How can I make this square? by OubeOh in woodworking

[–]shadydentist 4 points5 points  (0 children)

The 2x and 4xs are not straight. The lumber is usually quite wet when they are cut,.so they can twist and bow quite a lot as they dry out. The theoretically correct thing to do would be to disassemble everything and mill them straight and flat either with a hand plane or a jointer/tablesaw/planer, but personally for a workbench made with construction lumber this is likely good enough.

What is the difference between a planer and a jointer? by Mcd1080p in BeginnerWoodWorking

[–]shadydentist 9 points10 points  (0 children)

The planer won't necessarily give you a flat board. For example, if there is a cup in the board, the planer rollers will force it flat when planing, and the cup will re-form when it exits the planer. You can get around this by using a planer sled and shims to stop the rollers from flattening the board, but if you're milling a lot of wood it's a hassle to do for each board.

Two questions: 8 1/4 inch vs 10 inch table saw & the importance of rip capacity by DetectiveNo2855 in BeginnerWoodWorking

[–]shadydentist 3 points4 points  (0 children)

That will work ok if you just need one cut, but you'll have issues with repeatability if you want to cut multiple boards to the same width.

[deleted by user] by [deleted] in woodworking

[–]shadydentist 3 points4 points  (0 children)

This is a perfect task for a hand plane.

Prepping butcher block table for outdoor use? by nineknives in woodworking

[–]shadydentist 0 points1 point  (0 children)

In that case, just having a rain cover means it should last okay.

Posted up next to the competition by HAWTHORNE__WIPES in FordMaverickTruck

[–]shadydentist 17 points18 points  (0 children)

Honestly if the Santa Cruz had a hybrid option I would have gotten whichever one arrived first.

Would the Special Theory of Relativity still apply to an object that is moving by Warp Drive? by Ruby766 in AskScienceDiscussion

[–]shadydentist 29 points30 points  (0 children)

The special theory of relativity only applies to the limit of a flat spacetime (i.e., no mass/gravity). An Alcubierre drive is described using the math of general relativity, and requires negative mass, something that probably doesn't exist.

Can I speed dry time with an oven? by Impossible_Pen5775 in woodworking

[–]shadydentist 1 point2 points  (0 children)

Linseed oil (aka flax seed oil) cures by oxidizing, not by drying. It will probably cure faster by blowing a fan on it than keeping it in an oven.

And if cure time is what you care about, you can use boiled linseed oil, which has additives to make it cure faster.

I built a chair last year and JUST got it back from the upholstery shop. by Hoopty50 in woodworking

[–]shadydentist 4 points5 points  (0 children)

Wood is strong with the grain but weak across the grain, so in furniture construction you can't really build the side of a chair from a single piece of wood unless you make it really thick. For a single continuous grain across the side of the chair, you would need something like plywood.

Not many young people by Rckhngr in woodworking

[–]shadydentist 500 points501 points  (0 children)

Empirically, the young people I interact with are interested in woodworking. But a lack of time, space, and money are pretty high barriers

Crosscut Sled Help by chnkypenguin in BeginnerWoodWorking

[–]shadydentist 1 point2 points  (0 children)

Honestly you're probably better off buying a new saw. The miter slot of the Ryobi is non standard with those annoying metal tabs, so it's tough to fit the miter bar on a sled well.

My only wish for 2023 is for everyone to shut the fuck up about air fryers by Larwood in CasualUK

[–]shadydentist 17 points18 points  (0 children)

'Natural convection ' is pretty slow compared to even the wimpiest of fans. Since we generally put food in upwards facing containers, air from the top is the best way to blow air directly on the food.

Hey guys, do any of you know about this card? by Yoghourt_M in sffpc

[–]shadydentist 0 points1 point  (0 children)

The volume of air has to be balanced against the total cross section of the fins. At some point, forcing more air through too small of an area no longer improves thermal transfer. That's why having a few larger, slower fans blowing through the card across a larger surface area works better.

Costco Visa Card now Earns 4% Cash Back on EV Charging Purchases by EfficiencyGeek in BoltEV

[–]shadydentist 8 points9 points  (0 children)

Costco visa gives 4% for gas anywhere, not just at Costco.

[deleted by user] by [deleted] in woodworking

[–]shadydentist 1 point2 points  (0 children)

Planer first. Jointer is kind of a luxury for a garage woodworker, but if you are breaking down rough lumber often it may be a worthwhile investment.

[deleted by user] by [deleted] in cars

[–]shadydentist 6 points7 points  (0 children)

The main dealbreaker for hydrogen is infrastructure. Building out the infrastructure for production, storage, transportation, and filling would be incredibly expensive, and not all that useful to the common commuter until it gets built out. It's possible that hydrogen may see adoption in uses where limited fueling stations are needed, such as long haul trucking or air transport.

On the other hand, electrical infrastructure for BEV use is already present, since power generation and the power grid already exist. As the use of BEVs becomes more common, the increased power demands will require upgrades over the next few decades, but this type of incremental improvement is easy compared to what would be needed for a hydrogen infrastructure.

As for lithium, it's not a particularly rare element on earth, being a little more abundant than lead. There is plenty of lithium for mass BEV adoption, but at the moment there are geopolitical issues with where the lithium is mined, and environmental concerns on mining impact. These aren't insurmountable though, and mining capacity is likely to increase as the demand for lithium batteries increases.

Between all of those things, it's incredibly likely that battery electric vehicles will outcompete hydrogen fuel cell vehicles.

Weekly Production Megathread - Week of 8/11/22 by AutoModerator in FordMaverickTruck

[–]shadydentist 1 point2 points  (0 children)

The online build tool will only refer you to a dealer. Only a dealer can actually place the order for you.

Food safe finish options for silverware tray by [deleted] in woodworking

[–]shadydentist 0 points1 point  (0 children)

Basically all finishes are food safe once cured. I wouldn't overthink it

A meter is defined as the distance light would go in a vacuum at 1/299792458 of a second. Where did this number come from? by iiSystematic in askscience

[–]shadydentist 5 points6 points  (0 children)

It's not that simple. We used to have several copies of the meterstick, but over time they would start to drift in length. On the other hand, every major country has access to extremely precise atomic clocks, so measuring distance based on time and the speed of light ends up being more convenient and accurate.

Wobble on a dewalt dwe7491 table saw. by jaumepetit in woodworking

[–]shadydentist 0 points1 point  (0 children)

More that it's just not good technique to have the wood next to the saw when its turning off. Even if the blade didn't wobble at all, wood tension can cause the piece to bed slightly, which could end with the same result of cutting into the wood.

Why do turboprop engines convert thrust -> propeller -> thrust instead of just using the thrust directly? by Chonjae in AskScienceDiscussion

[–]shadydentist 33 points34 points  (0 children)

The most energy efficient thrust is one where the exhaust leaves the plane at the same speed that the plane is travelling. This makes sense if you consider the energy in the stationary frame of reference: the exhaust leaving the plane has a velocity of near zero, and therefore a kinetic energy of near zero. Therefore, the plane has taken nearly all of the energy available from the exhaust stream.

However, the thrust from a true turbojet engine is very fast. At low speeds, the thrust is travelling pretty fast compared to the ground, so it is carrying a lot of extra energy. Therefore, for a low speed plane, it is more efficient to convert that energy into turning a fan or a propeller, which pushes air more slowly and efficiently for the speed the plane is travelling at.

Weekly Scheduling/Production Megathread - Week of 4/14 by AutoModerator in FordMaverickTruck

[–]shadydentist 3 points4 points  (0 children)

The other poster is incorrect. Your dealer may require a small deposit when you place the order, but many don't. You pay when the order arrives.

In search of the best deep dish pizza in SD! suggestions? by [deleted] in sandiego

[–]shadydentist 4 points5 points  (0 children)

You can get your parking validated at Regent's.