Another question for you Monty

[trickyvic3]

Hi Monty
Ok, Time for me to move on with my motor building.
Ive got the basic blue printing pretty well down. So the next thing Id like to learn [ and please dont laugh ] is how to shunt wire. I know some will say its so easy a cave man can do it.:D Im not a cave man !! I know like everything theres a right way and wrong way. It looks fairly easy, but i,ve yet to do it.
How do I attach to shunt to the brushes? Also, does anyone sell brushes with the shunt wires already attached? As always, thank your for your help.

Vic

[[email protected].]

... that I don't have. It isn't that hard, but can be time consuming and you need a new tool - a brush groover (I sell them, incidentally). You also need some teflon tubing (sold by Koford, Camen, Alpha, ProSlot - use the thinnest you can find that actually fits over the spring legs - firmly is preferred) and shunt material. Lots of sellers, but use TQ: no arguements accepted from anybody on that one... use TQ shunt wire!!!!

The shunt is NOT ATTACHED to the brush. It is held by the pressure of the spring. Long ago, Champion and Associated sold brushes with molded in shunts, a common industrial process for power tool and larger motors. Unfortunately, they weren't the best materials and so were never accepted by the better motor builders.

Even twisted tightly, the shunt wire is about twice the thickness of the molded in groove at the end of the brush, thus the necessity of a grooving tool. The groove must be at least as wide as the wire (but not much more) and 1 1/2 times deeper than the width of the wire. It is possible, and in the distant past I used, some other implement like a needle file or even my dremel with a cutoff wheel... but trust me, a grooving tool will cut the brush, and your frustration level, way down.

Insulate both legs of the spring, don't use more than necessary as space can get tight. Rebend the spring retaining tabs into a loose hook shape to allow the spring plus insulation to fit.

All thats left is to form a small loop or tight Z bend (various builders do this differently, thus the need for pictures) before soldering the other end of the shunt to the bussbar. You need to leave some slack to allow for brush wear and the tendancy of the shunt to 'wick' solder, but not so much that it gets fouled on a tire or slips into the endbell and arcs the comm. This last is actually rather unlikely, but possible.

I know theres some nifty pictures of finished installations out there in cyberspace. If somebody posts some, I'll comment on anything I like or dislike about what I see.

Enjoy!

[trickyvic3]

Thank you Monty

I think I got the jist of what your saying. Maybe I,ll practice on some old brushes first? lol Ill pm you about that grooving tool.

Thanks again

Vic

[qtupro]

Monty...I hate to dispute but I would suggest the shunt wire that Port Jefferson gets from HOH motors.(Jeff Jones) It has good flexaility an dis soft. Easy to work withalso. This is the stuff a certain multi time National Champion uses(buef) uses.

[[email protected].]

Kurt,


Is it a 3 bunch rope-lay 117/44 like the TQ? From the occasional Beuf motor I've seen, it looks like it. Looks like a duck, walks like a duck, quacks like a duck and all that...

Send me an inch or two and I'll let you know if theres any difference that I can see. If they're substantially the same, wonderful.

Not to rain on anyone's parade, but I've no real information on Jeff Jones (what I've read seems good) and have no idea what he sells to whom. I wouldn't mind being enlightened. However, I do know TQ, know its readily available, know its easy to use, and I have at least 75 feet of it in my personal stash so I'm not changing real soon.

[qtupro]

Monty. I will send you some from my stash . I find it much more plyable than the TQ that I can get . It is an excellent product but a little stiffer and harder to work with in my opinion, an it i sjust that. I need your address and will send some your way.
Kurt

[[email protected].]

Monty Ohren/Best o' the West
16353 Northwood Dr.
Victorville, CA 92394

[Mic Byrd]

Monty is right about TQ shunt wire switched from pro slot to Tq much easier to work with .was told along time ago by a builder in southern cal make it as short as possible and don't hang the brush up . Monty and I raced at same track back in mid 70's

[[email protected].]

Vic,

I don't frequent that 'other' BB site, but I just caught the parrallel thread you posted there.

I like Andy @ AB, but I thoroughly disagree with several items in his photo essay!! First, use all three strands in the TQ shunt wire, twisted tightly. The assertion that just one is enough is just untrue for two reasons: one, the surge current in a G12 motor can be as much as 40 amps even if very brief, and two, the heavier shunt helps heatsink the brush. Done right, with a small loop or z bend, it is plenty flexible. Second, do not top load the shunt!! When side loaded, the shunt is held down over the full width of the brush face. Top loading is almost a point contact with the spring, less secure and less effective for both contact and heatsinking.

One of these days I'll get a camera... then I'll beg for info on uploading pics:confused:

[trickyvic3]

Ok, Thanks Monty I,ll go by what you say. I does make more sense.

PS- Get a damn camera will ya !!!:D :D

[Chasegtp1590]

I'll post a picture of what I do and let Monty chime in on what he likes/dislikes. Granted, this is on an open motor.


http://img222.imageshack.us/img222/7562/dsc01847d.jpg
http://img230.imageshack.us/img230/2545/dsc01848m.jpg
http://img230.imageshack.us/img230/9694/dsc01849b.jpg

[[email protected].]

Vic,

Notice, especially in the bottom picture where you can clearly see the yellow teflon insulation on the contact end of the spring, that the end of the shunt cannot be seen. It is laying neatly in its custom cut groove - although as a vertical brush, it may be one of the Koford precut variety. The three bunch wire, twisted tightly, fits cleanly with no frayed strands hanging out, and the wire will move as the brush wears in the same hood relief slot that the spring does.

Are there detail differences from my methods? Yes, a few but nothing that matters very much. On the loop that sits atop the hood to allow slack I usually form a full circle instead of the U shape, just a difference in style. Then, on the positive bussbar (the forward one) Chase runs the wire through the hole. Most group 12 hardware doesn't have a hole, but even on setups that do, I wrap two turns of shunt around the buss but avoid using the hole. I find it easier to remove when you do the rebuild that way, but it won't affect any functionality of the motor.

Oh, Vic, about the camera... X-mas is coming up:D :D

[trickyvic3]

Chase
Thank you for the detailed pics. This will help me alot !! Looks easy enough.

Monty
Is there a trick to keep the solder from wicking up the shunt wire? I do have some TQ shunt wire, but will have to get some insulation for the spring legs.
I should have some free time tomorrow afternoon when my helper comes for joe. Monty, Ill give you a call, and order some goodies from you.
Thank guys, for all the help.

Vic

[tnttires]

Go to an Electronics Store they use an Aluminum Heat Sink Clip that operates like a Skinny Clothespin. Just clip it to the shunt wire at the buss bar and it will keep the solder from wicking.
Just as Monty says I don't use the hole because it is easier to get off. I do put a bigger loop than Chase. But he is still learning at my Feet!!!!!!!! LOL!!

[Multiracer II]

As the teacher you should be teaching Chase how to clean up his acid and flux on a newly built motor. Check out that positive 5 coil spring ! Severe acid etching tends to make spring steel go "BOING" at the most inoportune moment.

[Chasegtp1590]

I noticed that, but that was after sitting in my box for 2 weeks after I raced it. I only use paste flux on my shunts, do you think the acid residue on the motor where I soldered caused the rust?

[Multiracer II]

When you see that condition on that side of that spring it comes from the flux spatter when you did the negative shunt.

[Chasegtp1590]

How do you prevent it? Or do you just clean it up after the race?

[Multiracer II]

When you build the motor.... clean the whole end bell area with a solvent or soap and water or both depending on the type of flux used to secure the shunts. Blow dry and lightly oil the bearing and a drop of oil on each spring will wick it's way around the post. Break it in on low voltage.
Step two after a day of testing and racing and soldering lead wires on, dip the whole motor in naptha and brush with a stiff brush. Blow dry and repeat the later part of step one.
This will at least neutralize all the copper/carbon from burnt braid, acids and fluxes, braid juices, glue, brush dust etc, etc. until you can tear it down and rebuild it.
This will also help prolong and protect the very thin gold plating found on most of our cobalt hardware.

[Chasegtp1590]

Thanks for the tips. I am new to opens so I am trying to learn everything I can.

[[email protected].]

Gentlemen,

Thanks for raising a few more salient issues! I thought we were just commenting on how to place/route the shunts, but since y'all mention them...


Wicking happens, but only when the shunt is hotter than the melting point of the solder. Yes, Tony, one could use a heatsink clamp, but I don't because wicking isn't a problem. Use a hot iron, solder rapidly, don't dwell and watch helplessly as the solder flows away...

2 weeks? Like Ron says, ASAP on the hose - down! Better yet, if you have even a few spare seconds after a motor change (I understand how you might have to skip this in the heat of battle), use a wet cotton swab to wipe down the fresh solder joint on the fresh motor. You'll avoid chassis, axle, and bearing corrosion as well as on the motor. And I don't mean wet with naptha, I mean SALIVA! Yep, stick that Q-tip in your mouth - keep a supply of fresh ones, of course - Enzyme laced water (spit) is the perfect acid neutralizer. I even build chassis with a stack of Q-tips on hand, and just a token dip in the sink with a bit of kitchen cleanser is all you need afterwards.

FLUX!!!!! Except for soldering to the chassis or installing the pinion (in which case you use the wet Q-tip) you DON'T NEED NO STINKIN' FLUX!!! The flux is the rosin core in the solder. New shunt wire, always, clean bussbars, hot iron, rosin core solder - thats all you need. That goes for lead wires too, both ends!! If you have problems with that, buy a cheap electronic kit at a decent electronic store, something with a PC board in it, and practice. For the price of a G7 motor, you can buy ten little useful kits.... AM radios, LED flashers, low watt pre-amps, toy motor controllers, signal injectors, the list goes on ad nauseum. My point is that electronic style soldering is an essential slot racing skill. Jeez, ya think guys like Les Wright, Jim DiFalco, Dan Ruddock or myself build power supplies, controllers, meters, or zappers with ACID FLUX??? No, and I mean HECK NO!!! Now, paste flux does have its uses, but paste flux comes in several varieties! Use one from the electronic store, not the hardware store, and look for the phrase "non corrosive" on the label. Without naming the victim (he's a great guy who has learned the lesson), I can tell you I have a motor in the shop for rebuild with the spring post CRUMBLED, from paste flux!

Oh, Vic - I have the spring insulation too, cheap.

[Multiracer II]

This seemed like good information while still involving a related topic. It is just what to look for and maintain once you learn how to install your shunt wires.

[[email protected].]

I'll admit that on my dim little laptop screen I didn't even notice the corroded spring, and sure, its well to point it out.

In my business, the appearance of new, shiny new, goes a long way. Applies to rebuilt things too, and as you can see I'm pretty sensitive to causes of corrosion. I have to scrape a lot of it off customer motors and armatures. Many don't bother to degrease their toys before sending them either.

I coined that phrase about clean cars used in my tagline back in the 70's. That will NEVER change.

[[email protected].]

Here I go mentioning it, and found it was gone!

Consider this post as a test to see if I've managed to restore it.

Ah... after preview, much better.

Anybody know if there's a way to make it retroactive to all my posts?

[Phil I.]

I go threw a can of electrical spray in 5-6 weeks. I clean my cars & motors every other week...AT THE LEAST.:D ...depending on how dirty the track is.
One newbe ran 2 1/2 (10 raced & practice) months and wondered why his car slowed so much. Complained he didn't get his moneys worth out of a sealed deathstar. I took his car OUTSIDE & sprayed it down. Body too! Left a large dirty spot on some white concret. Eyes went wide open when he saw:eek: all the BLACK fluid coming out of the motor & off the car....Body too.. Checked the brushes. Had 2-3 more races left on them. Put some nahptha on the comm to clean somemore..Checked it on my power supply.....AND WONDERS...And he found a SPEED SECRET:rolleyes: ........From Monty!

OLPHRT
PHIL I.

[Chasegtp1590]

Here I go mentioning it, and found it was gone!

Consider this post as a test to see if I've managed to restore it.

Ah... after preview, much better.

Anybody know if there's a way to make it retroactive to all my posts?
It will only show up in your posts since you made the change, not in any previous ones.

[JIMSPOVE]

Warm water, dish soap and a soft tooth brush are a slot racers friend. Also Camen springs will rust no matter how hard you try to keep them clean. A small drop of oil will delay that slightly. Electrical cleaner is a must also. A clean motor is a happy motor!!!

[Slidergreg]

I've even seen some motors from Monty with DOUBLE shunts.

There probably isn't much performance advantage other than a little heat sinking but they sure looked IMPRESSIVE!!

Greg G.

[Multiracer II]

and they listen even less now.

[[email protected].]

Ron,

Amen to that! Alan is 27 now, and I can't tell him much of anything anymore. In his defense, he IS employed, whereas I have to employ myself:rolleyes:

[Phil I.]

O Lord Monty..:o .......What happens when you have to go infront of the BOSS:rolleyes:

OLPHRT
PHIL

MIRROR, MIRROR ON THE WALL :D