So I was mitering some chain stays this afternoon and something wasn’t right. I have my drawing printed out 1:1 for reference. I marked my miters and set up my Miter’s touch. My drawing is 425mm and I set it up accordingly. I have a Bicycle Academy LCFF and it is also set up using the horizontal dimension which comes out to a little over 420mm. All checks out thus far. I miter the dropout end of the left stay, set it all up in the Miter’s touch, cut the BB miter, clean up the cut and when I place it in the LCFF it’s nearly 10mm short!? I double check and nothing has moved and the stay is the correct length on the drawing.
So I placed the stay in the LCFF and moved the BB Tower in to hold it and measured the horizontal distance and it’s 415mm and the center to center is 425mm. I checked the assembly and set up instructions and all looks good.
My question is: has anyone else had an issue like this? Did I set up the Miter’s Touch with the wrong dimension? It doesn’t seem so since the stay matches the drawing.
I’ve built quite a few frames on this jig and don’t remember this specific issue.
Thanks in advance!
CS on drawing:
CS in the jig:
CS Datum:
CS center to center measurement when jig is set to CS Horizontal measurement per instructions:
CS in jig when it is set at ~420mm horizontal for 425mm c-c:
Measurement when the cut CS is in the jig:
