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I have a Delta CK790E, basically it's the late 70's/early 80's CK780 pancar converted to E-drive.
I'm missing all kinds of parts for it, mainly original electric components.
I did find a period correct Astro 015 motor. Now I need a suitable pinion for it, the motor has a 4mm output shaft but I don't know where to look because I'm not sure what the pitch of the spurgear is...I do know that the pitch is the same for all Delta and Associated vintage gascars.
Can you help me?

The assembly instructions call for part number GR-11E but that doesn't give us any hint what the pitch is. The early 1/12 scale cars had 32 pitch pinion gear and that part number was GR32-11A so must have been some difference. I know another member here you have dealt with from Germany knows about the 790E and maybe he can help.

Do you have the instruction manual and blueprints for the 790E? If not I can email them to you.

Thanks Al! I sent you a PM.
I have a few original Delta GR-32-11A pinions, and the pitch on those does not match (too fine) the Delta spurgear of my 790E (same as spurgears for all non-diff Delta CK pancars)
I do know that I would need either a 9/10 or 11 tooth pinion....with a 4mm hole...but which pitch size?
Thanks again!

Mick, I sent you a pm.

If you've got a spur handy to measure, you can figure out the pitch, or module, by dividing the outside diameter by the number of teeth plus 2.

Thanks Al! How are you?
Yes, for some reason my PM was not sent....can't find it in my 'sent items' folder either...I clicked on 'post reply', is that correct?
Anyway, thanks for your help. Yes, I did receive the 790E instructions you so kindly sent to me through Aaron, thanks again!
Could it be that these gears have a metric size, where the term 'module' is used to identify pitch etc?
Anyway, I'll also send Gunther a message as you suggested.
Kind regards, Mick

Phin wrote:If you've got a spur handy to measure, you can figure out the pitch, or module, by dividing the outside diameter by the number of teeth plus 2.

Thanks Phin, I'll try that...the module may be metric on these...
Thanks!

The diameter of my Delta GR-A spurgear is about 53mm measured at halfheight of the teeth.
It has 50 teeth, so 53/50=1.06 plus 2 equals 3.06
I am inclined to call this a module 3 gear. That makes sense, the teeth are spaced 3mm apart.
So I guess I need an 11 tooth module3 piniongear...with a 4mm hole for the motorshaft.

Sorry it's od/(number of teeth+2)

And it's the full outside diameter of the gear...from the top of the tooth.

Sounds like your gears are metric Mod1.

Ok, I just ordered a Losi LOSA3571 mod1 11 tooth pinion...I hope it fits!
Thanks for the help and suggestions guys!
Mick

Received the Losi module1 11tooth pinion.
My motor shaft is 4mm, and the hole in the pinion is 5mm so I used my lathe to fabricate a small adapter (more like a bushing) and now it fits!

Nice work there Mick!

aip47-2008 wrote:Nice work there Mick!

Thanks Aaron!!