And another geared twin is born...

cmulder wrote:Is it a standard hex bolt as prop shaft?
It appears could be made just a drill press and then press fit the bearrings (spacer in between?)
What gear ratio does it have and where did you get the gears ?

yes...standard ACE hardware hex 1/4" bolt.
the gears can be anything you want, as long as you clear the Timkins 1/4" bore bearing in the middle!
I'm at work now, but i think the 48P gears are 18T and 35T...(let me write it down to come back and list) but your gears from the R/C car places....commercial gear will be upwards of $ bucks a piece!!!!!!....these gear are steel, cost total of 30 bucks. you will need to drill the main gear to exactly -.005 or so bearing bore size....then i bought a reamer off amazon for 8 bucks....
next one i will use 32P gears...more 'meat', bigger is easier to get the backlash good......
i got enough aluminum to built couple of dozen, i might just but some new blocks, and make a few...sell them cheap enough for you fellows to buy, and get some of my 'tooling' costs back....think anybody would be interested?

This could look and sound greath on a piper cub.
Would you be able to post a video of them running? the sound alone should sell a few
They fire 180 degrees from each other?

Another aplication would be using the new crankcases, killer bee crankshaft/backplate and td top end.
Then you can run them at high rpm and still have a more efficient slower turning big prop.
That should outperform engines like the os .10 la and look a lot better.

i looked: they are...#8258 21T 48P and#PHB48P5MM 35T
they started out opposite...but with those odd teeth, i think they will kinda 'rotate' in firing~next gear set, i'll get even teeth numbers, and 32P!

or:get 2 of these:
https://www.amainhobbies.com/traxxas-32p-heavy-duty-pinion-gear-20t-tra3950x/p717136?v=717136

and one of these:
https://www.amainhobbies.com/hot-racing-traxxas-unlimited-desert-racer-32p-steel-pinion-gear-w-5mm-bore-34t-hransg3234/p860084?v=827263&gclid=EAIaIQobChMIp-TLu57y_QIVVAatBh3JCwowEAQYDyABEgI0hfD_BwE

send me these gears, with 2 cox motors with this type of front end: Cox .049 / .051 Crankcase - Silver SKU: 4900CCS and for 50 bucks i'll make you a twin like i made James...
i've got the aluminum bar stock and bearings and set screws, the drill bits and reamers is what cost me~!..and i've got time........
marc