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Thread: My frame #1

  1. #1
    J_K
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    My frame #1

    Here's my first frame project.

    I used Bikecad for the base design and then transferred main dimension to Rattlecad to get miter lengths and angles.


    The front triangle is Reynolds 631 .9/.6/.9 with externally butted 32.7/33.1mm 30.9mm ID seat tube, Dedacciai 29er stays and Paragon dropouts.

    Here's a couple of shots of the jig




    Setting head tube bottom height


    Mitered front triangle



    Bottle cage is there just for the test fit.


    My first ever brazing.



    Next job is to braze top tube cable guides.

    TT .9 butt lengths are pretty short and I would like to know if there's any problems with brazing cable guides to butt transition area?

    Not sure yet how I will do the chain stay miters, I have plans for the jig but it will not be ready for this frame. Most likely I have to file them but I'm little bit concerned about how they will turn out without the templates.

  2. #2
    WIGGLER
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    Nice jig and a very good start on your frame!!
    PAYASO 36er.....Live the Circus

  3. #3
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    Great start, very good mitres and fit.

    No problem with cable guides, they go where they have to go.

    Can you give detail on your brazing: torch size, flux, rod type. There is a need to refine here.

    Eric
    If I don't make an attempt, how will I know if it will work?

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    Quote Originally Posted by J_K View Post
    Interesting, and have never seen this style ... I'm curious why you decided on this joint configuration ... Can you explain why ?

  5. #5
    J_K
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    Quote Originally Posted by Eric Malcolm View Post
    Great start, very good mitres and fit.

    No problem with cable guides, they go where they have to go.

    Can you give detail on your brazing: torch size, flux, rod type. There is a need to refine here.

    Eric
    Thanks for the info about the cable guides.
    I aware that I need to refine my brazing, biggest problem is my torch cheap propane torch. I used 56% silver there, it flowed nicely but focusing flame from the torch is tricky.
    I'll go to my friends place to braze cable guides with oxy-acetylene torch.


    Quote Originally Posted by bikeabuser View Post
    Interesting, and have never seen this style ... I'm curious why you decided on this joint configuration ... Can you explain why ?
    It's done that way because of 25mm offset seattube. By:Stickel does them that way and other builders also.

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    Ok, happy with Silver. I wondered if heat was the problem, not enough of it. You can tidy up by coating the rim of the bottle ferrules with flux and reheat again. The silver should draw into the hole you drilled to fit the ferrule into the tube. Don't add anymore silver.

    Remember to use plenty of flux. 56% silver should go flat and not be lumpy or fillet.

    Try the O/A, you should be able to control better the flow with a hotter heat source. If you need to improve your own home tools, the MAPP gas will do the job. I have re-learned from O/A to do a good finish with it. You've done very well to get a good jig, as mentioned, fit and mitre, so a good frame is there.

    Enjoy and learn heaps.

    Eric
    If I don't make an attempt, how will I know if it will work?

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    Subbed!!
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  8. #8
    J_K
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    I made little progress today.
    Downtube is tacked and top of the DT-HT joint is also welded as it was easier to weld it before toptube is tacked.
    I decided to weld the cable guides, because I didn't want to mess them with my poor brazing skills, not that my welding is any better. I'm happy with the result, I tried to keep most of the heat input on the cable guide to not cook the tube. I used ER312 1mm filler wire. Next time I'll try to get pressed cable guides from Pacenti.



    Last edited by J_K; 01-02-2013 at 10:41 AM.

  9. #9
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    I might keep an eye on the welded cable guides if on the thin part of the tube. Silver no problem. TIG might freak me out. Might be worrying about nothing, though.

    Also, and you probably already know this but just want to be sure: weld all the way around for the compound joints on the BB/DT/ST/gusset (or whateveryoucallit). I.e. weld the DT to the BB completely, then the ST to the DT, then the gusset to all three. (This description assumes I interpretted the intersection of the joints from your drawing correctly, so modify if what I said doesn't make sense)

  10. #10
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    Very cool. I like the BB-DT-ST joint. Building my first frame as well. Subscribed

  11. #11
    Nemophilist
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    Well;

    You've obviously TIG welded before! Looks like you are ready to crank some serious rock & roll here. Looking forward to seeing your progress.
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

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    Get the Pacenti guides for next time

    Those cast cable guides have always freaked me out because they're so rigid. TIG welding them is going to add to that stress-riserness, too. That said, IMO you are fine, go ride the darn thing.

    I prefer the Pacenti guides as they're less rigid (and they're stainless, which is nice once the paint wears off the guide). Looks like they are out of stock right now though.

    Very, very cool first project. Your welding looks great. Tacks a bit less so - try to start the tack on the non-mitered surface and not throw quite so much rod at it. Those are bordering on being problematic for causing failures from fatigue someday.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
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  13. #13
    J_K
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    Quote Originally Posted by Feldybikes View Post
    I might keep an eye on the welded cable guides if on the thin part of the tube. Silver no problem. TIG might freak me out. Might be worrying about nothing, though.

    Also, and you probably already know this but just want to be sure: weld all the way around for the compound joints on the BB/DT/ST/gusset (or whateveryoucallit). I.e. weld the DT to the BB completely, then the ST to the DT, then the gusset to all three. (This description assumes I interpretted the intersection of the joints from your drawing correctly, so modify if what I said doesn't make sense)
    Front cable guides are on the thick .9 part of the tube and rear cable guides are partly on the butt trasition area, but definitely not on the thin part of the tube. I'm not worried, but I will keep on them once the frame is in use. Rock Lobster seems to be welding all of his braze-ons.

    DT is welded to BB. Next I will tack the ST to the DT and the TT to the HT/ST. I will weld the gusset before chainstays.

    Quote Originally Posted by TrailMaker View Post
    Well;

    You've obviously TIG welded before! Looks like you are ready to crank some serious rock & roll here. Looking forward to seeing your progress.
    Actually I have not TIG-welded that much, but I find that lap joints(is that correct term for these kind joints?) are easiest joints to weld.

    Quote Originally Posted by Walt View Post
    Those cast cable guides have always freaked me out because they're so rigid. TIG welding them is going to add to that stress-riserness, too. That said, IMO you are fine, go ride the darn thing.

    I prefer the Pacenti guides as they're less rigid (and they're stainless, which is nice once the paint wears off the guide). Looks like they are out of stock right now though.

    Very, very cool first project. Your welding looks great. Tacks a bit less so - try to start the tack on the non-mitered surface and not throw quite so much rod at it. Those are bordering on being problematic for causing failures from fatigue someday.

    -Walt
    Thanks for the info Walt.
    I will use Pacenti guides next time. I was going to order them for this frame, but shipping was too much. Then they were not available once I decided to order them despite high shipping costs.

    I'm not proud of those tacks, I should have done some practice welds before I started tacking since it's almost month when I last time welded something this thin.


    Today I welded the DT to the BB, I'm pleased with the results. I was able keep HAZ small and pretty consistent. The Paragon Machine Works BB welds nicely as it is not very thick, I also cut 1" vent hole to the BB.

    Rotating jig for better welding positioning, need to cut excess of the main beam to be able to rotate it all the way around. I'll add also back purge fittings to the BB, HT and ST cones later. There's also my cheap tig welder, the torch costs about the same as the machine

    BB-DT joint welded, BB cones suck heat nicely.

  14. #14
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    Wow J K, you are a surprise package.

    Should have seen it coming, good jig, excellent mitres etc. Just not so good on braze, but a successful frame on the way first time. Will watch with interest.

    Eric
    If I don't make an attempt, how will I know if it will work?

  15. #15
    Nemophilist
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    OK...

    Well, TIG savant seems to fit then. Pretty decent work for no experience. Anything with parts at any angle to each other is considered filleting, I do believe, for what it's worth. Lapping is sort of short for OVER-lapping of some sort.
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  16. #16
    J_K
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    The front triangle is now fully tacked and pretty much fully welded.

    I had to improvise little bit to keep the seattube in place, in the future I will add tubeholder there.




    Gusset is also tacked in, will finish welding it once frame is out of the jig. The gusset was pretty hard file correctly, I had to redo it few times.
    I also cut off the cable guides as they were in really bad position.


    I'm trying to figure out how to miter chainstays, I have plans for the chainstay jig, but I'm not sure if I will get that done yet.

  17. #17
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    Looking fantastic! Keep us updated!

    Those ST/BB braces are indeed a huge PITA. I never figured out a quick/easy way to do it. So I got a tube bender...

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  18. #18
    J_K
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    Quote Originally Posted by Walt View Post
    Looking fantastic! Keep us updated!

    Those ST/BB braces are indeed a huge PITA. I never figured out a quick/easy way to do it. So I got a tube bender...

    -Walt
    Thanks Walt.

    I made this 3d desing based on rattleCAD dxf file and added 1 1/4" tube there and then flattened that tube to get miter template. I'm still wondering how I was able to do that . It was pretty quick to do draw it, it took about ten minutes once I figured out how the program works. I'll definitely get tube bender at some point.

  19. #19
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    Hey;

    You're already a better TIG welder than I am... jerk.

    Good move on the cable stays. Not sure what you were thinking there at first, but at least you kept thinking! I skipped them completely on my first frame. I knew I didn't know anything about them, and didn't want to botch them up like you did!

    Anything mitered at a severely acute angle like that brace is difficult. It takes a ton of patience and concentration - and sometimes 2-3 tries - to get a tight fit.

    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  20. #20
    J_K
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    Quote Originally Posted by TrailMaker View Post
    Hey;

    You're already a better TIG welder than I am... jerk.

    Good move on the cable stays. Not sure what you were thinking there at first, but at least you kept thinking! I skipped them completely on my first frame. I knew I didn't know anything about them, and didn't want to botch them up like you did!

    Anything mitered at a severely acute angle like that brace is difficult. It takes a ton of patience and concentration - and sometimes 2-3 tries - to get a tight fit.
    I keep trying, but there's still lots of room for improvements. I'm only showing my best weld beads anyway

    I'm not sure either what I was thinking with the cable guides First I had them clamped underside of the TT, but then I got that clever idea to place them side of the TT where your thighs will rub against them

    That's nice miter, did you file it or did you cut it with the hole saw?
    I'll keep filing the main tube miters, but I'd love to machine miter the chainstays

  21. #21
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    Hey;

    I apologize for insinuating my work into your thread, but I wanted to lend you some support and encouragement, and relate that it is tough for everyone, every time. That tube was shaped first by a rough chop sawing, then running on the top roller of my belt sander, and finally by hand filing. It was a very long process, but it fits perfectly!

    The machine miters are really only a good starting point in my experience. In many cases, they can get you pretty close. It is often down to luck, skill, of course, and the accuracy of your equipment.

    The closer the tube joint is to 90* the more likely they will be to fit up right off the bat. If a tube also simply goes where it ends up, like my ST-to-TT brace, it still takes an enormous amount of time, but is not critical. When a tube has to fit exactly in a given position between two other tubes, like a TT or DT, the control of filing your way into a perfect fit is immeasurably valuable. You'd machine miter yourself close, but plan on filing your way to a tight fit. If you hit the mark right of the machine, great, but it is better to plan on being a tad long and filing in rather than wasting a piece of tubing. When fractions of a millimeter count, you better have a seriously accurate setup or you will be wasting a lot of material!

    Being able to toss a piece of tube in a machine and get a perfect fit the first time takes some pretty sophisticated equipment (for a hobbyist), and an enormous amount of prototyping of both jigging and final parts to land on a perfect fit with little to no hand work.

    I machine miter my CSs on a dedicated fixture. As good as it is, I have still had variable results. My first attempt got me a perfect fit straight away. The 2nd attempt for my Kroozer, while workable, took some fine tuning to perfect. I was a little disappointed by that, and I'm not sure where things went awry, but at least I had the skills to correct it. People that never learn to hand miter well would be lost.
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  22. #22
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    Is that the end of the butt?

    I am guessing the line on the downtube in the drawing is something else, but if that's the end of the butt, you should start over. You should have at least 25mm or so between any welded joint and the end of the butt.

    I was actually going to ask what you're using for a downtube, since many of them don't have butts long enough to work well with this sort of design. 100mm or so of BB end butt is nice to have.

    -Walt

    Quote Originally Posted by J_K View Post
    Waltworks Custom Bicycles
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    waltworks.blogspot.com

  23. #23
    J_K
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    No that line is not the end of the butt, it's just line on the drawing
    There's over 100mm of butt left at both ends of the DT.
    I did lot of research about butt placement before I started, so I'm aware about what kind of the butt placement you should be looking for. The TT is another story, there's only about 40mm of the butt left at the ST end and about 80mm at the HT. Next time I would like to use True Temper HOX2TT for the TT, that has nice long butts.

    The DT is Reynolds 631 BX5179 X 34.9 0.9/0.6/0.9 714 120.30.320.30.214

    Quote Originally Posted by Walt View Post
    I am guessing the line on the downtube in the drawing is something else, but if that's the end of the butt, you should start over. You should have at least 25mm or so between any welded joint and the end of the butt.

    I was actually going to ask what you're using for a downtube, since many of them don't have butts long enough to work well with this sort of design. 100mm or so of BB end butt is nice to have.

    -Walt
    Last edited by J_K; 01-09-2013 at 08:56 AM.

  24. #24
    J_K
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    No problem at all Trailmaker, keep posting. Thanks for the great info.

    There will be now slight delay with the build as I'm still waiting my XX1 crankset to arrive.
    I want to check chainring clearance before I miter the chainstays.

  25. #25
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    JK

    You are doing well and clearly have researched your topic well, I like and encourage that approach.

    You have concerns about the chainstay mitering.

    Frankly, they are not difficult to file. Looking at your main triangle to date, you have filed all joints and have excelled. I personally am proud of doing better than a machine cut with a file and yours is up there with anything shown in the forum. You also did that gusset for the BB. Now that is a difficult piece, particulary to clamp and finish as well as you have. Doing chainstays is a breeze by comparison.

    I think you will manage easily.

    Eric
    Last edited by Eric Malcolm; 01-09-2013 at 01:45 PM. Reason: spelling
    If I don't make an attempt, how will I know if it will work?

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