25 replies to this topic

[philk]

Going through a box of stuff and have an old .470" dia. Camen set-up with an arm engraved 4/3. Is this 24 turns of 23 wire?

[MSwiss]

More likely 14 turns of 23.

I doubt you could ever fit 24 turns of wire that big on an armature.

You can post a pic if you want.

[philk]

Also has metal capped comm.

 

[MSwiss]

14 turn.

It would either be a drag motor, or a low power or qualifying motor.

[philk]

Thanks, Mike, was going to put this together for a buddy years ago but never did. Don't know why he picked that particular arm.

[zipper]

For qualifying, I used to burn a couple of 53's 10 years ago - they rarely could do more than one lap. Even capped comms didn't stand up.

 

Nowadays 74,5 or even 84,5 with high timing are used.

[havlicek]

More likely 14 turns of 23.

I doubt you could ever fit 24 turns of wire that big on an armature.

  Definitely!  (Although someone, somewhere, armed with a popsicle stick and bad intentions might have figured out a way.)

[philk]

Thanks for the info, don't know a whole lot about open winds or how to select them.

 

I take it then this is a pretty hot wind then. What would be a suitable air gap for it? Have not yet checked the set-up as it came.

[MSwiss]

Real hot wind.

You want a .480-.482" air gap.

IMO it's only usable for drag racing, or knocking down the bank for one or two laps before you get your controller too hot from not being able to drive it hard.

[Slot-Racer]

So can a drag motor be used in a wing car like a Beuf Light Express, etc.?

[havlicek]

So can a drag motor be used in a wing car like a Beuf Light Express, etc.?

 

 

Sure it can...why not?  If it would be allowed by an local rules would be an arbitrary kind of thing.  If the rules call for and define a particular kind of car ("rail", stock car body etc.) that would matter more than anything else.

[Ramcatlarry]

Many 'heads up' classes were based on specific motor as well as body style.  Most current racing is bracket where the ET time you can drive is more important.

[Slot-Racer]

Sure it can...why not?  If it would be allowed by an local rules would be an arbitrary kind of thing.  If the rules call for and define a particular kind of car ("rail", stock car body etc.) that would matter more than anything else.

Ok. I ask as I'm told they (drag motors) are not for wing cars which are long races and only for short bursts of racing? Guess that is not true?

[havlicek]

Ok. I ask as I'm told they (drag motors) are not for wing cars which are long races and only for short bursts of racing? Guess that is not true?

 

Well, a drag motor in it's most basic form (*aside from class limits on type, wind "watevah") only needs to go as fast as possible for a very short single burst.  Just like in 1:1 drags, the slot car version also needs to be able to "hook up" and put it's power to the track efficiently.  If you have a drag car with a really REALLY fast motor that just spins the tires or wheelies uncontrollably, the ET isn't going to be as quick as another that might be less powerful, but stays planted.  Now "wing car" (*and that's a really vague kind of type...since any car with "wings" could be called a wing car) motors can be really fast too...AND they could hopefully last longer and under more mechanical stress than a typical drag motor.  ***Then again, think about how fast a wing car could be off the line and how that motor could make for a good drag car.  Another way of putting it is, you could put a 19/24 armature in a strap motor or (on a longer stack probably) in a C can motor.  The smaller strap motor might not be the best choice for a drag car, and the larger C can motor not the best choice for an open wing car, but both could work well...although not necessarily be very competitive. 

***I don't think that modern open motors are used in drags (?), but that doesn't mean one couldn't be, and make for a fast dragster in the right chassis.

[Robert BG]

That motor is a little too hot to put a bunch of laps on.Chances are it'll go up in smoke after a few min.It's from a time when guys would qualify and run a single heat on one motor and then change it.I really didnt run opens back then but like Mike said its pretty much a qualifying wind that youu'd run a 2-4 hot laps with and that's it.Hence why they were recommending drag use for it,since it'd be a rocket and you'd get some time out of it vs tossing it in a wing car and baking it in 2 min.

    If you're looking to have fun with a wing car try and find a 9-5  arm for it and she'll go a good bit as long as the timing isnt too high.

[zipper]

84.5 is almost de facto standard on Gr 7 - 95 is too mild on fast tracks.

[Robert BG]

84.5 is almost de facto standard on Gr 7 - 95 is too mild on fast tracks.

 

I know a 9-5 is mild and I agree but this isnt a modern 12-24 mag motor either. I'm sure you're aware the newer multi mags tend to run a bit cooler than the older stuff.Plus  I doubt it'd be competitive too,so that is why I recommended a mild wind like a 9-5.With things like the older weaker mags and the smaller diameter arm that tend to create and retain heat I couldn't see recommending a hotter arm for a motor thats destined to be a play car.A milder wind will last a bit longer and give more enjoyment imho. 9-5 makes a great open/toy,car to get back up to speed with,or it can double as a really hot euro motor if the OP wants.

 

I personally have a few older opens with mostly 9-5's and a few 8-5's that I use as test mule motors.I'll put them in a 27 light chassis,choke them down and try different body and tire combinations etc.Or I'll take the choke off and use them as play motors in a open chassis for practice..Either way I race so little these days its great to have a few fast motors to practice with and get back up to speed instead of running the heck out of my 27's.

[Phil Smith]

What the timing range for open motors?

[MSwiss]

15-18 degrees.

 

Back in the 80's guys ordered special time arms, up to about 23-25 degrees.

 

That slowed down in the early 90's, when I came up with an easy way to make to high and low time endbells, using the stock, EDM cut, Koford factory endbell fixture.

 

Craig Landry set his World Record at the 93 Nat's, with a 16T24, 459 motor, I suggest he rotate the endbell on.

 

Unlike where I rotated the hoods on the faceplate of the endbell, since it was a non-race motor, he just rotated the whole endbell, and trimmed the bottom, for clearance.

 

IIRC, it was only held on with 2 screws, and crazy glue.

[Foamy]

Drag motors in AA/FC are usually 54's as 43's scorch the comms and melt the braid too easily.

Big pinions, small diameter stacks, lotsa timing. . .

Over 150 MPH these dayz!

[zipper]

 84.5 wind upto 24 degrees race, 28 degrees qualifying - plus 10 degrees on the endbell for qualifying; that's the latest high on fast tracks I've seen. Crazy!

[Phil Smith]

15-18 degrees.

 

Back in the 80's guys ordered special time arms, up to about 23-25 degrees.

 

Thanks Mike. I didn't know the timing of open arms, but I got the impression that the hotter the wind, the less timing am arm will have.  Comparing your numbers to the X12 arms I use to buy, that appears to be the case.

 

What's the physics/science (or whatever it would be) behind that?

[MSwiss]

Will bore you later with more detail, but an 84.5 has about 8 times less resistance than an X12, so it needs less timing to provide the more torque needed, for adequate cool running.

[zipper]

Koford default opens are 490 dia 84 23 degr and 94.5 18 degr. I think we are switching to 500 dia again - and we were running 459s 20 - 25 years ago...

[Slot-Racer]

Ok I did more research and thank you all for your input; Havlicek has it right. The type of wing car I was referring to are the ones that are Koford, light frame and used in the fastest classes, G7, G27, G12, C-12 etc. What I found is that they are not ideal for racing as they are more torque and not high RPM due to the short distance they are use for don't need high RPM. So not ideal for racing on a King or similar. Burning it up sounds right Robert BG and I agree. I checked with Slick-7 and they said the same. Even their website states the following; "Dragster Motors:

Just as Eurosports are the finesse motor in slot cars, Drag motors are the brutes on the sport. The drag motor requires a strong, but not overpowering bottom end torque, but a HUGE! Mid-range, the Dragster motor is operating most of the time within the middle RPM range of the motor and does not need to have the high top end RPM performance of a Wing Car Motor. This is because the dragster is at top end for a very short time, and spends most of the time getting off the line and up to 60ft speeds. The objective in drag racing is Low end and Mid range power, the motor is operating at top end for so short a time, top end seems to not matter as much.

The Key here is a small diameter arm for low inertia, and milder bottom end, then boost the bottom end with magnet and can."

Thanks all.