Will my MACH III 3 Flyer Head fit on the Firefly base?

If the MACH III head is secured to the base from the back it will fit onto the Firefly and can be screwed in for carrying by the handle. This is what makes the MACH III and Firefly a MODULAR series - you can switch the heads between the bases. The Firefly is essentially an Electric MACH III.

If the MACH III head is secured to the base from the side it will fit onto the Firefly but it cannot be secured to the Firefly. This does not effect performance, but it does mean that you will not be able to carry the MACH by the handle.

The newer heads (new: secured to the base from the back) will fit the older MACH III but cannot be secured (by the screw) into the base. This does not effect the ability to spin, but it does mean that you will not be able to carry the MACH by the handle.

Will my old non-magnetic bobbins fit my new magnetized SpinOlution wheel?

Old style bobbins that do not have space for the magnet and will not fit magnetized wheels. 

New style bobbins that do have space for the magnet will fit non-magnetized wheels. If you want to replace your old bobbins with new bobbins, we recommend selling your old bobbins on our Facebook Group or Ravelry page to other SpinOlution spinners who have wheels that will work with those bobbins.