Trouble with Assemblies

[Anonymous]

Hey Everyone,

I have been trying to play around with Fusion 360 lately and am working on a new assembly. I am getting really frustrated trying to mate the 2 parts in the photos below. I want to mate them such that the smaller cube slides along the dovetail (this design is intended to function like a dovetail way on a vertical mill or a compound on a lathe). The problem is that every time I align the horizontal surfaces (surfaces A and B in Fig.1) with 0 offset between them, then align the angled surfaces (surfaces C and D) the cube gets pulled down into the base part. In addition to the upper cube interfering with the lower base the direction of motion is not constrained. I can slide the cube front to back along the dove tail but I can also move it at the same angle as the slope in the dovetail (60deg slope). In figure 2 you can see the relief angle for the dovetail on the base to work with the dovetail on the top cube. Figure 3 shows what the intended clearance between the very bottom of the top cube and the horizontal surface. What am I missing here? I am more familiar mating constraints from programs like AutoDesk Inventor. I was attempting to first mate the horizontal faces then align the surface D so that I could assemble the gib strip (golden colored item in all 3 figures) in the model, which takes up the remaining space between the top cube and base. It is used to adjusting the slop out of this device in real life.

[araugh]

It seems like your best bet is to use joints instead of the align tool in this case. 

Does this video help?

[Anonymous]

Hey,

My terminology in my initial post wasn’t the most accurate and I apologize. I technically did use “joints” to create the assembly; I used the slider joint to be specific and it was when trying to select the edges/faces  for the align portion of creating that joint that things would get messed up. It would slide in the wrong direction such as along the slope or the components would be overlapped or the top box (component 1 in Fig 6) would rotate. Back when I had access to Inventor 2014 for work I could use a combination of constraints and joints but that doesn’t appear to be an option in Fusion 360.

My goal is to assemble component 1 (top block) to component 2 (bottom block) such that the horizontal surfaces (surfaces A & B, see figure 5) are parallel and have 0 offset from each other, the only allowable movement being in the X Direction (see Fig. 6). I also need surfaces C & D (the sloped surfaces) to be parallel from each other with 0 offset as well, sliding movement needed in the X direction again. The components must be assembled with the 0 offset in order for the gib strip to fit and also be assembled and functioning.

I appreciate the video clip. My application is a bit different since I cannot center the top block to the bottom in the dovetail groove. With the needed offset, I cannot get the same control options with the surfaces I need in contact. Due to the relief angle selecting the points on the surfaces doesn’t provide the correct alignment.

[araugh]

Great news! If I'm understanding you correctly this is just as easy as the previously shown joint.

Create a Sketch based on where your vertex in space is between the dovetail wall and the the top of the workpiece, then place a joint origin there. Now you can create a sliding joint based on this geometry.