Lorton bike 002 and 003

[sebaudet]

Hi, after building a first frame thanks Tom (oTm bike in Italy) last year, I spent one year to train in order to make a 2nd frame by myself... (pics on my flicker page), and to ride with my first bike as well, like during the "Too Tall's spring camp" (very pleasant rides for me ! roll on the next !)
Now time is coming to weld my second frame. This frame is not a real frame, it's just for training with tubes from an old stock of Vitus GTI tubes (perhaps you know this old set from the Saint Etienne's manufacture...CrMo 8/10), even the HT is a basic 31,7 GTI tube. So no possibility to ride with, just to train in order to buid the number 3 with a complete OS Cromor tubeset...
This morning I finished the mitering of the front triangle, here is a pic. I will try to post as long as the building is going on, and I hope I will improve my english at the same time . More pics of the process and tools on my flicker page.

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[sebaudet]

New settings on my profile to let you see the flickr adress Flickr: CyclesLorton's Photostream

[sebaudet]

Thanks ! mitering is not the more difficult with good tools and patience, but welding is asking for special skills...
Yes you can walk but it's better to ride...

[Too Tall]

Congratulations. I'm looking forward to hearing more about your progress. You certainly have the legs to test these bikes ;)

If I recall correctly, your father is a expert welder and machinist?

[sebaudet]

Hi Josh, thank you for your encouragement ! Yes my father is a former aluminium welder and machinist, helpful and it's a great experience to share with him

[Andrew R Stewart]

Very smart move to build a frame for the skill set only. So many want to dive in and ride/sell their early frames. Some of the questions they ask are scary. I'll look forward to your process. Andy.

[sebaudet]

This morning I welded the BB-ST, it was pretty easier than during my tests with a BB with 3mm thickness. Now I use a BB with 2,5mm thickness, perhaps the difference is very sensitive, and I didn't know the real alloy of the others, it was from the Vitus stock... This throw away frame has no chance to have back purge so we can see oxydation in the BB, but it's cheaper to learn... I used nozzle n°6, electrode 1,6mm and wire 1,6mm, I think I will try a 1mm wire for the rest of the triangle to have a smaller fillet weld, if somebody can tell if it's better ? For the BB I have to heat a lot and I am scaring to make a hole on the connected tube it's the reason why I take a "big" wire...

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[afwalker]

Wondering what you have for your tig welder settings?
Amps, background, any pulse?
Looks nice:)
cheers
andy walker

[sebaudet]

Thanks, I have 100Amps max but I use a pedal, so I think I don't go beyond 60 Amps, I have pulse because it's easier to control the puddle for me : 1,5sec period and 75% of the time with the high power. My TIG machine is a french machine, a commercy Citotig 1800, just DC but a lot of options and a I had it with a good price !

[sebaudet]

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This morning I have finished to weld the front triangle, it was the possibility to improve the ergonomy of my welding zone as well... It's better to train on a frame, I think I make more progress on this trhrow-away frame than on my previous tests. After the welding I checked the alignment, on the ST it's not too bad, 1mm, but on the HT I have 1mm between the top and the bottom, I think there are 3 reasons :
- a non-precise mittering of the DT, it was not perfectly centred... since I have found a method to perfectly centre my hole-saw on my milling machine
- my HT is very cheap on this frame, a 31,7OD tube with 9/10 thickness, too soft I think
- my skillness in welding, it would be better and better !

But I read some Guys misaligne their frame before to tackle, if someone know this technique I am curious because I just know the method of a good sequence of welding(learnt by Tom, I think he has learnt this at UBI)...

[Andrew R Stewart]

I don't weld but i do understand what people mean by welding the frame into alignment. When you have done enough of the same weld in the same secquence you start to understand how the parts warp/shift WRT each other. So you begin to set up the joint with a purposefull missalignment such that after welding with the same secquence you have before the finished result is straight. It's like target shooting in a cross wind. After a few shots you figure out the correction (windage) so that the shot hits the target. The key is how consistant the wind is. Builders do this all the time. The best example is to set the rear drop outs a bit wider then the finished width will be. With brazing the stays pull in a touch. Some builders will just cold set the stays after, some will antisipate the pull in and set the prebrazing width more by that pull in amount. Andy.

[TroySmith80]

Glad to hear that you're learning. I can't help you with the welding, but you also expressed interest in improving your English. It's already quite good, but maybe I can help a little if you like.

" it was the possibility to improve the ergonomy of my welding zone as well... " Most anyone would understand what you mean here, but a more accurate way to say it would be:
it was an opportunity to improve the ergonomics of my welding zone as well...

"my skillness in welding, it would be better and better !"
My welding skills, they will get better and better!

You are just a little bit awkward but only a little. Really your English is great for a second language. I'm a bit self-conscious writing this, hoping that I've not made any important grammatical errors! haha


Anyway, good luck with your frames! I'm here to learn as i set out on my first build over this winter.

[sebaudet]

Many thanks ! I took into account... it's almost as intersting as learning how to build a frame !

[afwalker]

Il parle anglais parfaitement! Ce n'est pas une problem ici a velocipedesalon, duh!
The french know a thing or two about cycling I bet.
cheers
andy walker

[zank]

Nice work. Try to find some 1 mm filler. It will require less heat and you'll be able to travel faster.

[sebaudet]

Thanks a lot, yes I tried a 1mm filler it seems to be a better way... I just hesitate for the welds on the BB
And congratulation for your work, I like it and I like to ride with Lionel on his cobble monster !!!

[sebaudet]

Welding these two frames is going slowly... I have welded the front triangle of the frame 003 (no photos for the moment) after many problems with the mittering... When my hole-saw is going down the tube it seems it's diverging a little out, not a lot but about 0,2 deg then the tubes are not in a perfect alignement... Now I use micro descent with my lathe and have corrected the angles... So a lot of time spent to manage all these adjustments !
For the frame 002 I began to cut the chainstay, learnt to braze the dropouts, alone with a lot of tubes in the rubbish ! For the seat stay I think I took the problem in the wrong way because I have adjusted the drop-out side before... so it was difficult to adjust the seat tube side : in conclusion I have made the seatstay shorters to well adjust, not a problem for this throw-away frame and a lot of lessons learnt.
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[Too Tall]

I really enjoy watching your work progress. Forza :)

[sebaudet]

To move the line faster we have to ride faster... you're agree with my conclusion ?

[sebaudet]

It was not easy but the throw away frame is finished... I have to improve my welding skills so I cut it and will weld the seat stays and chainstays an other time... Some pics of seatstays, welded with standard gaz lens and cup n°7 (thanks to WayneJ and RCP Fab for the advice)