Day: June 27, 2023

Wind-to-Heat: A Lot Of Hot Air?

June 27, 2023 by 84 Comments

Heating is one of the greatest uses of energy in human society today. Where we once burned logs to stave off the brutal winter chill, now we lean on gas and electricity to warm our homes and keep us safe and toasty. In some colder climates, like the UK, heating can make up 60-80% of total domestic energy demands.

However, there are alternative ways to provide heating. Using wind energy to directly provide heat could be key in this area, using a variety of interesting methods that could have some unique niche applications.

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Spindle Upgrade Makes PocketNC Faster And Smoother

June 27, 2023 by 21 Comments

Conventional wisdom says that rigidity is the name of the game when it comes to machine tool performance. After all, there’s got to be a reason for CNC machines that need specialized rigging companies just to deliver them. But is there perhaps a way for the hobby machinist to cheat a little on that?

From the look of [Ryan]’s PocketNC spindle upgrade, it seems like the answer just might be yes. The PocketNC, a much-coveted five-axis CNC mill sized for the home shop, has a lot going for it, but as with most things, there are trade-offs. Chief among these is a lack of the usual huge, heavy castings used for CNC machines, which results in the tendency for the cutting tool to chatter or even stall out if you push the speeds and feeds too far. After a good intro to some of the important metrics of machining, such as “material removal rate,” the video below delves into how MRR affects chip load which in turn results in chatter.

The easy fix for chatter, of course, is to take smaller cuts. But [Ryan] decided to increase the spindle speed to take lighter cuts, but to do it really fast. The hardware for this includes a 3,500 KV high-torque brushless DC motor and a custom spindle attachment. The motor is connected to the spindle shaft using pulleys and a drive belt, and the shaft is supported with stout bearings that can be pre-loaded to fight backlash. The end result is three times the stock 10,000 RPM spindle speed, which lets [Ryan] see a 300% increase in cycle time on his PocketNC. And as a bonus, the whole thing requires no permanent modification to the machine and can be easily removed.

We think [Ryan] did a great job breaking this problem down to the essentials and hacking up a low-cost solution to the problem. Continue reading “Spindle Upgrade Makes PocketNC Faster And Smoother” →

Escalate The NERF Arms Race With Self-Firing Missiles

June 27, 2023 by 2 Comments

NERF guns are a toy that appeals to adults and youngsters alike — if you’ve never had the chance to pelt your friends with safe and kid friendly foam darts in a surprise ambush, you haven’t lived. But just as with real-world weapons of the type superpowers put in shows of military strength, there’s an arms race in the world of NERF. Mere darts aren’t enough, and there’s a range of missiles for the bellicose youngster intent on skirting the brink of global foam dart annihilation. These come with a catch though in the shape of a lackluster launcher, and this has prompted [Joel Creates] to create a self-firing NERF missile with a secondary rocket motor.

A supercapacitor stores enough energy to light a small scrap of guncotton explosive when sent through a heater coil, and this should be enough to launch the missile. Perhaps this whole video should sit in “Don’t try this at home kids” territory, but try he does, with multiple dead ends along the way. The final try is a secondary rocket motor inside the missile that’s triggered by a micro switch upon leaving the standard NERF launcher. It’s not a resounding success, but we’re sure you’ll agree it’s an entertaining video to get there.

We’ve featured quite a few NERF hacks over the years, including this large auto-aimer.

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