Frame Building Course

Yeah! Go you. #envious

Quick update, an hour of removing the excess brass and burnt flux.

/attachments/79951 /attachments/79952/attachments/79953 /attachments/79954

Pretty happy with the outcome, just need to use the brass less sparingly this week and pile it in!

4 Attachments

i found this free ware the other day re design/cad
rattlecadd

#notmeaningtoshowmenanhowtosuckeggs

Cheers saarf will have a good play with that tonight!

yes, good stuff, been trying meself, got to get me shit together re Pythagoras also (

I may have to move to Manc.

Good work so far.

I've got a few questions about that joint, hopefully you'll be able to answer. Hopefully I don't sound like too much of an arse either!

It looks to me like the braze hasn't been pulled all the way through from the exterior tube/lug interface to inside the lug, nor has it been pulled all the way around the exterior edge of the lug. In other words, it looks like you may have a poorly penetrated joint, at least in the pictures.

Now, that might be the photos, but it'd really be worth checking that - you should see the bronze everywhere that it can be pulled via capillary/heat action. Obviously the danger is that if there are gaps, the joint isn't going to be as strong as it could be. Is the joint complete, or is there more work to be done?

Have you done a practice one and cut it open to see how the brazing material has flowed inside the joint? That's well worth doing.

Cheers for the feedback Mikenetic, but the joint is only about half complete we ran out of time, the downside of the course only being for 2 hours each thursday!

Ah right, that makes more sense then. Normally you want to keep the heat cycles to a minimum, but if it's only a couple of hours at a time then I can see why that might have happened.

Looks good, would definitely be interested if it was re-run!

Week 4 – Down Tube, Head Tube Mitre

This week’s session involved using a CAD generated template to profile the mitre angle of 73deg, I forget what program Darren used(may have been rattleCAD..), first off we created a centre line mark at each end of the tube and then attached the profile, 20mins later and the profile looks pretty good.

/attachments/80234 /attachments/80239 /attachments/80235

As can be seen in the above photos there is lug that will be used, unfortunately the frame supplier had sent the incorrect angle, this was only spotted after 20mins of facing the internal surfaces!!

We moved onto finishing off out Seat Tube – BB braze from last week.

/attachments/80236

A good hour of cleaning/filing the braze this weekend and im quite happy for my first brazed joint!

/attachments/80237 /attachments/80238

Doubtful of an update for a couple of weeks as the college is shut this week for half term.

6 Attachments

first off we created a centre line mark at each end of the tube and then attached the profile, 20mins later and the profile looks pretty good.

This might be stupid, but I have often wondered: How do you find that center/top line in both ends of the tube so that one is not rotated in relation to the other?

The method we used was very easy(that easy know one in the group guessed, I was going down the clamp and surface table route!), hold two tubes together on the work bench and mark each end with a marker where they touch.

very clever, thank you.

The method we used was very easy(that easy know one in the group guessed, I was going down the clamp and surface table route!), hold two tubes together on the work bench and mark each end with a marker where they touch.

That's a really good technique if you don't have the clamp and table.

That's how I do it, clamp the tube to the plate, run an engineer's square along the length, let the thin steel edge make a nice light mark along the tube.

post of great interest, I'm careful

After a week’s break due to the college facility shutting for half term, we were straight back into it preparing the dropout/chain stay joint.

/attachments/81095 /attachments/81096 /attachments/81097

Over to the brazing area.

/attachments/81098

Once again we were victims of the stopwatch and had to stop brazing, after a quick inspection looks like I still need to pull the brass further into the joint.

4 Attachments

I found out about this after it started too, very jealous.

Run this in London too and you'd be rich with the number of people interested

It's roughly the same price as a round down there.

Cracking session in the workshop last night, jumped straight onto the brazing equipment and cracked on with finishing off my chain stays.

/attachments/81180

Onto the head tube/down tube joint after a bit of filling within the lug it was ready for some brass! (was gutted when I realised I forgot to take a before picture!!) It was great seeing the brass being pulled through the joint by the heat, very happy with the braze, just lots of cleaning up to do this week!

/attachments/81181 /attachments/81182

I had a spare 5 mins at the end of the session and couldn’t help myself, I had to piece together the sub-assemblies, starting to come together!

/attachments/81183

Bit of homework this week also, lug prep for next week!

/attachments/81184

5 Attachments

That Head angle looks a bit on the steep side.

Definitely up for this course!!!

Please keep us posted on availabilty and I will drop them an email anyway...

That Head angle looks a bit on the steep side.

The down tube was mitred at 73deg and the lug was at 73deg, it may look steep due to the down tube only being push fit into the BB for the picture. Hopefully will look better by the end of the session this week.

Iphone photo's at an angle aren't the best for gauging geometry.