36V CNC Spindle Motor Driver

Skraćena veza: https://pedja.supurovic.net/veza/9675

Hobby CNC machines are usually based on Arduino/Woodpecker CNC controllers with cheap motor drivers and 775 spindle motors. Motors are specified to run on 36V but CNC machines usually run it on 24V. That means motors run on slower speed than what they can do. Some controllers are able to run 36V but 24V power supplied are delivered with them. Newer Woodpecker CNC controllers are specified to run on 24V only.

Some specifications claim that 775 motor used for spindle runs at 3000-6000 rpm when powered at 24V and gets up to 9000 when powered at 36V. I wanted to run spindle at maximum possible speed for better milling results. […]
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CNC Clamp Screw Locking Improvement

Skraćena veza: https://pedja.supurovic.net/veza/9634

With hobby mini CNC machines you get simple and very cheap clamps that are not easy to use.

It is hard to fasten it because screw turns along with nut, and as screw head is in T-slot of bead it is not easy reachable to block turning.

This is small rectangle peace you can attach to screw head that will block it turning within T-slot.

It makes using clamps much better experience.

You may make it from mdf, wood, plastic, metal, whatever you like.

Download from: https://www.thingiverse.com/thing:4160827

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Dipole Antenna Center Insulator for SO239

Skraćena veza: https://pedja.supurovic.net/veza/9625

Building dipole antennas is always some kind of improvisation. Center insulator is quite simple and may be made in short time with jigsaw and drill.

As I jumped in CNC world I need some simple tasks to learn how to use FreeCAD and other software. So, dipole center piece is ideal just for that. I’ve finished project and learned a lot in the process.

Finished projects is uploaded to Thingverse: https://www.thingiverse.com/thing:4149187

You may use CNC mill or 3D printer to make this part. Pay attention to use material strong enough to survive possible strong forces.

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Universal CAT and programming USB to serial TTL interface for ham radio

Skraćena veza: https://pedja.supurovic.net/veza/9536

Some years ago I posted article describing Universal CAT and programming USB to RS232 TTL interface for ham radio that I made.

Here is small update, adapter for YAESU FT-8900, FT-8800 and alike radios.

FT-8900 and FT-8800 and some other Yaesu radios use two wire interface. One wire is ground and other is both RX and TX. This is also known as CIV-I interface used in Icom radios.

CIV-I interface is quite simple. There is a diode (universal like 1N14148) connecting RX and TX, oriented cathode toward TX, with one 10K pull up resistor to 5V on RX. […]
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Vežbajte otpremanje Morzeove telegrafije samo sa ručicom i računarom

Skraćena veza: https://pedja.supurovic.net/veza/9225

Za usavršavanje tehnike otpremanja Morzeove telegrafije potrebno je odvojiti dosta vremena za vežbanje. Zgodno je ako to možete da radite kad god imate vremena.

Za to su vam potrebni ručni taster ili ručica i tonski generator. Taster i ručica se nabave (svaki radio-amater valjda to već ima) a kao tonski generator se obično koristi radio-stanica ili, ko se bavi elektronikom, može i da napravi.

Međutim, ako imate računar, on može takođe da završi posao. Postoji nekoliko programa koji rade kao tonski generatori a taster i ručicu na računar povezujete preko serijskog priključka na računaru.

MorseKeyer je jedan od takvih programa. […]
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Kako razlikovati BNC konektor za 50 i 75 oma?

Skraćena veza: https://pedja.supurovic.net/veza/8930

BNC konektor je jedan od retkih koji se izrađuje u verziji za impedansu od 50 oma i impedansu od 75 oma. Za neke primene vrlo je važno koristiti odgovarajući konektor. Kada kupujete konektor lako je, kupite onaj koji vam treba, ali šta ako imate konektor kome ne znate karakteristike?

Pogledajte kako je napravljen. Konektor od 50 oma sadrži prsten od izolujućeg materijala dok 75-omski konektor to nema.

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