3573 replies to this topic

[havlicek]

John, that thing is gonna be one bad mother

...maybe Vic...or just "bad" The wind itself is beyond the limits of sanity and the motor certainly won't be for racing. If it works, this thing will be a "hot lap special" or a drag motor. The kind of motor you do just out of the enjoyment of making motors and the curiosity of pushing the limits. I guess that there were probably at least some 23 wind Muras done by similarly-minded maniacs back then, but doubt any were raced successfully. For sure, whoever gets it, will have to do a careful job of setting it up in a car and watching how the motor is performing just as carefully. I've got the endbell mods done and just have to assemble the thing. If it runs smooth enough with just the static balance, I'm good to go...otherwise I'll send it out for dynamic balancing. That's assuming it will even run on my power supply, because it will no doubt draw LOTS of current, dimming the lights in Fresno!

-john

[Victor Poulin]

John,
Your right about the endbells needing some rehashing for shunts. I've got a couple I'm working on right now for a drag racer and they have been a pain in the butt because of the raised brush channels. Asside from that, I really like the Mura endbells. Even though they take a bit to blueprint, once their done the end product is worth the time.

The one your building should make one heck of a drag motor


Vic

[zipper]

Well, I did a 23 about 40 years ago - it has been sitting in a box since then, just tried a little to rev it and then archived. Some 25s of mine were usable however - they were allowed in a standard class in Finnish Championships but just for a single year; too fast and pricey/fragile...

[havlicek]

Well, I did a 23 about 40 years ago - it has been sitting in a box since then, just tried a little to rev it and then archived. Some 25s of mine were usable however - they were allowed in a standard class in Finnish Championships but just for a single year; too fast and pricey/fragile...

...a 23 eh?...I bet that one was a "zipper" 25's should be doable even in old Mura setups for some laps now and then, unless you run them hard and then tear them down. 21 or 22 turns of #25, maybe even 23 turns on a modern thin web arm down to 19 turns should get a car around a track pretty fast!

-john

[boxerdog]

That oughta be fun. We used to buy the Mura and Trinity open arms, 16 or 17t23, 18t24 and 20t25s in particular just to have one car in the box that would make people stop and watch! Of course, they didn't last forever but I was sometimes surprised how durable the 24 and 25 winds could be. With the magnets of today, it should be a real missile.

[Alchemist]

the wind itself is beyond the limits of sanity and the motor certainly won't be for racing.

"Beyond the limits of sanity" Now that's the kind of performance I'm looking for!! The armature looks like it's on steroids - You're not "pushing the envelope" you're "RIPPING the envelope" - awesome John!!!

For my next motor would you consider attempting 2 turns per pole of a wire clothes hanger - LOL!!!

Ernie

[Pablo]

It's THREE turns of coat hanger, isn't it ? Two would be too hot.

[Marty N]

14 turns of 23 is an off the self drag wind for cobalt and Neo motors. I've even seen 13/23 and 10/22's
I'm amazed you got 17 turns on it. Nice job as always John.

[havlicek]

For my next motor would you consider attempting 2 turns per pole of a wire clothes hanger - LOL!!!

I figure to make things simpler Ernie...I may just do one turn of 1/2" copper pipe

14 turns of 23 is an off the self drag wind for cobalt and Neo motors. I've even seen 13/23 and 10/22's
I'm amazed you got 17 turns on it. Nice job as always John.

Hi Marty and thanks for looking in. I based this wind on the fact it's going in a vintage setup (ceramic mags) as well as the fact that the arm blank I used has a rather narrow internal profile. I would have probably done something like 15T/#23 on a vintage Mura blank for the same setup.

-john

[Robert V.]

Hi john

Great work on that arm i will be curious to hear how it runs when it's finished and if it holds together, 23 that's some very big wire should scream.

[Victor Poulin]

I figure to make things simpler Ernie...I may just do one turn of 1/2" copper pipe.

-john

You mean you haven't already done that ??

[Prof. Fate]

Hi

Until recently, REH was still listing old Bubblegum 24s as NOS......endbell drive!

I have a survivor from the day. One of my bad ideas. That is given the car/chassis and motor limits, it was undriveable so, as is so often the case, it survived by not being used.

Fate

[Victor Poulin]

Hi

Until recently, REH was still listing old Bubblegum 24s as NOS......endbell drive!

I have a survivor from the day. One of my bad ideas. That is given the car/chassis and motor limits, it was undriveable so, as is so often the case, it survived by not being used.

Fate

Yeah but look on the bright side Rocky, you dont need to rebuild it

[havlicek]

You mean you haven't already done that ??

Honestly, I use way more #28, #29, #30 and #31 wire than any of the big stuff. It's a treat when I get to do the heavy gauge arms and especially for Bill Bugenis because i get to do a bunch at a time!

-john

[Victor Poulin]

Honestly, I use way more #28, #29, #30 and #31 wire than any of the big stuff. It's a treat when I get to do the heavy gauge arms and especially for Bill Bugenis because i get to do a bunch at a time!

-john

Hey John,

Not to get to far off topic but, Bill and Lou Pirro just announced the full production of the all new Atom arms. You may already know this but for those who dont, these new arms are being sold under the name of Model Electromotive . As of right now, they are offering 560dia 16-Ds, 540dia contenders, and 540dia X-12 arms. These can be ordered through Grand Prix Model Raceway or raceways can order them through GPMR distributing.

I've had the chance to do some testing on the 560 16-D arms, and was happily supprised at the performance. I was hoping these would be as good as some of the Viper arms i've had. I'm happy to report that I think these may be even better !!

The test motor I was using is an FX set up, fully blueprinted with stock magnets, G-D brushes and Champ light springs. I was really supprised at the power and how smooth it ran. I look foward to playing around with this new line , and can't wait to try the X-12s and the contenders on for size lol.

Ok, Now I will return you back to regular programing
I just wanted to put a little plug in for Bill .

Vic

[W. J. Dougherty]

John,

Really admire your craftmanship; the arms are beautiful.

Background: My very first race motor in 1967-68 was a Mura Pink Can Cukras kit (man do I wish I still had that one). The arm was a 28-29 Double. It was a tick slower than the 26s some were running, but ran much better on the American Yellow with power packs that we raced on locally. Many times guys would get mad because their 26s slowed as the packs weakened while my double was less impacted.

My question(s): What would that double be compared with today, any guess on how many turns it may of had and why was it able to not slow as much as power lessened?


Thanks,

[havlicek]

Hey John,

Not to get to far off topic but, Bill and Lou Pirro just announced the full production of the all new Atom arms. You may already know this but for those who dont, these new arms are being sold under the name of Model Electromotive . As of right now, they are offering 560dia 16-Ds, 540dia contenders, and 540dia X-12 arms. These can be ordered through Grand Prix Model Raceway or raceways can order them through GPMR distributing.

I've had the chance to do some testing on the 560 16-D arms, and was happily supprised at the performance. I was hoping these would be as good as some of the Viper arms i've had. I'm happy to report that I think these may be even better !!

The test motor I was using is an FX set up, fully blueprinted with stock magnets, G-D brushes and Champ light springs. I was really supprised at the power and how smooth it ran. I look foward to playing around with this new line , and can't wait to try the X-12s and the contenders on for size lol.

Ok, Now I will return you back to regular programing
I just wanted to put a little plug in for Bill .

Vic

Hi Vic,

Bill and Lou have been working on this for quite a while and it's no surprise the arms are working great. Speaking with Bill, he makes it clear that he's set out to look at every detail...every factor that can impact performance and try to take them all into consideration. When you get into this stuff the way Bill and Lou have...that's a LOT of factors I'm sure they'll appreciate your thoughts on this Vic!

-john

[havlicek]

John,

Really admire your craftmanship; the arms are beautiful.

Background: My very first race motor in 1967-68 was a Mura Pink Can Cukras kit (man do I wish I still had that one). The arm was a 28-29 Double. It was a tick slower than the 26s some were running, but ran much better on the American Yellow with power packs that we raced on locally. Many times guys would get mad because their 26s slowed as the packs weakened while my double was less impacted.

My question(s): What would that double be compared with today, any guess on how many turns it may of had and why was it able to not slow as much as power lessened?


Thanks,

Thank you very much! It seems to me as though double winds are more efficient with less power, but there's no "free lunch" in physics and there may be some loss in braking power over an "equivalent" single wind. Double winds seem to produce good RPMs and less heat...but I don't have the ability to do a real scientific study to prove that. Double winds also seem to produce a little softer torque curve than the big wire arms...but they still can spin the tires down the straight. The plus there might be a little better "driveability", so a person might produce better lap times with a double than the equivalent single even though the single might have more torque...maybe. The racers back in the day, had this stuff pretty well figured out and, from what he has said about this, Tony P seems to say pretty much the same thing. Mixed doubles like the 28/29 also made it possible to do a wind equivalent to a half gauge as well, so that was another reason to use them apparently, but it's easy to buy wire in half gauge sizes today. As for what would be an equivalent wind today, I would have to screw around with the arm blank and meter a single pole with different winds. I don't have any .007" lam Mura arm blanks to mess with right now, only loose lams...but I could probably come fairly close using the arms I do have. Thanks again!

-john

[Marty N]

I figure to make things simpler Ernie...I may just do one turn of 1/2" copper pipe



Hi Marty and thanks for looking in. I based this wind on the fact it's going in a vintage setup (ceramic mags) as well as the fact that the arm blank I used has a rather narrow internal profile. I would have probably done something like 15T/#23 on a vintage Mura blank for the same setup.

-john

That wind should knock those ceramics in the dirt in about one pull of the trigger.

[Alchemist]

I figure to make things simpler Ernie...I may just do one turn of 1/2" copper pipe

Pardon me John but I'm trying to figure out the logic in your using the 1/2" copper pipe. Would that be to save weight because 1/2" copper rod is a little heavy? LOL!!! Wouldn't 1/4" copper rod be easier to wrap around the arm?!

My plan is to put this motor in a "toothpick" chassis to save weight! Hey, they made a chassis out of popsicle sticks! LOL!!

Ernie

[Prof. Fate]

Hi

Nope, see, the electrons flow on the surface of the wire, not in the wire, thus "hollow" is better.

The problem is with the insulation.

What we need is someone to carefully drill out some coat hanger wire for the weight for us. Need a GOOD lathe!

Fate

[gascarnut]

Hi

Nope, see, the electrons flow on the surface of the wire, not in the wire, thus "hollow" is better.

The problem is with the insulation.

What we need is someone to carefully drill out some coat hanger wire for the weight for us. Need a GOOD lathe!

Fate

I think you will find that DC currents flow through the entire cross section of the wire. It's AC that tends to flow on the outer surface, with the frequency of the AC determining how deep the skin effect is, the higher the frequency, the shallower the "skin".

[havlicek]

Dennis is correct as far as I know. So called "skin effect" is a property of alternating current and as the frequency approaches zero (DC) the skin effect decreases as well!

-john

[Marty N]

Ah but an armature is an AC circuit....commutation.

[havlicek]

That may play "some small part" Marty, but an arm is really three separate DC devices being fed DC. If you google around looking at skin effect and DC motors, you'll find some interesting and sometimes confusing information about all this. Not really having a handle on the pretty complex physics involved, I just take it that even for a DC motor, skin effect doesn't play any significant role.

-john