Ammeter and 4 Position Switch

[Cub-Bud]

I am no electrician but, in the case of a switch, a FCUB switch to be more specific, you would want the grease to be non-conductive or unable to conduct current. The dielectric grease is an excellent choice for waterproofing, insulating, sealing out moisture and dirt, and preventing corrosion. I think John P. used dielectric grease in Missy's light switch....hey John, can we get a testimony

Here is what Webster Online says:

Main Entry: di·elec·tric
Pronunciation: "dI-&-'lek-trik
Function: noun
Etymology: dia- + electric
: a nonconductor of direct electric current
- dielectric adjective

[SundaySailor]

Dielectic stuff that was used to help keep sparkplug boots from sticking to the sparkplugs. Right now, I'd bet a RC cola and a moon pie that it says it is also for keeping the spark from arcing. Isn't that supposed to mean killing the electrical spark? I'm sure I have one in my little red wagon at home. Just have to remember to get the pack before it gets too dark. Just trying to stir the pot.


Rick

[Donny M]

Cub-Bud,

You are correct. That's exactly the reason not to use dielectric grease. The grease is between the contacts effectively keeping the contacts form perfect contact. Some contact is made due to the friction between the contacts but some contact however small, is lost due to the dielectric grease. Air is a great dielectric but you wouldn't put air between your contacts would you My point is, why put something on a switch that limits current flow when there are plenty of products out there that will provide the same corrosion resistance and not impede the current flow.

SundaySailor,

You are also correct. Ain't it great

[Ron L]

Donny. After sleeping on it, I think I agree with Big Dog and Cub Bub. Think about this. "Put grease that conducts electricity is like dumping water on it". Wouldn't it have a tendency to short out between the contact points?

[Bigdog]

Just type "dielectric grease" in any search engine and check out some of the applications.

[Donny M]

Ron L,

I wouldn't want a dielectric between the contacts. Putting a dielectric between the contact surfaces and the body of the switch to prevent corrosion (or arcing) is good, just not between the contacting surfaces themselves.

[Ron L]

Got it. That's why we have these responses - to learn. I ain't taking my switch apart, though unless it fails

Sure wish an elecronics expert would chime in............

[Cub-Bud]

The last cub switch I took apart had air in it. What other choices do you speak of, Donny

[Ron L]

Do you have pics of the re-assembly?

Rudi. Actually, the last two pictures are of the re-assemblies.

[Donny M]

Got this from one of those searched sites:

In addition to the things Jim listed it is used for a heat conductor when some electronic components are mounted on surfaces to dissipate heat (like the ignition power stage on 700/900 models and 240's 89-93). It is non-conductive, but when you slide the connectors together there is metal-to-metal contact and the grease gets displaced but the area around connector is protected from moisture. If the grease was conductive it would be too easy to get "bleed" from one pin to another in a connector if the grease got hot and liquified and spread.

I'll make one other point and then be quiet. (Not ) If you have ever used a dielectric grease like Dow DC4 then you know it is very hard to get it off your hands. Well that's the same as with switch contacts, they don't wipe clean
Years ago I was involved with the design of a 4 port waveguide switch. This waveguide was 15" x 7.5" and capable of power levels in excess of 300KW. We used a movable vain to switch from port to port. Around this vain were contact fingers, first lubed with DC4 (a dielectric grease). After the first power test at about 25KW it was evident that DC4 was not the way to go (little arc marks under the fingers). AERO lube was used on the contact fingers in place of the DC4 and the switch took ever bit of power we could give it (200KW) with no problems.
I know that comparatively we are talking much lower current levels. But my opinion is not to use it for switch contacts. There are too many other products out there.
Shoot now I'm out of breath Ain't this fun

[Donny M]

CubBud wrote:

The last cub switch I took apart had air in it. What other choices do you speak of, Donny

The switch you took apart did it work If so there was not air between the contacts.

You might as well put teflon between the contacts. Teflon the next best dielectric to air.

[Rudi]

Ron:

Rudi wrote:

Do you have pics of the re-assembly?

Ron replied:

Rudi. Actually, the last two pictures are of the re-assemblies.

Yup, noted. I just did not elucidate enough. Never seen the inside of one of these critters. Was hoping you had a pic of it dis-assembled and being re-assembled showing the innards. If not that is ok. Should be able to figure it out I think.

One other dumb question.

Some of the oil guages had brass bezels - mostly on H's and M's I think. The ammeters seem to have steel bezels. Which is more common - brass or steel and which is more accurate? ie - were the steel replacements or the real deal?

Guess it doesn't matter much if they get painted red, but I like the look of my brass bezel plate and was hoping I could find an IH ammeter with the brass bezel to match it.

[Donny M]

Rudi,

Do you mean like this



I found that once you remove the old paint you get brass. I put some clear coat on it so it wouldn't tarnish so fast

[Ron L]

Rudi. Mine seems older looking than Donny's. Guess you can check by the P/N's. It is steel, not as pretty as the brass. I would guess the steel was the original. Then maybe replaced by the brass. I believe mine is original with the tractor (1948). I would also guess that Donny's is more accurate with more nos. and lines

My 1st pic is the ammeter disassembled. 2nd is the 4-position switch re-assembled. 3rd is the ammeter re-assembled (front view). The only other one I have is a side view of the re-assembled ammeter (below). I didn't think of taking pics untill I re-assembled the switch (1st project).

Hope this helps............



Let me know if you want anything else.................

[Rudi]

Donny:

Yup, that's what I mean. Durn nice meter you got yourself there. Must work on mine.

Ron:

Mine is the same as yours with the steel bezel.

Must try to find a brass one to match the oil guage.

Ron, you did a great job on this little article. This also goes to what I have been saying for a long time. The simple stuff that guys do and think nothing of, can sometimes be challenges for those of us not quite so handy. Being able to document these LITTLE projects can help make the difference between some of us actually restoring our projects or totally destroying them.

Nothing is too simple or too easy, especially ifn you never done it before.

Now guys, I hear you can dissassemble the oil guage to spruce it up. Is that correct?

Ifn you do, please take pics all the way through the project.

Guys, have a good day. I am off to have some more cardiac tests done --- whooppeeee just what I wanted to spend my day doing. Wish me luck.....