Until 1995, 127 film was sold on metal spools with thin end flanges (approximately 0.75mm in thickness). 

The 127 film available today is spooled on injection-molded plastic spools. Two types are being manufactured: those made in Croatia have  a slotted brass insert at the winding tip; those made in Canada are of glass-filled nylon.

It is the Croatian brass-tipped spool that sometimes causes problems for Baby Rollei users. The plastic end flanges are about 1.15mm thick, rather than 0.75mm, and the exterior flange-to-flange distance is correspondingly greater. 

Some "Baby Rollei" users find the camera's film takeup chamber is quite tight, and describe problems with the film jamming when these brass-tipped spools are used as takeup spools. There is apparently no problem using brass-tipped spools in the supply chamber.

This issue appears to arise only with "Baby" Rolleiflex TLR cameras, and only with some of them. There are Baby Rollei users who say they have never had the problem. It has never been reported as an issue with any other camera.

The issue does not arise with Bluefire 127 film, which is spooled on an all-plastic spool. This spool has the same external dimensions as the canonical metal spools, and does not cause jamming in either the takeup or supply chamber.