3573 replies to this topic

[havlicek]

For sure Don. There seems to be a really healthy appreciation for the old motors over there...if anything, maybe even more than here!? I thought the Russkit was a 32 wind, but when the wire gets that small, I don't have anything to measure it against Anyway, when the old motors burn up it's no big deal because then we get to do what we all did 5 decades ago...we tear 'em apart and rebuild them, making them better than they were before! Now THAT'S what I call "retro"!

-john

[don.siegel]

Here's the two guilty Russkit 23s I was talking about, that both had problems at the vintage race in Belgium last weekend...

The one on the left, with the stripped arm, I lent to a friend after his hot rewind started smoking (not in the good sense) during qualifying. It ran well for three segments and then stopped! I took it apart and one of the wires was off the commutator, broken or burned off, not sure... The one on the right was in my Porsche Carrera Super Spyder, which ran very well most of the race, but started slowing considerably in the last segment and a half; but it still finished 4th and I was lucky to finish! Just took it apart today and don't see anything definitely wrong...

And then I also noticed that they're not quite the same! The one on the left has a commutator with slots, while the one on the right has the commutator with no slots and what seems to be a slightly longer stack, by a lam or two...

I don't necessarily want to wind these to exactly original specs, but kind of wondering what you would do ("you", the rewinder people...)? I have some 31 wire and have already done a couple rewinds with about 70 turns, with good results. I don't have any No 32 wire, which would have been my second choice, and seems 30 might be a little hot for the original magnets. Don't want to do a full hopup, but just get some reliable motors - and these Super Spyder cars are a blast to drive! Anybody know why the arms would be different on these two Russkit 23s? Any idea why the second one would have slowed up like that?

Don





The Super Spyder Porsche Carrera chassis

[havlicek]

Hi Don,

70T/#31 is a good wind and safe too...plus it's a solid step up from the anemic stock wind (#33 wire I think). On the "16" size Mabuchis, I pretty much do 70T/#31, 65T/#30, and 55T/#29...sometimes 50T/#29 if I'm feeling lucky. The 55T/#29 wind is what Tony tells me the Team Russkit guys used and it draws about an amp and can get warm, so it's better with post protectors. I also prefer to remove the blind bearing and install a "through bearing" and use a tail spacer to headspace the arm on the hotter winds. If the endbell has been beefed up a little (Tradeship endbell/post protectors/soldered heatsinks) and you use a better com like a Kirkwood or a Mura, you could do a #31 double wind...or maybe even a #30.

-john

[don.siegel]

Thanks John - I think I'll stick to a mild 31 wind! Have lots of other projects with beefed up endbells, etc. Have you rewound any of these leaf type commutators and do they hold up at all? I'm thinking of just using a Tradeship type arm with better commutator in this motor....

Don

[havlicek]

I used to use those when I was a kid sometimes Don...usually with a slight dewind only. Now I just automatically throw them away (I keep a few around just in case some period-correct fanatic needs things just so).

-john

[havlicek]

I just did several arms wound "hemi" style and (after the initial mind-screw because of doing things backwards) it's a pretty cool way to wind. Sorry no pictures on these as they're super-duper top secret and only on a "need to know" basis for those with level 5 security clearance or higher. When I do some for myself, I'll post pictures, but it's something to look into for those of you who enjoy sitting in front of a winding crank transfixed for hours while keeping an accurate count by completely ignoring people as they talk to you (you know who you are)

-john

[havlicek]

I'm assembling some motors for a Blogger who sent me the parts, and what a beautiful bunch of parts he sent! There are several options for each of the two motors and one of them will be a Champion setup (which is itself a thing of beauty) with a choice of #27 single armatures. I'm in a bit of a sticky wicket (as they say in the land of tea and crumpets) here as choosing between the two armatures is like choosing between two of the rarest fine vintages... of the same wine! Here's what I got:



On the left is a Mura Bob Green "Vulcan" 27S, and on the right is a Mura "Missle" 27S. The Green is self-explanatory, the "Missle" appears to be a Mura packaged for an English distributor (a guess since there's what appears to be an English address on the back of the card). The patterning on both is as good as it gets...near perfect visually, but just enough "off" that you know they're hand wound. Metering both, they are also as good as it gets... within a thousandth or two of an ohm from pole to pole and both done on Mura .007" stacks of course and coming in at a mind-blowing .115 ohms each. As I looked at two examples of armature goodness, it occurred to me that this kind of craftsmanship was very often taken for granted back then, and now here I am all these decades later finally being able to appreciate them first hand and in pristine condition. That these were done in any quantity makes them even more impressive to me! THIS is what the few remaining hand-winders should be shooting for in carrying on what I believe to be a "noble tradition" that is quickly becoming a footnote in history.

-john

[havlicek]

As promised, I did up an example of a "hemi" style wind. I assembled a stack from some lams I got from Bill Bugenis of a length suitable for a vintage Mura and loosely placed a Bugenis com on there so you could all see how these things work out. Note the wire at the com tabs and how that detail ends up as opposed to a normal wind. For the example, I used #27 wire as I had just been looking at some old Mura Bob Green arms in that gauge.



Everything is just on there loosely since I will be taking it all apart and this was just for illustration purposes. Anyway, "everything old is new again" and there are some advantages to winding this way. I don't know that those advantages will translate into better performance, but it's something to look at anyway.

-john

[havlicek]

Back on to this build. I had to wait for some stuff to get here to build these motors for a blogger. Of the two Mura arms, it really was a tossup as both were almost exactly the same pole to pole as far as resistance and each was almost identical pattern wise and resistance wise arm-to-arm. I decided to use the Mura "Missile" (I actually forget why I chose that one as both were drop-dead gorgeous). Anyway, a blind monkey could assemble a beautiful motor with the parts supplied here. It was like trying to choose an entree at a 5-star restaurant, maybe even tougher! The motors are going to be run in a vintage race series (in Europe I believe) and if this is what they're running over there, that must be one heckuva series! Anyway, no credit for me here as I was just an assembler.



I tried to get things right and it took some time and doinking-around to do the build, but the first is completed and it's a pretty frightening motor. My power supply only goes down to 5.5V, so I didn't run the motor no load very long but goodness gracious does this thing howl. Super smooth and with tons of revs even at 5.5V It draws around 3 amps at that voltage, but with the shunts and spring insulation doesn't seem like it will get too warm. For those of you that haven't heard one of these in decades, I wish I could more accurately describe what's going on here. For those of you that remember... it's just as good as you think a top-shelf Mura 27S in a Champion setup should be. Now THAT'S what I call vintage horsepower!

-john

[Jairus]

That is very pretty John! I have quite a few of those motors here that I assembled waiting to be inserted into appropriate conveyances.

[havlicek]

Hi Jairus,

Yep...they are some great freakin' motors alright! This kind of horsepower needs to go into a great chassis too! It's always a surprise when I fire up the old high-end Muras, they just roar to life after having "slept" for so many decades. Vintage Mabuchi rewinds are a pretty mixed and often disappointing bag, but these things are prescription strength.

-john

[Russell Sheldon]

That Champion set-up with the Missile arm is absolutely gorgeous, John! Now that's what I call a 'real' motor!

With kind regards,

Russell

[havlicek]

Hi Russell,

"Missile" indeed! Powering it up, the revs are off the charts even at 5.5V! The combination of the great Mura .007" lam blank and the stunning winds is something I doubt very much anyone could improve on still today. Those fat-web .007" blanks are like hen's teeth (I know Ron has a guarded supply), but the actual craftsmanship on the arms is just unbeatable. I can do a pretty good job winding at this point, but I bow in supplication to the "masters".

-john

[Russell Sheldon]

It's amazing to think that the components are around 45-years old. The craftsmanship is superb.

With kind regards,

Russell

[zipper]

Those Vulcans I have seen were never as neat as the Pooch/Camen arms from the same time.

[havlicek]

It's amazing to think that the components are around 45-years old. The craftsmanship is superb.

Absolutely, Russell! As I had said earlier, it's astonishing to think that such work was done on any kind of "production" level and that these things were simply bought off the shelf. They should be hanging in the Louvre.

Those Vulcans I have seen were never as neat as the Pooch/Camen arms from the same time.

I'm sure the Pooch/Camens were great also, but I have never seen any better craftsmanship than on the Mura arms Russell sent. Even more so than the way they look though is how perfectly they metered, and I can tell you that even on the most perfect-looking modern machine wound arms, that's not necessarily the case.

Speaking of which, the other motor I'm doing for Russell is a Mura Short Magnum. While these weren't the super high-zoot things of beauty that the Green can/Vulcans and the like were, I tested the "not-so-pretty" arm (a Mura original) and it meters pretty close to perfect as well! I'm sure it won't run near as well as the Missile 27S, but it should be a fun motor for sure!

-john

[Jairus]

That's because they were made in AMERICA!

[havlicek]

... I forgot we used to make stuff here, Jairus, and we were pretty good at it, too!

I finished off the Mura Short Magnum motor. Like I said, it doesn't run anywhere near the 27S "Missile", but it's a really nice and smooth motor. Draws around 2 amps or so and gets a little warm, but nothing alarming. I bet it will be tons of fun!



Seeing those beautiful old Mura 27S arms inspired me to wind one up myself. Unfortunately I don't have any Mura .007 blanks, but it should whistle none the less. I added a few turns to try and offset the way-different arm interior dimensions and it's pretty close at 30T/#27, coming in at .122 ohms (exactly!) per pole. I think it will whistle a pretty tune!



-john

[Russell Sheldon]

Oh my... all I can say is WOW... Thank you so much, John.

With kind regards,

Russell

[havlicek]

Thanks Russell...it's really no big thing as you sent some awfully nice parts. Like I said above, a blind monkey could make a fast motor out of the parts you sent!

-john

[havlicek]

I finished off the 27S arm I did trying to match the beautiful Mura 27 arms I got from Russell. This was done on a Bugenis stack and com:


...it really only needed to be balanced which turned out to be easy on this arm. I had a vintage but nice and tight Mura setup all cleaned-up and ready to go with a set of thumping magnets, so I popped it in and added a pair of shunts:



It sounds very close to the Mura and draws a solid 3 amps (no load of course) at 6V...which is to say it screams! The wind apparently is very close to the Mura both on the meter and it sings in about the same register too! NO...I'm NOT saying it's "as good as the Mura", that would be silly and presumptuous. What I am saying is that this wind (30T/#27awg) on this stack makes for a really potent arm that is still "reasonable".

-john

[Jairus]

Jes thought I would post a few of my hottest vintage motors. Hope John don't mind...

The first is my Champion gp20 "Orange Picker" motor that I cleaned, restored and modified with a more modern/updated/improved Champion endbell. Brush tube hardware, arm and magnets are stock, all I replaced was the weak endbell. It is quite smooth and powerful. Very nice and is looking for a nice period correct chassis in which to live out it's days.


The second is one I am still working on. The can is a "Bloom" milled "B" can with an NOS Mura endbell, Mura magnets, cool copper heat sinks and a bubble gum arm.
Not sure of the wind but think it's a #26 single judging from what I can see under the epoxy.
Has a nice thump, thump, thump when spun.


The third is this beautiful Certus, though Certus never made complete motors.
The arm is a Certus #26 CCW.
The can is a Mura derived Certus item.
Brush springs are Certus
Endbell is Mura made for the "A" can but with "B" can brush hardware.
The sound..... PRICELESS!
Very much the screamer at 6v and should be quite powerful on the track.


The last one worries me a lot.
The damn thing is so darned loud that I have to put cotton in my ears just to run it up to 5v.
Weird thing is it stays quite cool at the brush end. Would make a great wing car motor.
But I cannot wait to build a nice killer '69 proxy chassis for this one!

[havlicek]

Hi Jairus,

That's an awfully nice collection of vintage (and not so vintage with that last "B" ) horsepower! Man, you have a LOT of chassis and car building to do!!! In particular, I dig the Certus/Mura wikth the can shim. Why?...I don't know, it just strikes me as super-cool!

-john

[NSwanberg]

[quote name='Jairus' timestamp='1319595891' post='370506']
The second is one I am still working on. The can is a "Bloom" milled "B" can with an NOS Mura endbell, Mura magnets, cool copper heat sinks and a bubble gum arm.
Not sure of the wind but think it's a #26 single judging from what I can see under the epoxy.
Has a nice thump, thump, thump when spun.


Any chance that bubble gum is a 26 double?

[Jairus]

I doubt it. A double would have two wires running to each pole and not one. This arm has just one.... near as I can tell. As for the wire size, that is yet to be determined due to the epoxy.