AutoDrop not selecting the right size

[eholtzer]

I have a question about how Inventor decides which bolt size to select when using the AutoDrop feature in the Place from Content Center command. 

Our close, normal, and loose fit classes are set up in Inventor to match the min hole diameters of ASME B18.2.8 from the 30th edition of the Machinery’s Handbook (see picture attached). 

We’ll use the 1” and 1-1/8” nominal screw sizes for hex head bolts as examples. The min loose hole diameter for a 1” fastener matches the min close hole diameter for a 1-1/8” fastener, 1.156". If I try to AutoDrop a 1” fastener into a loose 1” hole, it places a 1-1/8” fastener instead. 

My initial thought was to simply change one of the two diameters in the clearance.xls excel sheet so that they no longer match. I changed the 1” loose diameter to 1.155” and kept the 1-1/8” close diameter as 1.156”. Unfortunately, I’m left with the same outcome as before. If I try to AutoDrop a 1” fastener into a loose 1” hole, it places a 1-1/8” fastener instead. I’m only able to AutoDrop a 1” bolt from a loose clearance hole if I decrease that loose clearance down to 1.125”. Therefore, I feel as if the clearance.xls excel sheet must have SOME influence on the AutoDrop feature; but decreasing it by .001” is clearly not enough of a difference for it to pick the 1” bolt. 

Is there a way for me to alter a code or setting for AutoDrop so that I don’t need to decrease the 1" loose fit clearance as far down as 1.125” for the program to pick a 1” bolt? I would like to keep this clearance as close as possible to ASME B18.2.8. 

Thanks, 

Erich

[eholtzer]

I have a question about how Inventor decides which bolt size to select when using the AutoDrop feature in the Place from Content Center command. 

Our close, normal, and loose fit classes are set up in Inventor to match the min hole diameters of ASME B18.2.8 from the 30th edition of the Machinery’s Handbook (see picture attached). 

We’ll use the 1” and 1-1/8” nominal screw sizes for hex head bolts as examples. The min loose hole diameter for a 1” fastener matches the min close hole diameter for a 1-1/8” fastener, 1.156". If I try to AutoDrop a 1” fastener into a loose 1” hole, it places a 1-1/8” fastener instead. 

My initial thought was to simply change one of the two diameters in the clearance.xls excel sheet so that they no longer match. I changed the 1” loose diameter to 1.155” and kept the 1-1/8” close diameter as 1.156”. Unfortunately, I’m left with the same outcome as before. If I try to AutoDrop a 1” fastener into a loose 1” hole, it places a 1-1/8” fastener instead. I’m only able to AutoDrop a 1” bolt from a loose clearance hole if I decrease that loose clearance down to 1.125”. Therefore, I feel as if the clearance.xls excel sheet must have SOME influence on the AutoDrop feature; but decreasing it by .001” is clearly not enough of a difference for it to pick the 1” bolt. 

Is there a way for me to alter a code or setting for AutoDrop so that I don’t need to decrease the 1" loose fit clearance as far down as 1.125” for the program to pick a 1” bolt? I would like to keep this clearance as close as possible to ASME B18.2.8. 

Thanks, 

Erich

[johnsonshiue]

Hi! I have contacted the project team to get better understanding of the behavior. It seems that AutoDrop does not consider Clearance Holes (from the Clearance.xls table). This is a limitation at the moment.

Many thanks!

[johnsonshiue]

Hi! I have contacted the project team to get better understanding of the behavior. It seems that AutoDrop does not consider Clearance Holes (from the Clearance.xls table). This is a limitation at the moment.

Many thanks!