Trainbike

Just finished this little rack for my around town bike, about 9"x9" lots of small things I feel like I can improve on but over all happy with it. Only the 2nd rack I've made, Would love any feed back or suggestions. Excited to make some more!

unterhausen

Tell us more about your materials. Is it stainless joined with silver? Is it made out of bar instead of tubing? I would suggest working a little harder on making miters, even if it is solid.

I make the stuff that gets stressed continuous if at all possible. I can't really tell, is the center piece continuous all the way to the crown?

Trainbike

It's 1/4 seamless 4130 tubing, brazed with brass. The crown is one piece from the crown to where it meets up to the edge and support, though I notched it with a hack saw in order to bend it, then filled it w brass, a silly way to do things which a little bit of forthough could have been avoided.
The fit up was definitely not ideal, I'm going to make some hardwood tubing blocks to fit this size tubing which should help. I didn't really have a way to hold it while fileing. To make the deck of the rack I layed everything out on a metal work surface and tacked it then brazed it in the vice. I used the fork as a fixture for attaching the supports. curious if anyone has tricks they have figured out it terms of fit up and fixturing.

unterhausen

I have various vises with wood jaws that I use for making racks. I also have some aluminum jaws that fit on my metal vise. It's one step up from holding it in your hand and filing. You don't really need tube blocks. I suppose it would be nice though. As far as fixturing goes, I generally use the metal vise and gravity to hold things together. I also have some modified c-clamp locking pliers and a grasshopper magnetic welding finger. It can be a bit awkward, but I'm not doing production runs. The question I always ask myself when I think about fixturing is if I'm really going to make that exact rack again. And the answer is usually no. I have some tube-based fixturing I can use for rear racks that I have never used.

I guess my main advice is to be patient and make sure the joints look good before you braze them. Otherwise it looks good.

Two things to consider for fixturing: you can get stuff laser cut pretty easily, and it can be really useful for fixtures. The other thing is that you can make a lot of useful fixturing with a 3d printer.

I make a lot of randonneur front racks, and I have settled on a process. So fixturing would probably be useful. I have to think about drawing some up.