Friday, October 9, 2009

Signature Snapshot: Titanium Cyclocross: 02

Now we are catching up with the titanium cyclocross frame we are building for Signature Cycles during the second alignment check on the alignment table. There are plenty of steps that I am skipping throughout the process..... but that is what future (and past) postings are for. You can also check out more of our process at The IF Experience on our website (not mobile device friendly). We base our frame alignment off of the center line of the frame and do our best to make the frame as symmetrical as humanly possible. A step I skipped was tapping and facing the bottom bracket. Unlike the bikes we make out of steel and stainless steel, we tap and face the bottom bracket on our titanium bikes right after we weld the main tubes together. We have found that the distortion caused by welding affects the bottom bracket just enough to give us inaccurate readings on the alignment table. Facing it gives us a perfectly flat and perpendicular surface to mount the frame to the table and makes our measurements reflect the frames true alignment.

First we check the seatube to make sure that it is on center. Then we check the headtube (above) for the proper height and make sure that there is no twist.
Then we check the dropouts to make sure they are properly spaced and centered.
Finally we check to make sure that the chainstays and seatstays are centered. After the frame is nudged into symmetry, it goes back into the welding department to have its parts made and welded on. we have our own machining center in the welding area that is set up just for this purpose.
Above are the completed parts.
The parts are first cleaned and then are tacked to the frame in their proper locations.
After tacking all of the parts on they are TIG welded to the frame.


The final step in the welding department is welding the dropouts. We go through a process called the "wheel check" just before welding. The wheel check process involves centering a tool in the dropouts that is used to measure how centered they are in the frame. To adjust them we heat up the tack weld and either push the dropout in or pull it out. This is one of the most delicate operations in the process, you must really have a thorough understanding as to how metal contracts as it cools.

After the frame cools down it moves on to the finishing department..... stay tuned....

2 comments:

andrew fields said...
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andrew fields said...
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