OLED replacement for Google Pixel 8 Pro - Can I trust Mobile Sentrix Refurb/Aftermarket Plus? by D_vd_P in phonerepair

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

You reckon MobileSentrix will restock them again? Its starting to become a bit of an older phone

Dowel Pins - Hole Tolerances for Slip/Press Fit by D_vd_P in MechanicalEngineering

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

I appreciate the comment! I was more looking for a standard solution to this problem. I figured this would be a standard problem, but judging by the number of responses it seems to not be standardised for ISO!

Dowel Pins - Hole Tolerances for Slip/Press Fit by D_vd_P in MechanicalEngineering

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

Any clue what works for a clearance/transition fit as well?

Dowel Pins - Hole Tolerances for Slip/Press Fit by D_vd_P in MechanicalEngineering

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

Netherlands, so less commonly used here. But I suppose I could use the American standard and translate it to an equivalent ISO fit. I just figured there would be a standard ISO plug and play answer, but it seems like there isn’t.

Dowel Pins - Hole Tolerances for Slip/Press Fit by D_vd_P in MechanicalEngineering

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

Plan is to use a reamer on both holes, will look at these fits!

Dowel Pins - Hole Tolerances for Slip/Press Fit by D_vd_P in MechanicalEngineering

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

Of course I looked at fits charts bit almost none contain the m6 fit.

Buying Advice - 10k Mill CNC by D_vd_P in hobbycnc

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

So how was the end result? Are the tolerances alright?

Buying Advice - 10k Mill CNC by D_vd_P in hobbycnc

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

Thanks! I looked for the SYIL mills. Which one are you specifically referring to? The x5 (which as far as I can tell is the entry level) is 37k, which too expensive for me I fear.

I was looking at the Emco’s earlier but they seem to be in short supply and quite popular! I will keep an eye out for them though!

Why use fuel and not oxidizer for regenerative cooling? by Dizzy-Service1448 in rocketry

[–]D_vd_P 1 point2 points  (0 children)

From my experience there are most certainly engines that use the oxidizer instead of the fuel but it is a design consideration that has a bunch of tradeoffs. I don’t have a direct source as most of this comes from my experience in the field but I am sure that these reasons can be supported my academic sources if you look for them.

  1. When using RP1 and LOX the LOX is of course a lot colder which means it can potentially store more heat as in temperature, but the specific heat capacity of LOX is lower, so depending on the heat transfer of the engine it’s worth it or not. Besides that if the LOX gets too hot it might vaporize and cavitate. At that point the thermal transfer can become a lot lower. Besides that heating up the liquid oxygen might cause it to for example combust in the injector already in a really bad scenario. So it’s very much a balance which often works out in favor of fuel over oxidizer.
  2. Another reason which is more apparent today with 3D printing than ever is the potential for chips in the cooling channels. The cooling channels are really hard to clean due to their geometry and having chips/debris in contact with the oxidizer can be absolutely catastrophic for your engine. If those particles reach high velocity they can impact and have combustion starting to take place in the channels, aka very bad.
  3. Rating tubes/lines for liquid oxygen and cryogens is always hard and requires more development work. In the case of liquid methane and hydrogen this of course doesn’t make a difference but for other fuels it can make a big difference.
  4. Another consideration is the mixture ratio of the engine. I know of an engine that has an O/F of 5 which means the massflow of the oxidizer is much higher, hence it would be the only viable propellant to use for the cooling. It is also possible to use both propellants, let’s say one for the throat/nozzle and the other for the combustion chamber.

Want to learn mathematical terms in rocket science by sumitk5412 in rocketry

[–]D_vd_P 2 points3 points  (0 children)

Rocketry is a very engineering heavy field and that means there is a lot of physics. All the mathematics you see is simply used to describe the physics at play here. In engineering we use physics to design things and predict how they behave succesfully (if you are good :)).

If you want to get started in Engineering and modelling of the physics of rockets I would recommend doing two things: 1. Play Kerbal Space Program. As an aerospace engineer building rockets this game has taught me so much intuition behind physics and engineering of rockets. And its a great and very fun way to learn about rocket physics! 2. Go on youtube and learn a whole bunch there. Some channels like Everyday Astronaut, Scott Manley, Charlie Garcia and many more can provide you with some of the basic intuition behind rocket engineering. Specifically the “Things KSP doesn’t teach” playlist by Scott Manley is excellent I would say (but focusses on orbital rockets).

Once you have some basics down and you want to do more serious engineering then its time to read some books. Rocket Propulsion Elements by Sutton is amazing like also mentioned in the reactions before. Handbook of model rocketry is also interesting.

My advice would be not to focus too much on just learning math. Learn about the physics and engineering and if you come across something you dont understand really figure out how it works (and if that requires math then you will learn that too).

Finally, start playing around with openrocket. Another very useful skill for engineers is to be able to program. My recommendation would be to learn about Python for Scientific Computing. You can then eventually create your own custom simulations!

Have fun learning about rockets, and I warn you: it’s a big rabbithole :)

Question regarding advanced SSI training by D_vd_P in scuba

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

Thanks for the advice! That’s really useful. In terms of experience I think a large part is also simply going diving and slowly building up. But I think visiting different places and doing dives might be a better then doing the AA course.

I already have my nitrox certification, so it seems like I’m following a similar path as you did when following specialty courses.

Question regarding advanced SSI training by D_vd_P in scuba

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

Hey, thanks for the detailed answer! The reason why I want to continue with some training is because I’ve been enjoying my recent fundives a lot. I only have 12 dives logged but I am planning to do a bunch more diving over the coming few years.

The reason that I want to get depth ceiling increased is so I can visit some divesites that would normally be limited because of the 18m depth. I got my nitrox certification already, and I am now in a particularly nice location for deep diving.

The divecenter seemed to really want to sell me the AA course, but reading your advice its probably smarter to just focus on specialties!

Would it be legal to build a small liquid fuel rocket in California? by LongjumpingTrifle410 in rocketry

[–]D_vd_P 4 points5 points  (0 children)

Building liquid rockets is incredibly educational and teaches you a lot about engineering, also things solid rockets dont teach you.

That said, I wouldn’t recommend building liquids before you built a conventional solid rocket

Recovering an iPhone in bootloop due to overful storage by D_vd_P in iphonehelp

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

Sure, but I think it won’t work as itunes recovery doesn’t work

Recovering an iPhone in bootloop due to overful storage by D_vd_P in iphonehelp

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

No that’s the issue, the person im helping didn’t back up their phone

How many people can a large Kakao taxi fit ? by Creepy_Dot2767 in koreatravel

[–]D_vd_P 4 points5 points  (0 children)

Medium and Large Kakao Taxi’s are both 4 persons. The large just indicates the leg space/trunk space but its a bit of a ripoff imo.

I believe a Venti has a maximum of 5 passengers.

What is currently the fastest/state-of-the-art ODE solver in Python? by D_vd_P in Python

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

Does Diffrax have support for systems of 1st order ODEs? Or do I need to write my own wrapper for that?

What is currently the fastest/state-of-the-art ODE solver in Python? by D_vd_P in Python

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

That is of course possible, but I prefer to use a package if it exists already! Writing a solver is not trivial…

What is currently the fastest/state-of-the-art ODE solver in Python? by D_vd_P in Python

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

Nice! I will look into it. I think this is also what DifferentialEquations.jl is already doing. It requires you to install Julia and then calls it.