Chris, I recently answerred a similar post to this. See if this helps:
Don O'Neil Give me your measurements in MM and I'll figure the spacing. It's much easier. I need large and small diameter and wrap length. It won't come out exactly the length you want so would you rather it were a little longer or shorter?
July 2 at 7:30pm · Edited
Billy Vivona SOmethign is not right off the bat. The diameter that you gave is huge, and you do FW rods. I'm going to walk through the process anyway because that is the point of this post to try and get you to understand what to do
July 3 at 7:33am · Edited · 1
Billy Vivona First thing you need to do is convert the inches to millimeters. Take your 10" .98 & .9 measurements and plug them into this conversion calculator website (bookmark this link). .98 = 24.89, and .9 = 22.86. 10" = 254mm
[
www.metric-conversions.org]
July 3 at 7:35am · Edited · 1
Billy Vivona Next you need to convert the blank diameters to circumfrence. Using the following website, just plug in the diameter...24.89 = 78.19 (round to 78); and 22.86 = 71.81 (round to 72)
[
www.math.com]
July 3 at 7:36am · 1
Billy Vivona So here are the new specs for you to find the taper offset spacing:
Butt: 78 Tip: 72 Length: 254
YOu will have to do a little math here. Rather than force yourself to use 254mm, use that as a guideline for about how long you want the wrap. Take the midpoint of this wrap which is 75mm, and multiply it by the number of repeats you want to use, and see which one is closest to your 254mm
2 repeats = 75 x 2 = 150mm
3 repeats = 75 x 3 = 225mm
4 repeats = 75 x 4 = 300mm
I will set up the spacing for both 3 or 4 repeats...and I am not going to worry that the blank diameter is a little different where you measured at 254mm, and 225 or 300mm - it's close enough
July 3 at 7:42am · 1
Billy Vivona 3 repeats - For the 180 spacing I will take the tip and butt diameters and filp flop them. The middle number will be calculated by the number that fits in the middle of 72 & 78...which is 75mm
****** 180 spacing: 72 75 78 ******
For the 0 spacing, you are going to divide the first and last number by 2 and fill in the blanks - you will have 4 spacing points marked 72/2 = 36 & 78/2 = 39
****** 0 Spacing: 36 73.5 76.5 39 ******
To make sure you did it right add all the numbers for the 0 axis, and make sure they equal the 180 spacing total.
July 3 at 7:48am · 1
Billy Vivona 4 repeats take tip & butt flip them. THere are 2 more numbers which need to be filled in between 72 and 78. IT works out pretty easily...
***** 180 spacing: 72 74 76 78 *****
For the 0 dived the lat two numbers by two, and fill in the blanks...
***** 0 spacing 36 73 75 77 39 ******
July 3 at 7:49am · 1
Adam Bricker Billy Vivona this definitely helped me understand how this is done , it is important for me as a rod builder to get this right & really understand how it works on paper rather than depend on a computer to do all the work for me . I allmost purchased Vi...See More
July 3 at 8:55am · 2
Billy Vivona No problem at all. John Fore asked how I got the 73.5 & 76.5 spacing on the o axis of the 3 repeat set up. IT is explained in my book in more detail (I think, somoene who actually read it please confirm, lmao).
Look at the spacing for the 180: 72 75 78...See More
about an hour ago · Edited · 2
Edited 1 time(s). Last edit at 07/23/2013 10:01AM by Tom Kirkman.
