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Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

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Old 12-09-10, 12:08 PM   #1
mudboy
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Homebuilt jigs & helpers

I needed some dummy axles. While perusing McMaster-Carr one evening, I realized they had everything I need to make a couple of dummy axles, and then I built a rear brake bridge jig that also works for barrel-type rear rack braze-ons. Rather than create a long, drawn-out post here, I uploaded the photos to my flickr account and made complete annotations.

Homebuilt frame jigs

I hope this helps someone. If you have any questions, post them to Flickr so I can answer there. The two dummy axles and the brake bridge jig took less than two hours.

I plan on building an Arctos-style jig at some point in the future out of 8020, which I will also fully document.

Pete
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Old 12-09-10, 12:36 PM   #2
unterhausen
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it seems to me that your brake bridge jig isn't going to hold the brake parallel to the stays.
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Old 12-09-10, 02:20 PM   #3
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it seems to me that your brake bridge jig isn't going to hold the brake parallel to the stays.
Yeah, I have yet to try it in practice; I angled the M6 screw downwards (upwards? Away from the base of the jig) a bit in the hopes that would properly compensate. I'm sure it will get tweaked once I have the stays in place. Worst case scenario is that I use a small U bolt to hold the bottom part of the fixture to the dummy axle.
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Old 12-09-10, 02:40 PM   #4
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I've never bothered with a fixture for the brake bridge or rack bosses.
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Old 12-09-10, 03:00 PM   #5
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Was there a jig for brake bridges at Trek? I don't remember one, but that doesn't mean anything at this point

the anvil fixture is awesome, and the Henry James is pretty nice too. Too bad i can't afford either right now. Brake bridges don't bother me too much, but I have problems getting rack bosses the way I want them for some reason. But I have seen plenty of evidence that a lot of people have problems getting brake bridges right.
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Old 12-09-10, 04:09 PM   #6
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Was there a jig for brake bridges at Trek? I don't remember one, but that doesn't mean anything at this point
Yeah, there was. I can see how it's a benefit in a production environment, but for a low volumes there are probably more useful fixtures to spend time on.

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the anvil fixture is awesome, and the Henry James is pretty nice too. Too bad i can't afford either right now. Brake bridges don't bother me too much, but I have problems getting rack bosses the way I want them for some reason. But I have seen plenty of evidence that a lot of people have problems getting brake bridges right.
Meh. Once you put a caliper on nobody can see the bridge anyway.
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Old 12-09-10, 05:44 PM   #7
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people are funny about stuff like that. I recall a post from someone that was convinced one of their seat stays was 1mm lower than the other
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Old 12-09-10, 07:02 PM   #8
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I think that is to deal with the pre-load one gets from having one side compressed by the drivetrain.
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