Optima 'HARDENED' final pinion gear.

[jwscab]

post some pictures of what you are talking about, though maybe through PM or a different thread? I'm not a kyosho guy, so I've only ever held an optima for a brief few seconds, I'm not very familiar with the chassis.

[Mr. ED]

I don't think there's much difference between pargu's gears and the option house upgrade. Both are aluminium with the surface hardened by anodizing. (Pargu offers them in different colours which wouldn't possible without anodizing).

[Coelacanth]

I don't think there's much difference between pargu's gears and the option house upgrade. Both are aluminium with the surface hardened by anodizing. (Pargu offers them in different colours which wouldn't possible without anodizing).

I had a talk with fireboy about pargu's gears, apparently he'd tried getting specific info about what aluminum was used, if they were hard-anodized, etc...and pargu wasn't exactly clear in his answer. His English isn't exactly very good either. At any rate, I have my doubts whether his gears will be as strong as a hardened steel gear. I have one of his gears installed and it has nowhere near the weight of one of the Dirt Burners or Option House gears (I own one of each). And for what he's selling them for...$20 each I think...it's a bit too much to spend for a single gear and not know for sure if it will hold up.

Time will tell with mine but I probably won't buy another.

EDIT: If I'm not mistaken, the actual gear name is "Hard Final Pinion", not "Hardened". The Option House gear seems to me to be hard steel, not hard-anodized aluminum...there's a noticeable weight difference between the stock gear and one of the "Hard" ones (I even weighed them both to confirm this). I don't see how hard-anodizing a part will make it significantly heavier...

[jwscab]

no, it won't make it heavier. It's more likely a hardened steel gear. An anodized aluminum pinion will have a hard surface, but it's only a couple mils(thousandths) thick, unless it's hard anodized, in which case the coating will be slightly thicker, but it won't be dye-able to any colors.

[Coelacanth]

That was my take on it, as well. Just anodizing something doesn't make it much harder, it's mostly just for coloring/esthetics. Hard-anodizing is a different animal.

[Charlie don't surf]

I had to go all the way through here to find out how there are 3 pages about a pinion gear now I realize it's not just a pinion. As far as Hard Anno vs Hardened- can you heat treat aluminum the same as say steel? Heat to cherry red and immerse in ATF fluid, tempering the metal?

[Lowgear]

Put a magnet to them. Then you'll know if ones steel.

[jwscab]

heat treating aluminum isn't like steel at all. the alloy has to be able to be tempered, and the heat profile is pretty complicated. Not easy at all for the layman, unless you have a nice ramp controlled oven that can hit 1000 degrees or so, I think.

[ROH73]

Aluminum can't be case hardened with rapid cooling from a high temperature like steel. It can be tempered with this process, which increases its strength/toughness, but its hardness is not greatly affected. Some surface hardness can be imparted to aluminum through strain/work hardening or aging. Compared to steel, however, the surface isn't very hard. The only effective way to harden aluminum is through hard anodizing.

[madmaxx]

What's up with fireboy??? I have been trying to get in contact with him on eBay but no answer... Need some parts.

[losiXXXman]

I've been wondering about fireboy also. It's like he closed the store or something. No listings, and its been that way for 2-3 weeks.

[RichieRich]

That guy was so overpriced.

[Lowgear]

I've bought a number of items from him in the past and always had a pleasurable experience but I agree with his prices being too high.

Shame if he closed up shop. Where did he get all of that stuff anyway? Buying out old hobby shops maybe?

[Coelacanth]

That guy was so overpriced.

Most of his stuff was, but he was reasonable on some other items that weren't advertised. I got a hard final pinion gear from him, and some other stuff that he hadn't listed that I asked about.

[Mr. ED]

no, it won't make it heavier. It's more likely a hardened steel gear. An anodized aluminum pinion will have a hard surface, but it's only a couple mils(thousandths) thick, unless it's hard anodized, in which case the coating will be slightly thicker, but it won't be dye-able to any colors.

You don't really want anything more than a hard surface. Rotating weight should be kept minimal and once you get beyond the coating your gear is worn anyway. If you keep running it longer you'll wear out the plastic diff gear.

The color in anodizing is not dying: the color is from a chemical which participates in the anodizing: simultaneous. Anodizing is a process where you oxidate the bare aluminium, so no extra layer is added: it's just the outer layer of material that reacts with oxygen. This oxidation stops at a certain depth because the inner material gets isolated from the surrounding air. So even fresh cut alu will get harder on the surface after some time exposed to air. With the help of chemicals the process is speeded up and forced deeper into the material.