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intimated by grail kit


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just got one of the lindberg motorized truck kits.   as a nine year old I was unable to get the motor to work on a friends kit and a few years later on my own kit.  now 45 years later I finally found another one-unbuilt and im rtill intimated by the motor which is hilarious as I have 87 hrs toward engineering degree, 9 years as professional metal fabricator/welder. taking a break fron can do kit and this is next...gonna b box stock except for tires. has anyone here built one of these with motor working? any help appreciated.

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I built one of these motors when I was in my teens when Lindberg reissued their 1/48 Stuka in motorized form. The motor did work, but not for long because (1) the hand-wound armature was probably unbalanced and (2) there were no bearings or bushings where the metal shaft went through the plastic housing, so before long the combined effects of heat and a "wobbly shaft" (In voice of Groucho, "And we all know how much trouble that can be!") smoked the little motor. Useful motor life: approximately five minutes (being generous.)

Groucho_Marx.jpg

Edited by John Goschke
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I built one of these motors when I was in my teens when Lindberg reissued their 1/48 Stuka in motorized form. The motor did work, but not for long because (1) the hand-wound armature was probably unbalanced and (2) there were no bearings or bushings where the metal shaft went through the plastic housing, so before long the combined effects of heat and a "wobbly shaft" (In voice of Groucho, "And we all know how much trouble that can be!") smoked the little motor. Useful motor life: approximately five minutes (being generous.)

Groucho_Marx.jpg

do you know which modern hobby motor would work? did the stuka fly or did motor just turn prop?

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I was not able to get my first Lindberg kit motor to work either....

However, I was rewinding slot car motors long before I got my degree in electronics.

That particular motor is a bit simpler than slot car motors in that it has only 2 field core windings (the wire wrapped around metal to create a magnetic field when energized) in this case a stack of "laminations" (term used in the instructions) assembled onto the motor shaft.

Most high performance slot car motors have 3 field core windings, I have seen as high as 5 field core armatures but those seem to be rare or not popular due to bang for the buck.

Wire wrapping armatures is just like winding thread around a spool, the main difference is that you have to solder the ends down once you finish, and that the wire length for each field core needs to be the same... both for balance and electrical reasons.

Make sure the wire has no kinks in it, work slowly, wind tightly, try to align each wind next to the last one (kind of like winding a hose or fishing line onto a reel) as long as you can...this will become impossible toward the last part of the wire but it helps early on.

This motor assembly will require some delicate soldering iron work and you have to remember to scrape off the enamel coating from the wire when you solder the connections to the commutator assembly (only scrape off the enamel where you need to solder, the enamel acts as an insulator so the wire windings don't short to each other).

Try to limit the heat applied to the parts when soldering, if you melt the plastic parts of the motor, you're done. I suggest "tinning" the spots that require solder (the tabs of the commutator where the core field windings get soldered on and the commutator brushes) before assembly, this will make soldering go much faster and keep melting to a minimum.

A little Vaseline or lithium grease applied to the motor shaft will extend the life of your motor but don't put so much that it contaminates the commutator.

This is a lot of info...let me know if you need more.   ;)

 

 

Edited by blunc
typos
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  • 2 weeks later...

I hope you're still working on this, if building the electric motor is hanging you up, just leave it out.

Other than the accomplishment of making the electric motor, there's really no good reason to build the electric motor...since running it after it's built leads to things getting broken.

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I hope you're still working on this, if building the electric motor is hanging you up, just leave it out.

Other than the accomplishment of making the electric motor, there's really no good reason to build the electric motor...since running it after it's built leads to things getting broken.

havent actuallly started yet...finishing up can do wrecker...plan is to mount it above surface so when motor running it will not run into things...lol

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A far more worthwhile use for that fine copper armature winding wire would be as detail material.

Like everybody has said, those little motors are jokes, probably intended to start the whole migration away from skilled work in this country because it's too hard, too frustrating...and so it would be for the vast majority of kids.

I've rarely seen a motorized kit that worked for more than a few minutes anyway. I had one of those "diving" ITC subs. First time out, dive she did, once, to the bottom of the pool...as the shaft seals on the props and dive-planes were nothing more than Vaseline. Probably why they didn't say "diving and surfacing" sub on the box. When I salvaged her and got her dried out, I tried every engineering trick I could think of (as a kid with zero practical experience making things) to get those shafts to seal. She sank and sank and sank...and I finally gave up and let her be a shelf model. She'd spin the props and wave her rudders and dive planes happily, so long as no actual water was involved.

I built a lot of motorized models back then, and MOST of them came with factory-assembled stamped metal things with fiber bearings...bearings which were almost invariably loose and caused the motors to shriek in agony, or allowed the armatures to jam. And if they DID run OK, the tiny brushes would fail in about an hour...which was probably just as well considering the attention span of most kids. 

I'd tend to think the chances of getting your little wind-it-yourself motor to spin are pretty good if, as an adult, you carefully follow the instructions. But I'd think it's also kinda pointless. I mean, they make tiny motors and lightweight batteries these days for things that actually FLY. Swapping in a powerplant from a cheap drone would make more sense...unless it's just the challenge of getting that awful kit motor to work...which I can fully understand.

Good luck.  :D

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