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Land of the lost.

Correct pick up shoe stamping got lost in translation. The leading edge needs to be slightly curved ... The MG+ shoe reflects a slight return to the idea. We want any aberration in rail height to be absorbed along this gentle curve rather than the a 90 degree edge bluntly scraping along.

Hard shoes are supposed to be doing what down the rail? Skiing.

So ask yourself ... do toboggans, skis or sleds have blunt or square leading edges? No they dont.

Just a touch is all it takes. Use an old shoe to practice if your shaky about it.

*

We have two ears. Use them. If a chassis at half speed goes by you and makes a nice swishing sound .... swwwwwhhhhhhhhhhhhhhhhhh ... yer pretty close.

If it goes by and around like a putty knife ... skkkkkkkkkkkkkkkkk ...
yer not close.

Learning to read the "burn" and adjusting it is what it's all about. A t-jet burn will be hour glass shaped. A 440 burn will be more of a the top half of that hour glass. This is due to the location of the guide pin not being centered in the contact patches. How the pin is situated is significant because it controls the pivot point of the available contact patch. The burn character differs from brand to brand unless the pivot relationship is identical.

Imagine just standing there and grinding the shoes onto the rails, as though you were lapping them in. It makes a unique pattern characteristic to the relationship between the guide and the contact patches of the model/brand.
This optimum pattern is the correct burn we're looking for; a lapping pattern developed by running the chassis.

To get the correct burn.

The approach angle, "the hangle", of the contact patch dictates how much of an optimum pattern appears in operation. It can reflect too much toe, to much heel, or the porridge is just right.

Alien? maybe a little. You'll get used to it pretty fast if you stay after it. Listen and watch!




Ya really need to make or buy one of these. Simply an old jewelers driver that had the philllips portion galled off. I split it with the dremel disc.
 

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Addendum to post #2:
In addition to the rest of the adjustments, turn the front of your shoes into skis.

Just did it and the car is (incrementally) quieter and smoother. Used needle nosed pliers and my fingers to get there, but will also be making that tool, which would make the process easier.

Thx, MM
Well, when I delve into the minutia, I always forget important or relevant little tid bits. It should be mentioned that magnet cars make a lot more racket naturally, than a T-jet or a gravity sled. Because of the added racket, ya might have to listen more closely.

In the abstract, I liken it to boating: When you are smooth and fast, you are up on plane, rather than wallowing in yer own wake.

It always bothers me to see cleavered up shoes
 

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The MG+ has copper metallic brushes. Now kinda lost knowledge, in the beginning it was found they can require more time on the break in. This is why listening to a motor break in is more important than assigning a time duration. In the case of your dog, remove the rear axle assem so you can turn the pinion and feel whether its the motor or the mesh. If the motor feels gritchy, it's junked.

The gear mesh should be silky smooth to have them at their best. The mini can isnt overly torquey to start with.

The motor was spec'ed with a 17 ohm wind and mediocre ceramic magnets. A can swap with poly mags was not the easiest task, yielded more heat with and no discernible performance advantage. Like putting polys on a 17 ohm T-jet, it makes a good hand warmer. As a knuckle head, I still have to reprove things that I already know. Their small size, delicate components, and precision soldering puts them well out of the range of the average bear.

Direct replacements are available as are upgraded cans, but someone has to do the soldering. While it is possible to dis-assemble the stock can without de-soldering to change an armature, it takes a brain surgeon's touch so I dont recommend it. The commutator is whimpey compared to other minicans. In the end, it becomes a question of what your time is worth.

As Rich stated above the forward current path has enough potential failure points to dictate a wholesale swap of the motor and pick up hanger module. Due to the precision soldering required, ya just change the whole enchilada.

Wheel and tire replacement involves the whole hog including axles, thanx to crudely knurled axles made of playdoh. (easily bent and ruined by you, but not easily shoved up lil Johnny's nose)

In a nutshell, some shoe voodoo, gear lapping, wheel and tire truing, and adjusting the traction magnet influence is all ya really get. As a hand wringing soccer mom approved can arrangement, they arent particularly hot rodder friendly when compared to other open fame inlines.

All by design of course, the same engineer(s) who ensured that lil Johnny couldnt eat it or it's bits, also prevents the home tuner from doing much. Still a wonderful entry level platform.

It can be both!

Edit: And there in lies the challenge... If you cant tune a piano, you cant tuna fish. When you dont verify your fundamentals, how in the heck do we know there's even a problem?

Throwing hot rod parts at something doesnt always guarantee performance. Changing a crazy donkey into a thoroughbred stocker through the application of fundamentals, is how you learn the craft: and gain what I call acquired intuition.
 

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Brush retraction. Ya might need this down the road. Some mini-cans have it, some dont. The AFX 17 ohm N20 does.


You can see the service channels in the brush plate


I use a paperclip-a-mabob to ease the brushes back.


Then ya dont snag the tail shim and wad the brushes/springs on the way in/out.



A rare 9 ohm N20 on a gravity sled.




An MG+ with a 2 ohm N30 neo magnet shoehorned in. Ballistic.
 

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Rich: "Finally, you could use a proper hardened axle, you might have to use aftermarket wheels as well."

Fiddling with, or using inferior parts is how the manufacturer's got ya here in the first place. This is why H0 and 1/32 have a big aftermarket representation. If and when the bug hits ya, you'll want quality parts.

I'm probably a coupla updates behind, myself. Rich's takes the time to keep his tutorials updated, something that isnt really found anywhere else. Set aside a block of time. Bring pencil and paper, extra food and drink, and maybe your light camping gear.

The underlying message is that indescrimnantly mashing wheels onto inferior axles is bad practice. duh. The factory included.
 
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