Questions about some lab tools I want to buy. - Page 1
Forum section: electronics / beginners

author: SH@RK
author_rank: Contributor
timestamp: May 12, 2012, 09:37:56 pm
content: HiI want to by some tools for my lab and I am not certen about brands .1:- Flux penhttp://www.radioshack.com/search/index.jsp?kwCatId=&kw=flux&origkw=Flux&sr=1Chose one of them to me . I do not know the deference between them .And I can get from RadioShack easy so I do not prefere eBay or amazone .2:- ArduinoI think this one has good price , and how many I will need ? Thinking of getting tow or three because I can not buy it easily an other time .http://www.radioshack.com/product/index.jsp?productId=122682623:- Octopus helping handsI only found this , if u can find better one will be betterhttp://www.amazon.com/Eclipse-902-227-Octopus-Helping-Hands/dp/B003WNY83M/ref=sr_1_1?ie=UTF8&qid=1336857042&sr=8-14:- OscilliscopeIn my place there is no good ones in local shops and shipping from USA will cost a lot .So I am considering the Owon SDS7102 and the shipping will cost around 120$ to Saudi Arabia .The SDS7102 is not heavy so shipping will not cost me a lot like if I got used Tektronix5:- Heat sink for solderingI did not search yet - if u Can suggest me something .6:- Crocodile clips and binding posts and banana plugsIf u know any place trusted and sell for good price let me know .I found this site but I do not know about themhttp://www.futurlec.com/Banana-Clips.shtmlLocally the are not cheap .7:- for the flash circuithttp://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=120870404525#ht_844wt_689Is it better and cheaper to buy it or making it in home .That is all in my mined nowThanks

author: vxp036000
author_rank: Regular Contributor
timestamp: May 12, 2012, 11:41:07 pm
content: These are lap tools?! Maybe I shouldn't ask...

author: free_electron
author_rank: Super Contributor
timestamp: May 13, 2012, 05:14:53 am
content: it would help if we know what you are trying to build ?fluxpen : unless you go about messing with SMD parts : not needed. solder has flux in itArduino : eh .. how many is up to you ...Helping hands ... useless. i never use those things. they fall over and are generally annoying. use thumb and index finger to hold solder , middle finger and ring finger hold wire to be tinned. other hand holds soldering iron ... done.heat sink for soldering ? you plan on putting that in the baking sun down there in saudi arabia , let it heat up and then use it to solder ? i think you mean soldering iron right ?flash circuit ? what do you want to do with that ? (i'm a bit spooked on this one since you say "this is all on my 'mined' for now "... )

author: Bored@Work
author_rank: Super Contributor
timestamp: May 13, 2012, 06:21:17 am
content: Every unhelpful hand with those dreaded crocodile clips is junk. The clips damage the PCB. But however strong the clips are, they still don't hold the PCB firmly in place.If you really want one, at least have some fun and build your own. The particular version you consider can easily be build DIY. Get some thick isolated copper wire, a sheet of wood some cm thick, and some clips. Drill holes into the wood, at a diameter the wire tightly fits, stick pieces of wire into the holes, remove some isolation from the other end of the wire and solder the clips to these ends. You need a powerful (non electronic) soldering iron for this. Then damage one or two PCBs with the contraption before you throw it away.I once modded a $5 unhelpful hand, the metal stand type, into a probe holder. It worked so-so. These days it might be a fun project for those with a 3D printer (Dave?). Construct you own holding attachment to attach an oscilloscope or multimeter probe to an unhelpful hand.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 13, 2012, 10:30:25 am
content: Quoteso i guess you never worked with very tiny pcb board which wind will blow it away easily.Quotere-fluxing old or "not so good" joints?QuoteHakko "heat sink" iron if you can get easily there. the hakko tip can "sink heat" to solder very well.Quoteoh that flash. please get a bigger one like thishttp://www.ebay.com.my/itm/2PCS-Godox-1000W-Studio-Photography-Strobe-Flash-Light-Lamp-Head-220V-240V-x2-/261022536991?pt=LH_DefaultDomain_0&hash=item3cc627d51fcharge it and hold both the largest capacitor with both your hand. end of story.(you should know thats a joke, it can kill you)dont forget if you want the flux, get solder braid as well, they both "partner".

author: Monkeh
author_rank: Super Contributor
timestamp: May 13, 2012, 10:36:39 am
content: Helping hands are good for a multitude of things. As long as you're not silly enough to try and hold a large PCB with them.

author: LEECH666
author_rank: Frequent Contributor
timestamp: May 13, 2012, 04:06:42 pm
content: Regarding the Arduino:Consider, that the Arduino in reality is just some convenient development board designed around an Atmel AVR micro controller chip.If you have a means to create your own circuit (point to point wireing, deadbug style construction, breadboard, stripboard/veroboard, perfboard, manhatten style PCB, self etched PCB, professinally manufactured PCB) you could always just the actual Arduino as a prototype board and when you're done and everything works wire up an according circuit and just use a "stand alone" ATMEL AVR micro controller with the minimum needed components. It's the same thing basically but much cheaper if you don't need all the fancy USB stuff.Check this tutorial for some more info.http://arduino.cc/en/Main/StandaloneWhat I am trying to say is:- Buy one Arduino to prototype- Buy a few ATmega168 or ATmega328 MCUs (micro controller units) + basic compentsFlorian

author: free_electron
author_rank: Super Contributor
timestamp: May 13, 2012, 05:21:33 pm
content: Quote from: Mechatrommer on May 13, 2012, 10:30:25 amtwo words : silly putty ....sometimes called 'poster gum'. you tear wa bit off , knwead it , tack it down on the bench and tack the board on the corners. presto.

author: saturation
author_rank: Super Contributor
timestamp: May 13, 2012, 09:34:24 pm
content: Yes, I concur. Most makers starting out could benefit from it since they work with small PCBs, and the hands are cheaper than a Panavise or clones. I also use it to hold many things, such as soldering wires to terminals or using it as a heatsink, holding probes in hot liquids etc., . In this photo during a test of the hot air workstation 858D, the cheapo HH easily survives facing 480oC hot air blown into the probe, and into it too. Note the hot air nozzle is also held by another HH.Silly putty? Nice idea. Works on PCB a bit too big for HH. However, I have 5+ HH, and can position them on each corner and then some, so it can work with even larger PCBs, but eventually it gets unwieldy I break out the Panavise.Sratching or damaging PCBs with the alligators? Put a small fold of sheet rubber to cover the teeth; then the clips hold mostly on pressure. In a pinch, just folded cardboard works.Beware, some are made far worse than others; when you buy one make sure its the Taiwan version or doesn't have the really low weight pig iron stand or omitted thumbscrews. The pics on websites and boxes often have the original Taiwan design but what's inside is the stripped version.http://www.amazon.com/gp/customer-media/product-gallery/B0002BBZ2Y/ref=cm_ciu_pdp_images_3?ie=UTF8&index=3Quote from: Monkeh on May 13, 2012, 10:36:39 am

author: Vredstein
author_rank: Contributor
timestamp: May 13, 2012, 09:51:42 pm
content: Quote from: free_electron on May 13, 2012, 05:14:53 amMaybe we have to choose that for him also.

author: Mint.
author_rank: Frequent Contributor
timestamp: May 13, 2012, 11:07:16 pm
content: Quote from: Vredstein on May 13, 2012, 09:51:42 pm

author: free_electron
author_rank: Super Contributor
timestamp: May 14, 2012, 12:42:55 am
content: what is wrong with the bench surface. This is the most stable place to put a board down ! especially if you have on of those non-slip ESD mats ( like hte lbue ones that dave has. i guarantee you : your board will not move a micron. The friction of that thing is so high the board does not move.even for through hole stuff you don;t need it. replace abroken part ? snip the pins off on the component side . flip board , heat and pull pin remnants out... after all you are trying to save the board. you don't care about the broken part... especially with doublesided and multilayer boards.assemblying ? poke leads through hole , bend 45 degrees on other side. once all parts installed : flip board over with leads sticking up and put flat on bench. solder to your hands content. i really have never had the need for such a helping hand. I have one to hold scope probes down on a board.. but to solder ? never. it always gets in the way , flips over and is generally annoying.and for SMT asembly : it is really annoying. try to focus the microscope on the board. as soon as you put a bit of pressure with the soldering iron everything goes out of focus... bah. useless things.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 14, 2012, 05:56:34 am
content: Quote from: saturation on May 13, 2012, 09:34:24 pmBzzzzzt. Holding? It just slides, wobbles and rotates. Not my definition of holding something in place.If I need to hold a PCB in place I use masking tape to stick it to the bench. If I need some more flexibility or need to avoid to burn the bench I use a working platform with rails and screw clamps. That is what I call holding.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 14, 2012, 07:23:23 am
content: Quote from: free_electron on May 13, 2012, 05:14:53 amIlikefluxpens-they are great for rework situations that you get while fixing stuff.Actually a bottle of Liquid Resin flux,& a cotton bud is better & cheaper,but seems the "safety" people have had their way,as I haven't seen the bottled stuff on sale for years.Arduino?--what's that?I agree,helping hands are,by & large pretty useless in their original form,but youcanimprove them.I think by "heatsink" the OP means those little gadgets that look a bit like flat alligator clips,that are supposed to be used to protect small leaded components,wire insulation which shrinks back when soldering,& things like that.I got a couple from work about a century ago,& occasionally use them.No doubt the OP will enlighten us about the flash circuit.

author: Monkeh
author_rank: Super Contributor
timestamp: May 14, 2012, 09:45:34 am
content: And again, the two of you are conveniently ignoring theotheruses of helping hands. Yes, you can put things other than PCBs in the clips!

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 14, 2012, 01:25:36 pm
content: I remember an old boss of mine who used to just use his hands to solder together two wires inline.Poetry in Motion, holding and manipulating four separate things, wire 1, wire 2, solder and soldering iron. Using the middle and index fingers to hold the wires.So quick and convenient.When I did it, and I could do it, I just had a high chance of burning myself with the soldering iron.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 14, 2012, 02:16:51 pm
content: Quote from: Monkeh on May 14, 2012, 09:45:34 amWhat's the difference between damaging a PCB or damaging something else with that rubbish? What's the difference between not holding a PCB firmly in place and not holding something else firmly in place?

author: saturation
author_rank: Super Contributor
timestamp: May 14, 2012, 02:56:36 pm
content: B@W sure is passionate about the uselessness of HH, but my devices are mostly hand held and portable. Spending $4-6 to find out won't kill the bank. I've seen them pop up in Bob Pease's show, I'm surprised to see it there. Maybe its not totally useless or its just a prop?Silly putty though, will give that a shot, makes for easy temporary standoffs. At Amazon, they are 6 for $10, about the same cost as a HH, as you'll need at least 2.http://www.amazon.com/Toysmith-Original-Silly-Putty-104-48/dp/B003UYTMNE/ref=sr_1_2?s=toys-and-games&ie=UTF8&qid=1337006177&sr=1-2

author: free_electron
author_rank: Super Contributor
timestamp: May 14, 2012, 02:59:59 pm
content: Quoteso do i , but .. Unless you do smd work you dont really need extra flux.Flux in bottles is still sold. Kester , multicore , alpha metals and others still sell that. I have a bottle RMA on my bench.Quoteoj... That myth again... There is no need for that unless you still build stuff with cat whisker diodes an point contact transistors like OC71's ...You can NOT damage a part with a (properly adjusted) soldering iron. Components go through final test in the factory via a burn-in cycle. At 175 degrees c for many hours.. So your pokey little iron is not going to do any damage. Parts are made for reflow soldering or wave soldering. They are in contact with 300+ degree C material longer than you poke at them with your iron.This used to be true for cat whisker diodes and point contact. Those could be destroyed by too much heat too long. Modern devices.. Not

author: free_electron
author_rank: Super Contributor
timestamp: May 14, 2012, 03:03:07 pm
content: Quote from: saturation on May 14, 2012, 02:56:36 pmIf you look closely at it you will see that it is actually tipped over all by itself... Proves once more it is useless junk.

author: Monkeh
author_rank: Super Contributor
timestamp: May 14, 2012, 04:07:14 pm
content: Quote from: BoredAtWork on May 14, 2012, 02:16:51 pmThey're quite capable of holding many things in place while you work, without damaging them.

author: Bored@Work
author_rank: Super Contributor
timestamp: May 14, 2012, 04:17:57 pm
content: This is not BP's lab, it is some bench staged for the video. And the unhelpful hand is in its natural operating mode, tipped over and being moved out of the way.Of course an unhelpful hand can be unhelpful with many more things, failing to hold them while you try to work.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 14, 2012, 04:20:04 pm
content: Quoteyou may call that.. feature!or even... "user error"failure to secure its centre of gravity, not taking into account all the involved external forces, you know... that vector sum of the "force"

author: metalphreak
author_rank: Frequent Contributor
timestamp: May 14, 2012, 05:20:12 pm
content: Slide some heatshrink over the aligator clips. Stops it from scratching or damaging PCBs and gives you a bit more grip(if your lab doesn't have a 'helping hand' and heatshrink in it, you're doing it wrong)

author: T4P
author_rank: Super Contributor
timestamp: May 14, 2012, 06:10:00 pm
content: Quote from: free_electron on May 14, 2012, 02:59:59 pmThat's a good point. Unless someone was an utter pillock, it wouldn't be easy to damage modern devices

author: saturation
author_rank: Super Contributor
timestamp: May 14, 2012, 07:20:04 pm
content: Not to belabor the poor HH but this thread covers more of issues as well as in the archives:https://www.eevblog.com/forum/general-chat/helping-hands-good-or-bad/?topicseen"You can NOT damage a part with a (properly adjusted) soldering iron."Temp cycling to 175oC, that's only during testing to meet is max operational temp spec of ~100-125oC, soldering temps are different spec. That won't melt lead, much less lead free solder.On soldering, Most components have specific limits, ~ MILSTD 202, or ~250oC for 10 seconds, lead temps. Its not infinite. However, the more you exceed it either in temp or time, the greater chances that components no longer meet the published specs. To put probability in your favor, temp regulated irons, limited exposure in reflow profiles, supplanted sheer technique to reduce the risk of parts injury.The worse is when the part isn't dead, but has changed spec. They it creates unpredictable problems that are best solved by prevention.http://electronics.stackexchange.com/questions/3252/what-kind-of-damage-could-a-soldering-iron-do-to-a-componentHowever, in hand soldering, most folks don't believe in keeping their irons even moderately in calibration:https://www.eevblog.com/forum/general-chat/do-you-calibrate-your-soldering-station-if-not-or-if-so-why/msg58268/#msg58268In all, cool is the rule, and the less exposure to heat you put your parts through, the more reliable the overall device will be and longer it will live, whether it be operational temp to exposure during soldering.

author: free_electron
author_rank: Super Contributor
timestamp: May 14, 2012, 07:42:01 pm
content: I stand by what i said earlier : if you look at the reflow provile JEDEC 20C: the parts are fully immersed in 270 degrees C ( for leadfree ) for up to 60 seconds....thus : You are not going to do any damage with a PROPERLY regulated soldering iron. If you know how to solder : apply blob of solder to tip , push tip in contact with to be soldered object , apply a bit more solder wire , retract tip. A trained soldering person does this in less than two seconds with a properly temperature adjusted iron with a decent thermall mass and wattage.Here is another common big mistake : confusing wattage and temperature.A lot of people are afraid to use 80 watt soldering irons on tiny parts. Instead they sit there and bake the part with a crummy 20 watt iron.The higher the wattage and thermal mass ( a big fat stem with a short tiny tip works better than a long skinny tip ) the faster the iron can transfer its heat to the, to be joined, elements. Get the iron in and out in a few seconds. IF you have no means to tranfer heat ( little thermal mass and slow re-heating due to low wattage ) you take 10 seconds to bring everything up to temperature ... not good !And another one : the proper technique is to make a wet-joint. : apply a bit of fresh solder to the tip , and then 'wipe' this dab of solder onto the joint area , adding a bit more after it starts flowing. 'Dry soldering' is the WORST you can do... the problem is again heat transfer. the contact area is very small between tip and object. adding a drop of solder to the tip before increases the contact surface and gives better and faster heat transfer. There is a second aspect : in dry soldering you heat the two surfaces that need soldering and then you apply cold solder ... this gives a temperature dip ( even though very short ) and causes thermal stress in the solder joint. If you have liquid solder on the tip there is only a single heating cycle without a 'dip' in the profile.

author: SH@RK
author_rank: Contributor
timestamp: May 14, 2012, 09:49:39 pm
content: Sorry for being late , I will try to reply all of you .Thanks for every one .QuoteI do not know what I am going to build yet . I am studying Electrical Engineering so I will try to experiment everything I learn in university , and will do other things like fixing electronics modifying them for my needs .I think I will do SMD so I will get the fluxI think I will not get the helping hands unless I need them in future . I will try your method .For the heat sink (I liked your idea , may be I try it) , I meant the clips that get the heat so it will not affect the parts .You may understand this better than my explanationhttp://www.kpsec.freeuk.com/solder.htmFor the flash , I want to use it as Joule Thief .BoredAtWorkI will try to build one and see if it works or not .MechatrommerI know it was a joke (it is good to be fun even in work)I will get the solder braid . Thanks for adding it .LEECH666Good advice , will try to build it myself and I will get tow Arduino .I think I will leave one fixed for lights in my house and one for work with it in my Lab .QuoteOnly I forgot to tell in first post .QuoteYes , this is what I meant .I will add what I have in my lab so you all can tell me what I really need to get .Now trying to get Fluke 87 v or better on eBay (I only have Sinometer MS8268) .I read that the fluke life warranty does not include what is sold on eBay .Do u think I will need the warranty so I will pay the extra money for an official seller ?Can I live without the warranty ?How much should I pay as max price for good used one or new one in eBay ?THanks for all of you

author: SH@RK
author_rank: Contributor
timestamp: May 17, 2012, 11:42:44 am
content: I want to buy a new Fluke 87v from amazon because there price is great for me (will save me 100$) .the problem is I do not know if they sell the ones with the GSM problem or not .Anyone can help ?I talked with amazon livechat but they have no idea about the problem .I sent an email to service.status@fluke.com but no respond since yesterdaythanks

author: robrenz
author_rank: Super Contributor
timestamp: May 17, 2012, 11:49:24 am
content: Just don't put your cell phone right next to the meter. Seriously, when is that an real issue?

author: saturation
author_rank: Super Contributor
timestamp: May 17, 2012, 12:58:30 pm
content: Hi free, I agree with you in spirit. But those unaware should know JEDEC or IPC standards for reflow are not one value either, there are various levels depending on the components you use, these determine the liquidus temperature and for how long to expose them. This link to a draft is free, the complete version can be distributed only to JEDEC/IPC members.http://www.ferroxcube.com/envir/info/J-STD-020C%20Proposed%20Std%20Jan04.pdfThe "-up to 60 seconds" depends on the factory engineer on what they want the machine set at, and I leave the true choice for temp maximums and times to those folks [not me, I don't work in production]. Most JEDEC levels are much lower than 270C. Also, hand soldering temp limits are different from reflow limits, and part of damage is also from thermal shock: getting too hot too soon and cooling down too quickly, versus gradual heating curves and pre-heating in reflow processes; these puts different stresses on parts than sticking a 300C iron onto a part at uncontrolled room temperatures.I agree parts are more robust that the spec sheets say they should, but temp limits are set by spec change or parts loss probability, its not absolute, so one can always play to win by keeping cool as the rule.Quote from: free_electron on May 14, 2012, 07:42:01 pm

author: T4P
author_rank: Super Contributor
timestamp: May 17, 2012, 05:40:23 pm
content: Nevermind, just keep all phones and Laptops with wifi away from a 87v if it seems so

author: SH@RK
author_rank: Contributor
timestamp: May 17, 2012, 08:22:21 pm
content: Quote from: robrenz on May 17, 2012, 11:49:24 amI will not , but hopefully my father will not (we share tools)I do not know if it is an issue or not , but since Dave made 2 videos about it I think it should be .Quote from: Dave.S on May 17, 2012, 05:40:23 pmI will , but the problem is my room is small and everything in it (my lab and computers and bed and even the main internet router in it)So I do not want to do it even accidentally .I will order it from amazon .I want another used one so I can do voltage and current at the same time .I am thinking of the same 87v used from eBay .So how much should be the maximum price for used one (assuming clean unit and with the test leads and yellow holster only ) ?observing the sold units last week all above 100$ and some even have cracks .Do u think I should not buy second 87v and search for an other model ?Thanks

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2012, 08:31:10 pm
content: If it's brand new from Amazon, of course it won't have the issue. They fixed it some time ago.

author: SH@RK
author_rank: Contributor
timestamp: May 17, 2012, 09:23:07 pm
content: Quote from: Monkeh on May 17, 2012, 08:31:10 pmthe newest comment said that the unit he received has the issue (April 30, 2012)new problemHow much should I consider the fluke warranty ?Because the units soled in amazon does not have the warranty .I just received the response for my email from fluke said"Since Amazon is not considered a Fluke distributor, anything you buy from them has no warranty.If you buy equipment from the States, most international reps/distributors will not honor the warranty.Regards,Fluke Customer Support"In amazon livechat they told me that amazon is Fluke distributor ,, so which one is nor wrong ?In the local Fluke distributor in my place 87v cost 1650 SR = 440 $So does thewarranty and local supportworth the 124 $ ?Or should I forget about the warranty and get one from amazon or eBay and buy other tools from the saved 124 $Thanks

author: M. András
author_rank: Super Contributor
timestamp: May 19, 2012, 12:34:45 pm
content: they wont even ship you overseas from the states, or they will lose the distributor rights to fluke (not talking about amazon, they are just a market place) this from tequipment and the local distributor in my country confirmed this too when i bought my 289 last month