PCB Libraries Forum : Axial Components Pitch Calculation https://www.PCBLibraries.com/forum/ Sun, 05 Apr 2026 19:54:04 +0000 Mon, 16 Nov 2020 09:21:07 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=1896 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Axial Components Pitch Calculation : V2020.03 is officially released...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11052.html#11052 Author: Tom H
Subject: 1896
Posted: 16 Nov 2020 at 9:21am

V2020.03 is officially released with this Axial Lead Bend formula fixed. 

www.pcblibraries.com/downloads 

]]> Mon, 16 Nov 2020 09:21:07 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11052.html#11052 <![CDATA[Axial Components Pitch Calculation : Tom H wrote:this feature update...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11044.html#11044 Author: SWB01
Subject: 1896
Posted: 05 Nov 2020 at 8:54pm

Originally posted by Tom H Tom H wrote:

this feature update will be in the V2020.03 release this weekend.
Great! Thank you!
]]> Thu, 05 Nov 2020 20:54:31 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11044.html#11044 <![CDATA[Axial Components Pitch Calculation : Note: this feature update will...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11043.html#11043 Author: Tom H
Subject: 1896
Posted: 05 Nov 2020 at 12:30pm

Note: this feature update will be in the V2020.03 release this weekend. 

]]> Thu, 05 Nov 2020 12:30:01 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11043.html#11043 <![CDATA[Axial Components Pitch Calculation : Looks like the formula changed...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11042.html#11042 Author: Jeff.M
Subject: 1896
Posted: 05 Nov 2020 at 12:27pm

Looks like the formula changed from: Old formula had Lead Length calculated as 1.5 diameters for least (< 0.8mm); 2.5 diameters for nominal (0.8<1.2) and 3.5 for most (1.2<).
Current has just one diameter for each lead length (not less than 0.8) and produces the following sample results. e = D + 2 ( L + r ) + b
]]> Thu, 05 Nov 2020 12:27:57 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11042.html#11042 <![CDATA[Axial Components Pitch Calculation : Ian S: Got it. Yes, I indeed misunderstood...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11037.html#11037 Author: SWB01
Subject: 1896
Posted: 04 Nov 2020 at 12:59pm

Ian S: Got it. Yes, I indeed misunderstood your reply.
]]> Wed, 04 Nov 2020 12:59:24 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11037.html#11037 <![CDATA[Axial Components Pitch Calculation : SWB01 - I agree that PCB Libraries...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11036.html#11036 Author: Ian S
Subject: 1896
Posted: 04 Nov 2020 at 12:57pm

SWB01 - I agree that PCB Libraries tool's axial component calculation for pin pitch is too large and does not match the calculation per IPC-2221A. I also agree that the SWB01 and Jeff's calculations are as expected.

PS. SWB01, in your original post you questioned why the tool came up with a figure of 2.4 mm, as opposed to 0.8 mm, for the 'lead length extension' for a lead diameter of 0.8 mm - I think you misunderstood my reply as I was demonstrating that the calculated 2.4 mm figure was referring to the distance from the component body to the centre of the drill hole and not the straight part of the lead (which the standard clearly defines as "Straight for 1 diameter, but not less than 0.8 mm").

Ian
]]> Wed, 04 Nov 2020 12:57:04 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11036.html#11036 <![CDATA[Axial Components Pitch Calculation : Jeff.M wrote: solution is correct:...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11035.html#11035 Author: SWB01
Subject: 1896
Posted: 04 Nov 2020 at 12:15pm

Originally posted by Jeff.M Jeff.M wrote:

[SWB01's] solution is correct: e = D + 2 ( L + R + b / 2 )
(Note that the calculation described by Ian S does not match this equation.)

If this is the correct formula, then Library Expert is wrong, since this is not the math that the Axial Leadform Calculator is using.

Example with b=0.5 and D=10:Pitch according to this formula = 13.1; Pitch according to the Axial Leadform Calculator = 14.0.

Example with b=0.85 and D=7.6:Pitch according to this formula = 12.7; Pitch according to the Axial Leadform Calculator = 16.1.
]]> Wed, 04 Nov 2020 12:15:06 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11035.html#11035 <![CDATA[Axial Components Pitch Calculation : Ian&#039;s solution is correct:...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11034.html#11034 Author: Jeff.M
Subject: 1896
Posted: 04 Nov 2020 at 11:13am

Ian's solution is correct: e = D + 2 ( L + R + b / 2 )
I write it : e = D + 2 ( L + R ) + b

Where:
b : lead diameter

D : part length, including weld beads if any

L : lead length extension

R : bend radius

m : bend radius multiplier, according to the table in Ian'smessage

e : pitch


]]> Wed, 04 Nov 2020 11:13:55 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11034.html#11034 <![CDATA[Axial Components Pitch Calculation : Ian S wrote:To calculate the...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11033.html#11033 Author: SWB01
Subject: 1896
Posted: 03 Nov 2020 at 10:29am

Originally posted by Ian S Ian S wrote:

To calculate the lead bend extension from the end of the part, you need to add the other parts of the calculation which are the value of the minimum bend radius (R), plus the radius of the lead.
For the total pitch, yes. But (at least according to the revision I'm looking at, as well as the diagram in Library Expert's Axial Leadform Calculator) the lead length extension (L) is from the end of the part (or weld bead) to the beginning of the bend. This value does not include the bend radius or lead radius. Those are added to L to determine the pitch.

So, in math, my reading of the IPC calculation is:

b : lead diameter
D : part length, including weld beads if any
L : lead length extension
R : bend radius
m : bend radius multiplier, according to the table in Ian's message
e : pitch

L = max( 0.8, b )
R = m b
e = D + 2 ( L + R + b / 2 )
]]> Tue, 03 Nov 2020 10:29:56 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11033.html#11033 <![CDATA[Axial Components Pitch Calculation : Should clarify that R is a variable...]]> https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11032.html#11032 Author: Ian S
Subject: 1896
Posted: 03 Nov 2020 at 2:42am

Should clarify that R is a variable as I missed a key word from the R calculation (sorry!). 
Correction below:
R = 1 diameter (for max lead diameter up to 0.8 mm)
R = 1.5 diameters (for max lead diameter 0.8 mm to 1.2 mm)
R = 2 diameters (for max lead diameter larger than 1.2 mm)
]]> Tue, 03 Nov 2020 02:42:46 +0000 https://www.PCBLibraries.com/forum/axial-components-pitch-calculation_topic1896_post11032.html#11032