Thomann "Orchestra Stand Premium" notestand top clamp repair

Edit 2024-04-08: After using this in practice over the past couple of months, I have concluded that the printed threads are not suitable due to stripping out and that brass inserts are absolutely necessary. I will upload a modified model in the near future.

For the Thomann “Orchestra Stand Premium” (Art. 264338) notestand.

The screw hole for the upper clamp of the telescoping mechanism had had its threads stripped over time, to the point where it could no longer hold the bolt of the thumb screw.

Fixing this does require replacing the entirety of the metal cap at the end of the telescoping segment. The original is tightly press-fit over the telescoping pipe and really hard to get off non-destructively. I used a hacksaw to slice it in half without damaging the pipe within.

With a bit of finagling, you may first want to remove the clamping insert ring that sits trapped in a recess at the top of the cap. I found it easiest to use a pair of pliers and twist it out.

You can then reuse the clamp (which I did) or 3d print a new one using the provided file. (Note that I have not tried printing this model myself, so let me know if you have any issues!). The 3d printed replacement cap can then be hammered in place with a soft mallet. It should fit tightly without needing any sort of adhesive.

Design considerations:

I did not have any suitable threaded brass inserts for the M8 thumbscrews used by the original, so I went the quick-and-dirty route of printing the threads. I normally avoid this, because 3d printed screw threads feel awful and require some post processing to get them to an acceptable tightness (especially when not parallel to the printing Z axis). If there is demand (or I order some inserts of the right size) in the future, I will update this model with a brass insert variant.

The clamp is modelled following the original injection moulded piece and does not have any logical printing orientation that avoids supports. It is possible that one could shorten the “ring part” of the bottom end to lie flush with the rectangular feature, hence making the bottom entirely flat. I did not attempt this, since I did not have an immediate need for printing this part and therefore could not test how this affected the clamping force.

Printing instructions:

• Print the cap with the top end (closest to the screw hole) facing the build plate. It should be possible to use either PLA or PETG for this without much issue.
• Print the clamp with the bottom end (where the “ring part” protrudes more) facing the build plate. This will require some support underneath the rectangular feature. I recommend using PETG for this, since you need some flexibility for the ring to contract around the inner telescoping segment.

The orientation for both parts should already be correct in the exported models.

See also:

I previously designed and shared the following models for other repairs for this brand of note stand:

• Replacement clamps for the bottom tensioning mechanism
• Thumbscrews for the top and bottom tensioning mechanism (M8 and M6, respectively)
• Plug for repairing stripped holes in the legs

(Evidently, these notestands are made very cheaply and of really poor quality metal. I do not recommend buying them.)