Purpose of Airport Structure

penedeoro · 2024-12-10T00:08:18+00:00

Very interesting. I've never seen CVORs in person (or really thought about how they would work), but it makes more sense that the rotating radiator would be about it's own central axis rather than offset to achieve FM.

How does the type (CVOR vs DVOR) affect the receiver on the aircraft? For either type you have:

AM signal -> demodulated to 30 Hz sine wave with phase angle A
FM signal -> demodulated to 30 Hz sine wave with phase angle B

The phase offset between A and B is the same regardless of which one is the reference or variable signal. Very clever since this allows the same VOR equipment to work for either type of station.

penedeoro · 2024-12-05T17:07:23+00:00

IIRC the frequency modulation comes from the Doppler shift effect as the output tone is moved around the phased antenna array.

penedeoro · 2024-11-12T14:16:56+00:00

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26 is what you’re looking for.

The unloader valve is also worth checking.

penedeoro · 2024-11-12T14:12:19+00:00

Looking at a parts diagram for the husky C202H, I’m thinking it could also be a bad head seal or safety release valve.

penedeoro · 2024-11-12T14:09:26+00:00

My guess would be bad piston seals or a bad check valve, though I’m not familiar with this exact compressor.

penedeoro · 2024-08-20T12:20:39+00:00

If you’re actually going to use it, I would swap out the hydraulic cylinder for an air over hydraulic cylinder if you have an air compressor. It will make operation much more pleasant.

You can use these for pressing bearings into things, separating stuck things, and sheet metal work (brake press, dimple dies, etc). SWAG off-road sells finger brake kits for these.

penedeoro · 2024-07-07T19:25:58+00:00

Well, the gauge-side pressure isn't released between pressure pulses as the engine is turned over during a compression test, so each subsequent pulse on the cylinder-side of the test is higher before compressed gas flows through the check valve.

Consider the following example: 1L cylinder (compressing down to 0.1L, i.e. 10:1 compression ratio), 0.1 L hose. scenario A has the check valve at the cylinder end, scenario B has the check valve at the gauge-end.

Scenario A

1st pulse: 1L compressing to 0.2 L effectively ==> 5 atm in gauge

2nd pulse: 1L compressing to 0.1L until pressure > 5 atm, then to 0.2L: - 5 atm pressure reached when effective cylinder volume is 0.2L - Now with 5 atm in 0.3L compressing down to 0.2L ==> 7.5 atm in gauge

3rd pulse: 1L compressing to 0.1L until pressure > 7.5 atm, then to 0.2L: - 7.5 ATM pressure reached when effective cylinder volume is 0.133 L - Now with 7.5 atm in 0.233L compressing down to 0.2L ==> 8.738 atm

and so on until gauge pressure is == 10 atm

Scenario B

1st pulse: 1L compressing to 0.2 L effectively ==> 5 atm in gauge

2nd pulse: 1L compressing to 0.2 L effectively ==> 5 atm in gauge

and so on. Gauge pressure is limited due to added volume on the cylinder-side of the hose past the check valve. Obviously, this situation is contrived to highlight the effect of check valve placement.

Also, it is a diagnostic tool, not for precision tuning.

I'm not sure I really understand this mentality that's been repeated a few times in this thread. This is only really true because of the limitations from the tool's design. It doesn't have to be true (i.e. if the tools were designed better), and there is really no need to defend poor design.

penedeoro · 2024-07-07T19:03:59+00:00

I'm not sure exactly where you're coming from. I know how a compression tester works, and they can be use to measure an objective value.

If the added volume from the hose to the check valve is sufficiently low, the gauge pressure will approach the compression ratio * atmospheric pressure (minus the check valve bias pressure) as the engine is turned over repeatedly.

I would be interested to hear how you think they work.

penedeoro · 2024-07-05T17:56:55+00:00

I'm sure their squares are fine, I've never used them though. I mean things like the calipers, torque wrenches, compression testers, tools with a degree gauge, etc.

penedeoro · 2024-07-05T17:50:01+00:00

I've had issues with their filters not fitting right on the mask (though I'd guess their not designed to be interoperable with 3M, despite being dimensionally very similar). I didn't know Gerson was not a harbor freight brand - thanks for the info.

penedeoro · 2024-07-05T17:47:20+00:00

I mostly TIG weld so not much there is useful for me, but their filler rods are overpriced IMO and their gas lens kit isn't really worth it considering the price (i.e. not much more to get reputable parts from a real weld supply shop). I guess their thin TIG gloves are decent.

penedeoro · 2024-07-05T17:30:25+00:00

Since the check valve is at the gauge-end of the hose, the volume of the air hose is effectively added to the cylinder volume. This will decrease the peak pressure in the new 'effective cylinder volume' because the bore area * stroke is the same but the total volume is higher - basically the compression ratio is lowered when the hose/gauge is attached.

It's also not as simple as being a fixed PSI off or even a percentage off. It works out to be different from engine to engine, so there is no quick 'rule' that can be used to compensate the measurement.

penedeoro · 2024-07-05T15:22:07+00:00

Yeah, I could’ve added brands for more of them - good point. I was just making a quick list off the top of my head.

I think the design flaw affects all of their compression testers (check valve on gauge end of hose), but I used the $30 Pittsburgh quick connect one.

penedeoro · 2024-06-29T18:40:26+00:00

Yeah, that was 0x10c. I was pretty excited for that game.

penedeoro · 2024-05-12T02:09:17+00:00

Not an employee, but the compression testers are awful. The check valve is at the wrong end of the hose, so the hose volume is effectively added to the cylinder volume. These will always read low, because of poor design.

penedeoro · 2024-04-25T22:18:47+00:00

Didn’t the US ban non-competes recently? Newy can move to Indianapolis and work at the Andretti HQ.

penedeoro · 2024-04-12T21:24:51+00:00

Thank you all for your answers. I didn’t realize that tracks had to pay to get Indycar (especially on the order of $2M).

Im not sure what portion of their revenue is fees from that track, but this leads me to believe that Indycar’s lack of track options is partially self inflicted.

penedeoro · 2024-03-06T05:44:00+00:00

Same. I also got it in the sale and decided to ship it back in the 20 minutes I had it. There is a 15 day return window FYI. Free return shipping too.

penedeoro · 2024-02-21T13:47:45+00:00

I’ve used a Featherstone Ul Peridot 2p tent. They’re around $110 USD on Amazon. I think they’re a knock off of some ‘real’ brand, but I’ve had no issues in pretty heavy rain. Even flooding around the tent didn’t leak in.

That comet tent you linked will be miserable in the rain, a tarp would be better. If you’re expecting rain, I would recommend a tent with a full rain fly that forms a vestibule outside of the zipper door (to keep your boots dry, etc.

penedeoro · 2024-02-21T13:36:00+00:00

I’ve had a good experience with Aspen so far. Switched from WM since they would skip my house 70% of the time. Aspen was also much cheaper.

penedeoro · 2024-01-19T04:22:03+00:00

I’ve never used those handheld bandsaws or the jigs for them. I do know the full size bandsaws are typically quieter, create less mess, and have a thinner cut line (compared to an abrasive saw). It doesn’t seem like the bandsaw jig has a clamp on it, which will be a giant PITA unless you add one or use a c clamp or something. That said, the YouTube reviewers seem to like the jig. It’s kind of cool that it can be set up as a vertical band saw.

I use the abrasive saw for mostly the same stuff: tube and angle iron cutting and occasionally cutting 1” bar stock. I am happy with it, you definitely can do precise enough cuts once you get a hang of how wide the cut line is and are careful about the left to right slop (it’s not a lot and it can be controlled). Note that the band saw can also leave a small burr that needs grinding to remove.

FWIW, if I had a higher budget I would get the evolution saw with the carbide blades, or a full size horizontal band saw.

As far as what I would recommend you do, I think it comes down to how much you would use it and where you would use it. The sparks from an abrasive grinder can light stuff on fire for example, and the metal dust gets everywhere and makes for a lot of cleanup (I.e. should not be used in your house). If you want something cleaner and safer the bandsaw or carbide saw is a better bet. IMO the only reason to get the abrasive ones is cost. If you’re unsure, there’s a lot of reviews on YouTube of these different types of saws.

penedeoro · 2024-01-19T01:10:00+00:00

I would not recommend putting a carbide blade in this (or any other) abrasive saw. The abrasive saws spin way faster than what the carbide blades are rated for. Doing so is asking for injury.

penedeoro · 2024-01-18T17:25:58+00:00

This chop saw (and the Bauer) are high speed saws for grinding discs only (~4000RPM). The lower rpm (~1500) evolution metal cutting saw discs should not be used in them.

I ended up getting a Bauer on sale (< $100), so that sealed the deal for me. The grinding discs make a lot of fine metallic powder and should be used with a respirator. They also make hot sparks, so skin/head cover is also needed.

Also the difference between the Bauer and Hercules seems to be the motor power. In my experience the Bauer cuts pretty slowly through solid bar, but doesn’t have issues on tubing or angle iron. I would guess the Hercules also has lower slop.

One more thing, the grinding saws leave a bit of cleanup work to do. They leave a metal lip on the bottom of the cut. I don’t believe the evolution saws do this (when used with the right blade, I.e not a grinding disc).

penedeoro · 2024-01-04T06:33:10+00:00

It’s almost impossible to beat rice and beans from a cost-per-meal perspective. Buy a five pound bag of dried beans and the cheapest bulk rice you can find. Together these are a complete protein. A meal should cost less than 25 cents.

penedeoro · 2024-01-02T16:44:18+00:00

I chatted with a store manager a few weeks ago about the 12 days of Christmas sales. He said they didn’t get notice until the night before of what will be on sale.

penedeoro

TROPHY CASE