AVX Motor Gear Mods

 Trying my hand at making new gears for the AVX motors. Seems that the pinion gear has the biggest error, so I'm going to look at making a replacement that is better. 

I'm following this thread for dimensions: https://stargazerslounge.com/topic/307873-avx-motor-disassembly/, but I expect that I'll have to do these myself. 

"it's a 9 tooth, 0.4 module gear. The motor shaft is 2.3mm in diameter"

For now I'm just learning how to cut gears so I don't think that my first ones will be very good anyway, so I'm just cutting metal. First I had to make an arbor for the USSR gear gutters that I picked up. I'm not sure if it will be possible to cut gears for the pinion since it is so small, but we'll see. 

Welp -- That didn't work!!

I guess that you cant trust everything that you read on the internet! Who would have thought? 

Turns out the gear diameter of the part that I was replacing was 4.48mm, not 5mm like the internet said!!  The inside diameter is 2.66667mm. -- Who knows if the modulus was correct either? So, sadly,  this gear will not fit. 

From the OpenSCAD gear calculator, here is what it should be for Module 0.4

"Outside Diameter: ", 4.48, "mm"

"Pitch Circle Diameter: ", 3.6, "mm"

"Base Circle Diameter: ", 3.38289, "mm"

"Root Circle Diameter: ", 2.66667, "mm"

I was able to establish the gear ratios though. here's the teeth arrangement with the 9 tooth being the motor pinion. >>  being gear meshes, and - being two gears solidly mounted on the same shaft. 

9 >> 27 - 11 >> 33 - 11 >> 33 - 16 >> 32

Ratios:

9:27  -- 3   3

11:33 -- 3   9

11:33 -- 3   27

16:32 -- 2   54

54:1

Worm ring teeth: 144

Total ratio of RA: 7776

(compare to Losmandy)

Losmandy G11

360 tooth worm wheel

motor gear 25:1

Total 9000

GM 8

180 tooth worm wheel

Motor gear 25:1

Total 4500

Shaft diameter: 0.1 inch, or 2.52mm 

Main output shaft inside diameter 1.92mm

Main output shaft outside diameter 5mm

Motor shaft diameter: 2.28mm                                                      

I'll work out the ratios later...

Here's the picts to confirm: 

And here is the gear that I cut to replace the main pinion, with the actual main pinion. 

OH, well...