alexandervdr

I did rebuild them according to the ncrs instruction written by Alann Boatright . Always surprising how much more comfortable one feels going into a task when assisted by an excellent write-up, tnx Alann

Now, the instructions specify the order of the two washers inside. One of my 2 motors had it the other way around. i assume Alann is correct? (the red arrow picture)

Next question: the set screw on the gearbox determines the backlash for the motor anchor (it wants to push and pull in and out depending on the turning direction ). Any suggestion how much is needed?

It's highly recommended to consider this simple rebuild. I was close to ordering new ones (at 360$ each, that is 500$ once they get through european customs....). But a couple of hours was all it took. Turning speed doubled while amps (unloaded) went from 9.5A down to 6.5A

alexandervdr

following up on my own thread
I noticed during the rebuild that the top pot metal casing really needs to be tightened down with the 4 screws as if a spring was holding it from doing so. That appears to be the big conical washer over the metal gear. I reduced the coning (with careful hammering) so as to reduce the pressure and friction it causes on the gear. Now I have no clearance and no friction. Amps went further down to around 5.7A.
I painted the motors with POR15 cause they were slightly corroded and could use some fresh-up.

Frankie the Fink

I actually have my original '63 motors out as I write and want to touch up the paint....is that gloss black correct or just something you decided to spray on there ??

I thought the motor housings were more of a silver color ...

alexandervdr

The black is personal fantasy cause that is the paint I had at hand, and por 15 is not a bad choice anyway when it comes down to surface protection. The motors are very well hidden in the body , hopefully I'll never see them again, nor the wrong paint color

Frankie the Fink

OK. Understand.

Vet65te

On that set screw for the armature lash, I believe the idea is to run it in until it makes light contact and then back it off around 1/8 to 1/4 'turn'. Just enough to have no binding in the mechanism but enough to prevent too much play.
Mike T - Prescott AZ

Frankie the Fink

I don't know about the 1/8-1/4 turn spec. I was taught to run the motor forward and reverse and find the 'sweet spot' between the two where the pre-load just lets the motors run at top speed in both directions with no 'drag' then lock the adjustment down.

I actually try to fine tune it a little further to see if I can get both motors speed synched up closely using the pre-load.

alexandervdr

I set the screw totally loose (say enough to have 1/8" backlash on the motor shaft). I then connect the motors to a regulated power supply with Amps read out. I turn the screw in till I have the slightest increase in amps. This goes very fast, only a little too much is needed to have to amps jump from 5.7 to 7 and more. When checking backlash again when done, it's very very little, less than 1/64".
I couldn't get it right till I flattened out the conical washer a bit. I guess it's conical to absorb (like a spring) the clearance caused by the not so precise pot housing castings. Mass production would not allow for individual checks. But we can solve that, it made all the difference in my case

Frankie the Fink

Interesting - I am prepping my '63 for possible judging and have tweaked my motors and found the correct "095" NOS headlight switch.

Before anybody asks I will be keeping my early Detroit Speed conversion (the good one with the clutch)!

1snake

1/8 -1/4 turn translates to .005 - .010 which is fine. DO NOT use the screw to adjust the speed of the motor. That's NOT what it's for. Assembled correctly and having the bucket pivots and wiring in good repair, the headlights will open and close within a fraction of a second of each other.

dplotkin

The idea of adding friction to synchronize motors is counter-intuitive to me as well...in the electrical world we don't impede mechanically to govern. I'd rather tell the folks who want to take points away to find something else.


Dan

alexandervdr

The amps method has the benefit of showing clearly how much effort it takes the motor to get the gearbox moving and how much it loads the electric system. I skimmed 8 amps down on both motors combined during restoration. I've redone the wiper motor too and that gave me a 4 amp win. 12 amps is not a rounding error in the total load on the electrical system.

Frankie the Fink

I reattached a power source after marking the current pre-load adjustment setting and re-adjusted for a bit back from the 'drag' position and the adjustment is so close to identical I can't tell a difference. Both motors are real close to 6 amps draw but I wouldn't bet the farm on my power supply regulation...

I'll install the motors tomorrow.....

1snake

This is common sense. I rebuilt the headlight motors in my first Corvette back in 1973 and have done dozens of them over the years. Unfortunately, Bubba is alive and well.

ChattanoogaJSB

I took the conical washers out when I rebuilt mine. The motors work quickly, exhibit no shaft play, and are always solidly "open" or closed. After cleaning my motors, contacts, gear lube, new pot metal gears, this seemed to improve performance best. (Just stating my results)

Frankie the Fink

I think people read a lot more into my simple description than what really transpired....lets just leave it at that....

I adjusted the preload off the drag point until the motor was free-spinning - did the same with the other motor; compared the two and they were running at unequal speeds by my observation so I readjusted the passenger side preload as I still found slight drag in the reverse direction..

ChattanoogaJSB

Yes Frankie I may have a little bubba in me. I like to think of myself the way many of our membership were in the 1970's... Enjoying my car and fixing it sometimes with "restoration" in mind and sometimes with "safe functionality" as the goal. Bubba fixes can be ok, as long as safety isn't compromised. Those are fightin' words to a few perhaps...

dplotkin

Frankie, I believe he was responding to the OP and the idea of inserting drag to sync the motors. Your posts don't say that you did that or thought it was wise. I don't think he lumped you in with Bubba.


On the other hand, and unrelated to anything you have written I take issue with the notion that there is a prescribed sync of the motors in the annals of Corvette assembly and maintenance directives chiseled in a tablet somewhere. If so, John Z can let us know. I understand that NCRS is entitled to say and do what they want in this regard in exchange for the points they issue or take away. If the motors in new C2's were perfectly synced I'd be surprised.


We all know that two identical electric motors, especially non-military or aircraft grade motors, will not draw identical current or produce identical torque or speed. The variables are many and include ambient temperature, winding resistance, resistance through the brushes and commutator, brush composition, wiring length and other immeasurable mechanical dimensions. I can't help but think the original designers would be spitting up their beer in laughter had they known 50+ years later guys like us would agonize over headlamp opening & closing speed.


My point, and the point made by the fellow who agreed with me is that motor speed is not properly controlled by inhibiting free motion with a preload adjustment. Slowing a motor down that way just heats up windings and stresses commutators and brushes. I'm no expert on these headlamps by the way, I'm just an old phone company guy that knows a little about electrical things.

I think what you ended up doing to get results you were happy with is what I myself would have done, or, in my case I live with slightly mistimed headlamps. I'm not after NCRS designations.


Dan

Frankie the Fink

We are in lockstep sir!!
I'm a journeyman avionics technician (after a 4 year apprenticeship)...not that it matters. I haven't burnt up any electric motors in 50 years of dealing with them.

Didn't get to put motors in today; got tapped by the household Christmas committee of one to put up blinking lights all over the house (* SIGH *)...