Dave, you are 100% right about the radial accuracy of Scott's arms.....how he got there is a long story with threats of patent infringement from the guy that was vendoring the arms for H9, as well as JR who initially refused to accept the fact that their metal output gear on the 8611/8711 series had poor quality control compared to what was on the 2721 and 8411's......I have seen the output gears Scott has measured right out of the box on new 8611's back when they first came out......no question, significant caliber differences......Scott's 8411 metal arms worked on some, but not on others, so JR said just stick with the 215 arms which worked fine, except when they stripped, mainly when banging a surface while transporting or in the pits.....

Scott is a master builder and flyer of Carden 40% stuff himself and could not stand the random orientation of the splines to the arms on all the metal arms available in the early 2000's, so he set out to make the best......

JR initially wouldn't hear of it.....they offered no locking arms for quite a while after the 8611's came out.....

Scott purchased the best broach money could buy and then used precision techniques to cut the splines, and then came up with the locking arm concept that now is used by others.....he thought about patenting his design elements, but way to expensive for a 1 man machine shop......so now we have all kinds of copies.....

I still use only Scott's....designed and manufacured by a local U.S. businessman......and IMO, still the best......

Like Harley pointed out, the cost is infinitessimal compared to his example $10,000.00 jet, or more like $18,000.00 bucks for the UB.....


Tom