The white machine is not the same as the black or tan machines.
The white machines body is made cast from the same aluminium alloy as the black and tan machines although the lifting bed extension is made of stamped sheet steel. This was but one production cost savings utilized by Singer so that they could keep producing a machine that had been getting too expensive to keep manufacturing and sell at a price that people would still afford.
The power cord does not unplug from the base of the machine as the earlier black Featherweights do which was another production cost savings. I prefer a machine that the electrical cord can be unplugged from for storage or carrying about. It really is not the end of the world for me but simply a personal preference.
The steel base extension works quite well and is strong. This base extension on the white machine is about an inch and a half shorter than the cast aluminum extension found on all black and tan machines. To some this might seem important but actually it doesn't change things much in use.
The most notable difference and the greatest money saver for Singer was to be found internal to the machine. The black and tan machines are all gear driven, but the design change to the white machine utilizes a cogged drive belt. This had quite the effect on the bottom line.
How does the cogged belt effect the white machine when compared to the gear driven black and tan machines? The internal belt drive (rather than gears) has proven to be very reliable and it typically runs quieter than its black and tan siblings. I have talked with Graham Forsdyke and Glenn Williams about their experience with the belt drive and they concur with what has been my experience, there is no problem with the cogged belt drive. Although Graham had seen one fail when a person was "adjusting" the belt with his pocket knife. Obviously, this is a design flaw.
In the 1950s, type-writers were cleaned by immersing them in a chemical bath not unlike the early dry cleaning chemicals. Type writers were soaked, shaken while immersed and dried. Then they were oiled again. Sewing machine service people tried this immersion in cleaning chemicals with Featherweights and found that it worked very well with the black and tan machines. In the 60's the white machine came about and the "sewing machine service people" put the white machine into the chemical bath and the internal drive belt melted in the harsh chemicals used for dry-cleaning back then. The service person had a three hour job ahead of them to remove the internal shafts and replace the cogged belt.The cure for this was that the service people told prospective buyers that "the white machine was not as good as the black machine, believe me I'm a service person and I know". If you are around white Featherweights long enough you will hear people say that "they had a Friend who said she heard that the white machine was not as good as the others. And now you know why. Telling this to prospective buyers kept the service people from getting their fingers dirty by having to clean a machine by hand rather than giving it a bath while they drank coffee. This is a "story" that you can take to the bank. I have talked with "old-timers" (which I am rapidly becoming) who have stated this is the truth.
I have had to replace the gears in machines before, but never a cogged belt. In my experience the white machine (which isn't white, it is "pale celery" according to Singer) is every bit as good as any other color and I think it can be adjusted to sew marginally better than a well adjusted black or tan machine. I believe it runs smoother internally which in my opinion gives the machine its edge.
I will not go so far as to say the white machine is better than the others, but it is not a compromised design as had been implied by Singer's own and definitely is not second place to any other.
Source: Dave's Blog