I have two pipes, blue & yellow wherein blue is wider than yellow.

I need something (lock) that will prevent the yellow pipe from falling if the lock is tight, and at the same time is able to loosen so that I can adjust the yellow pipe up or down whenever I want.

What I will hang under the yellow pipe is computer speaker, one in my left and right.

enter image description here

Speaker Weight:

Left: 239g (8.4oz), Right: 343g (12.1oz)

  • $\begingroup$ I was thinking of rachet and rack mechanism. $\endgroup$
    – Fennekin
    Aug 14 '16 at 17:07
  • $\begingroup$ How heavy are those speakers and how thick are the walls of the yellow pipe (how well could it withstand compression)? $\endgroup$
    – fibonatic
    Aug 15 '16 at 0:16
  • $\begingroup$ Why not grab the legs off any standard scope/camera tripod? $\endgroup$ Aug 16 '16 at 18:41
  • $\begingroup$ But why exactly do you want to change the speaker height? The sound field will not change measurably. $\endgroup$ Aug 16 '16 at 18:42

For this problem, I think that the way a bike saddle works would be ideal. You have a slit in the outer pipe, allowing it to bend inwards slightly when tightened to grip the inner pipe. Then you have an adjustable tension ring around the outer pipe, with a quick-release lever to grip with an appropriate pressure.

Diagram of saddle with adjustment mechanism

You can buy these clamps separately, so it should just be a case of finding the right size of pipes and clamps. A Google search for seat post quick release clamp is a good place to start.


If you don't mind only being able to adjust the pipe in steps, the locks that can often be seen on steel tube scaffolding or medical crutches might be a perfect solution to this problem! Here's a picture of what I'm talking about:


Otherwise, if the pipe isn't too thin, you might try cutting a thread into the pipes. Unfortunately, these may loosen over time if the fit is too loose or the pitch is too large.

You could also just drill a hole into the side of the outer pipe and put a wingnut through it, this will allow you to adjust on the fly. I don't like these very much because they tend to slip unless you really tighten them up, but then you might crush the pipe on the inside. If the speaker is fairly small, however, it might work.

  • $\begingroup$ can you give me picture of "if the pipe isn't too thin, you might try cutting a thread into the pipes" that you're saying? $\endgroup$
    – m0Onfang
    Aug 14 '16 at 15:54
  • $\begingroup$ Something like in this picture: cdn.mscdirect.com/global/images/ProductImages/3690308-11.jpg You would need a fairly long thread to get any range of motion, though. $\endgroup$
    – kruschk
    Aug 14 '16 at 16:05
  • $\begingroup$ Cheap shower curtain rails and telescopic window cleaning booms often use twisting mechanisms which I presume use some sort of threaded compression mechanism, the poles can be twisted at any point of extension and no external twist grip is necessary (but can exist) $\endgroup$
    – CL22
    Aug 16 '16 at 6:47

I guess you need something like a blockade lock. You might get some idea through this.

There are a couple of assumptions I am making here. One of them is that is a one-time lock that you need, like the ones they use to seal containers. I don't know how frequently you'll need to separate the two parts. If it is very rarely, like once in an year or so, such locks might do the trick.
My computer speakers are way too heavy (since they are old) for this kind of a lock, but the ones you have linked in the questions, don't really look that heavy. This kind of lock should do the trick for you.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.