What did you buy today? Post your latest purchase!

[Specmaster]

OK then, not quite today but a couple of days ago I decided to buy a set of smart tweezers to make working with SMD stuff easier and decided that maybe it might be better to avoid both ends of the market and go for something a bit more, middle of the road sort of thing so I chose these chappies.

More info when I get them delivered.

[beanflying]

Had an arrival of a Heatshrink pack so I needed to make a better storage solution for it. Required the purchase of another bottle of Glenfiddich and consumption of a bit of the contents while the printer made the joiners. #winwin

The little baggy of leftovers will finish up in a drawer at this stage. This tree should stop multiple bits of the same colour or diameter getting started 'in theory'.

I might add another hole or two at intermediate heights so the bits sit closer to the tube.


edit - added a more complete shot including hotsnotted joiners and holes.

[aargee]

Why didn't you make the lid a cup to hold all the short bits?

Doubles as a strawberry planter as well.

Mine is a length of 90mm stormwater PVC pipe, cheaper o than printing the 3D bits but maybe not as stylish! I do like the size holes up the side. :-)

[beanflying]

Why didn't you make the lid a cup to hold all the short bits?

I did think about it. Currently the baggy is sitting under the lid as the tube is fairly full so it doesn't drop down. Maybe a MK II Lid is needed 

The holes are well worth it sorting through a mixed tube to get to the started lengths just doesn't work.

[beanflying]

An emergency button

Hopefully it's the last time I will deal unsafely with live 220Vac voltages... 

Just remember those contacts in there are not rated for continuous operation at 10A, and also they are not fail safe when disconnecting into a high current. They tend to weld together under heavy load, so best used in conjunction with a sensitive 16A AC1 rated contactor. Those at least will, when paired with the appropriate overload, provide good protection. Hope you also got some LED power on indicators to go with them.

The contactor should not be operated correctly, it is a safety button with locking, these buttons are used to control the circuit breaker trip coil - the most reliable disconnection -   - the coil acts on the circuit breaker locking mechanism

Correct, these emergency stop buttons are only rated for the coil current only and should never ever be used as a means of breaking the mains power supply directly, only via a suitably rated contactor

I know this is a week ago but a pair of very similar ones arrived in the mail today. Quick non destructive teardown for information. Allegedly 15A rated  Maybe 3A would be closer and even then ? This pair is going on my CNC via a properly rated relay to the power supply/vfd.

[Specmaster]

An emergency button

Hopefully it's the last time I will deal unsafely with live 220Vac voltages... 

Just remember those contacts in there are not rated for continuous operation at 10A, and also they are not fail safe when disconnecting into a high current. They tend to weld together under heavy load, so best used in conjunction with a sensitive 16A AC1 rated contactor. Those at least will, when paired with the appropriate overload, provide good protection. Hope you also got some LED power on indicators to go with them.

The contactor should not be operated correctly, it is a safety button with locking, these buttons are used to control the circuit breaker trip coil - the most reliable disconnection -   - the coil acts on the circuit breaker locking mechanism

Correct, these emergency stop buttons are only rated for the coil current only and should never ever be used as a means of breaking the mains power supply directly, only via a suitably rated contactor

I know this is a week ago but a pair of very similar ones arrived in the mail today. Quick non destructive teardown for information. Allegedly 15A rated  Maybe 3A would be closer and even then ? This pair is going on my CNC via a properly rated relay to the power supply/vfd.

Hopefully a contactor, not a relay as relays tends to have silver contacts and can evaporate with arcing caused by motor currents. Contractors on the hand gave silver oxide cadium contacts to withstand the arcing.

[beanflying]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

[Cubdriver]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

The thing that comes to mind with that is, isn't a coffee maker typically pretty much a purely resistive load?  It's likely not an issue, but might be something to consider.  What sort of load will the CNC machine present - something more inductive and potentially arcy-sparky?

-Pat

[beanflying]

Power Supply and a VFD on the Head so no harsh on/off and under 3kW total (<15A).

Espresso machines are hard on or off and the contacts are 20A rated each x 3 so cruising in this case. I have never seen one of these fail in a modern machine and some are 7.5kW+ running the same contactor in a lot of cases.

[Specmaster]

It is in this case it is a contactor I salvaged out of a coffee machine they are designed to cycle 20-30 times an hour for years. Contacts unknown but it is a 3phase one so it should do fine.

The thing that comes to mind with that is, isn't a coffee maker typically pretty much a purely resistive load?  It's likely not an issue, but might be something to consider.  What sort of load will the CNC machine present - something more inductive and potentially arcy-sparky?

-Pat

I would tend to agree with you Pat. I used to look after many vending machines including coffee makers and they are mainly resistive loads. I have been called out to so many alleged faulty gear call calls over the years where people who really should know better have built huge great motor control panels for production process that have cost thousands of pounds in damages because the so called professionals used hundreds of relays to control motors on automation of production plants that have failed and ground the entire factory to a halt as a result. Replacing the relays with proper contactors cured the problem permanently and the same panels were still in daily use when they closed the factory many years later and demolished it to make way for housing and a retail park and the only difference is the contact material, a small but vital detail to get right.

[Specmaster]

Power Supply and a VFD on the Head so no harsh on/off and under 3kW total (<15A).

Espresso machines are hard on or off and the contacts are 20A rated each x 3 so cruising in this case. I have never seen one of these fail in a modern machine and some are 7.5kW+ running the same contactor in a lot of cases.

That may be so, but I would do my homework on the contactor / relay part number that you're using to make sure what the contact material is because contactor contacts tend to be rated as AC4 (inching and plugging as you would do on a crane) which is the most difficult load to switch on because of the massive inrush currents, switching off is not so hard to do.

Check the following link and look at the table there which details the massive inrush currents that contractors have to handle (AC2, AC3 and AC4 ratings, AC1 rating can be handled in most cases by a relay if there is very little inductive loading on the circuit.

https://electrical-engineering-portal.com/contactors-direct-on-line-starters

[beanflying]

Worst case here is likely to be a tool crashing into the bed which already has proximity sensors on it and disables the VFD. VFD failure and magic smoke release to short will likely trigger the ELCB or fuse board breaker before I can get to the stop switch.

So the emergency stops and contactor are more belts and braces to keep me happy I can manually kill it rather then yank the plug out of the wall (like its former owner used to have available) or if I lift the lid to do something with fleshy bits near the pointy bits keep the spindle from firing up. 


edit found a spec sheet AC3 12A / contact

[Edison]

Safety buttons on the industrial trigger are mechanically solved - by pressing, the contacts disconnect mechanically, not electrically (with the exception of security coils circuit breakers and switches). With electrical disconnection, this is considered to be a normal "Stop" button whatever its shape.

[Edison]

  Back to shopping     

[Gary350z]

This is a magnetic ferrite core memory plane.
("Plane" seems to be the correct term for this.)
I purchased this on ebay from the Russian Federation for $35 including shipping. The shipping time from Russia to the USA was about one week. I didn't have 100% confidance that it would arrive, but it did.
 
This magnetic core memory plane was made in the USSR in 1970s.
It is a 32x32 core memory plane that stores 1024 bits (128 bytes) of data.
The plane outside dimensions are 4.4" x 4.4".
This plane is one of 20 planes forming a magnetic core memory block. The capacity of the whole block is 2560 bytes.

[beanflying]

Very Shame I am trying to slim down the collection of 'stuff' but it is fairly slim and maybe in a frame ..... 

[McBryce]

Yup, they make a nice decoration when framed. Here's mine, probably from the same seller, that I bought a few years ago.

McBryce.

[KaneTW]

A HP 4140B and a Merck Spectroquant NOVA 30.

[cdev]

They are really amazing looking.

Tri-state memory!

This is a magnetic ferrite core memory plane.
("Plane" seems to be the correct term for this.)
I purchased this on ebay from the Russian Federation for $35 including shipping. The shipping time from Russia to the USA was about one week. I didn't have 100% confidance that it would arrive, but it did.
 
This magnetic core memory plane was made in the USSR in 1970s.
It is a 32x32 core memory plane that stores 1024 bits (128 bytes) of data.
The plane outside dimensions are 4.4" x 4.4".
This plane is one of 20 planes forming a magnetic core memory block. The capacity of the whole block is 2560 bytes.

[beanflying]

Yup, they make a nice decoration when framed. Here's mine, probably from the same seller, that I bought a few years ago.

McBryce.

That's just evil No No I won't succumb to the pretty pictures.   

[bitseeker]

You guys! Why do you do this to me? Very cool historically nerdy decor. For how long can I resist not buying one?

[McBryce]

You guys! Why do you do this to me? Very cool historically nerdy decor. For how long can I resist not buying one?

I'll post a link later to the deep frames needed to mount these, so you have no excuse not to have some core memory on the wall

McBryce.

[Kjelt]

One of my good intentions of the new year was and still is, to only buy stuff that I use directly or on very short term.
I can't find any practical use in 1kB of magnetic core memory so I am safe in resisting 

[McBryce]

One of my good intentions of the new year was and still is, to only buy stuff that I use directly or on very short term.
I can't find any practical use in 1kB of magnetic core memory so I am safe in resisting 

Really? How many of your past "good intentions" have you actually managed to keep? My current score is zero. 

McBryce.

[TerraHertz]

I bought a second hand book from a US seller in Baltimore MD (via abebooks.com) It's Vol 2 for a Vol 1 I've had for years.
Nice price: US$ 18.79 plus postage US$ 8.98

The packing was ... strange.

The bookshop put it in what is effectively a brown paper bag. The paper is tough, but stiff cardboard it isn't. The bag inside surface has a tacky coating, so the book doesn't slide around and excess volume of the bag sticks to the other side. Overall volume is basically the same as the book. But there's no resistance to impacts at all.

They put a customs declaration and address label on that bag.

Then someone in LA CA put that in a giant USPS plastic sack, dimensions flat: 1m x 0.7m.  Wiretied the neck of the sack, with another address label. 'INTL SURFACE AIR LIFT'
That has a tick box for "Books/sheet music" but it isn't ticked.

And that's how it arrived.  A book in a bag in a giant sack. This goes up there among the oddest packings I've ever received.
The book is hardback and survived more or less, but is sort of 'rounded on the corners.'

The sack seems pretty useful. Light and strong. Maybe for beach/snorkelling gear. But why was it added?