blending dissimilar shapes

Grompy989

Im trying to bled 2 different shapes together.  But im kinda at a loss for how to do it correctly, if it can be done. I tried the loft tool but it doesnt work. One of the faces has screw holes in it, and the other face doesnt and its not the same shape. Think of it this way, Im trying to blend a rectangle to a trapazoid with rounded corners, and its hollow in the center.  The end game is to make a enclosure for switches that are on a flat rectangular plate to a mounting surface that has a irregular shape to fit a pocket of a tray holder in a truck.  hope that makes sense?  heres my link to it..

https://cad.onshape.com/documents/804f59eac1e678268ff436d1/w/d97e03ba5660fc338ddc0d5c/e/027dd90adb927482eb9eea35?renderMode=0&uiState=65a4a04040bbb63623e2e8c7

martin_kopplow

There are several issues with your model, most are strategical. 

• The sketch has overlapping lines.
• The sketched arcs are not tangent
• the sketches are on the same plane, but translated somewhere unrelated
• Fillets in one profile run into a point on the other profile
  

It might be a better approach to put the profile sketches on offset panes, where they're really needed, keep tangiencies in sketches, make 2mm fillets at sharp corners, then loft and model the whole volume in one, shell it, add features like the mounting holes, and only split it after the fact.

https://cad.onshape.com/documents/6aff96cef6aa59041ffc6593/w/ca0b1a63770ce6ef7e68a10c/e/5157c972b26441885fd97238?renderMode=0&uiState=65a4ed0b77d3e37f9cc01f7f

Grompy989

you sir are a genius.  im new to this stuff.  thanks for the assist.