Coffee Whisker Suddenly Stopped Working - Page 1
Forum section: electronics / beginners

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 13, 2013, 12:21:00 pm
content: Hello technicians and electriciansI assume many here know what type of gadget I am referring to here? It is a coffee whisker operating on2 AA batteriesto make coffee with foam and save you time whisking with spoon. It is also more effective because it dissolves coffee and sugar better than it is stirring with spoon.So after using it for half a year, mine suddenly became very slow at rotating. Replaced batteries but nothing changed. After a few days the motor stopped working at all and became somewhat hot so I decided to disassemble.I have attached picture on the bottom for you to see and you can tell from picture that some parts of wires have melted. What I noticed is that as soon as I connectcable 2tocontact 2(middle one) with rocker pressed on, the wire gets hot and smoke starts to show. Same consition can be achieved when connectingcable 2to left contact of motor (I didn't mark that spot on picture).What do you think is the problem? Is motor shortening or dead? Fixing things is my passion, therefore I rather fix than buy new.

author: 6502nop
author_rank: Regular Contributor
timestamp: June 13, 2013, 12:57:49 pm
content: Brushes probably shorted to case (broken) or shorting adjacent windings (worn to stubs).The nice thing is that it looks like a bog-standard higher torque Mabuchi style motor, and is easy to tear apart and examine. Mabuchi themselves offer some very extensive interactive guides on how to do this:http://www.mabuchi-motor.co.jp/en_US/technic/t_0104.htmlJust pull any gear or spindle off the output shaft, mark and unsolder the wires, pull up the small metal case tabs holding the rear plastic backing plate, and pull apart.If you're lucky, it may be something got dislodged. Just reseat it, lube the bearings while you're there, and slide back together. If you're not lucky, something broke or wore out to the point of needing replacement. Still, one of these should only run between $5-10 (US), so it's not a big deal to replace.nop

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 13, 2013, 01:01:17 pm
content: Quote from: 6502nop on June 13, 2013, 12:57:49 pmThanks for your reply and reference guide. If I were to buy motor, I would just buy another whisker that costs almost $4. Or if too curious I would get motor though just to have learning experience.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 13, 2013, 03:57:37 pm
content: Quote from: Boris_yo on June 13, 2013, 12:21:00 pmi think santa is inside.Quote from: Boris_yo on June 13, 2013, 12:21:00 pmso dont open a thread, open a motor. its not rocket science.since you asked. from my experience dismantling cheap motors like this... from the picture alone, i'm "speculating" either you need a new motor, or if its not too expensive, you need a new whisker. i hope i can save your time with this statement

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2013, 04:32:35 pm
content: A key question with a device like this is .... can the motor spindle be turned easily with your fingers ? A motor that slows down and then stops with high current draw is often the victim if a seized oilite bearing. As the unit is used with fluid, the front bearing may have suffered fluid contamination and caused the failure.

author: SeanB
author_rank: Super Contributor
timestamp: June 13, 2013, 06:23:20 pm
content: Normally the motor "brush" dies with time. I use the term brush very loosely, as the brush assembly is just a phosphor bronze leaf running on the commutator. I have transplanted motors into these before, or you can use a back plate from another if you need a long output shaft and have none in the scrap bin. You find the brush leaves wear out and then short together, often you have a groove worn in the 3 commutator plates as well from it. If you have it apart a drop of oil on the front and back bushes will do wonders for noise, just use a drop of engine oil, nothing lighter. Lighter oils evaporate, and the thicker engine oil reduces wear as it forms a thicker hydrodynamic film when the shaft is rotating, as it often has a very large clearance either from wear of from manufacture.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 13, 2013, 07:07:36 pm
content: I opened motor cover and saw that its base is dirty which seems is the result of sparks. It feels as if current tried to spin motor but motor was stubborn. I tried to spin motor and a little resistance can be felt but I cannot tell 100% it is the motor that resists because when whisker was new I don't remember spinning it manually. What is strange is that after short while when I power on device, the motor spins for 1 second and then ceases to spin. If I try to power on again, then wire becomes very hot. After I wait again and power on, motor can spin again although it is not always so.Attached are pictures below and by the way, I cannot remove whisker's bar to reach bearings because there is plastic on the bar that prevents pushing bar to the end which would reveal insides of motor.Also I have penetration oil which I use to release stubborn parts. Would it be okay as lubricant? I also have cooking and olive oil and wonder if these evaporate.

author: marshallh
author_rank: Unknown
timestamp: June 13, 2013, 07:34:37 pm
content: Generally those motors are supposed to have a 0.47uF snubber cap across the terminals, it helps prevent the arcing of the brush dust.Buy a new whisker and solder in a cap, won't hurt.

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2013, 08:01:31 pm
content: Penetrating oil is only for freeing purposed and not much use as a lubricant. WD40 claims to be both so you could try that.Cooking related oils are totally unsuitable.My recommendation is car oil (new of course) or 3in1 oil.

author: SeanB
author_rank: Super Contributor
timestamp: June 13, 2013, 08:04:52 pm
content: Needs new brushes for sure, and then it will probably work. Car motor oil is the right lube for the front and rear bushes.

author: G7PSK
author_rank: Super Contributor
timestamp: June 13, 2013, 08:46:04 pm
content: Never use cooking oil for lubrication, not only does it dry up and go sticky it also contains acids which will corrode.

author: mrflibble
author_rank: Super Contributor
timestamp: June 13, 2013, 09:42:25 pm
content: Forget about repairing that junk. Get yourself an ALL-DROID Stirmaster!Two weeks skiing!

author: IanB
author_rank: Super Contributor
timestamp: June 13, 2013, 10:04:13 pm
content: Quote from: Aurora on June 13, 2013, 08:01:31 pmAlthough there is probably a low risk of contamination, car oil is not really designed for food use. It contains additives that are not safe for human consumption. I would suggest using food grade mineral oil from a pharmacy instead.

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2013, 11:02:00 pm
content: Good pointI don't normally deal with food related products.When all is said and done, these things are designed to be thrown away once the brushes expire. It may be a bit of fun for the OP but I would never spend time repairing one of these very cheaply built motors. I did rebuild a special (read very expensive) brushless motor in a Sony C5 Betamax video recorder many moons ago....but that's another story

author: eKretz
author_rank: Frequent Contributor
timestamp: June 14, 2013, 03:18:44 am
content: If he just wants to repair it for the heck of it he could always just put in a new motor.

author: KJDS
author_rank: Super Contributor
timestamp: June 14, 2013, 06:53:05 am
content: WTF is wrong with a teaspoon?

author: G7PSK
author_rank: Super Contributor
timestamp: June 14, 2013, 07:54:52 am
content: I think that this is the second time I have seen how to repair a coffee whisk on this forum in a year, the obvious answer is to get equipment that will last - something like this will last a lifetime.

author: amyk
author_rank: Super Contributor
timestamp: June 14, 2013, 10:30:01 am
content: 2 AA batteries are enough to cause some not-so-thin wires to smoke? Those don't look like ordinary batteries to me...

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 14, 2013, 10:52:46 am
content: Quotenext move... pull out the whisker (stirrer?) the black plastic part, and then pull out the amarture out of its body. i suspect the repair part is like mentioned by others... cleaning rust etc and oiling due to stucked motion. the coil looks clean so i'm not sure if they are burnt from inside, resistance check by a DMM might tell something? next lesson, putting it back together, hint: you need to "dilate" the brushes in order to put them back in, or otherwise by some specific skillful motion and rotation back and forth.reference:lesson learnt (or havent?) congratulation! next time dont peel out the lock (upper) until its broken (the metal part that hold the brushes' holder, the white plastic). if you want to go further, you can learn how the coil is wounded by de-wounding it, but that require buying a new one to continue whiskingwhich i highly suspect, in any way will be the case. thats how we gain experience, we pay a price for a piece of knowledge. nothing free in this modern world. keep messing around

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 14, 2013, 11:04:14 am
content: correction... not trying to discourage you with previous post, but if you are lucky, which mostly the case with me and onehunglow products... with the right fix procedure, eventually you might be able to make it a longer lasting product. onehunglow is nice in the sense that its cheap and you only need a bit to touch up to make it working charmingly and satifactorily

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 14, 2013, 11:57:49 am
content: Quote from: KJDS on June 14, 2013, 06:53:05 amBattery operated coffee whisker is more convenient at rapidly dissolving coffee and sugar. It also saves you time stirring and makes foam on top. Seems like useless gadget first but it is not so.

author: Gigawatt
author_rank: Newbie
timestamp: June 15, 2013, 07:43:02 am
content: Throw it away ! simple ! Then use the manual method no electrical power required then

author: Unknown
author_rank: Unknown
timestamp: June 15, 2013, 08:30:00 am
content: I've seen those motor on E-bay, really cheap to buy, get a couple spare for next time, good on you for keeping the old stuff going.

author: SeanB
author_rank: Super Contributor
timestamp: June 15, 2013, 09:51:55 am
content: Quote from: Boris_yo on June 14, 2013, 11:57:49 amSimple solution is not to use sugar.......... I like my coffee unsweetened, and will drink it black. With or without milk, with or without water and with or without coffee, I will take it, just need at least 2 of the components. If there is no coffee I just put in either Earl Gray or Twinigs or 5 Roses.

author: GeoffS
author_rank: Unknown
timestamp: June 15, 2013, 01:14:48 pm
content: Quote from: Boris_yo on June 14, 2013, 11:57:49 amThe proper solution is to drink brewed coffee, not that instant rubbish. Give up the sugar and you'll be able to live without your whisk.

author: SeanB
author_rank: Super Contributor
timestamp: June 15, 2013, 03:42:18 pm
content: Some nice Greek coffee will be good around now, nice and thick, just without the sugar, but with nice fresh cream on the side, or milk fresh from the cow.Looking at the little OHL motor it looks like the rotor is shorted as well, you need a new one. While they are the easiest motors to rewind ( 3 windings, no formers, no baking and no high voltage insulation and no slot fillers to insert) they are not worth it.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 16, 2013, 11:37:51 am
content: @SeanBYou buy real roses just to drink them later?@GeoffS"Instant Rubbish"? Heh. Does it cause cancer or just makes you tired?Quote from: SeanB on June 15, 2013, 03:42:18 pmI don't have cow around and the only way to get raw milk is driving to the middle of nowhere and I don't have car.Did you know you can use Xylitol or Erythritol as natural risk-free sugar substitute?

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2013, 12:28:23 pm
content: http://www.entyce.co.za/brands/3/pages/6That is five roses...........Milk is available at the farmers market on Saturdays.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 16, 2013, 12:49:26 pm
content: Quote from: SeanB on June 16, 2013, 12:28:23 pmOh those 5 Roses. Didn't know initially.Isn't it dangerous to sell raw milk in US? I heard a story where FBI busted into the house to get someone's raw milk. I bet rich families who "own everything" eat raw organic food while we major consumers eat food that slowly kills us.It is funny how organic food which is plain natural food which was once abundant is now scarce or just expensive. It is like world turned 180 degrees. Something that was once sci-fi is not becoming reality and reality becomes sci-fi if you know what I mean. Something that was previously considered offensive is now norm...

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2013, 12:57:19 pm
content: I live half way between Chris and Dave............That little bit of space on the maps marked " Here be lions".

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 16, 2013, 01:04:55 pm
content: Quote from: SeanB on June 16, 2013, 12:57:19 pmAll you 3 guys are in South Afrika?

author: dfmischler
author_rank: Frequent Contributor
timestamp: June 16, 2013, 02:47:13 pm
content: Quote from: Boris_yo on June 16, 2013, 11:37:51 amYes, the glycemic index of xylitol is about 7, but nothing that is fatal to canids can be all that good. I'll stick with sugar.

author: c4757p
author_rank: Super Contributor
timestamp: June 16, 2013, 03:08:05 pm
content: Quote from: Boris_yo on June 16, 2013, 01:04:55 pmPlease tell me you know where Dave is.

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2013, 03:10:45 pm
content: I think Boris does know Dave is NOT in Austria, but........................Geography is not really a taught subject in schools these days, aside from local geography and how clouds look.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: June 16, 2013, 04:09:55 pm
content: Quote from: SeanB on June 16, 2013, 03:10:45 pmNext to your username is South Afrika's flag and since you live halfway to Dave, I assumed he is also there. This all looked weird to me however.

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2013, 04:31:59 pm
content: Quick Geography lesson ....Chris Gammel lives in Cleveland Ohio, United States of America. I live in Durban, South Africa. Dave lives in Sydney, southern end of Australia. Each of these places is a different continent, North America, Africa and Australasia.From you in Moskva I am pretty much South of you, Chris is to the West and Dave is South East of you. All 3 of us fall roughly on a Great Circle path ( look it up, it will be educational) joining the 3 places.

author: IanB
author_rank: Super Contributor
timestamp: June 16, 2013, 10:47:45 pm
content: Quote from: SeanB on June 16, 2013, 04:31:59 pmAs I recall, Boris currently resides in Israel.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 17, 2013, 12:37:38 am
content: if i jump, i will end up falling on the daveland hows that? look at the map

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2013, 05:10:13 am
content: Just a quick boat trip away..........