Author Topic: heating a bearing in the microwave  (Read 12198 times)

Offline tom osselton

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heating a bearing in the microwave
« on: February 11, 2015, 04:06:51 PM »
I found this interesting.

     [ Invalid YouTube link ]

« Last Edit: February 11, 2015, 04:44:33 PM by dsquire »

Offline steampunkpete

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Re: heating a bearing in the microwave
« Reply #1 on: February 11, 2015, 05:52:02 PM »
And what happens if you misjudge the time and the cloth dries out?
Does it, or could it in some circumstances:
a) B****r the bearing?
b) B****r the microwave?
c) Potentially cause a hazard?

Answers on the back of an insurance claim form please ...

Offline awemawson

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Re: heating a bearing in the microwave
« Reply #2 on: February 11, 2015, 06:17:53 PM »
If that happens you'll possibly get sparks between elements of the bearing that might damage the surface..

Microwaves are a great way of 'erasing' CDs and DVDs.. Pop them in for a second or two and watch the sparks fly. I used to destroy old backups that way before they went to China with the recycling. Quite dramatic to watch, and a bit smelly!
Andrew Mawson
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Offline fixerup

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Re: heating a bearing in the microwave
« Reply #3 on: February 11, 2015, 10:10:43 PM »
I like it, but I wouldn't want to get caught by the wife :hammer: 
I've added this tip to my toolbox.
Thanks for posting!
Phil

Offline dawesy

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Re: heating a bearing in the microwave
« Reply #4 on: February 11, 2015, 11:51:03 PM »
After melting a pair of car lights to the rack in our oven I'm banned from using kitchen appliances for workshop jobs :( I wanted to separate the lens to refurbish them. 150c for a few mins but the thermostat was broke so it was around 250c. I was sat waiting for the temperature light to go out and didn't notice them sagging between the bars :'(
Lee.
wishing my workshop was larger :(

Offline vtsteam

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Re: heating a bearing in the microwave
« Reply #5 on: February 12, 2015, 09:41:40 AM »
I don't get the attraction of using a microwave for heating metal objects like bearings (I've even seen some rather sad videos of people trying to melt tiny amounts of metal and cast with them).  :bugeye:

What's wrong with a conventional toaster oven for heating bearings? I mean if people insist on using small kitchen appliances for smelly metal? It even has a thermostat, besides a timer.... whadda concept!

Better yet, these seem to get "upgraded" by swmbo every few years, just grab the last one before the recycler for use in the workshop -- some even come with under shelf mounts. They're Ideal for baking sand cores, too.
I love it when a Plan B comes together!
Steve
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Offline Manxmodder

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Re: heating a bearing in the microwave
« Reply #6 on: February 12, 2015, 09:47:20 AM »
Agree with you VT, I have a microwave combi oven/grill and use the infrared oven to heat bearings and collars.

I also sometimes put shafts in the freezer in a plastic bag to shrink them and increase the size differential effect even further.....OZ.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline dawesy

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Re: heating a bearing in the microwave
« Reply #7 on: February 12, 2015, 11:05:14 AM »
Toaster, now there's something I hadn't thought of!
I actually want to get an old dishwasher for parts cleaning too.
Lee.
wishing my workshop was larger :(

Offline vtsteam

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Re: heating a bearing in the microwave
« Reply #8 on: February 12, 2015, 11:52:40 AM »
Good for tempering, too. Set the thermostat for somewhat less than your tempering temp in case it's not accurate (likely). Check your part for color as you get close, and/or use an infrared thermometer. Adjust thermostat, as required to get what you want, and plunge when there. It's a nce even and slow process -- less danger of overshooting.

Also the glass is usually much clearer on a toaster oven than a microwave, since the latter has a screen in it, so with a toaster you can actually see what you're doing -- important when tempering. Put it up high, at eye level. The under shelf mount models are ideal. I have an old Black and Decker toaster oven with the shelf mount that was judged too small and old fashioned for our kitchen a decade ago. Quite happy with that!

New toaster oven $35.
New microwave about $70
and the toaster oven has half the footprint.
I love it when a Plan B comes together!
Steve
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Offline angus

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Re: heating a bearing in the microwave
« Reply #9 on: February 12, 2015, 12:27:46 PM »
Toaster, now there's something I hadn't thought of!
I actually want to get an old dishwasher for parts cleaning too.

i got busted this week.... swmbo came home from work early, and caught me with an engine sump in the diswasher :doh:

Offline hermetic

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Re: heating a bearing in the microwave
« Reply #10 on: February 12, 2015, 02:28:51 PM »
I find this all a bit odd, I have fitted literally thousands of bearings, in nearly forty years in engineering, and have never heated a bearing in my life! Not saying you shouldn't do it, but you certainly couldn't do it with the modern "sealed for life" bearings, it would melt the grease out. I would just cool the shaft in a freezer if you could get it in, or press fit the bearing on a press. If the shaft is machined to the correct interference size, there shouldn't be a problem.
You can fit a bearing quite safely with a hammer, but you dont "beat the heck out of it" you use a peice of tube that matches the diameter of the inner race, and tap it on with a 2lb hammer.

Angus, the most common problem which scraps a dishwasher is the water softener (where you put the salt in) reaches the end of its life. Ask at your local independant appliance retailer, as they have to take them in for recycling, and the "big boys" like Curry's etc won't like breaking company policy to give you an old one. It would keep you out of trouble with the wife too!
Phil.UK

Offline dawesy

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Re: heating a bearing in the microwave
« Reply #11 on: February 12, 2015, 09:14:59 PM »
Angus I actually asked swmbo if I could put my cylinder head in ours a while ago. Didn't get an answer just 'the look'
Lee.
wishing my workshop was larger :(

Offline steampunkpete

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Re: heating a bearing in the microwave
« Reply #12 on: February 13, 2015, 08:08:02 AM »
Quote
you certainly couldn't do it with the modern "sealed for life" bearings,

I think that Phil is right here, and it's what I was getting at in my first post. Depending on the spec and design of the bearing it could be degraded in some life-shortening way. A particular issue might be partial drying out of the cloth leading to hot spots or total drying out and over cooking.

There might be some configurations where it might be tempting to heat a rolling element bearing (if the right tools were not available for example), but I would always fit mechanically wherever possible.

Offline mechman48

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Re: heating a bearing in the microwave
« Reply #13 on: February 26, 2015, 05:11:46 AM »
I would steer clear of Microwaves & metal components   :zap:  IIRC when I used to fit bearings in industry we used a heated oil bath in the early days, with a thermometer, (not pre-sealed for life bearings ), then when the induction heaters came out it was easy peasy, set your bearing (only open rolling elements type ) on the bar on the two poles set the temp..(120*C iirc   :scratch: ) then wait for the buzzer / bell to go off.. but you had to be quick... & wear heat resisting gloves..  :bugeye:  but if the shaft clearances were correct then it was usually fitted with a press, or tube on the inner race assisted by a potential to kinetic energy converter of 2lb mass...  :lol:    If SWMBO has a used mini oven /grill going... go for it. Just remember as that 'most' of todays smaller bearings are 'sealed for life' application of heat in any form certainly wouldn't help..  :palm:

George.
George.


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Offline AdeV

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Re: heating a bearing in the microwave
« Reply #14 on: February 26, 2015, 09:18:18 AM »
Good for tempering, too. Set the thermostat for somewhat less than your tempering temp in case it's not accurate (likely). Check your part for color as you get close, and/or use an infrared thermometer. Adjust thermostat, as required to get what you want, and plunge when there. It's a nce even and slow process -- less danger of overshooting.

I use an ancient toaster oven (it came with an old tour bus I bought to haul the racing car around in). As the thermostat is very hit & miss, and i like to do reflow soldering in it, which doesn't like being massively over-temperature, I just added a cheap(ish) thermocouple, built a little arduino based device which reads the temperature out on some LED digits. Works great! If anyone's interested, I'll do a write up & costing.
Cheers!
Ade.
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Offline NeoTech

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Re: heating a bearing in the microwave
« Reply #15 on: February 26, 2015, 09:26:14 AM »
You gotta remember this guy, "Arduino vs. Evil" basicly lives for doing crazy ****.. Been following his videos since the start and he is effin hilarious.. But somethings, well common sense is really a aquired skillset for doing half of the **** he does. ;)
Machinery: Optimum D320x920, Optimum BF20L, Aciera F3. -- I have not failed. I've just found 10,000 ways that won't work. http://www.roughedge.se/blogg/

Offline vtsteam

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Re: heating a bearing in the microwave
« Reply #16 on: February 26, 2015, 09:59:05 AM »
Good for tempering, too. Set the thermostat for somewhat less than your tempering temp in case it's not accurate (likely). Check your part for color as you get close, and/or use an infrared thermometer. Adjust thermostat, as required to get what you want, and plunge when there. It's a nce even and slow process -- less danger of overshooting.

I use an ancient toaster oven (it came with an old tour bus I bought to haul the racing car around in). As the thermostat is very hit & miss, and i like to do reflow soldering in it, which doesn't like being massively over-temperature, I just added a cheap(ish) thermocouple, built a little arduino based device which reads the temperature out on some LED digits. Works great! If anyone's interested, I'll do a write up & costing.

Hey cool Ade, that sounds ideal, and I hadn't thought at all about re-flowing with one.

btw -- I wasn't recommending heating ball bearings at all here -- I've never done it -- just questioning in general why people would use a microwave oven for heating metal parts when simpler and cheaper small electric ovens are available, often free, and can easily fit in the shop. Like I said they work for baked sand cores, tempering, too, and now even solder re-flowing.
I love it when a Plan B comes together!
Steve
www.sredmond.com

RobWilson

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Re: heating a bearing in the microwave
« Reply #17 on: February 26, 2015, 12:05:47 PM »


I use an ancient toaster oven (it came with an old tour bus I bought to haul the racing car around in). As the thermostat is very hit & miss, and i like to do reflow soldering in it, which doesn't like being massively over-temperature, I just added a cheap(ish) thermocouple, built a little arduino based device which reads the temperature out on some LED digits. Works great! If anyone's interested, I'll do a write up & costing.


 :) I be one Ade .



Just as a side note  , If I need to heat a bearing up (or anything else without frying it) I just use a hot air gun ,cheep and works a treat  :coffee:


Rob

Offline vtsteam

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Re: heating a bearing in the microwave
« Reply #18 on: February 26, 2015, 12:12:08 PM »
Even simpler!   :clap:
I love it when a Plan B comes together!
Steve
www.sredmond.com

RobWilson

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Re: heating a bearing in the microwave
« Reply #19 on: February 26, 2015, 12:14:35 PM »
Even simpler!   :clap:


I am Steve  :lol: :lol: :lol: :lol: :lol: :lol:


Rob  :)

RobWilson

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Re: heating a bearing in the microwave
« Reply #20 on: February 26, 2015, 12:17:18 PM »
But I do think every shop should have a hot air gun , good for tempering small parts and other jobs  :med:


Rob

Offline awemawson

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Re: heating a bearing in the microwave
« Reply #21 on: February 26, 2015, 12:52:43 PM »
I have one in the shop for shrinking heat shrink sleeves. As Rob says useful for all sorts of things.
Andrew Mawson
East Sussex

Offline AdeV

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Re: heating a bearing in the microwave
« Reply #22 on: February 26, 2015, 02:12:05 PM »
Yep, a hot air gun is a vital accessory to the shop; I most recently used mine for stripping underseal off the Jag. Also handy for warming your hands up when the workshop heater's packed in again...
Cheers!
Ade.
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Offline dawesy

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Re: heating a bearing in the microwave
« Reply #23 on: February 27, 2015, 03:21:01 AM »
Hot air guns are very versatile. Mine gets used for anything from preheating aluminium prior to welding , to quick curing paint.  Even lighting charcoal on the bbq
Lee.
wishing my workshop was larger :(