Anvil Jig (3.1) Head Tube Arm Setting Question

[Jose Emmanuelli]

Hello to everyone and my best wishes to all in the new year.

the case is that i have an Anvil jig (3.1) that's giving me a hard time setting the the HT bottom height, the instructions manual that came with the jig are miss placed, if someone have the same jig
an can tell me the location point to reed the scale on the head tube arm, is on top, center were the adjusting key is or the bottom? I asking specifically for Type 3.1 I don't know if the other models
have same dimension on the HT arm.

thanks in advance

Jose

[Rody]

Jose,

I'm not familiar with the Anvil fixture, but you should be able to extrapolate the position of the bottom of the head tube with little effort.

Do you have a CAD drawing you are working from? If so, I would recommend setting your rear dropout position and then make a simple flat aluminum bar tool that represents your axle line. Drill a hole at one end of the long aluminum bar that slides over your rear axle. Machine and bolt a perpendicular "T" that attaches to your bottom bracket to hold the bar securely in place. Then, simple measure out to find your front axle point. Use your axle to crown length of your fork plus the headset allowance and that will represent the bottom edge of your head tube. Once this is known and the head tube is set, you should then be able to determine where on the fixture this setting for the scale is represented for future use.

Best of luck,

Rody

[progetto]

Anvil Frame Fixtures.pdf

[Rody]

Thanks for posting that Bill...

from the pdf

Head Tube Height
All Anvil frame fixtures locate the head tube’s vertical placement by a measurement we call “head tube
height.” This is the vertical dimension from the center of the bottom bracket to the bottom center of the
head tube. This dimension can be taken from your design drawing. Again, this the vertical dimension
from the center of the bottom bracket to the bottom center of the head tube. Head tube height is directly
read from the bottom of the top tube length arm on the vertical scale which is permanently placed on the
fixture’s base plate. A change in head tube angle will not affect the head tube height.