27 replies to this topic

[Mark Onofri]

Your chart was very informative. Up until now the only thing I had to go by was an article in an obscure newsletter which stated:

(gauge 1 + gauge 2 )÷ 2=gauge total -3. Here's an example for people who don't like word problems.29+30=59 ,59÷2=29.5 ,29.5-3=26.5awg.

 

When I started doing this you had a choice between white dot, red dot, or ( if you were really good at begging) yellow dot magnets. If I'm not mistaken, which I often am, usually only when I open my mouth, the only difference was the length. With the Advent of ceramics and other materials, is there a ratio between the Gauss of the magnets and the gauge of the wire? Seems simple enough, but then again, so does boundary layer physics until you just jump into it headfirst. Any ideas?

[Bill from NH]

There is no relationship between gage & gauss. In the '70s, I ran everything from Grp. 20 to 24S arms with the same blue dots or white dots. I had a zapper, so I always made sure the magnets were saturated, With that said, you don't need to run your strongest magnets at tracks powered by power supplies. Save your strongest for battery powered tracks.

[Isaac S.]

There is no relationship between gage & gauss. 

 

I don't agree. If you are winding close to the limit, magnets with either help or hurt. With the blue or white dots both a 24S and Grp. 20 would have plenty of gauss to do well. But with lesser magnets there is a clear difference. One example is the Champion 705 and 707, the 705 had stock magnets and a balanced "3V" armature, the 707 had ARCO's and was actually rewound and balanced. Therefore the wind is different based on magnets. You can wind to a much lower ohm with more powerful magnets. With more powerful magnets a motor will draw less amperage, therefore you can wind an arm drawing more amperage, to a point of course. 

[Bill from NH]

Isaac, I didn't get the impression that Mark was asking about 50 year old 36D motors. I know I wasn't. How do you apply your thinking to a modern, still available, 16D, such as the Proslot  SpeedFX? 

[Isaac S.]

Ok, I understand. Modern magnets for a 16D or similar have plenty of power. Until you get to crazy Grp. 7 drag cars modern 16D magnets will probably support most winds. 

[Mark Onofri]

I didn't realize this would be mired in such controversy. To make my statement a little more clear and concise, if I run a pair of ceramics with a 16 d Armature wound with number 30 awg will it make that distinctive, woomp, woomp , sizzle sound that most of my hand wound armatures make. Not that I would wind a 16d with number 30 wire, it's just an example to prove the point.

[Bill from NH]

Mark,  timing, arm dia., can hole size, gearing, & matched magnets are probably more important to building a good motor today than gage & gauss. I was racing slot cars 50 yrs. ago. At that time, shops & individuals had no means to measure gage or gauss, so neither was considered. From 1970 into the 80s, arms were .510 dia., most C-can holes were .530, giving a .010 airgap on each side. There was none of the multi-sizes you see today. If I was running on a short track layout or one relatively flat, such as a AMCR Orange, I ran 26S arms. On longer tracks powered with power supplies, I ran 27/28 double wound arms. They sucked less power. On king tracks & a Sovereign with battery power, I ran 24S arms for qualifying & 25S arms for the actual race. The 24S was faster, but I got more laps with the less brutal 25S, These arms were all interchangeable among  my identical motor setups. I played around building a few special setups, but they never seemed to work any better than my regular ones.

 

Do you run some of the old vintage motors at Syracuse, or was your initial post prompted by contemporary motors?

[Mark Onofri]

Some of the cars that I ran in the mid-80s, I'm trying to restore. Some of the cars I didn't have access to in that time period, I'm trying to recreate. I haven't kept up with all the new advances. The Advent of the strap motor, and a laser cut chassis, put these cars Beyond my driving capability. (Continued)

[Mark Onofri]

There's an example from scale auto racing, volume 23 number 12. 1975,white dot Magnets,19/24.1981,polymer,17/24.1982,17/26-27. 1985,15/24. It was written by John Ford, and the material was furnished by mr. Philippe DeLespinay. So it's got to be true. LOL(continued)

[Mark Onofri]

It seems that, and I do remember this,from my dear departed friend Gordy Root, at the magnets got stronger, the wire got thicker, and the turns got reduced. Some of the pros, were accused of running incredibly thick wire and glossing over it with a thinner size.

[Mark Onofri]

A lot of people fail to realize , that in slot cars and also in life, one size does not fit all. Given that, the usable wire gauge ranges between 23 to 31, 23 for fast clean batteries, 27 and above for lower power. So Bill, we're on the same page. Pointless to spend the money on a quad mag setup for these relics. Do you concur?

[old & gray]

Mark, I can offer some background on “vintage” motors as I raced in the mid 1970’s and late 1990’s.

 

In the seventies amateurs (as in not the pro’s) would have a choice of winds (wire size) the number of turns might be known, you could not expect to have a choice, and the diameter would be .510. The ‘pro’ motor builders were modifying cans (thinning the sides, enlarging holes), magnets were honed and shimmed with a gap of .527 to .532. They would sell to the rest of us but you didn’t specify what they were building. While the magnets got a fresh zap before each race I never heard of gauss readings or magnet matching.

 

In the nineties I was racing Group 12 and building my own motors. Since this was a restricted class the wind was 50 turns of #29 with a diameter of .513 to.518, however the manufacturers experimented with the cross section of the crown and web so there was a variation from arm to arm. The timing could be specified when you ordered as well. The cans were specific to each manufacturer so you could chose somewhat for magnetic field. The magnets were measured, matched and honed. I found (YMMV) the matching was more important than the strength in having a good motor

[Mark Onofri]

OG, now I think we're getting somewhere. The 90s SUCKED so bad in my area, the one track, that had been there forever, closed. At the new track, it was a cubic dollar Fest. People were running an Armature and sending it out after 10 minutes to have it balanced, a dozen at a time. I quit for 10 years. So I have a ten-year Gap that I'm trying to make up for. Sometimes, some years, the focus is on the Armature, while other years, it's on the magnets. Ain't Life Grand?

[Mark Onofri]

Let's try looking at it like this. Is there a point where the magnets will overwhelmed the windings on the Armature?

[LindsayB]

One thing someone said to me years ago when the power was not great and every one moved to thin guage armatures, he did the opposite he said when the power is low you need to suck as many amps as you can which is big guage wire.

[Mark Onofri]

I was gone for a minute. I'm not sure if the term is, I tossed my cookies, or inadvertently blocked my cookies. I don't know who came up with amateur keyboard racer, boy, they hit the nail on the head.

[John Luongo]

One thing someone said to me years ago when the power was not great and every one moved to thin guage armatures, he did the opposite he said when the power is low you need to suck as many amps as you can which is big guage wire.

on some tracks with marginal power, the trick would be to build an amp sucker motor. wouldnt go fast, but neither did anyone else. let off for a turn and everyone else would be flying off the track from the power surge.

[old & gray]

One thing someone said to me years ago when the power was not great and every one moved to thin guage armatures, he did the opposite he said when the power is low you need to suck as many amps as you can which is big guage wire.

 

It was a game on some low power tracks when the 24 wire motors were bogging people would move to 25 & 26 wire motors. If one brave sole when to a 23 wire he looked like a hero. If two people went to 23 wires they looked like fools.

[Mark Onofri]

Very philosophical OG. My concern was (is) , if you have a low gauge wire, and a magnet with the strength to lift a Volkswagen bug,( hypothetically) what would the point be? Inversely, if you have a large gauge wire, and magnets that won't pick up a paperclip what would the point be? I realize you can adjust anything with an air gap I realize you can adjust anything with an air gap I realize

[Mark Onofri]

I think my phone wants to be executed. What I meant to say was, an air Gap can make all the difference in the world. But now that they have cryogenic magnets, Cobalt magnets, nuclear fusion deleted plutonium magnets, LOL, is there a rule of thumb? Or to put it another way, if you're using 30 gauge down to 28 Gage, use this magnet. Excetera excetera

[John Luongo]

very interesting discussion. i think low powered magnets have their place and can be competitive on low powered tracks. but a motor and chassis would need to be built around them. on a track where amps are scarce, building a car/motor combo that wont need many amps to go fast would make sense.  light weight chassis, lite soft or low powered magnets, large diameter arm with medium gauge wire, and appropriate tire size and gearing could be competitive. may not accelerate quickly, but should be able to maintain a good rate of speed. best regards

[Mark Onofri]

I think we're on the right track!

[Mark Onofri]

As a last-ditch effort to try to Breathe new life into this. In the 54 year old ,July 1967 car modeler, page 82 ,column three ,line 9, Ted from Dyna rewind quotes : "an iron to Copper ratio", which is what I was referring to as Gage to goss. Any takers or, has this thred totally flatlined?

[John Luongo]

there used to be a "magnetic field" kit to observe the field pattern and strength of magnets. not sure who made it and i never used one. most of my magnet "testing" was done with an inductive amp meter. relative strength of the magnet was determined by the distance from the magnet that the gauge needle would begin moving. for me, a simple way to match magnets. best regards

[Mark Onofri]

Thanks for the reply John. There was one on eBay a few weeks ago oh, maybe a month. It look like nothing more than iron shavings and a piece of wax paper. I really like that inductive amp meter tip. Enjoy your weekend. Sincerely mark