Switched to my Victor way easier to control flame/heat, something is not right with the Purox.


the first 4 pics are as brazed without rinsing or soaking, if anyone has imput about temps, etc. I'm all ears. Some of the blackened areas may be paint, I didn't go nuts getting all of it off on the tubes.






second sess after soak and wire wheel shown in the pic below. I tried to build up a large fillet but still had mtl. where I didn't want it, but overall better than my first attemps in sess one.This was when I realized the cleaner the fillet the easier the finishing(doh1) All the fillets are tt brazed to dt and here I snugged up the piece of dt in a Park stand with a 1/2" pipe clamp, mounted the pipe in the stand and then could turn/rotate for the fillets, much easier than using the vise.








donor bike


third sess continued below

My goal here was to make a small fillet with good penetration, with minimal excess mtl., which I feel pretty good about. I also improved my flame/heat control over earlier attempts, but I can see I have a lot to learn about dialing in the right flame. Each of the sessions were done in the evening on different days last week.





this pic shows the bar clamp set up hold the dt piece, the other end of the bar was in the Park stand


soaked and wire wheeled below, no filing, getting a better feel for the process.

what are the gritty looking things in the fillet below, some type of contamination?


all the fillets had penetration equal to this pic







Being that these were my first fillet attempts I feel I'm beginnig to get a at least a rudimentary feel for the process

torches used, victor on the left and the probably needs rebuilding purox on the right.

Isn't that (penetration?) more a function of the miter?

Along those lines- Should I be spreading flux on the unmitered tube before I fit the tubes together and then fluxing over all that as well?

It's Friday and my beer tastes of metal...

Just did these today. It's a SPT, a stem/handle bar stub that clamps to the post to allow a handle bar bag to be mounted behind and below the seat. First (to my knowledge) done by Eclipse back in the 1970s. Also part of the job is a support strut set to span between the rear eyelets and the bag's rack. Normally these bags have a lot of bounce being canti levered off the bar/stem. With the struts the back end (or ft end if over the ft wheel) will have a vertical support brace. The SPT needs finish filing, cutting down the post clamp, cutting the binder slot and reaming for the 31.6 post. The struts are only begun. Andy.

Dan- Internal fillet/penetration is a factor of the brazing, not so much the miter. Getting the junction of the tubes hot enough so the filler can flow between them. (Without overheating). having flux on any surface you want the filler to go to is what i do. I also like to have a reserve of flux near by, meaning I'll flux beyond the area of filler placement. So, yes, I flux both tubes maybe a 3/4" or more past the junction. The post i just did of the SPT shows a tacked pair of joints. Note how far up the tubes the flux is. the inside surfaces of the non mitered tubes were also fluxed. This is why having sufficient vent/soak holes is a good idea. So the inside flux can be soaked off and the insides can drain/dry. Andy.

Wow, thanks everyone for the pics. I really need to stop mitering and do some brazing.

Random answers to questions posed above:
gritty stuff in fillet is probably un-melted constituent metal of some sort. Would probably need to do some metallurgical analysis on a section of the fillet.

Penetration is a matter of heat control, although if your miters are horrible it might be easier to get penetration by default. I'm a little to obsessive about miters to find out

Nice fixturing solutions and brazing Andrew.


I had to get myself out of trouble early this week. I have been building some bikes with integrated bearing head tubes and finishing them is some kind of nightmare. Although the cutters fit on park handles and work to dress head tubes on steel bikes, aluminum is a whole different animal. I got crazy chatter.

The only thing I could come up with was an internal expanding arbor. Thankfully it worked. the "RAW WAR" bike started it's trip to Australia.


30 146 by frankthewelder, on Flickr

The next thing was sanitary welding for local maple syrup producer. They tap 5,000 trees and produce 20,000 gallons of finished syrup. They have a good bush and get around $85.00/gallon.


30 147 by frankthewelder, on Flickr


30 148 by frankthewelder, on Flickr


30 149 by frankthewelder, on Flickr

And now for something completely different...

I built wheels today... the hubs are ours which are lovingly turned out by hand at the main shop.







These will go on my touring bike tomorrow...

Having a torch means you can fix other things... this Campy dropout tool came to me (free) because the threads were all but gone.

The cap on the threads might give you a clue what I used to repair it with.





I drilled out the old bolt and dropped in a length of 10mm chromoly axle and then brazed it in, the hollow axle allowed me to get some excellent penetration without interfering with the body.

Have yet to see how well it holds up but as most of the stress is at the face of the tool and not the threads I think it will work quite well.

If not, I will just build one from scratch.

So, I have thought about making hubs. It is pretty complicated. 'Lots of operations. Countersinking the inner flange holes must be a hoot. I have a big cincinnati dividing head that I would likely use for such a job with a carbide burr. How did you do it?

So, I have thought about making hubs, After seeing yours I don't see a need, they are beautiful.
It looks pretty complicated though. 'Lots of operations. Countersinking the inner flange holes must be a hoot. I have a big cincinnati dividing head that I would likely use for such a job with a carbide burr. How did you do it?

Bumping this for a progress report

Now for the next installment in the bike fabrication mayhem:

Cargo electric bike dude and I fell in love with this frame for a lot of reasons, one of which is that it gives us an excuse to build a bike with 20" wheel- this affords a couple of wins, one is a smaller/cheaper motor, but enough torque to get up the hills around here:


https://www.somafab.com/archives/prod...argo-frame-set

BUT, our fabrication skills aren't up to snuff yet, so whilst googling we came across this as a stopgap "truck bike" conversion solution-


https://jacobsgreen.bigcartel.com/product/the-zaftig

Now THAT is something we can fabricate, so we bought one of these:

and slapped it one a mountain bike I have in the hoard.

Which brings us to here:





We'll be fabbing the shelf on soon.

It's really weird to ride a bike with almost no trail. You CAN'T ride it no handed, even if you lean, it just tracks straight. This is ideal for a load, the lack of trail means that the weight of the load won't interfere with the handling of the bike. I hope.

In other news, I've started a job at a physics lab on campus where I now have access to a full machine shop and my own bridgeport and lathe. Suddenly mitering tubes to make a DIY frame isn't so impossible.

Nice sounding job! Looking forward to seeing the platform.

Brian

Damn Dan, that sounds awesome. If you need any tech support on campus, you have my info.

My home compute broke down but work at the shop progressed. I made a crazy weldment for repair of precision grinding machines. I got a frame back from paint and realized I put the cable guides on backwards (which sucked) and will now require a new top tube. I worked on a huge tandem for Lanie and I and...

The kids had a jump jam in the Liberty mill last saturday. We did shop tours all day, they loved the antique bikes. And...

I built another aluminum road bike where I had "full latitude" with shaping but the rider is huge so stiffness limited my selection of "tube torture" devices. I ruined the main photos but it will be back from age soon so I have another chance to get some good pics.

and for the Pièce de résistance, I started spring cleaning in the shop today. I had a heavy week and couldn't take any more serious work so I lost 1000 lbs of weight and tidied up a bit.

Enjoy


30 168 by frankthewelder, on Flickr


30 159 by frankthewelder, on Flickr


30 180 by frankthewelder, on Flickr


30 181 by frankthewelder, on Flickr


30 185 by frankthewelder, on Flickr


30 189 by frankthewelder, on Flickr


30 191 by frankthewelder, on Flickr


30 192 by frankthewelder, on Flickr


30 171 by frankthewelder, on Flickr


30 190 by frankthewelder, on Flickr

Nice dimes Frank, but thats just business as usual for you I suppose. Why do you have to replace the tt and not just grind off and replace the guides? I can't tell from the pic but is the tandem fork segmented?

thanks, Brian

The tubes on aluminum this aluminum frame are very thin and they distort slightly where cable guides are welded on. Not all welds come out looking that good. The ones in the deepest fillets come out nicer than the ones that are more flat.


The tandem fork is segmented with the crown tubes from .083 wall 4130 and true temper 1.5mm wall legs.

Today, I hope to complete the shop cleaning. I also have a Ti dropout repair job and cardboard recycling then a nap planned.

Ha, thanks, if you're still curious, I work here- https://lps.cornell.edu I have a feeling that a lot of research grants were renewed before the fiscal cliff, so there seems to be a lot of lab tech hirings as of late. I'm loving it so far, I'm more or less paid to know things and creatively apply that knowledge to solve compatibility problems. A perfect fit.




Might as well keep this all in one thread- would someone with a park headset press mind firing up their calipers and taking some rough measurements? I could use a basic lathe project and making the stepped guide seems like a nice and simple project with some residual function. I kind of need a headset press anyway.

I'm talking about these guys-

Found this online:



So I started in on my first lathe project, and ended up with this:

I got a good ride in yesterday finally. I have been spinning indoors quite a bit but the two hour ride in stiff wind totally wore me out but it was soooo awesome..

I made stuff. I got that shape-tube bike done, the shop looks great and I wrapped up another 20 pr of Bullseye cranks and got them shipped. My sugar-makers stayed out of trouble and only blew one steam coil. The people that made the coil used square tube for the manifolds at the ends. When the coil comes under steam pressure, the flat sides of the tubes flex out and cause a reverse root bend and failure. People should know this before if they are making and selling pressure vessels.


30 221 by frankthewelder, on Flickr


30 219 by frankthewelder, on Flickr


30 216 by frankthewelder, on Flickr


30 213 by frankthewelder, on Flickr


30 212 by frankthewelder, on Flickr

Frank, I hope you're getting paid in maple syrup! And that tandem is bad-ass!

Nice. I'm sure your fabrication world has opened widely. Have you previously used mills, lathes, etc?

Brian

I try to keep about two gallons of reserve in case of disaster. It's going for around $100/gallon for the light/fancy these days. Thankfully, it's one thing I never have to go without. I also get amazing organic veggies and meats. My wife bakes and with my welding we have most of it covered.

Thanks, the tandem was really fun to build. I guessed on the steering geometry and thankfully it has wonderful steering and even though we aren't an experienced team, we did our little test ride just fine. I still need to get saddles and matching tape for the rear and may be some extra brake hoods for the stoker. I think it's longer than the usual tandem but I wanted her to have room to read if she wants. I have a trip planned upstate late in the summer..

I was busy last Friday and then went away for Easter... finished that custom rack that I designed for my Surly Pugsley and am waiting for it to get powder coated.

Hoping to make this a production item.

Nice headset tool. Mild steel?

Not with metal. I have a wide mechanical background (carpenter, cabinet maker, plumber, mason, heavy equipment operator, mechanic, artsy fartsy brazer type...) so while the processes aren't totally there necessarily, the majority of the aptitude is already. I'm catching on quick.


Aluminum. Only stock we had in the right diameter. Ill probably have to turn another pair at some point, but it's not like it's going to get used daily. Ive been making a point to learn/teach myself as quickly as I can with the least expensive failure modes- the softness of aluminum is perfect for this.