TOPIC:

Ok, I've been looking at part numbers, I think this will cover most Tamiya cars ... if someone could sanity check my ?'s that would be helpful

3515001 - 13T 0.8 mod
3515002 - 14T 0.8 mod ? (not sure this exists)
3515003 - 15T 0.8 mod ? (not sure this exists)
3515004 - 16T 0.8 mod
3515005 - 17T 0.8 mod
3515006 - 18T 0.8 mod
3515007 - 19T 0.8 mod

3515009 - 16T 0.6 mod ? (not sure about pitch)
3515010 - 17T 0.6 mod ? (not sure about pitch)
3515011 - 18T 0.6 mod ? (not sure about pitch)
3515012 - 19T 0.6 mod ? (not sure about pitch)
3515013 - 20T 0.6 mod ? (not sure about pitch)

50354 - 16T & 17T AV (0.6mod) two pack
50355 - 18T & 19T AV (0.6mod) two pack
50356 - 20T & 21T AV (0.6mod) two pack
50357 - 22T & 23T AV (0.6mod) two pack

Of the 14 and 15T 0.8 mod I can confirm that they exist at least...

There are also modern parts numbers for some 0.8 mod pinions - used in the DT-02 :

84181 - 17T 0.8 mod
84182 - 19T 0.8 mod

I'll try and keep adding info to this topic.

Seidel in germany has got the Carson steel 3.2mm pinions 0.8mod 10T to 19T but they are pretty heavy

I've just made this topic sticky in order to give you guys all the attention you deserve.
I'll have a look later to see if I can add this to the database.

Lars

58088 Sauber Mercedes C11 - 16T (#3515009) - 0.6 mod
Also confirming the data a few posts earlier :

JR wrote:

3515009 - 16T 0.6 mod ?

58089 Bullhead - 13T (#3515001) - 0.8 mod

58090 Tyrell 019 Ford - 17T (#3515010) - 0.6 mod
Possible range is 13T-20T 0.6 mod / AV. Also discovered some other (out of production) parts numbers here :

53063 12T/13T HP steel pinion gears (0.6 mod)
53064 14T/15T HP steel pinion gears (0.6 mod)

JR wrote:

50354 - 16T & 17T AV (0.6mod) two pack
50355 - 18T & 19T AV (0.6mod) two pack
50356 - 20T & 21T AV (0.6mod) two pack
50357 - 22T & 23T AV (0.6mod) two pack

24T & 25T AV (0.6mod) two pack also exists with "seperated" number 50477.

More to come...

Edou wrote:

...

What can make it a bit more confusing is that some brands seem to use both measurements at the same time...
Even for 48dp and 0.6 module.
In that case it's worth figuring out what it actually is - can't be both simultaneously.

I think I've got to the bottom of this - 0.6 mod metric and 48dp imperial gears seem to mesh together fine ... however, they're not entirely interchangeable - 0.6 mod gears are a larger diameter than their 48dp counterparts... this is fine where the car has slotted motor mounts, but where they are fixed holes (like of most Tamiya cars) the gears won't mesh.

Added 58035 - Wild Willy M38 - 15T 0.6 mod

Also believe all SRBs are 15T or 20T 0.6 mod, haven't added that yet as I need to check all the permutations.

You have to be careful with the DP/MOD calculation with small (Pinion) gears as the outside diameters can vary wildly for a given pitch & tooth number (It's the PCD that's important, but this is nearly impossible to measure accurately). If you can, measure the largest gear with the same pitch that meshes with the pinion (Eg the counter gear) to get a more accurate result from your calc

Tough stuff guys...
But here are the basic parameters :

Metrics in engineering

DP = Diametral Pitch (measured in inches)
MOD = Module (measured in mm - what Tamiya uses)
PCD = Pitch Circle Diameter

I was planning to put some work in this list so I might as well try to give an overview on the engineering...
With the hope to make this more accesible for newbies too.
My brain is cracking at least.

@eddrick : from what size pinion do you reckon are DP pinions safe to use?

Oooo that's a goodun.... I'd say it depends on the relative diameter of the gear - visualising a grasshopper pinion, you should be fairly safe with something that size/pitch. Lunchbox, forget it, find a bigger gear that meshes & measure that instead. F2 pinion, again forget it, & any similar sized/pitch, especially if there's any wear/deformation. Also remember, the smaller the gear, the more accurate your measuring needs to be too. My HPC gear book says
Outside diameter = (Number of teeth + 2) x module.
Re-arrange gives: module = OD/t+2.
HPC also say the formula has to be corrected to: mod = OD/t+3 for 8 to 17 teeth (8t being the smallest you can sensibly make). DP = 25.4/mod if you wanted to check if it's an imperial one