3573 replies to this topic

[havlicek]

that's the spanglish translation Pablo.

-john

[HarV Wallbanger III]

Big Blocks! YA! Go John!

"El Wappo"

[havlicek]

Hey Barney...thanks Yeah this "V-8" oughtta go good in a stocker or a sidewinder thingie or something I wound a better set of springs and have to tear it all apart and do some final clean up and other minor things, but it's a smooth runner for sure and only draws around 1 1/2 amps. There is some arcing at the com though so I also have to figure out what that's all about. All in all, I'm really pleased with the motor and the 3/32 axle for a motor shaft is a relatively easy way to get bearings on a 36D that actually fit. The side benefit being you have a strong/straight shaft. Thanks Barney!

-john

[Bill from NH]

John, I don't have the trademark on the "NH Special Blue," you do! Another fine looking motor John. Guess what what was given me, well it was a swap, last week? It's fat, chrome, & black.

[havlicek]

hmmm...fat chrome & black. A Colt Anaconda?...my fave! Oh wait...is is a slot car motor? Maybe a Cox? Igive, what is it?

-john

[HarV Wallbanger III]

Brushes are like Blueberry muffins John.... I'll tell ya that little story when we talk next.

[havlicek]

I like that Barney So, when I took apart the motor to do the last doo-dads, I noticed brush dust between two of the com segments and not the third (even though I trued the com). I guessed that a bad brush would have left dust betwen all three. Assuming that there must be some tiny burrs or something, I did the old "burnish the com slots with a ball point pen trick"...and et voila, no more arcing! To finish-up, I trimmed the shaft, soldered the brush hoods and wound a nicer set of springs again out of .016" electric guitar string. I call it "done" and into a plastic bag it goes.


-john

[havlicek]

Every once in a while, I get a motor to do that surprises me like this itsy bitsy modern Mabuchi. This is one of a couple of motors I'm doing for a Blogger and truthfully, I really didn't see the point in putting all that affort into a 75 cent motor. Actually, I wasn't at all sure I even could do the motor and if I did...whether or not I could reassemble it without messing things up After saying so, I was given the go-ahead to give it a shot anyway and see what's what. So I dissassembled the thing, cut as large a hole as I could in the can for ventilation, drilled the can for screws, painted it and did a #29 wind. Some epoxy/kevlar and balancing finished things up. The arm was originally wound with what has to be the thinnest magnet wire I've seen and drew around .25 amps from what I remember. After putting it back together, it draws around .7 amps and spins surprisingly well. I have no idea how long it will last, but it is kinda cute and unique

Anyway, it started out looking like this:


...and came out looking like this (shown next to a Champion 16D sized motor for scale):



-john

[don.siegel]

Very interesting John - presto, chango!

What did you do with the brushes, if anything? And do these kinds of motors have real brushes, in fact? The cheapo motors I remember from my childhood just had brass rubbing on the commutator...

Don

[havlicek]

Hi Don,

The brushes were left as is. They're like miniature versions of the Pittman brushes with regular carbon-type brush material at the end of brass arms. They're attached at a clip-on plastic retainer that snaps into the endbell proper and it's a pretty fiddly thing to get the whole thing assembled. It's even more fiddly because the shaft is so heavily splined that you can't get the endbell bushing off the shaft, so removing and replacing the arm means doing it all with the bushing in place. You have to spread the brushes just enough to slip the arm and bushing past them without damaging them and lessening the tension on the brush arms. A real PITA Like I said though, it runs really nicely now...for how long, who knows???

-john

[havlicek]

Another SCX motor, but this time the "Pro Rallye" model. Besides not having the contact arms like the RX42B, and having a double-ended (and very long) shaft, this motor has a much longer stack. I guess they're going for more torque with this thing or something. It also appears that the lams on this arm are much thinner than those on the RX42B...kinda neat. Anyway, I still think that these motors are (for modern motors) the coolest ones out there for rewinding. Very easy to work on, in fact just like an old Mabuchi. The com is sufficient for what you might want to do with the thing and the magnets seem surprisingly strong. As this motor also has a roughly .510" or so diameter arm, the way they get it so skinny is by using really thin magnets...but they work! Anyway, since the motor's going back into a 4WD car I didn't remove any stack lams and wound it as I would if it were a short stack with #29awg wire. It spins really well, runs smooth and only draws about a half an amp. Tolerances are pretty tight with these SCX motors as well and the airgap looks as though you probably couldn't do much if any shimming. Like I said, neat motors!



-john

[Prof. Fate]

Hi

The First motor is a mabuchi code "FC130" Usually listed with letters after the 130 to indicate the wind. The motor Don remembers without the little carbon numbs is coded "FA130". Both start with a wind of 300 turns of 36 wire and various applications get fewer turns. The stock Fly/Scalex etc motor for the 1/32 plastic cars is 160 turns of the same 36 wire!

The SCX motor is a direct decendent of our 60s FT13uo like the Monogram X88. Unlike that original, the endbell takes a lot more heat and is a valid candidate for building a "proper" motor with.

I love them. My usual "plan" is to talk clubs that require a spec motor like the NC1/8 or the FC130 to give/seel me the ir SCX motors. Most of my motor builds are for cars that will never be legal for anything except pick up races with my friends around here.

Fate

[havlicek]

...yep, they're cool little motors and can fit all kinds of cars. Better yet, at $8 a throw, they're a huge bargain.

-john

[HarV Wallbanger III]

Cool little motor John! How thick are the mags?

[MrWeiler]

Verrrrrrrrrrrry Coooooooooool

[havlicek]

Verrrrrrrrrrrry Coooooooooool

...thanks Mike

Cool little motor John! How thick are the mags?

Thanks Barney. The mags are VERY thin...around .111", but surprisingly good and this is another area where these motors don't suffer the way the 13UO Mabuchis did. They also use a good sized motor brush and an enterprising hot-rodder could probably figure out a way to use stouter springs without too much difficulty. The real kick here is that modern C-can endbells can easily be modified to fit the can and that opens up all kinds of other possibilities for commutators, ball bearings etc. Trying a couple out, the ProSlot endbell seemed the best fit of the ones I had. I built one like that and it was a real hoot...Mike Brannian got that one.

Ed Miller is the guy here who first asked me to rewind one for him and I'd never seen one before that. I immediately saw the possibilities in this motor for all kinds of "extra-curricular fun" and did a little web browsing to find out what's what. It seems the first generation RX42 was ragged by a bunch of guys for it's anemic power output...hmmm...that right there was like an invitation to dig deeper. Tearing the motor apart, it's all pretty much familiar territory. .078" shaft, pretty ordinary arm that could have come out of any vintage or modern motor, an endbell that makes disassembly/reassembly a snap and can take some heat and the option to mount them either endbell or can drive with a hole pattern that's very close to FT16D specs to boot! Like I said above, at $8 or so...they'd be a cool motor to build a series around running either stock or open classes or both to keep the racer's costs down. Because of the size, they can easily go inline for those extra skinny bodies, or anglewinder in a nice light chassis.

-john

[Prof. Fate]

Hi

Where are they 8 bucks each? The only ones I have seen are more than twice that. Sigh.

Anyway, the complaints about the RX42s in the early days were two fold. First the wind was very mild. 200t/36! Second, the com was this really awful press fit leaf commutator like on the FA motors that Don mentioned.

The magnets in the FKs and this FT 130 are a better upgrade for vintage 13uos than zapping them. On my meter, the originals never measured over 120 guass and would "zap" irregularly. The more modern ones read about 300 to 350(not counting the neos and cobalts).

Anyway, in the 70s the brits made modern endbells for these motors. Almost impossible to find, but worth looking for. What you want are "p can" endbells from Inphinity and 101. Thinking on it, i should probably look around myself, I have a period survivor with a melted purpole inP on it!

Fate

[Edo]

...Another SCX motor...

Man, oh man, John!

That SCX is certainly not my cup of tea, but what a beauty!

Actually, whichever motor you lay your golden hands on, magically becomes a beauty (yes, even those horrid little modern chinese motors

Ciao John!

E

[HarV Wallbanger III]

Hey John I may have some of my old Front Line R&D mags that are about that thick or a little thicker if you want to hone them. Next care pak will send ya some.

[havlicek]

Where are they 8 bucks each? The only ones I have seen are more than twice that. Sigh.

Pretty easy to get them for that price. Tower Hobbies (where I got them) has them for $8.49. Hobbylinc has them for $7.59. Horizon Hobby has them for $8.49. Of course, you can get them on E Bay and pay a lot more, but that's normal

Anyway, in the 70s the brits made modern endbells for these motors.

Completely unnecessary...as I mentioned above a regular old Pro Slot C can endbell can be fitted with just a touch of trimming (takes less than 5 minutes) and then you have a motor that you can take even further.

Man, oh man, John!

That SCX is certainly not my cup of tea, but what a beauty!

Hey thanks Edo. Tell you what though...a little tweaking and they can be made to look very "vintage". I certainly understand the appeal of the old motors (heck I love them too!), but these things are cheap, easily available and great fun to work on. You never know what projects using these SCX motors in a traditionally vintage application might surface. I think of them as a modern Russkit 23...except skinnier

Hey John I may have some of my old Front Line R&D mags that are about that thick or a little thicker if you want to hone them. Next care pak will send ya some.

Hi Barney. That would be cool! If they can fit (or be made to fit), that would be the next step up for hot-rodding these things. A set of those magnets, a C can endbell, ball bearings on both ends, shunts and a #27 single wind would be a pretty potent little sonofagun. I gotta see about that

Thanks for looking guys...

-john

[havlicek]

I'm going to see about how far I can take one of these SCX motors and have a fairly reliable and strong-running result. I think I'm going to do either a #28 wind...or maybe even a #27 (depending on whether or not I keep the stock magnets). In preparation for the "nuts and bolts" stuff, I did-up the can first. I removed the factory bushing (which BTW is magnetic material of some sort???), and reamed out the can for a 6mm bearing. The stock bushing is 5mm, but I wanted to remove the flange that is formed into the can for a cleaner "vintage" look...and also just because I like the way it looks to have the bearing exposed. I then filled the can seams and the magnet-stop holes with solder...again for a cleaner "vintage" look and removed the can tabs...I'll drill this one for screws. Once done, I sprayed the can yellow first and then gold over that figuring it would help make the gold "pop" more. This is what I got so far, I think it makes an attractive motor. Better yet...it's done with a cheap and available motor...but one that "feels" vintage.



I'm waiting for a ProSlot endbell to get here so I can set the arm length and start winding...but I'll also be replacing the com on this one with either a Tradeship or a Mura. I'm leaning towards the Mura as it wil fit with just opening up the inside of the endbell around the brush holders a little bit AND should be bulletproof.

-john

[Pablo]

Sorry for off topic, but can anybody tell me why I absolutely have to have fiber stacks outboard of the outer most lams ?

I know I need to insulate against shorting if the wire insulation is compromised, but since I'm going to coat the lams with epoxy before winding anyway, why bother?

Why would the upper and lower lams be more prone to shorting than the insides ?

Thanks !!

[havlicek]

Hi Pablo,

The place where the magnet wire is most likely to short against the stacks is at the sharp corners around the top and bottom of the stack...which is where the fiber insulators do a great job. On the sides of the stack, the wire isn't likely to short unless you really manhandle it. Having said that, you don't need the fiber insulators at all if you're careful and I use them only on the older motors because they look cool . I often coat the stack inside with epoxy, slightly scuff it up with a wire wheel on the Dremel after it cures and then add a generous coating of high temperature paint for extra insurance. I do all this after I have already slightly relieved those sharp edges with a very small diamond grinding point in the Dremel. I've come to this method after trial and error as doing less works less reliably.

I know I need to insulate against shorting if the wire insulation is compromised, but since I'm going to coat the lams with epoxy before winding anyway, why bother

Those laminations are obviously punched from steel sheet as you can see that one side is slightly sharper because of the way they're formed. That means one end of the stack is pretty sharp and often just coating the arm with epoxy doesn't work well enough unless you really butter it on there. Doing it heavily enough to really protect those sharp corners (where the epoxy doesn't easily build) can make it hard to do a neat job winding. Give it a try...you might get lucky!

-john

[havlicek]

Hi Again Pablo,

I forgot to mention that the fiber stack insulators are also just wider than the actual stack profile. If you check them out...they sit just proud of the stack which keeps the magnet wire from even touching the metal...much less shorting out against it. However, that also makes winding neatly a little more difficult and also makes it more difficult to use as many turns as you might want on some winds. If I use the stack insulators, I epoxy them to the stack so that they stay centered and then trim them flush with the stack after curing so that they still protect those sharp edges...but don't take up any additional space when winding.

The other thing about these that may or may not be a negative (?) is that they are obviously not magnetic. As each pole of the arm is energized when spinning, it may or may not produce as tight a field with the coils separated from the stack ends by the thickness of the insulators...the physicists with a specialty in magnetic flux theorey can clear that up . Since I don't really know if this is the case, I also run a Dremel sanding disc on the insulators to thin them out to about the thickness of a lam or less as they are relatively thick.

-john

[Prof. Fate]

Hi

It doesn't SEEM that way, but in fact, every time the stack is powered, the wire MOVES. Epoxied, it MOVES. This is why you refurbish serious motors by getting them rematerialized and this is what causes them to die eventually. Epoxy is actually less mallible than the copper wire and coating. And old arms get little micro fractures that cause a leak through the coils to the stack. This "leak" changes with heat as well as everthing else. Thus, a motor that gets slow when hot, but doesn't show a short to the stack is usually subject to this epoxy crack problem.

A long way of explaining WHY the fiber ends and their being slightly proud of the stack itself. Doubles or more the lifespan of a given wind and makes refurbishing work more often.

Your mileage may vary!

Fate