Angled or twisted armatures

[crazyjr]

I raced slots in the 90's and spent most of this decade in rc, I am always looking and thinking in terms of better performance. One thing i noticed before the brushless revolution in RC, was a line of motors from astroflite. These motors were standard 540 type (1/10 scale) motors using cobalt magnets and a twisted or angled arm, I believe they also used 6 or 7 pole coms. My question is, Has anyone tryed this style arm in a slot car? I have seen them in drag racers and pullers (RC) and they are strong and capable of great power.

As i said, I'm just curious. I am sorry i couldn't find a pic of what i was describing

[Mike R]

If you are talking about skewed stacks or laminations on the armature, the answer is yes, it's been done, as far back as the early 60's in some of the train motors that were used in slot cars. And I believe I saw a pic on another forum somewhere of a Group 27 arm that had skewed stacks. If it worked that well, it would still be around and everyone would be doing it.

Mike R

[fl_slotter]

Skewed stacks

Segmented stacks

Shimmed magnets

Skewed and Segmented stacks

Just about any combination of the above and lots more.

All things tried many, many years ago.

Each had their characeristics, pros, cons and such.

In my opinion, the best performance advantage you can get today is simply spending more time on the track, controller in hand, becoming the best driver you can be.

Of course, this is simply my opinion and 2¢.

[[email protected].]

Larry,


Yes, skewed stacks have been used before. Actually, they are ubiquitous in high torque applications, where they will run with reduced current draw and therefore less excess heating. In addition to model train motors, they're common in handheld power tools (drills, circular saws, belt sanders). In the case of the Astroflite motors, the purpose was to eliminate the gearbox in large prop powered gliders - but RC drag racers found they were robust enough to handle battery packs with far more than the usual 6 cells, as many as 20! Of course, just as in cobalt motor 1/24 drag cars, they needed comm servicing in just a few passes at such elevated power levels.

There are a few glaring differences in design applications when comparing slot racing to RC which act to reduce the number of good ideas that can extend to both. In RC, especially before lithium cells, the challenge was to go fast WITHOUT KILLING THE PACK during a timed heat. This means a lower current draw was an advantage for a given wind. In a slot car, the challenge is to go fast without burning up. Since the power supply is NOT on board, it is for practical purposes unlimited. If you can make the slot motor draw MORE current, it tends to go faster right up to its failure point. Slot cars also handle better when the motor runs at higher RPM, at least in anglewinder configurations. Therefore, shorter stacks, higher timing and hotter winds are all effective. Slots also place a higher premium on lighter weight so that good startup torque just isn't as helpful as it would be in the RC car. Certain losses are deemed tolerable in an RC car but not in a slotcar, like a friction adjusted differential. Brushless technology doesn't transfer to slots because theres no tolerance in space or weight for the speed control.

[crazyjr]

Thanks guys, I was more curious than anything. I understand the hows and whys, was just curious if it had been tryed, figured it had.

Mike R, skewered was the word i was looking for.