Jig Build


Getting Jiggy with it…

Unfortunately, although my jig has many nice qualities, ended up being a bit of a bear. But here is what I did and I will try to make comments on what I would change for next time.

Oddly enough I would say my biggest problem was not starting with a straight line. I would suggest starting with a long straight line on the floor board and orient everything around that. I would also suggest using a frame as a template. It can be surprisingly complicated to design your own bike. Although tools are available like bikecad online. Don’t ask me how to use it though.

The hardware I use are long carriage bolts (4″ or so), nuts, large washers, and pipe clamps. I retrofitted the carriage bolts onto the pipe clamps by cutting out some of the rungs with my dremel and tungsten cutter #9903 1/8″. (This thing rocks you NEED one not optional unless you want to build your bike out of sweat.

Things I learned

1) Keep things straight
2) Orient the bike in the jig using the carriage bolts, not the jig around the bike. (this is particularly important for the rear triangle, which is a pain)
3) Glue and PVC dont work well together. Instead fix the PVC joints using some screws.
4) You might do better tacking together the front triangle using a flat surface and a large piece of paper and an outline of your bike.
5) Mitering properly is hard when things are in your jig
6) It would have been nice if I could have integrated my actual rear wheel into the jig setup, this would allow me to get all the clearance I needed around the rear triangle. This is more important than I realized and as result will need to bend my dropouts to make sure everything is aligned.



Links to better designs

Semi-Pro Metal Jig

Semi-Pro Metal Jig

http://twomorrowbikes.com/ – Another good design from one of the blog readers!

4 responses to this post.

  1. Hi, I finished my jig, it works perfectly:
    https://sites.google.com/site/kobikedesign/adjustable-jig
    Have a nice day,
    Gabor

    Reply

  2. Cheap 2×4 jig, <$20 in parts, this is for my next bike, currently being built.

    http://www.pinkbike.com/photo/7673035/

    Because this jig is made of wood it can move around on it's own, if you are going to make one re-measure often to make sure that everything is still square as you build up the frame.

    Reply

  3. Posted by Henry on October 12, 2012 at 1:38 am

    Has anyone tried to use a frame donor and replace the metal frame tubes one by one? I dont have a jig and was thinking that this may be the best way to keep a good frame geometry. I havent seen this asked in any other of my research, maybe im missing something? Thanks in advance, I love this site, such a wealth of information!

    Reply

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