I am a frame builder AMA

Thanks. Interesting that about titanium, I had mostly only read good things recently when looking at different frame materials from an end-user standpoint.

That is my subjective point of view of the material. The thing is, I'm never going to sell something that I wouldn't want as I wouldn't reccomend it. Again, it's not that it's a bad material it's just that I don't want to work with it as it's a pain and I don't enjoy riding it.

Thanks for the info.

No doubt if I had space for a mill I would get one. No room as already have a pillar drill..

Want to mill an ally box section to slide tubes through for a cargo bike a'la donky bike.. think I just need to become friendly with a mill owner!

I guess I know the answer is just buy the tools but..

So let's say one were to try knocking up their own lugged frame in their back yard, shed, garage etc, how does one go about finishing it off - facing the bb and head tube, reaming the seat tube. Those tools aren't cheap I imagine. Taking the frame to the shop seems like a cop out.

Perfectly acceptable to take it to a bike shop.

Yep. Unless you know someone who has the tools, taking it to the shop is the only realistic option. It's not something you can really do without the proper kit.

Am looking to make my own disc brake forks for a brompton.

Any advice?

How you planning in doing it? Do you have any fab experience? Worked out whether your chosen brake is going to clear folding mech etc? See the stuff Ben cooper from kinetics does to bromptons?

This is a kinetics one. His rear ends are really cool too.

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At the mo it is at the wondering stage. Planning on getting the bits from ceeways and brazing it together. Ben stuff gave me the idea. But I have not looked too closely as I don't want to steal his work.

I learnt to weld on old cars and have tinkered with cars.

I agree with your comments about titanium being very hard to weld well. Have seen titanium being welded in the aviation industry and at that point knew it is for someone else with the right equipment.

Does anyone know anywhere in the UK that still does Panto / engraving, specifically of Fork Crowns / Top Eyes / BB Shells?

http://www.pantograph.co.uk/ in Leeds might? No experience of them though.

What TIG pulse / amps etc are people using for 4130 or similar tube? The settings I use for 1.2 and 1.5mm ERW mild steel (chairs, not bikes) don't seem to work that well for cromoly.

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1 second, 15cf argon. Amps dependent on joint, 20a always base. 20a/110a for drop outs, 20a/90a for BB joints, 20a/60a for head tube joints and 20a/40a for seat tube/top tube. At some point I will buy a digital version of my welder as it is hard to know my exact settings on the dials, but I really only use it for one thing so it doesn't matter too much.

Forks are suprisingly hard to build, so I'd suggest just reading lots and getting a good fixture set up.

Thanks for that topic and all those who already posted questions and answers, that's super interesting :) Some questions from me then.

• How do you bend chain stays when doing bendy chain stays?
  
• When using lugs, I guess the tubes have to be mitered anyway? Is there more leeway than when going down the fillet brazed route?
  
• Is there any shared workshop space of some sort in London where one could go and experiment? Basically I don't have any space myself, I suppose I could rent one and then rent the gear but then I don't have any car to ferry said gear around (then I suppose I could also rent a car etc. but a shared workshop just makes everything easier at this point)
  

Buy bent stays, or buy serious equipment (diacro or similar) theres not really an easy way to do it.

Yes they have to be mitred, they should be as tight as any, but having seen what came out of raleigh factory 30 odd years ago and lasted for 30 years, they don't burst into flames if the mitres are a bit shit.

No there isn't, but @Jingle_Jangle is in the process of sorting something out I think, check in the Frame builders co-op post.

Thanks a lot. I shall go and have a look in that other thread.

Has anyone got a recommend on an affordable, versatile TIG machine (postman affordable rather than pro-footballer affordable).

http://www.r-techwelding.co.uk/tig-welder-240v-dc-160amp/

R tech are a great company, strongly reccomend.

+100

Thanks.

Thanks! So that's 50/50: 1 second high, 1 second low?

Yeah. I can't really deal with the high frequency stuff, but that's just me.

What welder do you ue @danstuff?