look at what I have so far.
My design criteria for the hitch was as follows:
1. No drilling into the interior of the vehicle.
2. No disabling of the 5/8mph rear bumper
3. No cutting of anything
4. Completely stealth when not in use.
5. Stronger than the standard NA hitch.
I started out by lifting the car and removing the rear - wheels, fender well liners, bumper assembly, valance, and fuel fill cover. I also dropped the muffler and muffler shield. Then I took about 40 pictures and measured just about anything I could imagine. Typically holding the measuring devices in place while taking the picture. I then put everything back together.
Next, at the computer I manipulated and printed several of the photos. Also during this time frame, my car had several occasions with the back-end raised on the ramps while I lay there staring at its underside, trying to get ideas for the hitch design. Most of the time I carried the ramps and a pair of coveralls with me to work so that I could check things out in the parking lot during my lunch hour. I also used a plumb-bob and level to project measurements down to the floor and establish elevations.
I decided on these four points on each sub-frame for mounting the permanent frame rail components.
Back at the computer with an idea, I began generating 3D solid models of all of the components and assembled them at they would be welded together. I was also able to visualize the assembly on the car by overlaying model renderings onto photos of the car.
The cross bar below is 46” long to work with a 46”x20” carrier that will slip into the outside tubes. When the carrier is not in use the tube ends can be covered with rubber cups. The hitch is shown white here and without gussets and fasteners for clarity. The final product will be painted to match the valance. The bottom of the crossbar sits .125” below the bottom edge of the valance
At its lowest point (bottom of receiver ring), the hitch sits exactly 2” below the bottom lip of the valance.
This second design shows the crossbar cut back flush, with the tubes mitered.
I then generated a material cutlist from the component models. From the cut list I made physical models out of appropriate thickness cardboard. Hot gluing them together as they would be welded. After several fittings under the car and consultations with a couple dozen steel distributors and fabrication shops, I ended up making 5 different models because of fitting issues, material availability, and manufacturing cost. In the end, the final design turned out to be a class II assembly.
Keep in mind that all of the hitch assembly that you see in these pictures is easily removable (less than a minute if pinned – probably less than five if bolted). When removed nothing is visible in any view except when looking behind the valance, up from underneath to the sub-frame.
Several of you have emailed me with inquiries about the hitch I have designed for my 03 Golf. You all want to see the final result and many have asked the process that I used to create the design. At this moment I am waiting for the steel distributor to call and tell me my materials are ready. When they are, I expect about two weekends to get the assembly, welding and installation done. Until then, I thought I would try to answer some of your questions and give you a look at what I have so far.
My design criteria for the hitch was as follows:
1. No drilling into the interior of the vehicle.
2. No disabling of the 5/8mph rear bumper
3. No cutting of anything
4. Completely stealth when not in use.
5. Stronger than the standard NA hitch.
I started out by lifting the car and removing the rear - wheels, fender well liners, bumper assembly, valance, and fuel fill cover. I also dropped the muffler and muffler shield. Then I took about 40 pictures and measured just about anything I could imagine. Typically holding the measuring devices in place while taking the picture. I then put everything back together.
Next, at the computer I manipulated and printed several of the photos. Also during this time frame, my car had several occasions with the back-end raised on the ramps while I lay there staring at its underside, trying to get ideas for the hitch design. Most of the time I carried the ramps and a pair of coveralls with me to work so that I could check things out in the parking lot during my lunch hour. I also used a plumb-bob and level to project measurements down to the floor and establish elevations.
I decided on these four points on each sub-frame for mounting the permanent frame rail components.
Back at the computer with an idea, I began generating 3D solid models of all of the components and assembled them at they would be welded together. I was also able to visualize the assembly on the car by overlaying model renderings onto photos of the car.
The cross bar below is 46” long to work with a 46”x20” carrier that will slip into the outside tubes. When the carrier is not in use the tube ends can be covered with rubber cups. The hitch is shown white here and without gussets and fasteners for clarity. The final product will be painted to match the valance. The bottom of the crossbar sits .125” below the bottom edge of the valance
At its lowest point (bottom of receiver ring), the hitch sits exactly 2” below the bottom lip of the valance.
This second design shows the crossbar cut back flush, with the tubes mitered.
I then generated a material cutlist from the component models. From the cut list I made physical models out of appropriate thickness cardboard. Hot gluing them together as they would be welded. After several fittings under the car and consultations with a couple dozen steel distributors and fabrication shops, I ended up making 5 different models because of fitting issues, material availability, and manufacturing cost. In the end, the final design turned out to be a class II assembly.
Keep in mind that all of the hitch assembly that you see in these pictures is easily removable (less than a minute if pinned – probably less than five if bolted). When removed nothing is visible in any view except when looking behind the valance, up from underneath to the sub-frame.
