Calculating weights on an assembly

[normc]

I am doing a design on a Fly Reel that consists of 30 parts. An important criteria is the final overall weight of the reel. So once the materials were specified on each individual component, I first did an overall weight of the assembly and got 9.7 ounces. (after conversion from Kilograms to ounces). Then I redid the total weight by summing the individual part weights and totaled the results and got 9.2 ounces total. This is close to a 6% difference.
I redid all the calculations again to confirm.

Am I missing something or is someone else seeing that their weight results different if calculating as an assembly or using the sum of individual parts.

 

[dwc]

I have never seen a problem with the calculated weights of assemblies.
Could it be that some part exists several times in the assembly and only got included in your sum once?
(I got caught on that once)
Don

 

[normc]

Hi dwc,
Well I went over my spread sheet numbers one more time and found that I had to be careful which selection of accuracy to pick (4 levels to pick from) to do the calculations on Alibre. Otherwise, I get different results.