[Fred Turton]

I am to the point that I am ready to redrill my Thunderbird IRS hub to the 5 X 4.5" pattern. I have a friend with a Bendix (? sp) machine that can drill the holes accurately. My friend needs the drill points as x and y coordiantes, however. Does antone have these coordinates or enough trignometry smarts to figure them out?

TIA for your help.

 

[Fred Turton]

Perhaps I am not getting any responses to my question because I screwed up on the type of machine my friend has. He has a Brigeport milling machine. I hope someone can help.

 

[raceral]

if you are using the 5 on 4.5 bolt pattern
i think this will work..
starting in the center and going up

y2.250 top tophole
x-2.1398y-1.5547 2nd hole
x.8173y-2.5155 3rd hole
x2.645 4th hole
x.8173y2.5155 5th hole
x-2.1398y1.554 back to top hole
y-2.250 back to center

i think my numbers are right not sure about the + and -....

 

[Fred Turton]

Thanks, Al. I asked my son the math wiz to figure it out and he came up with the following:

0,2.25
2.1399,0.6953
1.3225,-1.8203
-1.3225,-1.8203
-2.1399,0.6953

He is positive this is correct and showed me why by plotting the points on his graphing calculator. I would love to be 17 and perfect again!

 

[Russ Thompson]

Wouldn't do me any good, I couldn't do that when I WAS 17.