[toddshotrods]

Originally Posted by JRP3

...DC controllers tend to fail full on when they fail so killing power quickly is important. Most people also use a physical disconnect in case your contactor gets welded shut.

That has the makings of a good action movie! As the car winds silently down the mountain road, the controller fails full on, and the contactor welds shut! Barreling towards sudden death...

Seriously though, good points. The racer in me gets that loud and clear. I will incorporate a standard race style physical disconnect device. I might need that anyway at drag strips; in the future. I have the theft prevention covered already.

I went and talked to the machinist today. He already has the Chevy engine/trans pattern in CAD, so we just have to get the motor specs digitized. He loaned me some gage pins and a longer caliper, so I can start the process. I need to scrounge up a TH400 yoke and an old clutch disc too, for the coupler.

[JRP3]

Theoretically if the controller goes full on and you hit the brakes the main fuse would blow from the high amp draw.

[toddshotrods]

I'm using Fiero front suspension, that will look nothing like this by the time I am done with it. The first step is taking 17.5" out of the middle to suck the front wheels in. Then, eventually, I'll be doing some boxing and shaping on the crossmember. I haven't decided what the control arms will be yet. As an intermediate step, they might get a little boxing and shaping.


The rack is already narrowed. I just need to make alignment bushings for welding it back together; then turn some oil-imprenated bronze bushings for the ends, to locate the rack shaft in use.

[toddshotrods]

I'm going to pick up my chassis tomorrow, and the actual building begins. Until then, here's a look at what I want the end result to be:

[Dennis]

S and F are interchangeable.

If the letters "F" are used then it is denoted to mean shunt field not series field. Sorry they are NOT interchangeable.


Toddshotrods , seems you have picked a up shunt-wound motor if the field terminals are denoted with F instead of S as that of series-wound motors. You will have to check the windings inside. Are they buss bar shaped or are they small like noodles and have many turns? Please post pictures of the insides if you cannot tell.

[Qer]

Originally Posted by toddshotrods

That has the makings of a good action movie! As the car winds silently down the mountain road, the controller fails full on, and the contactor welds shut! Barreling towards sudden death...

Sorry to rain on your movie plot, but most (all?) DC-controller deaths tends to give uncontrolled power for a brief moment (probably less than a second, maybe even a micro second), then something gives and the controller has turned into a smelly paper weight. In worst case all the heat set something on fire, something that's not entirely uncommon even in an ordinary gasser.

That said, I don't object to a manual breaker. Precaution is always a good thing.

[JRP3]

Originally Posted by Dennis

If the letters "F" are used then it is denoted to mean shunt field not series field. Sorry they are NOT interchangeable.

Are you sure of that? I really thought that was a series motor. If not then the controller he bought will not work.

[JRP3]

Here is a direct quote from Jim Husted about reversing my series wound motor:

To switch the motors direction,
just switch the two A term cables with each other, or
both F cables with each other. Give it a 12 volt test
to determine the needed rotation.

That's where I got the idea that S or F would mean field.

[toddshotrods]

So much for my smile I finally went and picked up my chassis yesterday. It was a long grueling day, but I did get it here. I have been grinning from ear to ear all night, and woke up with a smile today. I was even excited to see that someone had posted in this thread - until I started reading.

I have school work and some stuff to do today before I can even think about messing with the motor. Not even sure I want to know.

[toddshotrods]

I couldn't concentrate, so I went straight to the source (of my future race-build plans), Jim Husted. Here was his reply:

I see both "S" and "F" on motors. Look into the housing and see if you can see the wire connected to them. If it's beefy, then it's a series motor, if it's pencil lead size then it's a sepex.

Here's what I saw. The arrow is pointing to the wire going to the F1 terminal.

Sorry that's a sepex motor 8^(
Jim

My day is completely ruined