Diiference between black and white gears

Could white gears be nylon and black ones be plastic?  Both are probably not metal which would be better.

They break or spin much more often than wearing out. I don't think I've ever seen either one wear out - but ask Elliott(BigBoy) about that - he used a lot of plastic geared engines at EnterTrainment.

Nylon is a plastic.

 

Metal is more dependent upon user lubrication, and some metal gears are of poor quality. 

 

The color may be just that; I do not know.

Color?

 

My guess: White - nylon Black - Delrin.

 

Here is a web site on Delrin

Wasn't Delrin a character on Justified?

The MPC motor truck had a alco type motor assembly. But, a plastic insert was used between the 4 pieces of swaged metal. This insert performed the function of the pinion gear studs  The worm gear shaft and the power pickup strip for the rollers on the bottom.

 

I was originally going to replace of the gears with bronze/metal. But, being the pinion gear studs are plastic that is out.So, the worm gear is going brass to replace the plastic one. I was also think if replacing the main drive gear at the end of the worm gear shaft with a metal one. So, looking for suggestions.

 

As far as the black and white gears. I'm trying to ascertain if one is a better choice over the other. Are they different materials,

 

Suggestions?

 

 

My guess is
White: Nylon
Black:acetal

Both are light duty, inexpensive, injection molded plastics.
They do not really require lubrication but everyone I know uses plastic compatible gear lubes that quiet them down for a few minutes till it flings off.

I doubt it is Delrin which is usually a material used for tight tolerance small run gears. Weaver and P&H Hobby used it at one time.  Done call it "aging" but if not annealed properly prior and after ma hinging it can fail due to unreleaved internal stress. It usualy splits. Tough stuff. Far superior to the ones used by Lionel. But of course, more expensive.

I've got both the black & the white plastic gears in locos from the MPC & LTI eras & I'm here to tell you they both fail just the same. Usually they don't strip, it's almost always a crack starting from the center hole going out to the edge or it spins on the metal axle.

Is it the worm gear (which has its own issue) or the main drive gear that cracks.

If it's the metal drive gear.  I could then replace it with a "metal" drive gear. So, much for the cracking.

 

So, the final gear makeup in the drive line would be 1-wheel gear (metal) 2-Pinion (plastic) 3-drive gear (metal) 4-pinion (plastic) wheel gear.

 

How would the plastic pinions survive wedge between all metallic gears?

 

My issues have been with MPC & LTI FM Trainmasters & F3's. They have plastic/nylon/derlin/whatever white or black gears on the outside of the truck gear box frames, directly behind the wheels. They split at the center hub radiating out to the teeth, or the gear will not crack but spin on the splines at the axle.

Nylon can be black or white, or just about any color. Delrin (acetal plastic) is usually black and superior to nylon is just about every way. If you have a black gear and it cracked then its probably nylon.

 

Pete

I wonder why they would use 2 different materials?

 

Well, they wern't mixed on the same loco, the ones I have are either all one or the other, so I'd guess it was based on what cheap vendor gave them the lowest price at the time. These units were all spread out over the timeline 1983 to 2003. Out of one Trainmaster & 4 F3's that Jr & I own, we've had one white center gear spin on it's splined axle while one white & one black gear with the crack I mentioned. Oddly, they all failed within a couple months of each other & I got real discouraged about buying further models with these type of gears because changing them is a little bit of work. 

Just finished my second MPC truck rebuild. Brass worm gear and metal drive gear. Lets see how the plastic pinion gears survive.

hello guys and gals.......

 

My lionel #18117 blue and yellow F-3 ABA set also had black plastic outside gears and white plastic worm gear. I changed to postwar metal side gears and brass worm gear, now they are just as good as the postwar #2383 but with better painted shell or body. It really runs well after 2 hours of breaking in. I guess my hard work really pays off.  I just bought a Williams F-3 ABA set and this engine already has metal gears !!!! so that makes it a better engine than the lionel F-3 is.  The Williams F-3 frame has better casting finishing and thicker.  

 

Tiffany

quote:

I wonder why they would use 2 different materials?

 

 

An engineer may have determined that a different plastic was a better material.

A different material may have been cheaper.

I Think new plastics are still developed from time to time.

 

Maybe PaperTRW has some info.

White vs. black gears...

 

If we can compare this MPC question to the vast, painful experience of another market...axle/drive gears in dozens (hundreds?) of 2-rail mechanisms largely built in Japan for brass models during the 60's thru, say, 80's...there may be a clue.

 

The (typically) white gears that split radially were usually made of nylon.  The black gears that followed in later production...as well as those made by folks like Northwest Shortline to provide corrective rebuild of specific models...were usually of an acetal resin....Delrin, Celcon, et al....stronger, 'slippery', longer wearing,....

 

AND NON-HYGROSCOPIC.  Hygroscopic, the moisture-absorbing characteristic, is often the downfall of nylon parts under stress.  A small gear pressed onto a shaft...often a knurled shaft...is under a fair amount of stress from the press fit.  Here is a couple lines from Wikipedia's discussion re Nylon ...

 

"All nylons are susceptible to hydrolysis, ...   The molecular weight of nylon products so attacked drops fast, and cracks form quickly at the affected zones."

 

Also, Nylon as a thermoplastic, must be dried to a specific moisture level during the molding process...."When being molded, nylon must be dried to prevent hydrolysis in the molding machine barrel since water at high temperatures can also degrade the polymer."(Wikipedia)...a step that is somewhat a nuisance to deal with for small volume parts runs.  Acetal resins...and other thermoplastics...do not require the same precautions during the molding process, a further advantage to the small run manufacturer.

 

So, since there are black-colored nylons, too, it's difficult to say that this is, indeed, the nature of the OP's question/comparison.  However, in this hobby, the nylon-gear-cracking-problem is legion, and seems to resurface every time a new manufacturer comes onto the scene.

 

It's somewhat like the "Zinc Pest" problem.   We learn faster, nowadays, but the mistakes never seem to go away completely, we don't seem to learn from the past (Now THERE's a loaded statement!), and it's often all about the $$$ that get's us into the problems we have.

 

'nuf said.

 

Meanwhile, back at the ranch...

 

KD

 

Out of curiousity, I did a few searches on the Lionel web site:

 

Delrin - three gears - the picture I checked showed a white gear.

Celcon - six gears - the picture I checked showed a black gear

Nylon - three gears - the only one with a picture is black.

 

These searches returned other parts too.
I tried searching for "gear", and got over 500 items. I think the search was too generic to try to evaluate. Most items do not specify the material.

Honestly, sometimes I get the feeling certain manufacturers don't want to learn anything. It almost seems like a 'planned obsolescence' is being built in to further parts, repair, or replacement sales down the line.  

 

I'd be interested to know where to get direct replacement metal gears & what the part #'s are for MPC & LTI F3's & a Trainmaster.

Me thinks this is not a black and white situation!

Yeah, I'd be a lot happier if it was an all metal situation. 

Agree with black being delrin and white most probably being nylon. Specified delrin plate for buffer stem replacement on commuter passenger railcars mechanical  properties & wear properties very good, machining properties(drill through and countersink) mounting holes good. 

A black substance is added to nylon to make more tolerate of Ultra Violet for use outdoors at least thats what tie wrap manufacturers say. It may change the properties in gears too but its still inferior to delrin for all the reasons KD mentions.

 

Pete

quote:

I'd be interested to know where to get direct replacement metal gears & what the part #'s are for MPC & LTI F3's & a Trainmaster.

 

Check with the Train Tender. He has some metal replacement gears.