Issues using an 8mm ER-11 collet?

Because I can’t read, I bought the wrong version of the McFly - the one with the 8mm shank. I ordered an 8mm ER-11 collet, and I’m fine with using them both, as long as there’s no downside.

Is there any downside, or should I exchange cutters and eat the collet? there must be a reason almost nobody sells 8mm ER11 collets.

The descriptions are:

  • Shank Diameter: #602E 1/4 (suitable for Carbide Compact Router/Dewalt)
  • Shank Diameter: #603E 8mm (suitable for ER11 Spindles)

To me, it sounds like the 602E is for some product I don’t own, and the 603E is for the Nomad, but I’m obviously wrong.

The 8mm ER11 collets work fine in my experience, and 8mm tooling is far more rigid than 6.35mm — I think you’ll like it and find it worth the added expense assuming you have a Carbide Compact Router w/ an ER-11 collet.

If you don’t, you should get an 8mm precision collet for the Makita RT0701/0700 which will also fit the Carbide Compact Router:

Neither of the McFlys are suited for the Nomad, save in the softest of materials w/ the lightest of cuts (and even that isn’t recommended).


I run 8mm end mills in my c3d er11 router with no issue just make sure it’s tight. I’m not sure if the nomad spindle would have issues unless your feeds and speeds are not correct.


Thanks. I guess I’ll just return it.

I didn’t return it, and I’m glad. This thing is a monster at facing wood. taking 3/4mm DOC at 1000mm/m at 16k rpm and ZOOOOM it’s great