# Modifying Magnets???



## Dslot (Sep 2, 2007)

Reading the *New Life for my AFX* thread made me wonder if a modern magnet (like a JL or Dash) could be modified to fit in a Slimline chassis and give little brother a bit more zip.

Would a stronger magnet by itself actually translate to more power at the rear wheels without endangering the chassis?

Here's an approximate comparison of a standard Tjet and Slimline magnet.
And a possible modification.










The modded standard-size magnet lacks the extra mass at the back in three places. It needs something to anchor it in the chassis. If that were a couple of iron or steel slugs (and the back of the mag was faced off and polished) it might increase the magnetic force a bit, though it's so far from the arm, I'm not sure it makes that much difference. Or would it?

How 'bout it, motor tech wizards? Any chance for improving little brother with kitchen-table technology and skills?

-- D


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## alpink (Aug 22, 2010)

find some poly magnets for an inline and compare the inner circumferences. poly magnets are plastic with cobalt particles suspended in the mix. therefore they can be cut easily with normal tools and not disturb the magnetic field. ceramic magnets do not cut easily and will likely shatter. in the event you were able to cut it to the shape you want, it will have lost most of it's magnetic properties and need to be zapped. gump, Alan Galinkos friend has been using this poly upgrade for slim lines for about ten years.


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## smalltime (Jun 3, 2006)

Dslot said:


> Reading the *New Life for my AFX* thread made me wonder if a modern magnet (like a JL or Dash) could be modified to fit in a Slimline chassis and give little brother a bit more zip.
> 
> Would a stronger magnet by itself actually translate to more power at the rear wheels without endangering the chassis?
> 
> ...


Two big problems with the slimmy besides the crappy magnets:

The armature is actually pretty hot (like 6 ohms)

And the brush springs are WAY too week and are at a bad geometry.

If you run a slimmy in reverse it is ALWAYS faster. The easy fix is to cut the rear gear box and flip the rear crown gear to run on the passenger side. this will load the brush springs so that they work better.

But they still get hot.

I would think that if you used a neo magnet from, say, a set of reed switches. Cut and fit them to suit, and then had them zapped correctly, you would be close to a really good running slimline.


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## alpink (Aug 22, 2010)

I have upgraded brushes to t-jet size in slimlines to get better conductivity. and, as long as one is enlarging the hole for the brush, might as well advance the timing a little. be careful, there is not a lot of room for error.


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## Boosted-Z71 (Nov 26, 2007)

You can also put in brush cups & use magna-traction brush springs, but it's really tight to get it the brushes fully seated on that tiny armature. I have one chassis modified with a set of inline motor poly mags, it runs really well.

Boosted


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## Bill Hall (Jan 6, 2007)

smalltime said:


> snip*.....
> 
> I would think that if you used a neo magnet from, say, a set of reed switches. Cut and fit them to suit, and then had them zapped correctly, you would be close to a really good running slimline.


Yessiree!

In the way back of momu you'll find that trigger magnet modification. It was well worth the minimal effort it took to create the super slimmy. 

I was thinking that a brush cup modification might be cool too; but never pusued it beyond, "uh-oh that looks kinda tight stage" as Al mentioned.


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## Hornet (Dec 1, 2005)

You might also check with these guys for a Neo mag that might be close.
Scroll way down for their small bar mags.

http://www.kjmagnetics.com/products.asp?cat=168

Another Neo mag outfit we've dealt with is these guys.

http://www.indigo.com/magnets/neodymium-block-magnet.html.


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## Boosted-Z71 (Nov 26, 2007)

You guys may find this hard to believe, but I have a slimy that runs pretty strong in terms of T-jet's and its totally stock, and yes I am afraid to tear it apart to see why & how. I know it's the one in a million. It gets treated like a shelf queen.

Boosted


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## plymouth71 (Dec 14, 2009)

Whats a slimie and where can I get some


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## Dslot (Sep 2, 2007)

*Thanks to All*

Whoa!







Such a lesson I got!

Many thanks to everyone. 

I haven't worked with my batch of Slimlines yet, but I like the idea of open-wheelers that don't look like blimps. I figured their lack of oomph was just due to the mini-armature & short magnets - no idea about the springs or heat or brush placement. But I never see the slimzers mentioned and didn't think anybody cared enough to have done much work boosting their performance.






















_*I shoulda known better*_ with a board like this. 

I'll be putting this whole thread (and Bill's *Model Murdering* SuperSlimmy posts) in my Tech Tips folder for when I start working with the little critters.

-- D


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## Dslot (Sep 2, 2007)

plymouth71 said:


> Whats a slimie and where can I get some


Ask these guys ...


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## Bill Hall (Jan 6, 2007)

Scroll a bit here. I'd traded off all my slimline stuff some years back, but wound up with this lone chassis in a later trade. 

http://www.hobbytalk.com/bbs1/showthread.php?t=215904&page=45

It should be noted when I said "relievd it", I mean that the chassis was lapped forward, backward, inside out and upside down ...LOL!

The "cut the rear deck out and flip the gear thing" only applys if you have one that pipes up better in reverse...of which there are plenty. I only note it here to remind us of why we do....so we just dont go do it cuz.

If you listen to the third vid, there's no doubt that she has some serious snarl now, and wakes right up coming out of the turns. As badly as I wanted to run the 3R wires to keep my whole MG project in sprit, concentric rims are a must. No slimmy can afford to scrub ANY speed off. The switch to the AFX mag improved BOTH speed and handling. Tars are PVT front and rear. Very smooth and forgiving.

The shoe swap came after the maiden voyage. The stockers are heavy, clunky, and kinda draggy. Again, a noticeable jump in performance was realized. Again, both speed and handling.

Maybe not everyones cup-o-tea, but it was a fun lil afternoon project.


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## Boosted-Z71 (Nov 26, 2007)

I have about 10, ranging from the indy bodies & pickup trucks, Oddly enough the one that runs good has a wide lexan wedge on it.

From what I have seen it does not take much for them not to run, either well or at all for that fact & the stock slim motor brushes have been hard for me to find as well. There are some listed on E-bay for $10 a pair, too rich for my blood.

Boosted


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