RC10Talk - The Net's Largest Vintage R/C Community

good information to know thanks

Guys the Hardened pinion is NOT a pinion more a reduction gear with a grub screw. Its 3 times bigger than a pinion. It's alloy and soft. Yes it melts very easy.

Nothing to do with a pinion on a motor shaft.. The Ultima has a revised version out of nylon ....

Very hard to find. I have 2 more on the way.

nice info... keep it coming!!!

Why you need hardened pinion gear for a nylon spur gear? If you just want the hardness you can heat it red hot dropped it in some petroleum oil base motor oil for 30 sec remove and reheat slightly. D.I.Y. Hardened steel.
You-tube has video's. Might be good for grub screws from rounding out easily.

The original gear is aluminum. It's bare and pretty soft.

Mad Racer wrote:Guys the Hardened pinion is NOT a pinion more a reduction gear with a grub screw. Its 3 times bigger than a pinion. It's alloy and soft. Yes it melts very easy.

Nothing to do with a pinion on a motor shaft.. The Ultima has a revised version out of nylon ....

Very hard to find. I have 2 more on the way.

This part is inside the tranny, on the top shaft.

i got a "roller" out of ebay and took it completely apart and found that all the gears at the rear gear box are pretty worn out specially the final pinion "aluminum" gear, ordered one from pargu2000 but still looking for the other two...

Thorp and RRP made replacement gears for the outside! This Thorp set would help you a great deal.

http://cgi.ebay.com/VTG-DIRT-BURNERS-THORP-OPTIMA-FINAL-PINION-GEAR-4738-/270777606087?pt=Radio_Control_Parts_Accessories&hash=item3f0b9a5fc7

Aaron

madmaxx wrote:i got a "roller" out of ebay and took it completely apart and found that all the gears at the rear gear box are pretty worn out specially the final pinion "aluminum" gear, ordered one from pargu2000 but still looking for the other two...

I can probably help you out with the glass-filled nylon gears, but not the final pinion. Let me check tonight and put up some pics.

going by the specs of 19tooth, .8module, 5mm bore, robinson makes one.....
http://www.amainhobbies.com/product_info.php/cPath/1_25_1466_663/products_id/115511/n/Robinson-Racing-Extra-Hard-Steel-5mm-Bore-8-Mod-Pinion-Gear-19T

I can't see how the gear won't work, it probably won't mean anything if the gear is a little narrower than the original part, it's much stronger material, and its already used on the motor in this type of application. a couple of shims/tubes to properly space it and you are running down the road....

jwscab wrote:going by the specs of 19tooth, .8module, 5mm bore, robinson makes one.....
http://www.amainhobbies.com/product_info.php/cPath/1_25_1466_663/products_id/115511/n/Robinson-Racing-Extra-Hard-Steel-5mm-Bore-8-Mod-Pinion-Gear-19T

I can't see how the gear won't work, it probably won't mean anything if the gear is a little narrower than the original part, it's much stronger material, and its already used on the motor in this type of application. a couple of shims/tubes to properly space it and you are running down the road....

My concern with a thinner gear is not that it won't mesh, but that it will put extra stress on the plastic gear it mates with due to the smaller surface areas making contact. Like running on snow with runners instead of snow-shoes--you're much more likely to punch through. Especially if you're going to slap a powerful BL system in it. Mind you this is based on logic, I wouldn't know the real-world results of swapping out the original gear for a narrower one.

well, my thought was that in a similar(probably MORE powerful) situation, it meshes with a plastic gear that is the same or close width, ie, spur gears are the same width, and they handle it OK.

I dunno....

if I had my choice between a non-running car and possibly getting it up and running with a cheap and available solution, I think I'd try it....

Well, he did say he already had a pargu aluminum gear, which should be fine for a light, infrequent runner. Heck, I have a handful of those stock aluminum gears now, some in still good condition. But for serious running/racing, I'd want the hard final pinion.

You gotta think Kyosho made the gear to those dimensions for a reason...but chose the wrong material to make it out of.

they probably made them that wide because a narrower gear in aluminum would only last a couple packs

it's like the soft aluminum shock towers....what were they thinking? hahhah.....man they have some cool lexan though....

Actually, another weak point is the metal "chin" skidplate that the gearbox screws onto. I was looking at trying to figure out a way to strengthen this area, something like the nose-tubes used on RC10's, but there's no easy way to do this. Too many other components interact with that area, including the front shock tower, upper camber link mounts, the stock U-shaped front brace, etc...maybe something will come to mind when I'm further along with Project Barney. I don't like the idea of adding the alloy pargu brace, as it screws directly to the gearbox and would just transfer a front-end shock to the gearbox and possibly rip screws out of holes or deform the gearbox halves...