First thing I did was bolt the speed demon rails to steel tubing rails. I got about 8 bolts in before I thought to check if the roller blocks could be installed with it bolted down. They can't. So I got it lifted back up and slid the blocks on and then bolted it down.
A couple of things to note, the bolt holes (in the speed demon rails) have very little extra play in them. If your drill bit wanders when you put in the bolt holes (in the steel rails) you may have problems. Mine were just noticeably snug. The counterbore has a little extra room, so you could just drill the holes out a little (in the speed demon rails) if you run into trouble.
Then I bolted the rail assemblies to the lower frame. I just finger tightened them as I will be adjusting them during the gantry install. The eccentrics on the roller blocks were set to remove play at this time also.
At this time I had a buddy come over to help lift the gantry into place. Remember the side plates and their gussets are still just loosely attached. I got a couple of bolts in the side plate / bearing blocks and it was stable enough to let go of it. Next I installed all the roller block to side plate bolts and tightened them.
At this point I was able to slide the gantry's 8020 extrusion just a little to get it perfectly centered, then I tightened all the side plate and gusset bolts. This makes the entire gantry down to the speed demon rails very rigid. It's also worth noting that all that tightening was done with the gantry above the rail to lower frame bolts (still finger tight) on the near end of the frame.
The install instructions describe a "floating in" procedure to set the width of the rail assemblies. Basically you just use the gantry to hold the rails at the right distance while tightening the bolts. So I tightened the set of bolts under the gantry, then slid the gantry to the next set, tightened, and then did the third set.
Lastly, I hung the x gear reducers temporarily, set the gear depth on the shaft to mesh with the rack, then removed them, loctited them, and re-installed them.
Last thing to mention. I got the longer bolts that I mention in a previous post. These are the lower frame to rail bolts that needed to be longer because I welded on the extra set of plates.
Cost 7.82
Grand total currently at: 6223.57