rotary tool Cut off wheel diameters

I like the larger diameter.  I also square off with a bench top 1 inch sander.

Micro mark has a nice variety.

I've always used the 1 1/2" fiberglass-reinforced wheels with a flex shaft attachment.  The tool at the end of that shaft is MUCH easier to control than the fat Dremel itself.  You can get nice, vertical, controlled cuts with this combination.

@Drummer3 posted:

What size rotary tool cut-off wheel do you use for cutting gargraves track?   It seems that the common dremel  1-1/2"  diameter is not large enough for a square cut.   I see that there are 2" and 3" sizes available from other mfg's.

I got the 3" gyro cut off wheel. Purchased from a tool dealer at the Allentown, PA show.

There is a right angle attachment.  I found this to be a bit more user friendly. 

Also, another tip- the newer brushless Dremel tool 8260 has changed my life when it comes to cutting track. Unlike your traditional motor tool that slows down as you load the cutting wheel or attachment, this one tries (and does) maintain constant RPM. Because cutting wheels often are or become unbalanced, this limits the top RPM you can safely spin them at. It cuts through Atlas solid rail faster and easier than anything I have ever seen before at speed setting 15 and is near silent by comparison. It will blow your mind. Again, what makes this unique is a huge custom brushless motor and speed control. But even then the motor is run at constant phase and the controller just modifies the current to the phases as the load increases. With a cutting wheel no longer do you have a high unloaded RPM and then bog down as you put pressure making the cut.

I use the 8260 with a 90 degree attachment and it works great.

I'm with Ron, I use the 90 degree attachment and a 1.5" wheel.

I cut most of my track using a $30 Harbor Freight chop saw.  When I have to trim in place, then I dig out the Dremel.