35 replies to this topic

[Bill from NH]

Doug,

 

I was looking at the pictures of your three-motor car again just last night. I won't say I'll ever build one, but I won't say I never will either. A quick look reveals a sports coupe or a NASCAR body might be the easiest to fit on this chassis. I got a hard body Chevelle station wagon that'll fit, too.

[Mark Wampler]

Hey, nice project. 

 

Have a question about wiring. It's more practical to wire it in series to save space and hassle, but performance-wise would parallel be better than series?

[Champion 507]

I'm no electronic genius but logically speaking, it seems to me that parallel is the way to go and the only way I have ever built a multi-motored car. I have never read any info to the contrary.

 

I have a body for the three-motor car but have never painted it. It's a JK repop of an AC Cobra. However, to make the body fit a current chassis, they had to make the mold of such proportion that the body is actually "overscale". If you've ever seen that body, you know what I'm talking about. It fits this chassis perfectly but is so very thin. And with the chassis being heavy, this doesn't make for a good combination when you go to pick it up.

 

After it's painted, I may reinforce it on the inside with a bunch o' tape.

[Mark Wampler]

I'm no electronic genius but logically speaking, it seems to me that parallel is the way to go and the only way I have ever built a multi-motored car. I have never read any info to the contrary.

 
Maybe I'm missing something. Parallel wiring would mean you would have six wires plugged into your guide. Series is what you have.

[James Wendel]

You're missing something.

[Champion 507]

James,

 

You are correct.

 

Mark,

 

I understand what you're thinking, but let me see if I can explain it.

 

The current comes off the track into (let's say for argument) the braid of the guide that's attached to the green wire. The reason I'm choosing the green wire is that we can see all three terminals where the green wires are soldered. Let's just say all 3 of those terminals are the negative pole of each motor. 

 

The green wire feeds all three motors at the same time. Conversely, the blue wire from the guide is connected to the positive pole of every motor.

 

Okay, are you familiar with some old strands of Christmas tree lights from years past? When one light goes out, they all go out. Remember that? Those lights were all in series. The current would go through one light, then on to the next and so on. If ever a light burned out, it would break the current flow and the whole string would go dark. Here is a very crude way to illustrate:

            

______/\____/\____/\____/\____ If any link is broken, all lights go out.

 

Look again at my car. If we left everything soldered but cut one solder tab off the front motor, juice would still get to the back two motors. The front motor would stop but the back two would continue to run. Am I making any sense here? Crudely illustrated parallel wiring:

 

_______________________________________________

____$______$_______$________$________$_________  Pretend the dollar signs (motors) are connected to the top and bottom lines. No matter which dollar sign you cut in half, the other four will continue to work. 

 

 

Hence, my car is wired in parallel, not series. I just made jumpers to like poles of the motors to reduce the number of wires going to the guide.

 

If any others have words of wisdom, please jump in. Thanks.

[Mark Wampler]

The illustration I show is what I was comparing my thinking to. It's not a big deal.

[Mark Wampler]

The illustration below is what I had in mind.

[Mark Wampler]

[Mark Wampler]

I see what you're getting at with how you wired the motors. My point was that instead of a single wire for + and a single wire for - to feed all three motors, I tend to prefer each motor with its own separate wires connected to the guide. 

 

Well, semantics and our viewpoints can be a little confusing. 

 

Peace

[Gator Bob]

 

Left - series the resistance doubles the watts and amps are half, the car would be approximately 1/2 as fast much slower.  

 

I see what you're getting at with how you wired the motors. My point was that instead of a single wire for + and a single wire for - to feed all three motors, I tend to prefer each motor with its own separate wires connected to the guide. 

 

When multiple +'s or -'s are common it is a 'bus'.

 

If a car is wired with a single lead from the 'buswire' to the pick-up brush: 

• Simpler and maybe cleaner to build up.
• Very slight increase in resistance. We all say boo to that but if I paraphrase Mr. Mike Swiss... how come a rental car will run just as fast with lead wire hanging on by only one (1) strand of wire?

If a car is wired with three leads to a solder tab the tab is a 'bus bar'

• Less voltage drop/resistance.
• Harder possibly messy to build up....  but I like wire so if it is neatly done bravo.

 

Great car, 507   and... you had the will power to leave them stock.