Author Topic: What did you buy today? Post your latest purchase!  (Read 1718266 times)

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Offline Microcheap

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Re: What did you buy today? Post your latest purchase!
« Reply #10525 on: December 14, 2020, 05:34:12 am »
I didn't pay attention and didn't followed the official links so I ended up with a cheap clone TinySA "Spertrum" Analyzer that won't pass self test and don't have the internal shielding. Maybe it was damaged by "static disqharge"  :palm:

And a somewhat better quality tool to make sure my beer is at the right temperature:
« Last Edit: December 14, 2020, 05:36:18 am by Microcheap »
 

Offline _Wim_

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Re: What did you buy today? Post your latest purchase!
« Reply #10526 on: December 14, 2020, 09:21:42 pm »
Just search fiber laser engraver on YouTube, and I don't see many use this in an enclosure.

FYI, those are marketed in China for use in the open public, for engraving souvenirs on street side markets or tourist destinations.

Sounds scary, but so far no reports stating they have blinded anyone.

Again, I need to stress the fact that those lasers are NOT collimated. They use a technology called f-theta lens, which allows for large area engraving without losing focus.

Essentially, the more the light bends, the longer the focal length is, so effectively at the same vertical distance it is always in focus, regardless what the hypotenuse length is.

However, once the vertical distance changed, it goes out of focus very quickly.

Typically you get ~3mm of travel before the laser loses enough focus and loses capability to do any damage to even organic matters, and for metal engraving, ~1mm, and I will be at least 30cm from it when it runs.

Before the F-theta lens you have a collimated but expanded beam (expanded to protect the galvo mirrors from burning in due to the very high peak powers), and the F-theta lens refocusses the expanded beam exactly at the same height everywhere on the working area of the lens. Due to the very fine focus the peak power / area is enormous, which causes the material to vaporize.

If for example the beam before the f-theta lens has a diameter of 8mm, and the working distance of the F-theta lens is 200mm, then the reflected beam will have again a diameter of 8mm at 200mm reflected distance.  Remember these laser can generate pulses in excess of 10kW, which takes quite a distance for attenuation even if the beam is not very collimated. Laser safety glasses typically of an OD of >6 (attenuation of 1 million) for a good reason!

I can imagine as long as the engraved object is perfectly flat, this probably creates no major issues as the beam is reflected back towards f-theta lens. But if the marked object only slightly refocuses the reflected beam is your direction, I cannot imagine safety is always guaranteed.

Apart from videos on youtube, I have never come across one in industry without a safety cage. Agreed, I have not seen hundreds of laser marking machines in my job, but I have come across at least 25 of many different brands. That why I asked if you are aware of any datasheet from a reputable company that states one of their products can be used without a safety cage. 

I would still recommend to be careful, and to use a good quality pair of laser safety glasses for you and anyone nearby.

« Last Edit: December 14, 2020, 09:23:55 pm by _Wim_ »
 
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Offline DrG

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Re: What did you buy today? Post your latest purchase!
« Reply #10527 on: December 15, 2020, 12:18:41 am »
I didn't pay attention and didn't followed the official links so I ended up with a cheap clone TinySA "Spertrum" Analyzer that won't pass self test and don't have the internal shielding. Maybe it was damaged by "static disqharge"  :palm:


I looked into that as a result of your post. I looked into the genuine TinySA (genuine spelling of spectrum). It's only US$50! This, right? http://www.randl.com/shop/catalog/product_info.php?products_id=75243&osCsid=ha9cd162ojp4v041la6a18bv47

Very cool. I am thinking about it as a holiday gift...for myself...not that I really have a need for one, but still..:)
- Invest in science - it pays big dividends. -
 

Offline Ground_Loop

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Re: What did you buy today? Post your latest purchase!
« Reply #10528 on: December 15, 2020, 01:30:14 am »
Got my hands on a fine Starrett tap handle. [attach=1]
There's no point getting old if you don't have stories.
 
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Offline rfclown

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Re: What did you buy today? Post your latest purchase!
« Reply #10529 on: December 15, 2020, 03:46:27 am »
Hard to resist the cheap Chinese stuff. I've got an decent HP counter, but with a crap reference, so I use an external ref. Wanted a second counter for my day job (since my employer has only one counter for many engineers, and no good reference). I was going to build one, but saw this on eBay, and it wasn't worth the time making a better one. The reference alone in this thing is something I get $25 bucks for on eBay, and the counter was $130 shipped from US. It's a BG7TBL FA-2. As received the internal reference was only 0.11 Hz different than one of my rubidiums. Tweeked the adjustment pot to bring it closer.
« Last Edit: December 15, 2020, 03:50:51 am by rfclown »
 

Offline Gary350z

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Re: What did you buy today? Post your latest purchase!
« Reply #10530 on: December 15, 2020, 12:51:23 pm »
HHIP 4401-1597 Granite Surface Plate for checking flat things. $41 from amazon with free shipping.
Not top of the line, but good enough for me.
 

Offline Syntax Error

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Re: What did you buy today? Post your latest purchase!
« Reply #10531 on: December 15, 2020, 09:10:15 pm »
Paint the Whole World with a RAINBOW DIP Switch. Or two.

Part No: ERG_SDS-8-023
 
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Online I wanted a rude username

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Re: What did you buy today? Post your latest purchase!
« Reply #10532 on: December 16, 2020, 03:19:23 am »
Love the fact that the colours match up (presumably intentionally) with those of a standard rainbow ribbon cable.
 
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Offline Ed.Kloonk

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Re: What did you buy today? Post your latest purchase!
« Reply #10533 on: December 16, 2020, 03:44:50 am »
Love the fact that the colours match up (presumably intentionally) with those of a standard rainbow ribbon cable.

If birds fly...
 

Offline IDEngineer

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Re: What did you buy today? Post your latest purchase!
« Reply #10534 on: December 16, 2020, 04:56:59 am »
HHIP 4401-1597 Granite Surface Plate for checking flat things. $41 from amazon with free shipping.
Wow, that's actually a great deal if the accuracy is as claimed. I might have to get a stronger Christmas stocking.
 

Offline Calambres

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Re: What did you buy today? Post your latest purchase!
« Reply #10535 on: December 16, 2020, 10:55:07 am »
Just ordered this beauty:




An RPN queen for sure!


 
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Offline richnormand

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Re: What did you buy today? Post your latest purchase!
« Reply #10536 on: December 16, 2020, 07:16:17 pm »
@Calambres

Drooling...... and envy :)

Still using my HP33E on the bench so I should not complain too much.
RPN rules.
Too bad most engineering graduates I meet have no idea. On the other hand, my calculator does tend to stay on my desk and they are stunned I finish a calc sooner than they do.

My SO has to one with the magnetic cards and that still works too.
REPAIR, RENEW, REUSE, RECYCLE, REBUILD, REDUCE, RECOVER, REPURPOSE, RESTORE....
 

Offline IDEngineer

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Re: What did you buy today? Post your latest purchase!
« Reply #10537 on: December 16, 2020, 08:47:53 pm »
RPN for the win! I have three HP10 series calculators on my desk, my wife uses 12C's exclusively, and I think I still have my original HP35 and HP55 in a box somewhere.

EDIT: Almost forgot the HP11 emulator on my OnePlus cellphone, too.

Someone once asked to borrow one of my HP calculators. I waited for the inevitable "Where's the equal sign?", then told them it was in the battery compartment. Being one of the original series, its triple-NiCd pack fell right out... depowering the calculator... yet they still searched in the compartment for the equals key. :palm:

RPN everywhere, all the time. Accept no substitutes.
« Last Edit: December 16, 2020, 11:11:44 pm by IDEngineer »
 

Online Mr.B

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Re: What did you buy today? Post your latest purchase!
« Reply #10538 on: December 16, 2020, 08:49:29 pm »
Time is the overseer of all things.
 
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Offline Gary350z

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Re: What did you buy today? Post your latest purchase!
« Reply #10539 on: December 16, 2020, 09:41:37 pm »
HHIP 4401-1597 Granite Surface Plate for checking flat things. $41 from amazon with free shipping.
Wow, that's actually a great deal if the accuracy is as claimed. I might have to get a stronger Christmas stocking.
With amazon you get free shipping and FREE RETURN SHIPPING so you can't go wrong.

...and your wife says you got a rock in your Christmas stocking. ;D
 

Offline Gary350z

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Re: What did you buy today? Post your latest purchase!
« Reply #10540 on: December 16, 2020, 10:26:22 pm »
tinySA spectrum analyzer for $50
I ordered it today from Aliexpress.
Frequency range from 100kHz to 350MHz
Be aware it is small (screen diagonal 2.8"), and has limitations.

Information:
https://tinysa.org/wiki/pmwiki.php?n=Main.HomePage

Only buy from official stores to avoid clones:
https://tinysa.org/wiki/pmwiki.php?n=Main.Buying


« Last Edit: December 16, 2020, 10:35:54 pm by Gary350z »
 

Offline IDEngineer

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Re: What did you buy today? Post your latest purchase!
« Reply #10541 on: December 16, 2020, 11:08:35 pm »
...and your wife says you got a rock in your Christmas stocking. ;D
I could argue that a Granite Surface Plate IS a rock in my Christmas stocking!  :-DD
 

Online coppercone2

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Re: What did you buy today? Post your latest purchase!
« Reply #10542 on: December 17, 2020, 08:25:53 am »
yea put some 4000$ pink granite parallels in the stockings from starrett

I got a 4 inch thick pink starrett one could make a good valentines gift or something



I would try but I think the weight limit is like 100lb.

I do think that since I have had it the molding in the house looks off and it slightly annoys me.

the pink is supposed to be a better surface that does not stick so much IIRC.
« Last Edit: December 17, 2020, 08:33:36 am by coppercone2 »
 

Online Mr.B

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Re: What did you buy today? Post your latest purchase!
« Reply #10543 on: December 17, 2020, 08:39:04 am »
yea put some 4000$ pink granite parallels in the stockings from starrett
I got a 4 inch thick pink starrett one could make a good valentines gift or something
I would try but I think the weight limit is like 100lb.
I do think that since I have had it the molding in the house looks off and it slightly annoys me.
the pink is supposed to be a better surface that does not stick so much IIRC.

WTF...
Time is the overseer of all things.
 

Online coppercone2

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Re: What did you buy today? Post your latest purchase!
« Reply #10544 on: December 17, 2020, 08:45:49 am »
yea you need to treat a 4 inch thick piece of granite like a non stick frying pan for steel and clean it only with ammonia. And its not compatible with aluminum despite being a giant piece of rock. and you can only place things on the edge and slide them over and everything you need to place needs to be cleaned with a sharp clean flat stone.

the whole concept is a massive WTF

its also super hip to use it as a coffee table at work. I assume the bacon egg and cheese aluminum wrapper is a bigger hazard then the bacon grease and ketchup. It's like charging your phone with a jospeh junction to be extra toxic. I hope those were fake youtube comments I read.
« Last Edit: December 17, 2020, 08:52:43 am by coppercone2 »
 

Offline blueskull

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Re: What did you buy today? Post your latest purchase!
« Reply #10545 on: December 18, 2020, 06:40:39 am »
3 * ITECH IT-M7722 DC+AC PSU (no CC mode but with OCP) and 2 * Siglent SDS2104+, for a low cost student lab.
I highly NOT recommend this AC PSU unless you are really tight on money (600VA, 300VAC/400VDC, 6A $2400 w/o tax). But for our needs, it suffices well.
 
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Offline Gixy

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Re: What did you buy today? Post your latest purchase!
« Reply #10546 on: December 18, 2020, 08:46:33 am »
I have a DM41L for several years, it's great! Same software than its grand-mother, with a modern microcontroller.
 

Offline DrG

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Re: What did you buy today? Post your latest purchase!
« Reply #10547 on: December 18, 2020, 07:51:41 pm »
- Invest in science - it pays big dividends. -
 

Online nctnico

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Re: What did you buy today? Post your latest purchase!
« Reply #10548 on: December 18, 2020, 09:29:17 pm »
I bought myself a wood router for some upcoming wood work projects (including a kitchen renovation). After weighing pros and cons for a long time I settled on the cheapest model from Festool instead of a cheapy for $50. I already have a Festool circular saw (which was a gift) with guide rails and those guide rails can be used with the wood router too. The circular saw is a joy to use so I opted to cry for a day and enjoy a good tool from then on rather than being annoyed with a tool which just doesn't work very well.
« Last Edit: December 18, 2020, 09:34:35 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline viewtek

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Re: What did you buy today? Post your latest purchase!
« Reply #10549 on: December 20, 2020, 08:38:26 am »
Hi everyone
New member in VietNam .  everything bought today from a liquidation factory
 


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