Steve's Corner - Parts Specifications
I have noticed that in the more recent comments on the group emails, and on requests directed to me, that there have been questions on the subject of parts specifications. The questions seem to be more related to requests for information that would allow parts reproduction than general information or curiosity. My reluctance to respond comes from my desire for accuracy and the knowledge that the complexities of originally making the parts makes the reproduction of some them very prohibitive. If they are not made correctly, the damage to the customer and the product's reputation is extensive.
Almost all parts and assemblies were produced to exacting specification drawings that were kept on file at Fender. Parts specifications not documented by a drawing were documented by a model or reference part (the hammer cam curve design is an example of this aspect...I still have the model for the Mark V cam curve). Fender has physically packed up and moved its locations at least twice, and the possibility of it keeping drawings of an instrument that it stopped producing over 15 years ago is slim. It is quite normal for a manufacturer to discard drawings, as Fender did with Rhodes-related parts and tooling many years ago. It was fortunate that John McClaren Jr. was there at the time and had the presence of mind to request and receive a significant supply of these scrapped parts and tooling. So, without the availability of the drawings, the other major sources of technical information not already published in the manuals are designers such as Horst Absmann (the other main designer) and myself. Horst is normally not available, and I am hesitant in quoting some information without the drawings. After all, it has been 15 years since I thought about a lot of this, and I am not fond of giving inaccurate or incomplete information.
Please consider that many parts have critical aspects that are not obvious. All moving parts were life- and performance-tested to ensure their lasting capability. One example of a feature that is not obvious is the 2 large sets of holes that are drilled into the tone bar rail and the pickup rail of the models considered as Mark II's: these are tooling datum locators. All location measurements on the harp, pickups, harp frame, edges, tone bar mounting holes, etc. are located in relationship to the 4 datum holes. Four simple holes are critical to the accurate manufacture and assembly of a main part.
Other considerations are cost and economies of scale. Plastic parts are molded, and many molds are very complicated and therefore expensive. The only way to get a part without having the part cost a fortune is to make them in massive quantities. The hammers and hammer combs are examples of this. At this point we hope the supply will outlast the demand, or that in some cases we can fix the hammers instead of replacing them.
So when you buy replacement parts or see an ad saying that someone is now manufacturing a new supply of a certain part, ask yourself: is this organization capable and qualified to make the part? and is the part an accurate duplication of the original?