I'm new around here, but did a thorough search of the archives and couldn't come up with more than passing references to C-extensions for doublebasses. I posted a little in a thread about bridge adjusters, but for a slightly better chance at an answer here's my situation in total. I made my first C-extension about 6 years ago, for a VSO player. It was a 4-capo type, as he wanted access to a lot of natural harmonics for new music stuff, and the odd older composition requires low pedals. The player had asked for a really solid 'lock' at each semi-tone, so I tried bullet catches. They seem to help a little, the ball bearings being pushed firmly into little detents in the stainless armatures. But I found that the springs 'sang' in sympathy with certain pitches, so an injection of silicon grease was needed. Since then, he's been happy. The long slots in the ebony for tuning the adjusters have never been needed. I'd suggested that these were not really necessary, but I suppose my explanation of the 'rule of the 18th' (actually 1/17.835) inspired insufficient confidence. Add in tapped holes with nylon set screws to make little adjustments to the pressure applied by the leather pads' leading edges, a foot to support the wheel end, in case of knocking into doorways - unpleasantly complicated, not to my tastes. Sorry for the fuzzy pictures; just used a little digital add-on to my Pocket PC to copy a couple of snapshots in incandescent light, for use here. Over the next few extensions things simplified. I tried to see just how maintenance-free and accurate I could make them. Nothing earth shaking, but people seemed happy. Getting a big, slack C string not to buzz is the hardest part, with really consistent and solid feeling capos being second. Here's one of those, made last year for another Vancouver player. She's small, hence the dropped nut for a fairly short scale without moving the bridge out of balance on the belly: All along though I've felt there must be a better way. Every C-extension is different anyway, so why should they not improve in design, not just execution? Thoughts of hydraulics kept coming to me from players, but I'm not that high tech in the skills department. And levers, springs, cams, they all make me nervous. And I've worked on enough mechanical, piccolo-type extensions to know what a nest of hornets they can be for maintenance. What about using drill rod, little bar stock bent to act as precise capos? A bit of small tubing should make it work, no? And now I see that someone is doing this, but only for the upper capos, not the E. The confines of that region at the nut make the old swinging capo a better choice, apparently. This from the Merchant site: I have this guy coming on Wednesday, again. He listened to me think out loud for an hour yesterday, and seems to trust my work from having seen enough in repairs and in his cohorts' C-extensions in the symphony, but he also wants more. He's asking me to experiment on his old Italian, to make a proper C-extension. He's used one from another local luthier for about 10 years, but it's wobbly and the only capo on it is not capable of holding a string for long without buzzing. There's not a lot there to work with, no way to add capos, so it's time for a new one. I am seeking ideas, drawing a blank. Can anyone help me with this? Suggestions, cool stuff you've seen somewhere on the web or even have on your own basses? Pictures of anything out of the mainstream would be helpful perhaps in triggering something in the little grey cells. I've seen Barry's sliding version, and it's not what is needed here. Instead I want to make a 4-capo thing he can blindly reach for and have it respond with little fuzz and effort, both applying and releasing capos. What can you tell me? Thanks in advance for anything at all.