I am curious why there seem to be so few twist to open razors that also have an open comb. While I am certainly ignorant of many, these are the ones I do know. There is the GEM/Eversharp MMOC From Gillette we have: Regent Tech Early Aristocrat Early Senator Early Sheraton Pearl makes some Open Comb Twist to Open razors What else is out there that is both a one piece design (visually) and open comb?
At the risk of being controversial: Open combs were harder to manufacture with pressed brass plates. They were also subject to damage in the factory when dropped, relative to closed comb. I think this is why Gillette et al moved away from open combs as close combs proved their worth. In modern times, open combs drain cream/soap/scum away from the blade a little more efficiently so that's why they feel more aggressive to a lot of people when all other aspects of the head design are the same. All that to say : I don't think you'll find many open comb TTO because those were mostly made from pressed metal plates and closed combs were favorable to the manufacturer for those designs. (I'm making a lot of assumptions here based on my own experience with Gillettes and with designing a few open comb heads...)
Yes. Unless I am mistaken, the Pearl open comb has about six teeth. Contrast this with 11+ for most open combs. I'm not trying to distract you from getting the list of products you're seeking; I'm just trying to lay down some reasonable expectations. TTO + open comb isn't great for the guy having to make them.
That could well be, yet many companies make three piece open comb razors today. A lesser number of companies make TTO razors today. What is different between a base plate for a three piece open comb and a base plate for a TTO open comb?
That is a great question. Back in the day, folks made specialized equipment for manufacturing. Today people want generic equipment for manufacturing, so models can change every year (or even season). The TTO are most easily made by pressing metal sheets into the necessary shapes. 3-piece razors (today) are typically made with a mold - molten metal is poured into a hollowed shape. Molds are far less risk and far easier to reconfigure than machines that press sheets of metal. 3-piece don't require assembly either. So 3-piece are cheap and easy while TTO require more commitment. I hope I am being helpful to your quest...
Going back to @drone115b's post... TTO razors require a thin baseplate which is achieved by using stamped metal. Most three-piece OC razors are made using cast or machined baseplates. The cast/machined razors are actually cheaper to make as they don't require the special dies and stamping machines. This is the real bottom line- economics. Back in the day, Gillette could make stamped OC razors because it had the investment in the equipment. Even with that, I imagine there was a higher reject/rework rate due to the comparative frailty of the comb teeth. (This is probably why the Peal OC TTO has so few teeth- better rigidity.)
One of the reasons why I like 3D printing is because it puts some of these manufacturing constraints on their heads. The complexity of the shape is not relevant, only the volume and material. So an open comb can actually be less expensive to 3D print than a closed comb! I am leaning heavily toward open combs in my current and future 3D designs.
