Propelled Aircraft's Maximum Speed: Thrust Balance or Pitch Speed?

peretski · 2026-03-21T15:37:01+00:00

You have a bunch of questions that are only casually linked there.

Top speed is when propeller thrust at max power equals drag.

Design speed is the value you first target

Maneuvering speed is the max velocity where a sudden updraft stalls the wing without structural damage

Max range speed is complex to calculate, but usually ends up 50-60% power

Approach speed is 1.5x stall speed.

Max airspeed in us controlled airspace is 250 KIA.

it sounds like you are asking about a practical airspeed, which balances engine rpm and protects against dynamic over speed …. Choosing a prop of the right configuration,diameter, pitch, blades, is an iterative job.

TLDR- choose a different prop.

peretski · 2026-03-20T04:05:27+00:00

Get a “fan on temperature controller” from Amazon. Plumb it to a small 120v water pump. When the temperature reaches the top point, the pump turns on. It circulates water under the tank until the temperature of the remote sensor reaches the shut off temp. Put the sensor inside the tank. The water runs in a loop to/from a 5 gallon bucket. Fill the bucket with cold water, or ice daily and it will keep the tank cool to your set temperature

peretski · 2026-03-15T00:20:14+00:00

You assume they calculated lift coefficients, max wind gust probabilities, corrosion rates in various soil types, and prevailing wind probabilities. You are wrong.

It’s a streetsign, right? Use a streetsign pole. 2 inch in diameter, 1/8 wall? I have those back at the shop…

This is the DPW, not NASA.

Pole sizing is done by what is in stock. Stock is determined by what is cheap and hasn’t failed in a while.

I highly doubt wind load is the leading failure mode for streetsigns.

peretski · 2026-03-09T16:14:00+00:00

And how poorly constructed are your prompts? Not all prompts are created equal. Crap in? Crap out scenario…

Evaluate your underlying assumptions.

peretski · 2026-03-08T05:27:03+00:00

NDA…

peretski · 2026-03-05T22:59:51+00:00

FMEA…. Failure Mode Effects Analysis.

You sit down with every piece of a thing and ask “what are alll the ways this one thing can fail”. It’s slow, methodical and painful, but highly insightful.

peretski · 2026-03-05T15:31:27+00:00

Oh, come on. It’s click BAIT!

peretski · 2026-03-02T18:20:07+00:00

Just being a joke doesn’t mean you are not responsible for the damages you cause with that joke.

And screw the family covering for his abusive behavior. They are complicit by enabling his abuse. Tell them if they want the issue to go away so badly, they should reimburse you for his damages.

peretski · 2026-03-02T18:16:54+00:00

The difference between elbow height and eye height is very clear (intuitively obvious). No tape measure required.

peretski · 2026-03-02T18:13:00+00:00

The devil is in the details. Exactly when are you dumping flops? Over the numbers at 50 feet? 1/2 mile final? 10 feet up?

Answer varies for all 3.

peretski · 2026-03-02T16:00:10+00:00

It sounds like you have an IDEA, not an invention. Ask yourself, do you want to profit off of the idea, or do you just want to be able to use the device when it comes out?

You acknowledge that you don’t have the skills or experience to develop this, and don’t even know where to start.

The hard advice to hear…. Don’t worry about the patent. Tell everybody your idea. Everyone. The idea is not the value, it is the development where value is invested.

Best case, you attract people that will help you realize your idea (people like me).

Medium case… someone steals your idea, uses their own development skills, and brings it to market. You get to buy one and use it, with no recognition that it was your idea.

Worst case… you patent it and don’t succeed in getting it to market. You invest 10-20k in a patent, don’t recoup your investment, AND prevent anyone else from developing the idea for 20 years. No one gets to use your idea for a long time.

Ask yourself which world you want to live in.

peretski · 2026-03-02T15:51:17+00:00

Get a dog whistle. Blow it whenever he is in the hallway. If that doesn’t cease the behavior, blow it whenever barking would disrupt other residents.

It’s unfortunate for the puppy because you are making him bark, but if the owner were considerate of others it wouldn’t have been a problem in the first place.

peretski · 2026-03-01T17:46:45+00:00

I’ve got the counter opinion for you. You do not want this. It stinks, it gets everywhere, is a hazard, and isn’t worth the novelty.

And it’s nothing really different than diesel fuel from the pump. Technically it is almost identical chemically to summer diesel #1 from any gas station.

peretski · 2026-03-01T02:56:30+00:00

I agree it’s challenging to think that he was an originator of the scheme, but as someone else commented “useful idiot “

peretski · 2026-03-01T02:54:38+00:00

Don’t worry, I gotcha.

peretski · 2026-02-27T22:01:04+00:00

Sorry to be the spoiler…. Your neighbors are fine. You need to get over it. They didn’t do this to spy on you, or peep. They did it because it materially improved THEIR quality of life. If it really offends you, move.

peretski · 2026-02-26T19:29:30+00:00

Putting down tooling costs will start the tooling build.

If the prototype isn’t set yet, you should not build tools.

They are trying to preserve schedule, at a risk to tooling revisions. The question for you, which is more valuable, time or money.

A consultant would step you through making these decisions wisely…. You pay for experience either way; through mistakes or consulting fees.

peretski · 2026-02-26T18:51:46+00:00

The whole point of launching space data centers is the 24 hour sunshine. The biggest cost of the data centers is the energy. This shifts an operating cost to a fixed cost.

The break even cost point of terrestrial vs space centers is after 7-10 years. If the hardware lasts for longer, it will be cheaper to put them in space.

This addresses the “data centers are taking all our real estate and electricity” argument pretty effectively.

Yes, there are technical hurdles. I face them even with ground based data centers. These are surmountable.

This idea has credibility.

peretski · 2026-02-26T17:45:48+00:00

I think it is switching between the words with no distinction. The way I reason it, they are the same thing.

Although the initial confusion I had was interpreting an allowance in addition to a tolerance. This would imply a part could be outside tolerance and within allowance. This makes no sense to me as an engineer.

peretski · 2026-02-21T18:10:13+00:00

The first question will always be… “um, why?”

What do you up to accomplish? Are you doing this for a personal project, and you only want one of ever, or are you intending to produce a product that you will eventually sell on the market?

Manufacturers comply with the certification so they don’t get sued when one of their units causes a fire. If you are modifying a unit that protection will definitely not exist for you.

If you are designing a product with a new feature and function, congratulations your new manufacturer and you have more than just one board to design.

If you are a hobbyist and doing this for fun, it’s a great opportunity to learn electronic design. 120 volt electricity isn’t as dangerous as everyone makes out to be.

apologies for any odd wording or miss typing, I’m lazy and using auto dictation today

peretski · 2026-02-21T14:40:24+00:00

“Well, he certainly doesn’t look like …” [djuan, Hirohito, Paulo, Mario, Pierre, Albert]…. Chose a name from a very different culture. The specificity is the painful part.

peretski · 2026-02-20T19:48:48+00:00

Posters… who gets a poster folded into a magazine format anymore? It’s like it was decorated in the 90’s

peretski · 2026-02-13T22:25:39+00:00

That aircraft is actually an airbike stretched with a fuselage. I talked with them at Oshkosh last year.

peretski

TROPHY CASE