It helps to have the flame reeeaaalll small otherwise you don’t get much build up. Trying to lay tight beads like that is good practice for heat control. I was keeping the torch moving in little circles and backing off/coming in to control heat and time my dabs of filler.
With proper paste flux it’s a lot easier to see what you’re doing since the flux has already gone clear and liquid when you start laying the filler down instead of bubbling and fizzling all over the place.
first frame should be a monthly special off nova to be thrown away. Get the $100 kit because you are going to make that much $ in mistakes on Zona or anything nice.
My first few machines don’t have dimpled chainstays and they’ll fit Confreries w/o any problem, flat magnets tightly. And dimpling is stupidly simple to do; if you’re fretful that you’ll mangle a chainstay just dimple them before gluing them into the frame, so fucking up won’t fuck up the whole frame.
Also seconding the ‘el-cheapo Nova tubeset’ idea; The standard diameter eNt often shows up in 8/5/8, which will be more supple than an O/S 7/5/7 tubeset, and in any case will help build up a ridiculous stockpile of seatstays (like mine. I need to sort out the lightest ones I’ve got and dump the rest of them.)
Ooh, I figured out the spellwork for modeling drivetrain loads in f360. You arrange a bunch of Ritual Pyramids around the object under test, cast Rigidify in groups, and if it works right you’ll get a plausible result like how the BB flexes more under the left pedal than the right:
FEA is telling me some interesting things! Some learnings:
Seatstay bridges do work a bit to reduce the stresses where SS joins ST/TT, but are probably only necessary if you’ve got S-bent Hellenic stays or such.
Chainstay bridges, on the other hand, are bullshit; they don’t reduce but just move around the stresses where CS meets BB, at the cost of making new, equally severe stresses where bridge meets CS. I kind of expected that since most of the GIS results for “cracked chainstay” seem to originate at either the bridge or at a dimple. So if I just need a fender mount I’ll use a U-shaped bridge across the tops of the CS; If you actually want to stiffen/reinforce the chainstays you’re probably better off putting plates across the tops and bottoms of the CS rather than a tube at the middle.
Which planes more, fastback or Hellenic stays? Fastback, probably! Didn’t expect that. Guess I’ll be trying an English style monostay next.
Yes, flatmount on a steel fork should work at a similar weight to IS tab. Still iterating on how the bracing will look.
Veeeeery interesting! And I have two frames almost ready to braze together, so I’ll need to discard my traditional 5/16ths tube for something else that just holds a fender mount.
I’m not at all surprised == that third crossbar (TT/ST/fender-or-brake bridge) makes even pencil stays stiffer than they look.
Frame #11.5, mocked up (8/5/8 & 8/6 front triangle, most likely pencil stays, maybe disco fever?) and about to be stacked in a corner with my travel frame while I run over to airgas for another bottle of oxygen:
