3573 replies to this topic

[havlicek]

Can is cut and after I looked at it for a while, I remembered that you don't even have to measure the cut to do this and it can easily be done with a Dremel and no fancy cutoff machines (although one would be nice anyway). In this case, I used one of the Mura Challenger setups I got from Ernie but I have a set of HEQs that I may substitute after testing the motor. Pictured behind the Walnut is a regular Mura C can so you can see how much shorter these things are. I just have to drill the can for the endbell retaining screws, but the result leaves just enough room for the arm (at .904" overall length) and a thin washer on each end.




Here's a shot of the Mura Walnut and one done from an SCX motor. The SCX one is shorter in all dimensions, but especially the height and the width. That one runs like the dickens too


-john

[Alchemist]

Exceptional John! The guitar string ball you used to replace the OEM com really looks good and also looks to be quite sturdy. Did you polish it? Can you turn it if need be?

Would the walnut work in one of the "over the counter" stamped chassis? I'm presuming that the SCX motor (depending on the wind) can put out a bit of torque also?

Really exciting stuff John! What SIZE can are you gonna call these "gems"?

Thanks for sharing my friend.

Ernie

[Jairus]

Those are pretty little motors!
Magnets will be the determining factor however. I did the same with mid 80's Mura and installed a ProSlot G27 arm. The car ran hot all the time and progressively got slower and slower. A set of good cobalt magnets are what I need, but who can spend that much on a plaything?


(Well, some can, but I cannot.)

[havlicek]

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Would the walnut work in one of the "over the counter" stamped chassis? I'm presuming that the SCX motor (depending on the wind) can put out a bit of torque also?

Hi Ernie,

Sure it would (as long as it was for a modern C can). As for what to call the size...um...I'd just call it "walnut size" Anyway, like I said, these sorts of things have been done many times and this is just my take on the concept. It turns out that the Mura C can happens to be really easy to do this with, there's a LOT more work in the arm than the can

Quote

Those are pretty little motors!
Magnets will be the determining factor however. I did the same with mid 80's Mura and installed a ProSlot G27 arm.

Hi Jairus,

Thanks. I think these newer cans are a much better candidate than the old ones and even a set of Red Dots seems to be a good match for at least a #26 wind from the report I got from Jeff Easterly. On the other hand, I wound this one a little hotter (although still a #26) and that's why I may put in those Pro Slot HEQ magnets. A lot is shade tree mechanic stuff though, without doing the kind of testing of field strength properties I can't be bothered with. The little guys do seem to run like the dickens and not get egg-frying hot. I can't really tell what's what though until I get my power supply problem sorted.

-john

[Robert V.]

Here is my first rebuilt and rewound 36D, this motor is being used as an experiment because i did not use epoxy i used heat resistance engine enamel paint it's a lot cheaper and is good for 500 degrees, i have already tested it on my power supply to 13 volts to see if it would fly apart and it worked great. I rewound the arm using 100 turns of 31 gauge silver wire that accounts for the odd color wire. I also converted the stock brush gear to more modern 16D setup that will make tuning and getting parts much easier and i get a performance gain.

[Champion 507]

Robert - MITEY fine job on the 36D mill! The silver wire really sets that arm off. In the "for what it's worth department", you can go 55 turns of #28 on a 36D and not get into the "red zone". Just a thought for any future 36D's you might try.

There's nothing like a modern set of Parma brush hoods to roll the odometer back on an old Mabuchi endbell and give it new life. I kinda gave 2 right side brush hoods a retro look on an old crusty 26D here a while back: http://slotblog.net/...pic=17068&st=60

Keep up the good work!

[Robert V.]

Thanks Doug, I agree with you on a hotter rewind for the 36D but this was just an experiment to see if the paint would work the next motor with be a step up from this one to better test the adhesive qualities of the paint may be a hot FT 16 D that should be interesting.

[havlicek]

Hey Robert, verty cool job on the 36D and it seems you can definitely go hotter with the motor paint. Lots of arms have been coated with some sort of lacquer/paint coating over the years and have held up fine. The stuff you're using sounds like it should be significantly more durable and heat resistant than whatever that stuff is. As for the actual winds, a lot has to do with the magnets and the 36D only has one choice (at least as far as vintage goes) that I know of for an upgrade and that's the Arcos. There are some much stronger than stock magnets in newer non-slot motors that can be adapted, so when you come across a weirdo motor, hang onto that thing and tear it open. There could be some "buried treasure" in there Again, NICE job!

-john

[Robert V.]

Thanks John, I am pleased with the results so far, i will keep pushing the performance of the the motors to see when this paint lets the motor blow, wright now i just can't afford that expensive epoxy on these early practice and play motors, my guess is it may work on a modern 16D and will not on a modern group 12 that should be an interesting experiment.

[havlicek]

Hi Robert,

Definitely keep pushing the envelope, because failure is really the only way to test the limits of a material or a technique. In other words, you will never know for sure what the limits are until you pass them! I wouldn't rule out the paint for hotter winds. The temperature rating is fine, even if it is a little optimistic, the bonding characteristics of the material will be more important since some of these toy motors spin amazingly fast. The force trying to tear apart an arm at those speeds is not insignificant. So you want a material that will build a film that hardens to hold the coils together, but still penetrates the coils...besides the temp thing. Just because people have used epoxy for this, that doesn't mean that there aren't other suitable alternatives. I like the fact that you've kept an eye out for less expensive alternatives, if I had to reorder the epoxy right now, it would be really tough with the way the economy is!

-john

[Robert V.]

Thanks John, next up a High performance Parma Death star 16D rewind that should really start to test the limits of the paint, stay tuned.

[Krash]

Well here is the arm from last week after its trial run. As you can see the stack didn't hold together.
It was sounding great until it hit 10 volts and then it came apart.
After disassembly, I also noticed that the end bell started to melt at the bushing.

Try, Try, Again…




K

[Robert V.]

That's to bad Kelly that arm really looked good i assume it came apart because the balancing holes were to wide, maybe next time smaller but deeper holes.

[havlicek]

Hi Kelly,

The depth and width of the balancing holes will really depend on the shape of the inside of the arm. Most have a fairly wide inside and the crown area is pretty thick, but you still have to try and "picture" how far and wide you can go when drilling according to what's in there. Starting off with a 1/16th bit, you can define the maximum depth and if you need to take off more than that, go with wider bits, but only really using them to chamfer the original holes so you wind up with a wider/shallower cut. It's still a great looking job you did and will help you figure out the balancing thing. You also know a lot more about the rest of the stuff like tieing the com and how well that seems to have held up, not shorting the arm on the stack, epoxying etc. I'm sure you and Robert will be winding some real missles soon!

-john

[One_Track_Mind]

Hi John,
Look at what I seen in Ohio over the weekend!

[Mr. Frank]

Thanks brian for posting that picture... My so called kid put pictures in the thingie forum but never fixed them.. I guess he's to busy playing veido games [ LoL ] and tells me he's working Mr. Frank

[BoomerDog]

Brian,

How did it run? I'm sure it turned a few heads!

[Prof. Fate]

Hi

Are you saying the 31 got hot enough to melt the 36d endbell? If so, something else is wrong with the set up. In order to test the paint, we need to isolate the variables.

Fate

[havlicek]

Hi Brian...yep, thanks for posting the picture.

Quote

How did it run? I'm sure it turned a few heads!

I was wondering the same thing...so...how did it run Brian???

-john

[One_Track_Mind]

Hi John,
I'm sure Mr.Frank will be by to read this thread,as he can tell you how it runs as I never got to see this one run, just the twin motor Falcon car under this one.

From what Mr.Frank claims it SCREEEEEAAAAMMSSSS!

[Mr. Frank]

'One_Track_Mind', on 01 Mar 2010 - 8:26 PM, said:

Hi John,
I'm sure Mr.Frank will be by to read this thread,as he can tell you how it runs as I never got to see this one run, just the twin motor Falcon car under this one.

From what Mr.Frank claims it SCREEEEEAAAAMMSSSS!

Yea guys, IT SCREAMS, Thanks john for the motor, just want to see how long it lasts now. Had a body from RAY NODA and put a chassis togather in about 3 hours, nothing fancy but something for flat out speeeed. YEA and thats what I got S P E E D. That car is geared 7-27 and it just RIPPS the tires. Runs low 5 on our AMERICAN KING, that is what our flexis GT/1s run with an 8-28 deathstar motor. More is on the way.. Yea it turns some heads, they see that motor and says WHAT THE %#*$!@^ is that..

Mr. Frank

[havlicek]

Hey thanks for the info guys. Frank, you might be able to race Brian soon as he's cooking-up something very similar It's all hush hush...black ops right now, but maybe soon...

-john

[Mr. Frank]

Cool john, can't wait to see it. Brian is one hellof a crafter. Is it gona have one of your motors in it? If so it should SCREAM..


Mr. Frank

[havlicek]

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Brian is one hellof a crafter

He sure is Frank!

Quote

Is it gona have one of your motors in it?

...there's some talk that he does have one to stick in there

-john

[Kim Lander]

John....sounds like Frank had the same type of reactions to his motor as did I, I still get all warm and fuzzy when I put my Hondo Rocket on the track and people just drop their jaws, then ask .."what the heck is that thing". Turns a lot of heads........Kim