M-592

[Martyn]

Monty, have you had a reason or chance to test the new Koford M-592 radial magnets? If so expand please? Also to you answer to the imbalance post, what would you consider and unacceptable miss match?

Thanks

[[email protected].]

Well Marty, you actually got me to look in the Koford catalog.

I've long maintained that a radially oriented magnet, if the mass were similar, should be a better solution than any amount of multi-segmenting. At .165" thick, by the time you finish honing, these magnets should have more complete wrap around geometry even with a small gap as favored by the drag racing community. This is a surmise based on not actually seeing them, I assume the tips are not truncated. Stu is only claiming a 4% better field strength, not an unreasonable claim.

As for your other question, as you know I use a Trik-Trax meter, and on said meter C magnets are usually mid 400 range. I try to keep a match within a single point. I guess that means to within 1 part in 400, or 1/4 of 1%. For any given brand and make of magnet, the total range they are found in is rarely over 30 points, so the single point can be a 3-4% spread of the total population.

I have seen various magnets sold by several entities as "matched" where the spread was 5-10 points. To me, this is little better than random. So, to some purveyors, matched means there is indeed a positive and negative magnet in the bag:D Always satisfy yourself as to the accuracy of a match

[Martyn]

I believe what Stu claims is that the M-592 in the new heat treated M-593 has 4% more gauss thant the Pro Slot Purple Dot Quad in the Pro Slot PS-714-B can. When I posted him on this it was on the like hole size of .520. The PS B can is an 860 ID can so by default the magnet is thicker based on the same hole. A bold claim. He also claimed that they were 11% stronger than the old, but second generation M-533's which were also about .165 thick (first sets were .150 thick) Anyway the second sets, best I ever got was about 385 on the meter.

As you know I also use the Trik-Trax and find most magnets, singles anyway, to measure about 430 ish. I just recieved a set of the M-592's and was stunned with a 540 read and 2 points of difference!! I remeasured some Mura's to make sure my meter wasn't flipping a bit. A good bit more than 11%. Thing is I've never measured a set of the quads. I must say this is unhoned so were looking at .165 versus .150 ish +/- .003 so I did expect some difference but not quite that much.

Oh, no tip truncation. Look like a Mura but a much better finish over all. I think he hit a home run here.

Okay, so now on the other question. Yes, I have bought "matched sets" to find them 8 to 15 points different which prompted the question. Thanks.

This is going to be fun watching tech in single mag classes sort this out, eh?

[team burrito]

Let's just go to cobalt magnets & be done with it. ;)

[[email protected].]

Marty,

I've been saying this for a long time, and I honestly beleive it to be true, that BIGGER IS MORE POWERFUL. Faster also? Maybe... When the design of chassis, body, gears and tires catch up, then yes of course faster also. I'm talking not just drag racing, but roundy-round as well, particularly wing cars. The faster those speedbowl tracks get, the more truth to the hypothesis.

The problem, as I see it, is that RULES everywhere are based on MINIMUMS, because years ago the solution to more speed was to make things smaller. Now we have a can larger than a typical C can, but not illegal to race with C cans 'cuz the rules specify minimum dimensions. We have BIG Neo magnets available and confusion over Topgun class records. The post is here on OWH:
"Team P/S runs .483..."

Hey, 9 years ago, I said it out loud to the late Chris Gallegos at Buena Park Raceway (on the occasion of his putting up a new Ogilvie King track that was, at the time, very fast) "congratulations, you now have a 155 foot circular dragstrip". I'm not sure he ever quite forgave me, and truth to tell, he was just humoring certain speed crazed customers. I've asked Gary Gerding if he intends to ever build a 'drivers' king... he replied that "nobody hires me to build a slower one!" Gr7 motors are adding segments all the time now, and armatures have gone from .480 to .490 with even larger experiments hitting the track from time to time... I had occasion to build a 36D powered 250 gram hardbody car for some BPR racing done on the Gerding when it was new 2 years ago. With ARCO 33 magnets and a hot wind, that brick could spin tires anywhere on the track. Truly spectacular spray of styrene parts when it launched the bank.

Newsflash: Lou Pirro wns ROC VIII 1/24 eurosport race with 10 mag motor fitted with BOW .495" dia. arm. Thats 3 major east coast euro races in as many months for that 'big' arm...

Newsflash: Incoming USRA Div.II tech director Roger Schmitt has requested
I find a way to identify any G12, Contender, or Stinger arm that is LARGER than .540" on sight, so he doesn't have to 'tear them all down'. You see, USRA has a .540" dia. limit in Div.II (.518 for Div.I), but ISRA does not! Both ProSlot and BOW make the .540" arms out of their .560" blanks!

Wake up, rule makers! Drag and roadrace, wing or scale, if you want to stop the escalation of technology and create classes with fairly close competition, the technical specs are going to require limits BOTH MINIMUMS AND MAXIMUMS.

To paraphrase some long dead Greek guy: Give me magnets and armatures big enough, and I can move ... a Prius!! (apologies to Archimedes, a VERY wise man)

Sorry about hijacking your thread with this rant, thought it important.

[Martyn]

Just finished my new 16-C motor with the M-592's and made some dyno pulls. About 12% more torque than the M-533 magnets with but a 1300 rpm loss in no load rpm. Gained over 3% in peak efficiency. 90% of the gains were between stall and 50,000 rpm, quickest spool up of any 16 wind motor I've ever built. Stuart hit a home run here!!

[Phil I.]

MARTYN,

What kind of dyno do you have? I have not seen but heard of one. Did you build it or ??

PHIL I.

[Martyn]

MARTYN,

What kind of dyno do you have? I have not seen but heard of one. Did you build it or ??

PHIL I.

Yes Pro Slot Phil but one could be made. These generate allot of information but a simpler one is possible that gives you point of reference information such as did the change I just made help or hurt with less detail.

http://www.kahale-martinapmachine.net/Technical.html

Basic formulas are in the tech section. Print a copy if you like. It will only be up about another week or so and I don't keep copies myself.

[Martyn]

First passes on new M-592 motor package. This is a S16C arm in a Mura can motor. 15.8 volt battery 1/8 mile track in a 78 gram S/G type car. .5125 at 50.32 mph. Old motor used M-533's, same armature. I that configuration ran
.5511 at 48.39. NO changes to the cars gearing, tires or track prep. Car was 2 grams heavier and a small brace was added in the chassis at the strut. Same arm in a Red Dot set up went .5808 at 45.48 I'd say they pass muster.

[Foamy]

The magnets are ground from blocks. Why would a radial oriented magnet be cast in a block? It is just not done according to the magnet vendors I have spoken to. Radial magnets are always cast in arcs.

The magnets are not as fast as Proslot magnets or the last Viper/RJR magnets in Heads-up Class Drag Racing.