I have a new cube and its really really fast. the whole process takes alot of time but its worth it. first let me say that the seven towns and rubiks.com cubes are in transition from the 2008 molds to a newer master mold that is very slightly different, I'll explain. I have destroyed 3 seven-towns cubes from 3 stores, just to find out whats in side and if its useful. also ordered some white rubiks.com DIY and compared them down to every detail and tried every hybrid possible. the new store-bought cubes have larger cubies. you cant see it though. the cores are larger thus the shorter stem on the centers. the inside surface of the centers is slightly farther from the core, probably cause of the bigger core. and the center caps are slightly larger, making them perfect for anyone who has problems with caps falling out.
what you'll need:
*Rubiks.com DIY white (use everything except the cubies and caps)
*2007-summer2008 storebought rubik's (use the cubies) 2006 probably ok too
*NEW storebought rubik's, fall 2008-current (use caps) $10 for caps is a little ruff but you'll have an extra cube leftover
start with the 2007 cube. shave mold flash imperfections. assemble and break it in for a while. one week later, take it apart and shave down the sides of your edgies. don't shave it down flat, thats not what we're doin. just try to roll off the edge that is near the centers. the more you take off the better. its time consuming with a nail file. there is a youtube video for this. this greatly improves cutting corners.
lube it with CRC or jig-a-loo or similar silicone spray. liquid wrench not acceptable. I'm assuming you know how to do this or you can look on youtube. very important to spray it on the surface of the tabs that hold everything together the faces of the cubies aren't as important. then you'll want to assemble it after you've done two sets of lube just to test it out. thats three coats on corners and two coats on edgies for each set with 15 min's minimum between coats. should take you at least an hour and a half.
assemble your white rubiks.com DIY core & centers using the supplied hardware. its important that the larger spring end is touching the plastic and the small end is on the screw head. do it slow making sure that the screws go in VERY straight. tighten it until it is about 1-2mm. use the 2007 as a reference visually.
take a razor and very carefully cut the glue spots out of the new 2008 storebought cube center caps without cutting the internal snap ring. just put the centers on the edge of the table and press down with a straight razor in the crack with a flat even motion. rotate the center and repeat 4 times total. it should fall out. repeat for all six caps and save caps.
place caps into white rubiks center-core assembly. they should be snug and require no mod but if they do fall out, use loctite, NOT glue. loctite alows you to remove the center caps for adjustments. don't use too much cause it will slow down your cube if it oozes out. use the cubies from the broken in and lubed cube, the 2007 one.
VOILA! when I say fast, I mean its like too fast. try it. i will post links to the three youtube videos I was talking about. or if anyone has a link post it. BTW this is wayyyy faster than the white DIY type A II I was talking about earlier so don't bother with that one.
I will be making this in short runs of 10 for me and my friends. I will be at WCA newark, NJ coming up in november. see you there if you want to buy or trade.