ohm armatures

[Austin]

What do the ohms mean ? less is better ?
I see 19 ohm armature down to some one saying they have 5 ohm armature

Dash 2 lamination 16 ohm armature

Dash 3 lamination

I am new at HO scale and just ordered 5 Dash T-Jet chassis setups and silicone rear tires

How do you test the ohms

I know I am diving right in over my head, but I am a fast learner.

All ready have over 125 pancake type cars, I drive them all, I must be going nuts

[dr fabio]

Ohms is the unit for electrical resistance (after the German physicist Georg Ohm who discovered the relationship linear relationship between voltage and current.) Generally speaking the lower the resistance the faster/more torque the motor will produce as more current will flow through the windings. Its a little bit more complicated than that as you need to take into account the number of turns as well, but its a good rule of thumb.

Im not exactly sure what the Dash means but I suspect that it refers to the number of laminations in the armature stack. For a given length stack the more laminations the better as it reduces the eddy currents that flow. Eddy currents oppose the current that flows through the windings (Lenz's Law). That's a bad thing.

To measure the resistance just place a multimeter across the rails of the car and select Ohms. Rotate the wheels to turn the armature and read the values. You should get 3 steady values and as you rotate it the values will go crazy for a little while as you rotate from one pole on the armature to the next and then it will go steady again.

Hope that helps.

[RichD]

You may not get good ohm readings if you take them across the pickup shoes. It is better to take readings directly across the commutator segments. I have included a detailed description of the proper procedure with pictures in my T-Jet tuning article. If you would like a copy of the article PM me with your e-mail address or look in the files section of the HOCOC Yahoo! site. The ohm value of an armature is not always a good indicator of how it will perform on the track. Different combinations of wire gauge and length can get you the same ohm value. Pancake armature seem to be much more problematic than inline armatures. Two armatures that appear to be identical often can have big differences in performance.

[ninjatek]

[BIG E]

I'll leave the explanations and the numbers concerning armature and controller resistance to others posting the forum this time around.
I for one, am very happy that the DASH T-Jet chassis is finally here. It puts everyone on a level playing field when constructing cars for racing series or just for casual racing. I also believe it is the best of the modern interpretations of Aurora's original design. Today's manufacturing techniques give it a distinct advantage in quality, where it's being considered the best of the offerings from Model Motoring, Inc. and Auto World (which were also constructed with these techniques). All three of these manufacturers do the hobby a great service by all the products that have been made available for racing and modifications. For the most part, many of us are now spared the decision of choosing which 40+ year old body or chassis we want to modify (unless that's what's intended, of course) because of the availability of these new products. Please don't misunderstand me, I'm not knocking MMI or AW, and I'm glad they are a big part of our hobby. The sheer volume of products from AW alone has allowed many new and former racers to find an easy way back into the hobby, along with our longtime friends at A/FX, of course. MMI was all that people could talk about when they were presented to us in the 1990's.
All of this also means that the hobby will grow even more, without further depleting the always shrinking supply of
NOS Aurora Thunderjet 500 chassis, which are essential to restorations, collectors and such.
And that's important to a "hardcore" Aurora guy like myself! :>)
I'm wising continued success to all three aftermarket manufacturers supplying our hobby with new ready to run T-Jet cars, and also to all the specialty manufacturers for tires, wheels, electrical parts, ect. "Thank You"! from all of us in the hobby -- Ernie

[Austin]

Thank you just what I was looking for. I am really understanding what is happening now

Thanks Ernie, Dr Fabio, & ninjatek

Rick thanks and I will check out the HOCOC Yahoo site

[Ralphthe3rd]

[BIG E]

[Ralphthe3rd]