[R-390] Ultrasonic cleaning

[barry williams]

I fly model airplanes and do a lot of engine work on them. My buddies 
would laugh at worrying over bearings in an ultrasonic cleaner. We buy 
them from either Boca or RC Bearings. They run at speeds up to 15,000 
rpm for sport flying, and about 25,000 rpm for racing.

My cleaner uses plain old water. I do put in a little dishwashing 
detergent just to cut through burn on castor oil better. I don't know if 
that helps or not, to tell the truth.

The best method for all metals is to use an old crock pot outdoors on 
low heat. Put your gears in the crockpot, cover them with antifreeze and 
come back in about 3 hours. I don't know if that's long enough for just 
gear gunk but it may be. For burnt on castor and other lubricants we 
usually go for 8 to 12 hours on engine parts. We have to be careful 
because a lot of the engine is aluminum and it discolors easily.

the other Barry


> It is dependent upon the "strength" of the ultrasonic bath itself.
>
> The stronger the movement, the more things will essentially *beat* 
> against each other.
>
> That is the reason I brought up the issue of bearings.
>
> During the period that they are in this cleaning solution, the 
> lubricant WILL be removed.
>
> A bearing is either a ball, roller, or needle type of construction.
>
> Once the lubricant is gone, then the balls, rollers, or needles will 
> be vibrating against each other, the cage if such is used, and the 
> inner and outer races.
>
> The result WILL be something that has an significantly increased 
> clearance than it started with.
>
> At that point, you would be *much* better off with simply getting the 
> sizes, dimensions, and clearances *before* they go into the ultrasonic 
> cleaner.
>
> The reason is simple.  You *WILL* be trying to order new ones from an 
> outfit such as Boca Bearings.
>
> If your numbers do NOT match what is off the shelf, then they will 
> have to make "custom" ones to fill your order.
>
> Custom anything results in the moniker - "BOHICA".  Interpreted, "Bend 
> Over Here It Comes Again".
>
> Bob - N0DGN
>
>
> On 7/31/2014 9:53 AM, Barry wrote:
>> I don't have access to an ultrasonic cleaner so it's a bit of a moot 
>> point for me, but just curious what happens when cleaning things that 
>> touch in an ultrasonic bath.
>>
>> I assume the advice to not clean the split gears is only when they're 
>> assembled (e.g. disassembling them and cleaning them separately is 
>> fine), but what does that do to the mating surfaces when they are 
>> cleaned when assembled?
>>
>> Just curious...
>>
>> Thanks,
>> Barry - N4BUQ
>>
>> ----- Original Message -----
>>> From: "rbethman" <rbethman at comcast.net>
>>> To: r-390 at mailman.qth.net
>>> Sent: Thursday, July 31, 2014 6:46:06 AM
>>> Subject: [R-390] Ultrasonic cleaning
>>>
>>> If the split gears shouldn't be cleaned by an ultrasonic cleaner, the
>>> I
>>> would have even more reservations to placing the bearings in one!
>>>
>>> In my mind, I see the bearings eating themselves!  Not a good idea.
>>>
>>> Bob - N0DGN
>
>