Material suggestion for a small gear?

[kafie1980]

Awesome, keep us posted.

[nadroj]

I used a 6mm reamer on the PLA gear's bore, to match the spindle's diameter.
For a positive drive, I installed a 1.5mm roll pin into the spindle, and put open-ended slots on the gear.
That method also makes it easy to remove and install new gears.
I'll put it on the motorbike tomorrow and, weather permitting, take it for a trial run.

[nadroj]

A little more progress - the drive assembly is installed to the wheel, ready to test.
I have some silicone paste for electrical use, so I used that for lubricating the gears (plastic to metal) as it's greasy stuff.
I'll keep an eye on it in case it melts in use.
The spindle turns when the wheel is spun. That in itself is promising, as I made some guesses for working out the gear's required helix angle.
I've run out of time today, and will report further when I've had a chance to go for a ride.

[nadroj]

Today I took the motorbike for a 50km ride to test the speedo operation.
It works fine, so far.
After some more distance, I'll disassemble the speedo drive gearbox, inspect and report here.

[nadroj]

Weather is getting better for motorbike riding, so I added another 70km on the odometer today.
Total = 120km on the new printed plastic speedo drive gear.
It's functioning well so far.

Jordan

[nadroj]

I went for a weekend ride, now have 300 kilometers on the PLA gear.
It has worked perfectly so far.
Removed and cleaned, result is a slightly more furry-looking gear, with wear on the ends of the helical teeth.
The wear is on the opposite sides, compared to the original steel gear, and about the same worn width of about half the tooth flank at the ends.
It is progressively less towards the centre, where there is evidently no wear.
My guess of 40 degrees instead of the original 30 may need to be adjusted to 35 degrees, for a better result in future.

I will use the PLA gear until failure. It may be that it'll last long enough to put up with regular new replacements.
It is very easy to remove and replace.
It's nice knowing that the steel worm gear it meshes with won't be distressed by the soft plastic imperfect gear.