I"ve heard many conflicting stories about BMDC's but none of them involve "..pretty good prices..." and EMI in the same sentence.
About 3 years ago, I priced a BMDC from Hardinge directly and (sadly) didn't buy it when they wanted $1500 outright. Since then, the price has gone to $1200 to #1500 EXCHANGE from EMI. Last time I heard of an outright price, it was over $2500 and I don't believe they even offer then outright anymore - EMI apparently needs/wants to keep control over the "cores".
The BMDC is NOT exceptionally pricey when you look at individual components. The IC's are essentially older generation micro controls. Some of the associated IC's are exactly the same as those used in the long defunct Amiga computer. A quickie calc shows that the IC's can be obtained, mostly surplus, for around $250, usually much less.
The PCB is a multi layer one, which in its day, was pricey to make - today, not so. When I asked why EMI did not make "new" boards, I got conflicting "stories". Like, "no artwork" (readily doable with today's software), "no schematic" (there is one published in Bridgeport manual), "no info on the programmed IC's" (they are readily copyable according to aftermarket guys who fix them) and the topper "we don't have the technology to do 4 layer boards" (you can download it for free from a number of prototype board houses) and the ever daunting "there are copyright issues" (always resolveable via licensing and the payment of royalties - reasonable or otherwise).
Depending on the validity of the copyrights and whether or not they were PROPERLY protected (few people do so PROPERLY), this may be a paper tiger that is easily surmountable - especially if you KNOW and study the 17 USC copyright law.
I think the real reason is a bit more obvious - money. The market for the boards has slowly shrunk and the folks who need them are becoming more and more dependant on the remaining source for parts and service - spend what the sole service outlet asks (no other choice) or replace the machine. Spend a few thousand or ten times that much. Do the math, it is a simple answer.
There is value in scarcity and the BMDC's are becoming scarce. Keeping them scarce makes for good end of product life business potential. However they are NOT unduplicable rocket science technology. Rather, the BMDC is orphan tecnology that some enterprising soul hasn't expoited yet.
If folks can can clone a PC and have OEM software run on them not run afoul of IBM patents/copyrights, I don't see why the same can't be done to the BMDC. Especially when there isn't a single solitary copyright or patent registerrf in the C/R and/or patent office on/for them by Bridgeport or anyone that is readiliy associated with Bridgeport. Maybe EMI can't do anything with the "trade secrets" contained therein because they worked at BPT on the development of the BMDC, but surely, someone else not so burdened could.
The BMDC is a pretty neat control scheme that works on a lowly and now essentially FREE DOS based PC's - and it will readily do 3 or 4 axis controls of lathe, VMC, and/or mill with one single card and the various somewhat generic BOB's. Why someone hasn't cloned it is beyond me.....  |