[R-390] Ultrasonic cleaning

[barry williams]

I have always been interested in the model dragsters. If you get on 
RCUniverse you will see where I'm a moderator in glow engines. I don't 
know about Chinese made engines discoloring worse than others, but I'll 
start paying attention to the discoloration stories from now on.  I'm 
more and more into Saitos nowadays. I think the quality far surpasses 
other engines, including overpriced OS engines.

Another excellent cleaner is Dawn Power Dissolver. That may be enough 
for gears. It is excellent for castor build up but you have to leave it 
on for 15-45 minutes for aluminum. I suppose you could leave it longer 
for steel and brass. It cuts through gunk fast and is pretty safe for 
metals. That is a must have solvent for model airplane engines. You 
could spray your gears, etc and lay them aside for a while as you do 
other work before using a toothbrush to remove old oils. I always spray 
alcohol afterwards as a wash before oiling.


the other Barry


> I have flown R/C aircraft for a decade or two.  I've rebuilt more 
> engines than I can remember.
>
> I'll add that R/C helicopters is in this mix also!
>
> The aluminum or whatever the base metal of engines that come out of 
> China discolors the most.
>
> Burnt on castor oil is a pain to get off!
>
> Either Boca or RC Bearings are excellent sources!  Ever single bushing 
> on R/C cars or the Helicopters were immediately replaced with Boca 
> Bearings!
>
> I'd have to say that the RPM of the R/C cars exceeded that of the 
> aircraft.  When you use electric motors and get into the very fine 
> pitch gears, and ceramic clutches, hit speeds on a junker that exceeds 
> 60mph, (Real Speed - NOT scale speed!), then the RPMs are really up 
> there.  Racing the cars on an oval banked track and hitting 90mph real 
> speed, you KNOW the entire gear system and motors are beyond the 25K RPM.
>
> The most brutal are the drag racers!  A 1/10th scale rail that goes 
> through a 1/10th scale 1/4 mile speed trap that end up in the real 
> speed arena of 132mph puts stresses on things that folks can't imagine.
>
> This is why my experience of "observation" of others using a very 
> strong ultrasonic cleaner on bearings has led me to my conclusion. All 
> SS bearings are one thing.  These in the R-390A gear train do not 
> appear to me to be all SS.  I see brass.  That gets me concerned.  
> Even if only the inner and outer races are brass, they will take a 
> beating.
>
> My $0.02 worth!
>
> Never lost a Boca bearing that was properly taken care of!
>
> Bob - N0DGN
>
>
> On 7/31/2014 12:20 PM, barry williams wrote:
>> 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
>
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>