# T Jet Commutator Gouging



## shogun (May 8, 2010)

Hi Guys,

I've have two comms with gouge marks. One, pretty bad, with the brushes catching and digging little ridges. This is from a t-jet with gold wire, using original brushes, medium tension. The other comm is a Christmas tree, original brushes, medium tension, and the scoring runs in regular circles around the plate. Both cars ran noteably smooth before this happened, then roughness prompted me to find this new trouble.

I've sanded both to smooth them, and this has worked (just a hand sand... got to get one of those tools). 

My question is, why did this happen out of the blue, and how can I prevent it? What do we know about this?


Thanks in advance.


----------



## Bill Hall (Jan 6, 2007)

*magic eight ball sez...*

Resistance is usually the culprit. Hidden two ways....mechanical or electrical. Based on your description I'd ease some tension onto the brush springs by gently poking them while in test mode.... and see if they perk up.

Too much brush tension causes undesireable mechanical resistance.

Too little brush tension causes undesireable electrical resistance. 

Either one can hurt yer comm. 

Sounds like your on the light side of the happy medium required.


----------



## shogun (May 8, 2010)

Hi Bill... thank you for weighing in on this. I set my tension so there is a very slight, or sometimes no, increase in RPM's. With the T-Jets I'm not sure I've ever added enough to give them much "brakes", as by then the brushes are so far up they won't stay in the holes. I've made the little bend close to the rivet to add more on some, but not these cars.

Now, if these cars had too much electrical resistance, would this make them hot? They were both cool runners.

Anyway, you've given me something to think about, and I'll double check. Heck, I'm always happy to tighen up the brushes... I just never wanted to go past the point of gaining RPM, as I thought this would be unnessisary wear?

As a follow on, how much can a comm be sanded before it's worn out?


----------



## Hornet (Dec 1, 2005)

I'm not a T-jet guy,but if you have a black residue on your com,you're usually too light on brush tension,and electrical resistance is the enemy,and if the gouges are shiny,odds are you're probably running to much tension,and mechanical resistance is your enemy.
These are my experiences from in-line mag cars,so don't take that as the gospel truth for a pancake car.
Rick


----------



## Bill Hall (Jan 6, 2007)

Squeeze 'em up a bit and see!

If yer setting is light, normal brush wear will take them out of range pretty quick.


----------



## shogun (May 8, 2010)

Okay, I'll tighten them!  Black residue - yep, I got it. But, I thought this was totally normal, no? I mean, that's what the eraser is for... right? 

This will be interesting, actually. 

It bring to mind a question, though. How much life do you get from your brushes? I mean, when do you say it's time to put new ones in? Worn to 3/4, get new ones? Less, more?

Thanks.


----------



## slotking (May 27, 2008)

> f the gouges are shiny,odds are you're probably running to much tension


Rick most t-jet guys do not come close to the tension I run on my fray cars.
I have very little issues with the comms.

I do remove te brushes to not weaken the leaf springs.

I also use the VRP comm toll to keep my comms flat.
then I run an ball point ink pen over the air gap. this removes any sharp edges that the brushes may hit


----------



## ajd350 (Sep 18, 2005)

If all else fails, dump the original comm brushes for some Thunderbrushes or Wizzards. They run much cleaner and faster.


----------



## Bill Hall (Jan 6, 2007)

Black....hmmmmm. 

Consider that the brushes could be oil fouled.


----------



## shogun (May 8, 2010)

Oil fouled... yes, that's possible. 

I'd have thought the oil would make them run smoother... but perhaps it mixes with brush residue and gets gummy, then the brush shifts and catches an edge. 

I never considered there was any downside to over-oiling other than having to re-clean.

So, just so I can get this brush tension thing right... should I continue tightening tension even if their is no RPM increase, as tested by ear on the old transformer? I've always liked a couple feet of roll to stop, after top speed. Less roll than that and it seems the car is less smooth and precise in the corners.


----------



## Sir Slotsalot (Jan 23, 2010)

Along with proper brush tension tweaking, Aerocar "Conducta Motor Drops" comm lube helps greatly by reducing brush wear, improves conductivity, performance and prolongs brush life. Available at Slot Car Express:

http://www.slotcarexpress.com/Chemicals---Supplies.html


----------



## shogun (May 8, 2010)

I love the sound of that. What is it made of to make it work like this?

Thanks to all you guys for this awesome information. Too bad the South has no T-Jet activity that I've found.


----------



## Sir Slotsalot (Jan 23, 2010)

Sorry, the formula is "proprietary". This stuff works on any slot car motor, either pancake or in-line. The cool thing is that unlike most oils which are non-conductive and can foul operation, Aerocar "Conducta" enhances conductivity while it lubes. Anyone reading this post that has the stuff please "chime in". This is one of those products that actually does what it says. I use it myself and have no regrets.


----------



## 1976Cordoba (Sep 20, 2000)

Is this your standard comm-drops type stuff that the RC crowd uses?


----------



## Sir Slotsalot (Jan 23, 2010)

Doba,

Could be used for "brush-type" R/C motors but not really intended for that. "Conducta" is designed for model trains and slot cars to improve operation and extend motor life. You can purchase directly from Aerocar:

http://aerocarlubricants.com/index.php?main_page=product_info&cPath=1&products_id=4

Or, if you want to save a little, I do offer a discount to HT forum members


----------



## shogun (May 8, 2010)

I'm not chemist enough to steal anybodies formula... but I was wondering if it was some kind of light oil with some metalic molecules... or something : ) Just a laymans curiousity about what makes it different and better. Sounds worth a try.


----------



## Boosted-Z71 (Nov 26, 2007)

I have used the conducta lube, a polished arm and wiz brushes, and if your setup right the com stays looking brand new race after race and you don't get build up on the brushes, or the comm. 

Its good stuff, I used to race 1/10 scale electrics and had previously tried pretty much all the RC comm drops in the T-jets and nothing works like the Conducta-lube. I also place a drop on the pickup shoes / braids and in the hangers as well, you will notice a difference. Let me say too that the dispensing tip on the bottle is very good and a bottle will last you a long time when used at the correct rate. 

SirSlotsalot how do we HT members go about getting the discount? I will be replenishing my supply soon, and may even try some of your oil as well this time

Boosted


----------



## Sir Slotsalot (Jan 23, 2010)

Hey Boosted,

Thanks for the "plug". When you email your order, just include your forum "user-name" and forum/s you belong to. After that, you're information will be in my system and each time you order, you'll get the forum discount for all products listed on the SCE site. I'm curious, how did you discover "Conducta-Lube"? BTW, You may want to try the Slot Rail & Braid Cleaner/Conditioner. As it cleans, it too also provides a "conductive" treatment to the power rails.

Shogun,

I can tell you that "Conducta" does not contain "conductive metals" even at molecular levels.

What got me started?

I had experimented with "Voodoo" brand comm drops only to find that it worked great and gave a real performance boost for a few laps. After it wears off, it actually dries the comm and brush surfaces to the point of scorching from pure friction. I'm not bashing the Voodoo guys but Gee-Whiz!! they could at least warn you of the effects before you find out the hard way and fry your favorite motor.

When I began searching for "comm drops" that were not harmful, I had seen conductive greases that actually contained metallic particles. These are generally used for large motors and would be way too viscous for anything in the hobby realm. I also tried potentiometer lube which I use on the studio mixing console but that also was too thick and way too expensive.

I just kept on searching until I found "Conducta-Lube". It has conductive properties at a molecular level but non-metallic. I'm not a chemist "per say" so it's the best explanation I can give. I just know it works and is one of the coolest hobby products available. Cheap too. A little goes a long way.


----------



## slotking (May 27, 2008)

btw if your looking for the most speed you can get
then use the Slottech brushes and left shoe = BSRT and right shoe = slottech or 2 slottech shoes


I can point you to a test vid if you interested


----------



## Boosted-Z71 (Nov 26, 2007)

Sir Slotsalot said:


> Hey Boosted, I'm curious, how did you discover "Conducta-Lube"?


I found it looking for rail cleaner / conditioner, and knew that what I was using (RC car drops) was not working the way I wanted, like you said So I tried it and I really like it. Yes the rail conditioner is awesome as well, I bought it for my Tomy track as it is heavily landscaped and difficult to clean the entire track, one good cleaning and an application of the track conditioner and I have not touched it as far as cleaning the rails for quite some time, dust it off & drop a car and go.


Boosted


----------



## Sir Slotsalot (Jan 23, 2010)

Boosted,

Glad to hear the products are working well for you. Any pics of your track?


----------



## Boosted-Z71 (Nov 26, 2007)

Here is the Tomy track, Jaybird Speedway http://www.hobbytalk.com/bbs1/showthread.php?t=261791&page=14

and here is The GlassRing, http://www.hobbytalk.com/bbs1/showthread.php?t=332306&highlight=The+Glass+Ring

Both are really fun tracks to run

Boosted


----------



## Sir Slotsalot (Jan 23, 2010)

Wow!! Both tracks are landscaped beautifully. Talk about a small world, my first race set in 1961 was a 1/32 Eldon with (2) Ferraris for Christmas. I'll have to scour my Mom's house to see if I can find anything left from it. LOL!!


----------



## shogun (May 8, 2010)

Slotking, let's here it about the two different shoes and test vid. Sounds interesting.

Sir Slots... I'll be placing an order.


----------



## Hornet (Dec 1, 2005)

LOL,now i know what you mean about moving things around.:wave:

Rick


----------



## slotking (May 27, 2008)

Crap,
I know I made a vid showing the the Difference in brushes on the DYNO, but it's not on the ho-tips site. so I have to try to find hopefully on my hard drive. 

So I have now made a new forum on the ho-tips site called VIDs and will place all vids there and in thier respective areas as well


----------

