Frame Fixture
I am building a frame fixture using 8020 and some simple machined parts. This is based on my learnings from the simpler one that I built, plus inspiration from photos of the Arctos Jig.
My fixture has these design goals:
* Flexible so that it can be used for oddball bikes (cargo bikes, tandems, etc)
* Breaks down into small linear sections for storage
* Cheaper than a used Nortac or similar jig. It looks like my total cost will be about $300 and ~20 hours of machine time.
* Not annoying to use, but also not designed to be very quick to dial in like most professional jigs. I have no plans to become a professional framebuilder and don't mind spending 30-45 minutes setting up a jig.
* My first jig was too adjustable, which made it easy to get things off of the centerline. On this one I fixed the centerline at 2.5" and am machining parts accurately so that I don't need to make them adjustable.
I'm highly influenced by the Arctos jig since that had a lot of design similarities (with much nicer execution) to my first jig. The rear triangle dummy axle is going to be a complete ripoff of the Arctos since I never came up with a design that I liked before. The Arctos is much slicker when it comes to setting angles.
Read MoreMy fixture has these design goals:
* Flexible so that it can be used for oddball bikes (cargo bikes, tandems, etc)
* Breaks down into small linear sections for storage
* Cheaper than a used Nortac or similar jig. It looks like my total cost will be about $300 and ~20 hours of machine time.
* Not annoying to use, but also not designed to be very quick to dial in like most professional jigs. I have no plans to become a professional framebuilder and don't mind spending 30-45 minutes setting up a jig.
* My first jig was too adjustable, which made it easy to get things off of the centerline. On this one I fixed the centerline at 2.5" and am machining parts accurately so that I don't need to make them adjustable.
I'm highly influenced by the Arctos jig since that had a lot of design similarities (with much nicer execution) to my first jig. The rear triangle dummy axle is going to be a complete ripoff of the Arctos since I never came up with a design that I liked before. The Arctos is much slicker when it comes to setting angles.
Current jig progress. Front triangle is mostly done.
The main components are:
* A center spine made out of 2040 extrusion (2" by 4")
* Two diagonal supports, one for the HT and one for the seat tube. Those are 1010 extrusion (1" x 1")
* Connecting blocks to connect the diagonal supports to the main spine
* Tube holders on the diagonal supports.
