Second frameset done- Mtbr.com
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  1. #1
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    Second frameset done

    This is my second frame, learned a lot from my first, but still a ways to go. Ended up tig welding most of it.
    Things I did better:
    1. The jig helped me make sure my tubes and angles were right before I tacked. The fork jig really helped, as my first fork was all sorts of off without.
    2. I had better miters this time and I was actually able to keep the stays symmetrical.
    3. Welds are slightly improved. I probably have a couple hundred hours under the hood by now, but it's been over 5 years.
    Things I could do better:
    1. I need to improve my miters, closing gaps is really difficult on this thin walled stuff.
    2. I don't think the tubeset is ideal for a welded bike. Head tube is a bit thin (1mm), so I added a reinforcement ring on the bottom.
    3. I can't friggin drill holes on center apparently. The fork is good, but half of the mounts on the frame are off center.
    4. I miss measured at some point and both angles are a degree steeper than designed.

    Question: At what point do you really trust your own work? My first bike has about 400 miles on it over a year, but nothing extreme.

    Having trouble with the uploader, so here's a link to the album of the finished bike.
    https://imgur.com/a/CFev895

  2. #2
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    Reputation: Little_twin's Avatar
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    Second frameset done

    Without knowing what process your using to drill holes here is what I do with my mill.

    1) attach a tube block. I make sure itís in a location that it wonít be in the way of anything I need to do. It stays there as a point of reference until Iím finished with that tube.

    2) drill holes using tube block to clamp. Sometimes Iíll add a second block for additional support in the vise. You can center based off the tube block. Center drills tend be less prone to skirting off to one side of the tube ore the other.

    If youíre using a hand drill or some other method a tube block can be used as a guide. When I did my mitering and holes without the mill the first thing I did was scribe a line from one end to the other. I then attached the tube block, cut and filed my miters, then used a tube block with a hole drilled in it as guide to keep the drill bit on the scribed line. Again, the first tube block was the reference from which all work was done. It works well since most of the time you are working at 90 degree angles around the tube.

    Every frame you do will get better. My first couple were complete garbage but I learned a lot. Analyzing your work and identifying points of improvement will only lead to better quality.


    Sent from my iPhone using Tapatalk

  3. #3
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    One of my first steps of tube prep is to use a strip of angle iron to strike a single line along the length of the tube. I can then always reference my mitres, holes etc back to this 1 line. A tube block (or similar) can be re-aligned to this 1 mark visually with a fairly high degree of accuracy. My tube blocks have quadrants marked on each face for transfering from my datum line on the tube. Centre punch and centre drill will do a great deal to help keep hole centres where they should be, if you still end up wandering, then as Little-Twin suggests, a guide hole in a tube block should solve that. (As long as you can produce the guide hole accurately!!)

  4. #4
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    I picked up one of these for drilling tubes: https://www.amazon.co.uk/gp/product/B00CYNOFM0/

  5. #5
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    Reputation: scottzg's Avatar
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    Cool! I love the classic lines with no braces and the smart layout for carrying a load.

    Why did you add seat stay bosses and no bosses at the dropouts?
    What was the reasoning for running the brake on the top of the seat stay?
    What are those things on the shift cables, doubled up adjusters?
    Just curious!

    For aligning brazeons, i draw a line like cord, then use a punch to put a dimple for my drill bit to sit in.

    How are you mitering? I've been using those paper printouts you wrap around the tube. Pretty easy to get a flawless miter using that method. I rough them in with a hacksaw, then clean up the tips with a small grinder, then file to perfection.
    "Things that are complex are not useful, Things that are useful are simple."
    Mikhail Kalashnikov

  6. #6
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    Well, I wasn't sure where to put the lower braze on without interfering with the brake, but I know I am going to use the upper mounts for a bag stabilizer. I'll add the lower later.
    Brake on top was for ease of adjustment and running a smaller dropout. I actually ordered the paragon low mount, but they ended up looking too bulky for my taste.
    Yes, doubled up cable adjusters because I took this build straight off another bike (that I recently did cables on) and the previous bike didn't have adjustable cable stops. I didn't want to run new cables and re-wrap the bars! Very observant of you.
    I'm using a cheap harbor freight tube notcher, which is getting retired. I did draw the line and punch the locations, but the drill bit drifted, so I'm going to try some of the suggestions that have been mentioned.
    Next up, build the front rack or some bags? Planning lower frame bag under the bottle cages (need to move the seat tube cage up, did 3 bosses for adjust-ability) for tools/tube, and a bag under the top tube for snacks and such.


    Quote Originally Posted by scottzg View Post
    Cool! I love the classic lines with no braces and the smart layout for carrying a load.

    Why did you add seat stay bosses and no bosses at the dropouts?
    What was the reasoning for running the brake on the top of the seat stay?
    What are those things on the shift cables, doubled up adjusters?
    Just curious!

    For aligning brazeons, i draw a line like cord, then use a punch to put a dimple for my drill bit to sit in.

    How are you mitering? I've been using those paper printouts you wrap around the tube. Pretty easy to get a flawless miter using that method. I rough them in with a hacksaw, then clean up the tips with a small grinder, then file to perfection.

  7. #7
    Let's get weird
    Reputation: kampgnar's Avatar
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    I use center drills for making holes in tubes. They are much more rigid and easier to control than a standard twist drill. I use a punch prick to lightly place a point where the hole needs to be, emphasize "lightly" because it is easy to dent a tube. I've found it quicker to to these by hand using a cordless drill. The beauty of the center drill is that you can see where the pilot hole is going before you drill to the finished size.... if it's drifting you can use side-to-side pressure to guide it back to center.

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