STRANGELOVE
- Thread starter velomaniac
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jimihendrix
MacRetro Rider
Stunning work Si, those welds are lovely 
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Dr S":3hv0fgut said:
Some folk add faux fillets to hide crappy welds. I just want to show you that these welds are pretty neat. Almost a shame to cover them up actually.
Si
Very neat welds indeed.
Can I ask why you are welding then faux filleting rather than just filleting?
Is it a strength thing, an ease of construction thing, some other thing?
Loving this thread and looking forward to your updates.
Hi. Good question.
Couple of reasons.
Firstly for extra strength.
the main tubes are Reynolds 853. It's an air hardening tubeset and brazing doesn't get the tube ends hot enough to get the process going. Brazing is in the 800-900 deg range and TIG is 1500 deg range. the tubing needs to get to 1400 deg minimum to get the extra strength.
Secondly, the fillet will help dissipate stresses further along the joint and prevent cracks forming along the scales of the TIG welds- the most common starting point for a joint failure. The small scales of the welds can act as a stress raiser. My background is automotive- mainly race cars and this is where i've seen problems in the past. I suppose its different from what most frame builders think but i'm just applying 20 years of experience from other sectors to make sure my frames are strong enough.
Finally, i love the oldschool looks of a fillet brazed joint. Yes there is a slight weight penalty, but I'm not a weenie. I want something that will ride well for years to come. i won't compromise this just for the sake of a few grams here and there.
Incidentally, true temper (who i use for my seat stays) did lots of destruction testing on joints joined by braze, tig and a combination of both and the tig joints always failed first, and the the joint always broke. the brazed and braze over Tig joints lasted longer and the tube distorted around the joints but didn't snap- in other words, if this type of joint fails, you still get to ride home and keep your teeth!
cheers
Si
Couple of reasons.
Firstly for extra strength.
the main tubes are Reynolds 853. It's an air hardening tubeset and brazing doesn't get the tube ends hot enough to get the process going. Brazing is in the 800-900 deg range and TIG is 1500 deg range. the tubing needs to get to 1400 deg minimum to get the extra strength.
Secondly, the fillet will help dissipate stresses further along the joint and prevent cracks forming along the scales of the TIG welds- the most common starting point for a joint failure. The small scales of the welds can act as a stress raiser. My background is automotive- mainly race cars and this is where i've seen problems in the past. I suppose its different from what most frame builders think but i'm just applying 20 years of experience from other sectors to make sure my frames are strong enough.
Finally, i love the oldschool looks of a fillet brazed joint. Yes there is a slight weight penalty, but I'm not a weenie. I want something that will ride well for years to come. i won't compromise this just for the sake of a few grams here and there.
Incidentally, true temper (who i use for my seat stays) did lots of destruction testing on joints joined by braze, tig and a combination of both and the tig joints always failed first, and the the joint always broke. the brazed and braze over Tig joints lasted longer and the tube distorted around the joints but didn't snap- in other words, if this type of joint fails, you still get to ride home and keep your teeth!
cheers
Si
toons":2nbbmqap said:
Just a few pics. reamed the set tube and head tube yesterday so its all ready for paint. Fork is also finished. Fork was hard to build. I need to go back to the drawing board and re-design my fork jig to hold everything in place better than my current fixture- fitting the disc tab in the right place was a headache!. I can also make the segmented forks that i love too. Still it turned out nice and straight.
A few pics
Sorry about the crap phone pics
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Top post Si, every day is a school day
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Dr S":1g3hqltl said:
Thanks for the comprehensive answer.
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That's super sweet Si. I can see many PM's coming your way offering $$$ for frame builds!
Been there, done thatbrocklanders023":2h23rvw1 said:
Nice to see a work in progress, saves me asking for pics!
I would recommend trying to get some really nice pics of your work Si, even though the pics you have posted look great a much better pic will really help show your work in much better clarity and detail, your work deserves to be shown in the best way possible
