“New” seatstay bridge bender…

arch-bender

Step one. Find an old wire spool and see if it works.

archbender-result

Step 2: try out some 1/2″ x 0.035″ 4130 tubing. Sure, a little ovalized but it’s just a bridge. Kinda like that look actually.

done-rear

Step 3: Braze or weld it in there. Not bad for a free bender!

Process shots from Adam’s 29+

Adam’s frame is 95% done. I just need to cap the wishbone stay ends, put on a few cable guides, ream/face, and clean up before posting any final parting shots.  It was a challenging build not just because the bent tubes but because it was so interrupted by time away from the shop. I have to say, if i wanted a custom 29+ this is what I’d order too.  Maybe with internal cables though.  I’ll post geometry and more details when I post the ‘final’ shots before it goes to paint. But for now here are some process shots for the FB dorks out there.

Favorite uses for magnets

Fixturing with magnets.

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The magnet on the top cap of the fork is the latest discovery for me. Holds it to the leg no matter which way I tip it! So easy to braze now.

20130918-191642.jpg

These pivoting magnets from I can’t remember are great for fixturing fork legs to crown pieces and tacking while upside down. I use these a LOT for various things that typically used to fall and clang on the floor while balancing.

Drill Chuck setup

Something to share that made mill setup just a little easier and faster.  I replaced my R8 arbor drill chuck a 5/8″ drill chuck with a 3/4″ straight shank arbor I found on eBay.  Whenever I center the spindle, tram, drill holes, etc I would normally unload whatever Paragon 3/4″ hole saw arbor was in the mill, along with the R8 collet itself and load a regular R8 arbor Drill chuck.  Then I’d use the edge-finder in the drill chuck to center the spindle. Then either load a drill bit to make breather holes or whatever or reverse the last toolery setup so I had the needed tooling in the spindle whether it be a hole saw arbor loaded back up in the mill or an endmill holder.  Not hugely time consuming but enough that this new setup makes a nice difference and it also works in the horizontal mill.  The drill chuck fits up to 5/8″ diameter and slides right into the R8 collet.  Now I almost never have to remove the collet from the spindle since all i ever use are 3/4″ Paragon arbors and this chuck.  Very exciting.

drillchuck-straightshank-R8

Top 10 favorite framebuilding tools

It’s hard to pick just 10, there are so many. No, they’re not all file types and sizes. These are just the first that come to mind.

  1. Wilton Tradesman vise (5″ jaws) and some copper soft jaws. I bought it new to last me a lifetime and then some. Good luck finding a good used one. It can be done, but i looked for a year and found only junk.
  2. 6″ steel rule – metric on one side, ‘merican on the other. In my pocket at all times.
  3. 8″ half-round file (Fine) for smoothing out the miters that are inevitably rougher than I want straight off the mill.
  4. Hacksaw. Duh. 32tpi blades.
  5. Digital angle finder (so so many uses).
  6. Anvil Main tube mitering fixture. Seriously gucci but worth it. The newer version can fixture almost any size, taper, and orientation of tube including chainstays and seatsays for slotting.
  7. Diamond horizontal mill.  Three speeds is enough – it copes, it slots, it’s old and grey, it will live forever.  It may be small, but it’s light!
  8. Paragon tube blocks. So many uses from drawing tube centerlines, to mitering in the vise, to phase keeping, to flat plate ‘fixturing’, to…
  9. My brown iron workbench/table. It weighs more than my mill and is the centerpiece of the shop. So much is attached to it or resting on top…I just wish it were twice as big. But then I’d wish I could move it.
  10. Bringheli C-channel alignment plate. It’s not just for checking frame alignment. I use this more than I ever thought I would. This thing has taught me more than I ever thought it would which was a surprising side benefit.
  11. Anvil Journeyman 3.1.  It just IS. More than needed, such a privilege to own and take for granted. I hope to deserve it some day. That one is worth making the list go to 11.

 

You learn some things the hard way

From the start I’ve been all about full disclosure on this blog….so you get to share in my triumphs and face plants. Here’s one of the latter.

The last two bikes I made were singlespeed cross frames that were nearly identical.  One for me, one for a friend.  The main difference was that mine had a wishbone seatstay and the other had 16mm straight (half)fastback seatstays.  I have been wanting to make a little Nifty Tool to check chainring and crank clearances on the drive-side chainstay for awhile now…but just never got around to it.  But really, that would show me that i messed up after the fact (after mitering and tacking the stays).  I really should just drawn up the crank and chainring clearances…I already had a drawing for rear tire clearance after all. Double DUH!

Well, what happened is I completely overlooked this one thing on BOTH these frames and had to put a huge dimple in the outside of the drive-side chainstay to get the SRAM Rival crank and chainring to clear.  What a stupid dummy…lesson learned the hard way.  I always mock up the tire clearances on paper and in BikeCAD, but just have neglected to mock up the cranks.  For one, the info is hard to find online, and when you find it, it sometimes doesn’t have the measurements you need (it’ll have the distance to the inside chainring but not to the inner crank bolt that sticks out from the chainring).  Chainline is even hard to find sometimes.

It’s the component part of building bikes that has turned out to be the most frustrating for me.  The diversity in parts and their clearances, all the new “standards” popping up seemingly yearly (i.e,.  For bottom brackets you have: BB30, PF30, BB86, BB92, PF30, eccentric BB, English threaded, Italian threaded, Bombay threaded (Ok, that last one was a joke)).  But see what I mean? It’s silly! The advent of carbon mass-produced bikes has led to all the new ‘new standards’ for various reasonable reasons. But for steel frames, the good ole’ threaded BB is pretty much great.  Anyways, where was I? Oh yeah, self-deprecating myself into the bottom of a pint glass.

So here are some photos of how I post-dimpled the outside of the driveside chainstay.  Not pretty, but it works.  I used some old oak blocks for this and a 4″ clamp.  The inner is a 1.25″ block cradling the inside of the stay, the outside is block that I whittled down to an elongated oval shape for dimpling for tire clearance (before I got a small arbor press for the tire clearance dimples instead).  The chainstays on frame 14 (orange one) are the same wall thickness as the stays on frame 15 but a different oval profile.  They are both OX Plat True Temper.   Holy crap it was hard to dimple 15’s stay.  I actually had to change methods and put it in a table vice with a Paragon 1.25″ block on the inside of the stay and an aluminum formed dimpling block on the outside to get it to dimple enough.  Never again (hopefully).  Luckily, both frames are still fine to ride but they aren’t quite as pretty as before.  What was interesting to me is that the dropout spacing didn’t change at all before and after dimpling on frame 14, but it did on #15.  I just had to cold-set the driveside dropout back into 130mm axle spacing and it was right as rain.

The new-to-me milling machine

I found this little mill on Craiglist in Santa Rosa, CA. I contacted the seller in October while still living in Colorado, knowing we’d be moved to CA in the next month or two. The back and forth we had on email made me pretty sure I was the one for this mill. He basically took if off CL and ‘reserved’ it for me to see first.

It’s really hard finding a good horizontal mill. I had looked all year and this is the only one I found that most closely matched my search criteria. I didn’t want a massive Cincinnati or the like that is too much machine and needed a significant overhaul. Those are what commonly show up from old machine shops selling stuff through CL. They don’t know the history of the machine, or even if they work!  On the other hand, this Diamond mill was in a nice guy’s garage, weighed 800lbs (similar but lighter than a Nichols which I was holding out for with no luck), and he had received it from his dad who had used it for many years previous. His dad had bought it from their cousin some years before that. So the history of this machine was well known and that’s helpful for something made in the 40’s or 50’s. I rented a little Uhaul trailer and my engine lift to his house to check out.  I knew I wanted it and after talking and testing it out, I paid him $500 and we started loading it up.

It wasn’t until then that he asked me what I was going to primarily use the mill for, and I said I was going to be mitering tubes to make bicycle frames and forks.

Funny thing, he said, his cousin used the mill to do that exact thing after high school many years ago. He asked if I had ever heard of “Tom Ritchey”…

“Um…yeah, I’ve heard of Tom Ritchey…”

“That was his mill!”, he said. “My dad bought it from him years ago!”

Um, COOL! I have Tom Ritchey’s milling machine!! (Tom, if you randomly stumble upon this humble blog can you please verify?)  I had to believe the seller as I had already paid for the mill, so he didn’t need to make the hard sell. What’s weirder is that I contacted this guy just after posting this blog about Ritchey, linking a Vimeo video about him and showing him brazing a frame in his lap.

So the mill has some bicycling heritage behind it which I hope to continue. The table has seen some use, but the ways look and feel great. I have done no testing/tramming to see how square it is to the spindle. The motor was replaced with a 1HP/220v GE from a 3/4HP 115v stock motor. Not sure why but this made it so I have to run 220 in series to this and my welder.  It came with a small 4″ mill vise with no brand marked on it, the vise wrench is an Armstrong so maybe it’s one in the same. The mill is belt-driven with two belts running for each speed. So yeah, it’s only got 3 speeds and I have no clue what they are yet. The slowest looks to be around 100 or 150 rpm which will be great for coping tubes.

I was planning on setting it up with the chainstay mitering fixture trammed and bolted to the table. It’ll hang off the left side a lot but doesn’t get in the way of anything (only one X-axis feed on the right side of the table). The vise on the right side of the table would be used with tube blocks to slot stays and make bridges. But first, I’m going to try and mount the 8″ rotary table and Anvil MTMF on it. I’m told that there’s a newly released horizontal baseplate attachment for my MTMF in the mail from Don (!!). That’ll give me a reason to take if off my vertical mill and mount it up to the Diamond. I really hope it fits, as it can do a ton of different miters when used horizontal like slotting AND unicrown blades. The rotary table may hang off the side too much and not be rigid enough, we’ll see.