I put up a video review of the SCG-10 last night on my blog.  It also goes over the accessory, how to calibrate it (a different way than the one described in the manual), and a couple demo 90º joints mostly to discuss how the key to the guide isn't so much that it self-centered, but that it gives you equidistant references.

Extract from the blog article:

...If you've followed my podcast at all, you've seen me use some third-party narrow-stock spacers that are fitted to the front of the pin-style Domino.  The pin model is harder to find these days so the fast pencil-free registration offered by the spacers hasn't been available for everybody.  The SCG-10 solves that problem.

In this video, I'll show you the product, how it fits to the Festool Domino body, and how to calibrate it easily.  I then do a series of demonstrations to show forming a 90º joint (like a rail/stile joint) using the SCG.  One demonstration shows using the SCG for its centering function and the other emphasizes the equidistant offset provided by the SCG and how you can use that to offset mortises.

The calibration procedure shown in this video isn't the same as the one outlined in the manual. The manual's procedure assumes the center line on the bottom of the Domino base is reasonably accurate.  For my Domino, it is considerably off, but I calibrated my cursor hairs exceptionally well.  The basis of my calibration is to use the cursor hairs to get it done in one try.


Here's the video:

Domino Self-Centering Guide SCG-10

[ Edited to put the video inline in the post - Shane ]

PM,

Great video of Floyd and again, great job on the tool Rick!

Terry, For the typical user, just visually sighting down the seam between the stops will be very accurate. For higher accuracy, you could also try the razor blade method that Jesse Cloud suggested a couple of days ago. I think it will be an easier method for most people, and is the method I would use if the lines on my Domino were not already aligned. 

nice vid Paul

The Rick and Paul-Martel show is awesome.

Great job Rick on the tool.  Great setup / demo Paul-Martel.

I think you should go on the road!

neil

Rich,
Absolutely!  And the whole rationale is that sometimes the Domino does not cut centered on the scribed line on the base.  While you can't recalibrate the scribed line, you can move the plastic cursor around.  So, if your Domi cuts centered to the scribed line, the razor blade should be on the scribed line.  And as Rick pointed out, if your not a half-blind old fart like me, you probably can do this by eye and don't need the razor blade at all.

As to sequencing, I would do a quick check to see if your Domi centers on the scribed line.  If so, follow the process in Rick's manual.  If you need the razor as a visual aid, use it on the scribed line.  If the scribed line doesn't show the center of the cut, use the procedure in Rick's Domino manual to adjust the plastic cursor, then calibrate against the plastic cursor, using the razor blade if desired.

ha ha, the Floyd thing kinda fell out my mouth, but it worked   Wonder how long before Rick gets an email asking for instructions to order a 'Floyd'.

I like your adjustment procedure, Jesse.  For whatever reason, I didn't picture it well when I first read your reply, but then Rick's picture made it very clear.  I can't sight that through the crease between the stops.  For me, the block was easier especially with the tape trick; it is really easy to get it dead center of the scale, although as mentioned before, if that scale is off, you may as well use Floyd as a keyhook instead (or more seriously do the calibration the divide-n-conquer method).

Regardless of how you get it calibrated, once there, I think it will be very nice to use.  I'm fast with the narrow stock spacers, which sound exactly like Ron's offset blocks; with the SCG, it should be faster.

I shouldn't have mentioned the keys cuz now I'm thinking of where to hang it between uses...   

Paul     Great Video, pushed me over the edge and I placed an order for one.... I really like you method use use for the rails and stiles.
            Will be trying your method on the 10'  Five Piece China Cabinet I am presently in the process of making for a customer.

Thanks
Sal