Hello, I'm making some tests with the module sheet metal.
I made a simple bend with this parameters:
- sheet metal thickness= 1mm
- internal bend radius= 1mm
- bend configuration: 90° bend with Kfactor=0,5
other dimension are summarized on picture and FC file attached.
When I use the unfold command, I obtain a sheet metal long 198,356mm but, making some math calculation, the lenght should be equal to:
L1+L2+(T+Kf*T)*pi/4=98+98+(1+0,5*1)*pi/4=197,178mm
where L1 and L2 are the lenght of the straight plates, T=thikness, Kf=neutral factor, pi=3,14...
I don't understand where is the error.
Is there any configuration that I have to tune?
Attachments: FC file, picture with dimensions.
Best regards.
[SOLVED] Wrong sheet metal unfold dimensions?
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[SOLVED] Wrong sheet metal unfold dimensions?
- Attachments
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- bend test.FCStd
- (15.74 KiB) Downloaded 36 times
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- bend dimensions.png (5.89 KiB) Viewed 1232 times
Last edited by FIBMCad on Thu Oct 17, 2019 7:38 pm, edited 1 time in total.
Re: Wrong sheet metal unfold dimensions?
Sorry there is a mistak in the formula.
The correct one is:
L1+L2+(Ri+Kf*T)*pi/4=98+98+(1+0,5*1)*pi/4=197,178mm
where L1 and L2 are the lenght of the straight plates, T=thikness, Kf=neutral factor, pi=3,14..., Ri=internal bend radius
The correct one is:
L1+L2+(Ri+Kf*T)*pi/4=98+98+(1+0,5*1)*pi/4=197,178mm
where L1 and L2 are the lenght of the straight plates, T=thikness, Kf=neutral factor, pi=3,14..., Ri=internal bend radius
Re: Wrong sheet metal unfold dimensions?
I have a different formula which uses pi/2 and not pi/4.
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Re: Wrong sheet metal unfold dimensions?
Dear chrisb, thank you for your reply.
Yes you are right!!!
Sorry for my big mistake
Yes you are right!!!
Sorry for my big mistake
Re: [SOLVED] Wrong sheet metal unfold dimensions?
There is another error in your formula. According to my book the formula is for an angle of 90° (or less):
L1+L2+(Ri+Kf*T/2)*pi/2=98+98+(1+0.5*1/2)*math.pi/2 = 197.963
which is exactly what SheetMetal WB delivers. Besides that, according to my book th K factor should be 0.6 for a ratio radius/thickness of 1
L1+L2+(Ri+Kf*T/2)*pi/2=98+98+(1+0.5*1/2)*math.pi/2 = 197.963
which is exactly what SheetMetal WB delivers. Besides that, according to my book th K factor should be 0.6 for a ratio radius/thickness of 1
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: [SOLVED] Wrong sheet metal unfold dimensions?
I think that dipend on the definition of Kf. In "my" formula Is defined as the ratio between neutral axes position taken from internal bend (t) and tickness: Kf=t/T.
I have found this definition in the file attached (i'm sorry It is in italian language). In this file neutral factor Is indicated with "e".
I have found this definition in the file attached (i'm sorry It is in italian language). In this file neutral factor Is indicated with "e".
- Attachments
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- 2009-10-28-CALCOLO_SVILUPPO_LAMIERA.pdf
- (631.55 KiB) Downloaded 51 times
Re: [SOLVED] Wrong sheet metal unfold dimensions?
Look at Page 7, picture 8.
Re: [SOLVED] Wrong sheet metal unfold dimensions?
I'm afraid that with that formula you cannot use the same K factor as used in SheetMetal (or in my formula).
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