You don’t have to have all 3 switches in the stack connect to the S3048, the stacking ports can transfer to one of the other N3048 and use those links.
hello, I have one stack  ( 2 x N3048 ) . This stack is connected to another stack ( 2 x Force 10 S3048-ON )  Now, I need to buy and connect an additional N3048 . It will be connected in the same N3048 stack. How should I re-cable the uplink between the new ( 3 x N3048 ) stack and  [IMAGE]Force 10 stack ?  This is how the current cabling look like.  S3048-ON is using all 4 x QSFP ports ( 2 for stacking and 2 for uplink )
Connect 3rd N3048 switch into existing stack