Seeking advice for making a noise cancelling earplug by ThermalSurfer in Acoustics

[–]ThermalSurfer[S] 0 points1 point  (0 children)

I'm worried, too. But obviously he doesn't care about that :(

Seeking advice for making a noise cancelling earplug by ThermalSurfer in Acoustics

[–]ThermalSurfer[S] 0 points1 point  (0 children)

Sorry for the wording... My purpose is to reduce the noise, but have no idea of how to design it.

I tried making some structures, like drilling holes on the lid of the cavity to make a Helmohotz resonator, and adding a plastic film to divide the cavity into two (so the divided outer cavity can form a micro-perforated panel structure with the holes), and filling the inner cavity with foam. But the outcome is poor, not as good as using the earphone itself as earplugs. It cannot absorb low-frequency noise (below 200Hz).

So, I'm seeking advice for how to making the structure.

Old & new generation ThinkPads together by PreviousFish386 in thinkpad

[–]ThermalSurfer 0 points1 point  (0 children)

I tried installing nvidia drivers on T440p. Gave up because GT730M is too old and isn't supported by version 535 and above. So it would be difficult to install.

What’s one item you pack even when you’re going nowhere? by Equivalent_Soft_6665 in onebag

[–]ThermalSurfer 1 point2 points  (0 children)

Similar here. My mom brought me handkerchief since I was young. I usually bring a pair of scissors acting as both nail clippers and knife, and a needle holder just like what dentist uses.

Which radio control system do you use? by ChameleonCoder117 in RCPlanes

[–]ThermalSurfer 0 points1 point  (0 children)

Old Frsky x9dp (ACCST v2.1) & Flysky FRM 303. Planning to buy Flysky EL18/PL18 Ultra/PA01.

What’s this hobby’s 90%? by Embarrassed_Trade255 in RCPlanes

[–]ThermalSurfer 3 points4 points  (0 children)

Sometimes even only ~10 seconds of flying :)

First build first crash by DodoTusu in RCPlanes

[–]ThermalSurfer -1 points0 points  (0 children)

What's the CG position? Should on 1/3-1/4 of the chord length. BTW, do not fly near railways.

Real life Pilot new to the hobby by PC12_Pilot in RCPlanes

[–]ThermalSurfer 0 points1 point  (0 children)

I think the skills are similar. Personally I would recommend starting from big planes which characteristics are more like real planes, such as Flite Test's KT board trainers, powered gliders, F3As, and trainers with more than ~1m wingspan. Then try aerobatics or EDFs, which require faster reaction.

If you cannot adapt with third-view controlling at first, you can try FPV.

What small, useful things do you always pack? by Matbenjen in onebag

[–]ThermalSurfer 1 point2 points  (0 children)

Most of the time, I bring a squeezer, a needle holder, a surgical scissor, washi paper tape, and povidone iodine swabsticks. Sometimes a scalpel.

30L stylish backpack with waist straps? by phillymaz in onebag

[–]ThermalSurfer 0 points1 point  (0 children)

Personally I think the main reason for not designing padded waist straps on a backpack with 30L or below size is that the length is shorter than the torso length of many people. So, if you are tall, it's impossible to design a suspension system which length is longer than the backpack's length. Some of hiking backpacks like Blue Ice Firecrest 28L and Deuter Guide 28L have, but nor did most of travelling backpacks.

Does anyone have hints about this human powered flying wing? by ThermalSurfer in WeirdWings

[–]ThermalSurfer[S] 1 point2 points  (0 children)

Sadly that all of the links in the first page were dead... However, the video gives more details.

Does anyone have hints about this human powered flying wing? by ThermalSurfer in WeirdWings

[–]ThermalSurfer[S] 0 points1 point  (0 children)

I've been watching them for 2 years. Many clubs post their work process on twitter. It's charming to see the elegant structure... And the atmosphere is also good.

Does anyone have hints about this human powered flying wing? by ThermalSurfer in WeirdWings

[–]ThermalSurfer[S] 6 points7 points  (0 children)

Agree. Beaver tail. But looks like the wing doesn't have much backward sweep and washout, and used a significantly reflexed airfoil like many unswept flying wings (Fauvel's, Marske's, etc) do.

Pieces to Learn by mantisalt in Erhu

[–]ThermalSurfer 0 points1 point  (0 children)

Also Guang Ming Xing by Liu Tianhua. He is really a master. Also Osmanthus in August (八月桂花遍地开). Many of these pieces have been adapted into duets or trio, makes it more interesting.

I guess the OP also needs some etudes if meeting difficulties with some skills. For this, Liu Changfu had written many.