Advice on constraints?

Hello folks of the forum. I've attacehd a screen shot of the second ass'y I've ever created, and I feel like I completely hacked through it. The part modeling was no problem, but being an ACAD user, the assembly environment is a foreign land to me. I've got the following questions:

1) I tried to make the bolt holes in the lower brackets adaptive and locate them with Constrains to the bolt holes in the upper (blue/grey) base plate. The upper plate is my base feature and is grounded. Bolt holes were placed "Linear" without picking references so I was hoping those references being empty would allow me to locate the lower holes to match the upper holes with Constrains. IS that possible? I wasn't able to make it work, but I think it relates to my second question...

2) Could someone please offer some advice on how they would have constrained the assembly? I got everything fixed except for the wheel which can rotate about the long axis of the axle, but I really just kind of choked through it. Some guidance on a good way to approach it would really be appreciated. It took me 13 Constrains to get it behaving, just looking for a more efficient/elegant way of going about it. I know this offers the potential responder no direct benefit... maybe the thread could wind up helping others in a similar position though. All I can offer is my sincere thanks. I'll try to attach a screen shot and the ass'y file.

Couldn't add the .zip of the .iam and associated .ipt files, here is a link to Box instead: https://app.box.com/s/pzizihyi8zxrkofaac5y1x4mfrgrq4ol

Hi, you should be able to constrain each part using just two constraints each, for the bracket to base plate i just used the centreline of the holes then the edge of the faces, see screen shot.

You probably wouldn't need all them work planes if you sketched from a two point centre rectangle when starting the base plate and then used the origin planes to constrain.

Also i would have sketched and revolved the shaft around a centreline for the same reasons of utilising the origin planes for constraints.

I hope this helps...

That does help, thank you. I've created another assembly today and made better use of the origin and the 3 planes given as opposed to work planes. Thanks!