35 replies to this topic

[Tex]

Do any of y'all break your JKHR's in in water? If so, have you noticed any "deterioration" of the twine used to wrap the comm?

[gotboostedvr6]

Not related to your post but food for thought.

How do you clear the comm slots after they they filled with gunk?

[Tex]

I haven't done that with any of the FK-style motors BUT..... when I did do that with some motors, I'd use a sharp Xacto to cut a toothpick at an angle and use that fine sliver at the end of the toothpick for cleaning the comm slots.

[Fast Freddie]

Not hard to clean comm. slots in FK motors. Just have your wife get you a eyelash brush or get a couple of dental flossing brushes. They both work and the dental flossing brushes can be bent to fit into the FK openings easier. The dental flossing brushes are also softer.

[Pablo]

David P. I don't know why you think water breakin dirties the comm slots. If anything, they stay cleaner on a water breakin because the brush material gets washed away as opposed to staying there. I'm sure your opinion differs, but you make it sound like it's a known fact they fill with gunk on a water breakin.  Not everyone agrees with you, I happen to be one of them. Monty Ohren preached water breakin, and even had some motors for sale in packaging that advertised "brushes seated in an aqueous solution".

 

Having said that, I will say this to Tex. My experience with lots of water breakins on many different types of motors, including FK's, the last couple years is tricky business because the brush hardnesses are so unpredictable from batch to batch. One day you'll do a motor and the water gets black within 15 seconds and poof, no more brushes, you just wasted a motor.  Next day different motor (of same type) and after 1 min 30 secs the water is clear and the brushes have barely changed. Therefore, lately I'm scared of it. The best situation to use water breakin is a hand out 16d or S16C race where you need to break in a new motor real quick

[gotboostedvr6]

Here is a typical comm of mine after 561 race laps.

It had zero burn and only took a light cut to clean up. You will find comms that have been water broke in have corroded from cavitation near the slots and will instantly start arcing on the trailing edge of the comm segment.

Water also breaks down the super glue that most use and rusts the motor.

There are other reasons I'll detail tonight when I get off work.

Attached Images

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[Samiam]

Not related to your post but food for thought.

How do you clear the comm slots after they they filled with gunk?

Line one:

[Dominator]

I did this once with a falcon 7 and the brushes were gone after a few seconds. Personally I oil it, put it on the supply for about 20 minutes at 3.5 volts, and in the car it goes.

[Tex]

What I'm most interested in is whether or not the twine which is used to tie the comm in a JKHR suffers due to water break-in(?). I have my reasons for such a specific, narrow question. If anyone has used water to break-in a JKHR, let me know if the twine suffered any deterioration. Thanks.

[Noose]

Tex,

I know a couple of guys that have done it and there was no problem with the comm tie. Now that was for a couple. Don't know if it will in general.

[Zippity]

No deterioration.

[Tex]

Thanks Joe and Ron!

 

Anyone else?

[Gator Bob]

Tex,

While I don't believe in this practice please consider "your water may vary"

Well or distributed water can be treated with 'stuff' that may alter the result.

If I was to do this kind of break in I would use distilled H₂O only.

[JohnnySlotcar]

CH3 CH2 OH works to pass the time while it is breaking in.

[Gator Bob]

Oh?

Or  while it works.    

[Samiam]

CH3 CH2 OH works to pass the time while it is breaking in.

Do you mix it with water,soda,orange juice,or just ice? And how does it affect your lap times?

[Gator Bob]

 Johnny ... have you tried drying then grinding up the ghosts and put it in a coffee filter to make HOt water?   

 

Everyone wants a hotter motor.

[Tex]

OK, try to keep up here guys. Pay attention. Key word: "twine". I asked if anyone noticed any deterioration in the twine as a result of breaking in a JKHR in water. READ the question. Answer the QUESTION. Thanks. 

[MSwiss]

I've done it a few times.(Water dipped the motor. I actually just submerge the whole back of the car with the motor installed )

 

No problem.

 

Both times when I counted the turns on the arm, the twine took some effort to cut off as it was impregnated with epoxy.

[Bill from NH]

Tex, what problems have you experienced with the twine on JKHR motors that have been broken in with water?

[Gator Bob]

I've done it a few times.(Water dipped the motor. I actually just submerge the whole back of the car with the motor installed )

 

No problem.

 

Both times when I counted the turns on the arm, the twine took some effort to cut off as it was impregnated with epoxy.

 

Kevlar^TM (arimid fiber)  would cost about .00001 cents more per foot more than hemp or rice rope ... or what ever that stuff is.

 

Tell Jerry ... for the next batch.  

[Tex]

Ah, so the twine is impregnated with epoxy... very interesting.

 

And, just for the record, I've not had any problems with the twine 'cause I don't break my motors in in water. I asked 'cause someone ELSE told me during tech inspection that the twine on their JKHR fell off as a result of breaking it in in water. Sounded fishy. Turns out the guy was trying to pull a fast one and slip a Hawk 7 through tech(illegal in TRRA retro). But the endbell end of the arm shaft was flush with the bushing and all machined and rounded smoothly on the end; he could cut the shaft with a Dremel but there was no way he could emulate that machining. BUSTED. But we're a low-key bunch of guys; since I'd already let him know he wasn't slipping anything past me, I let him race it anyway for 2 reasons:  (1) I told him if he won, I'd DQ him and  (2) if anyone else noticed and said something, his shame would be public. I just asked this question online in case there could be some plausibility regarding the twine coming off. It doesn't sound plausible even when the JKHR is broken in in water. Case closed. Thanks for the input specifically regarding the twine.

[Jason Holmes]

Did it on the 2 I got at the FB no problems just ran one of the motors today and after 5 months of setting still very fast

 

Jason

[John Streisguth]

I would be more concerned about the magnets...being that they contain iron, unless they are well coated, rusting will start to occur and they will start to disintegrate.  Unless you plan to use the motor up pretty quick, it's not something I would personally choose to do

[race301]

I would not do any mini type motor in water, not that it would hurt it but uses it up quicker. Just go 5 volts for 15 minutes dry. (also never free rev a mini you can break a winding easy)

 

I always do my D can and C can motors in water 2 volts just for 20 seconds, then spay out with pure and dry run for 5 minutes. makes a great radius