# AFX G-Plus brush removal and replacement photo guide.



## Jisp

Hi all.

I have accumulated many cars that when they arrived to me, weren’t quite ready for the track. Missing parts here and there, worn parts, in need of cleaning up and de-gunking – I’m sure many of you are the same. When time permits I grab one or two out and rebuild them to add to the runners collection.

This last weekend my wife took our two girls for the weekend to spend the night at her friend’s (plus her daughter) new beach house. It was a tough decision... spend two days with six yapping females or claim to have a long list of things needing doing back home. Took me all of .1 second to decide and as my wife drove off I pushed the “to-do” list waaaay out of sight and loaded the fridge with beer. Cleared the dining room table and two kitchen benches and loaded up with slot car gear and tools. Cranked the music up a notch.....all set.

First out of the box was an AFX G-Plus chassis, the only one I own. Been eyeing it off for a while but always passed it over because I don’t have spare parts for this chassis and because I have always read that the brush arrangement was insanely difficult to work with. Looking the car over, everything seemed in surprisingly good condition except for the tyres. The only part I couldn’t check visually or by feel was brush wear.

After reading about various methods for brush removal & replacement I decided that the method involving removing the brush barrels was probably right for me. This photo guide picks up right at the point of removing the brush barrels only because it was at this point that I thought to grab the camera as it may help someone else.

It’s important to note that removing the motor and magnets isn’t required if you merely want to check or replace the brushes & springs. I opted to remove the motor (and mags) because I wanted to do a little work on the motor commutator and check a few other things along the way. On the flip side, removing the mags and motor is the only way I know of to remove the brushes if your preference is to not remove the brush barrels.

If you don’t need to remove the motor, pick up the guide at the first photo which details removing the brush barrel retainer clip and the barrel itself. Keep in mind that you will need to take care not to launch the brushes into space.

Should you decide to remove the motor and mags, here’s how I did it.
-	Remove the mag retainer clip by easing each end away from the chassis with a small flat head screw driver. It’s easiest to do from the underside opening of the body clips.
-	Remove the mags by pushing them straight up. They won’t clear the armature stacks so turn the armature until the bottom inner edge of the curved face sits between two stacks. Further pushing and easing the armature around releases the mag. Further into the guide is a photo of the reverse procedure which may help explain.
-	Push the rear of the armature up until the bush pops out of the rear retainer. Lift it a little further and slowly draw it towards the rear to clear the front of the shaft from it’s bush (which remains clipped in). Now, either continue drawing it very slowly to the rear or lift it straight up, vertically. Either way, the brushes will gently click together and stay there when the armature is clear.
-	To remove the brushes use a tiny flat head screw driver or tooth pick to push one brush all the way into the barrel which will release the other. The second brush now just slides straight out. Carefully tip the car to one side, tap the barrel and the spring should fall free. For obvious reasons don’t do this over your lap...... do it over a large flat area to avoid losing the tiny spring. Repeat for the other side.

Soooo, the barrel retainers are held in place by tension. The small vertical section at the front of the retainer is held in place by a lip on the plastic upright adjacent to it. The lip is barely visible while the retainer is in place. Simply slide a tiny jeweller’s flat screw driver or similar object between the two and the front of the retainer will pop straight up. Gentle manipulation then allows the entire retainer to be lifted straight up, clear of the chassis.






This photo clearly shows the plastic lip under which the retainer is held in place.




At this point I checked and cleaned up all of the electricals. The brushes were not overly worn and will be reused along with the springs. The slot in the brush goes to the spring end, not the comm end.




The motor comm was cleaned and polished. While I was at it I gently ran the rounded tip of a ball point pen back and forth between the comm segments. This gives the otherwise sharp edge a smoother transition as it passes the brush.




Interestingly to me, while inspecting the arm I noticed that one of the windings had slipped free at the rear. It was comfortably nestled up against the end of the stack. I considered using a little epoxy to hold it there but figured that once the motor was back in place it really wouldn’t represent a problem. I’m a home racer and it seemed perfectly at home in it’s new location. Btw, the arm “ohms” out at a respectable 6.2 on each stack.

 


Further poking and probing showed the rear axle had a crazy amount of slop, much more than any car I can recall working on. Having not tried the ol’ super glue trick I figured now was the time. I coated the axle with candle wax and popped it back in place taking care to make sure it was centred and the splines were not against the holes. A tiny drop of CA (10sec) was applied to the point where the axle went through each hole. I then gave the axle a few turns back and forth to work the CA into the hole. Several hours later I used some light action pliers to twist the axle free. Holding the pliers at 90 degrees to the axle gives the splines on the plier’s jaws excellent grip without damaging the splines on the axle. Some back and forth rotation with the axle splines in the newly formed holes gives the axle the tiny amount of play it needs. The CA flash and wax left on the chassis after removing the axle is easy to clean up with a sharp knife edge.


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## Jisp

The shoes and springs still had plenty of life left in them and after cleaning them up all of the electrical components were good to go.




Both the pinion and crown gear were in good shape. After applying a little oil to the bushes the arm was popped back in place. I give the gear teeth a very light smear of hobby ceramic grease but any of the common lubes should do the job. Give the arm a spin at each stage to ensure that it’s moving fre





The magnets are then pushed back down into place paying particular care to ensure that the lower curved face edge sits between two of the armature stacks. Ensure that the mags are pushed all the way home, flush with the bottom of the chassis, before clipping the mag retainer back in place. Again, turn the arm a spin with your finger. You’ll feel intermittent resistance and attraction as each stack passes the mags but it should be smooth and not clipping the mags which indicates they are not seated correctly. 








Hmmm, now to the brushes that had us all freaked out in the first place. This step is far easier to do than it is to explain. I’ll try...... sit the chassis flat and load up one barrel/retainer with the spring and brush. Roll the very tip of the shoe hook into the chassis opening, towards the comm, until the brush rests on top of the comm.


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## Jisp

Using the index/pointer finger of my right hand I kept light, steady pressure on the brush in the direction of the barrel while gently rocking the barrel holder down until it was nestled against the chassis. The brush slips further into the barrel while following the face of the comm, as the barrel retainer slides down into position. My dexterity must be all to the right because I was not able to repeat this the other way around on the other side. I used a square toothpick to push the brush in while wriggling the barrel retainer into place. In each case the front of the barrel retainer is still sitting up. Using a small flat screw driver it is pushed home with a little pressure to the inside of the 90 degree bend.








With the top end electrics complete, again give the arm a few turns to make sure that everything feels right. Yup, I keep saying that but there are so many areas where things can go slightly wrong that it is well worth your time to test at each stage of the assembly.




I removed the front wheels so as to not obscure photos. Time to pop them back on. I’m a big fan of indy front wheels. A small pair of pliers makes short work of removing and replacing the hollow front wheel pins.




Flip it over and reinstall the shoes and springs. You’ve no doubt noticed that the shoes are a little different to what I’d call conventional. Drop a spring into place and hook the end of the shoe into the hanger. Now ease the shoe towards the front of the chassis until it’s hook prevents it moving further. The front of the shoe should now ease over the front plastic pin allowing the shoe to then slip back to it’s normal position. (Should have taken photo with one on, one off – oops)




Yet again check everything for correct movement and very lightly oil the axle holes. A battery test is a quick and easy way to ensure that your little puppy seems to be running well before heading to the track.




Looks like I’m off to the tyre shop..... the tyres that came with the car comprised of two different size fronts and typically perished rear foams.




With retrospect it would have been nice if I had thought to do a photo guide prior to the point of removing the brush barrel retainers. Having said that I hope this helps a few punters take the plunge on this very interesting and well regarded chassis.

Cheers,
Michael.


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## cwbam

Brilliant
& great photos!


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## GTPguy

Nice step-by-step tutorial, and clear pictures. 
I had a really frustrating time when I had to replace those brushes a while ago. This will definitely help fo next time. Thanks.


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## joegri

man that was a great read!! the photos are perfect for guys like me that need a helping hand the first few times. i think i have maybe 2 of these chassis in pieces in a box somewhere in the cave that after reading this i might just dig,em out and start wrenchin on,em! thanx so much for that jisper. oh and i do have something for ya i just gotta pull it together for ya. great job man. and i hope you emptied the fridge before the TM got home!


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## Bill Hall

Micheal, thanks for the professional expose. 

Your camera and editing work set the standard and support the idea that a picture is worth a thousand words. The crisp macro shots clearly illustrate the process and provide the great detail that visual learners like myself and so many others require.


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## alpink

always good to read a concise tutorial on a specific issue which many find challenging.
I sure butchered a lot of them years ago. finesse cannot be explained, but can be shown. good pics. thanx.


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## Jisp

Kind thanks for the feedback gents, it's genuinely appreciated and welcome encouragement. Like most of the people here (seemingly) I'm also a visual learner. That's the sole reason for the photo guide.

I reckon it's important to note that in a way, it's a joint venture. Each of the additional steps taken like the CA trick, the comm edge smoothing tip etc was learnt from guys like you on forums like this.

If the guide helps only a few punters take a leap and have a go I consider it worthwhile. If I had several of the chassis and some spare parts I may not have been so diligent in inspecting every detail before proceeding with a stage. With only one chassis and no spares there wasn't a lot of fudge factor.

Thank you.

Cheers,
Michael. :thumbsup:


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## pshoe64

Most excellent work and the process of getting the brushes and barrels back into an original G+ doesn't seem as challenging now. Great tutorial.

-Paul


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## Bill Hall

Who you foolen' ?

Take a bow as well Paul. Your consistent dedication to reviews, how-tos, and education in general has set a very high standard in our hobby.


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## Jisp

Thanks for the feedback Paul, it's hugely encouraging.

Bill, you are 100% correct in your observation of Paul's long term, dedicated contributions. Paul, I reckon you must have Red Racing Oil in your veins. It's the excellent standard set by yourself and many others here, from which I draw inspiration.

Cheers guys,
Michael. :thumbsup:


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## Grandcheapskate

Excellent work Michael!

Whenever I look at the brush configuration on a G-Plus, I wonder why the brush barrels themselves never slide out from under the retaining clip. I guess there is enough pressure to hold them in place even though they are under constant spring tension trying to push them away from the comm. There may be a slight lip on the brush barrel which (somewhat) prevents it from sliding back (and under) the brush barrel retainer clip (and away from the comm), but still seems like a design which has a bit of a flaw in it.

Joe


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## Jisp

Thank you Joe.

Interesting timing with your comment regarding the brush barrels as I was intending to make a follow up post about them. You are right, they do have a lip which prevents them sliding back through the holder/shoe hanger. The barrels are a snug, snap-in fit in the holders but I guess AFX just wanted to ensure they wouldn't slip away from the comm. I popped one back out and took a photo, which I should have done originally.



I guess the ideal solution would be to either find an adjustable brush barrel, from elsewhere, that works with the G-Plus setup. Either that or modify the stock barrels to take a grub screw. I did some hunting around and about the only existing adjustable barrel I found that looked like it may work is from the AW Super III. Thus far I have not been able to find any dimensional specs.

Here's the specs for the G+ barrel. If anyone knows of an existing adjustable barrel that's a likely match please post the details.

Cheers,
Michael. :thumbsup:


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## Grandcheapskate

I'm getting a little out of my league here, but if you wanted to move the barrel slightlly closer to the comm, you might be able to find a washer which fits over the barrel but not over the "lip". You would place it between the lip and the retaining clip.

I don't see an easy, non-destructive way to move the barrel away from the comm except to get a more narrow retaining clip.

Or get stronger or weaker springs. Longer or shorter brushes.

The G-Plus is what it is. After all, I never read about anyone racing them so they are probably for your own personal enjoyment. As long as the barrels don't move, you ready to run!

I have a number of still packaged G-Plus cars but only about 4 runners. I couldn't use them on my Aurora L&J track because the downforce was too much for my liking. They are better on Tyco/Mattel, but they still seem too low and really bang around a lot - leading me to believe they have to be taking a beating, especially at the track joints. I did get to run them on a Bowman routed track and they were much, much more fun.

Joe


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## bobwoodly

Jisp - enjoyable reading. I was reading your stuff while trying to imagine a Aussie accent holding a Fosters.


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## pshoe64

BSRT used to make a threaded brush barrel for the original G+. I'm guessing those are out of production, but maybe there are some stashed away? I have a set I kept from eons ago. They sure made swapping motors and brushes easier.

-Paul


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## swamibob

Any pictures Paul? Sounds like a really cool idea.

Tom


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## gordonmoney

Wizzard threaded barrels, brushes and springs all work well in the G plus. After the change over, brush replacement, and armature removal and installation are a breeze.


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## SDMedanic

The Super G+ took over from the AFX magna-traction RO cars and were raced in various forms and configurations until the Tyco 440X2 became the top dog in the Mid 80s. One problem with the G+ is that a high resistance connection can develop between the hanger clip and the brush barrel. This can be addressed by keeping them squeeky clean or with a small dab of solder to bond the brush tube to the hanger.


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## sssscamaro

Years ago I realized how simple to make my own threaded barrels. Simply purchase a 2-56 tap and corresponding drill bit (#51 if memory is correct) and some 2-56 set screws. My grandfather hooked me up with the tap at age 10!
The "secret" is to only tap as far as needed to allow the 2/56 screw to thread in flush or maybe a thread more than end of the barrel. You can get 2/56 screws and also brush barrel heat sinks as well from the big 3. 
I also always tinned and solderd the brush barrels to the holders.

I am going to be restoring a Gplus car I won my first official race with 33+ years ago. Russell cobalt magnets ajs a bomb arm etc... I had the first car in our club with threaded barrels ...I was 11.

Also another neat easy to make tool....take some thin brass stock ....or even an old pickup shoe. Bend it into a U shape about an inch long.make sure the two ends of the U are smooth and flat. You can use this to slip between the commutator and brushes allowing removal of arm (assuming you don't have threaded barrels). Works well.
Ryan


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