Hi,
In the past, someone mentioned elsewhere on this forum the possibility of making the Vectrix's gearbox quieter by using nylon (I think it was) planet gears instead of the stock steel ones. When this idea was suggested, 3D printing was in its infancy and it would not have been practical to print them. Now it is different but does anyone know if the sorts of plastics available for 3D printing would make this a practical proposition?
MW
Nylon 6 = very slippery & easily formed [bends] & melts at ~320°.
]Teflon [PTFE] is an even tougher, slicker plastic, that machines nicely, and often used for gears. [Not sure if suitable for printing].
The "machines nicely" is what made it unique to other plstic for many decades.
EWheels EW475 eBike LiFePO4 36 V 10 AH Bat
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Nylon 6 is very slippery, formable plastic, which melts at ~320°.
Teflon [PTFE] is an even slicker material, much stronger, and it machines very easily. I am not sure if the PTFE would print, but it is available in thin sheets, as well as rods, thick pieces, and thick sheets.
EWheels EW475 eBike LiFePO4 36 V 10 AH Bat
I would expect that service life of nylon/plastic sun gears as direct replacements for the existing metal years would result in early failure, due to the high stresses of full-throttle uphill acceleration that will be imposed by the relatively small SUN gear driving these synthetic planet gears. After replacing numerous PONTIAC camshaft drive gears/sprockets made of nylon composite, I would not feel very secure about such a modification!
Robert M. Curry
I'm really out of my depth here, but as far as I remember what I saw and read from others here, I think that the Sun Gear is of good quality and should remain as is. This post is about replacing the planetary gears with something better than the poor quality in some of the original VX-1 gear boxes.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
The torque and horsepower being transferred in the VECTRIX gearbox would be likely to cause short life of nylon sun gears used as direct replacements! The small size/diameter of the existing SUN gear would impose severe demands on the planetary gears teeth under hard acceleration, possibly stripping the weaker nylon teeth. A re-design, using a LARGER sun gear, and/or thicker gears, might work, but the overall package would be bigger, and might not fit! Helically cut gears are generally quieter, but less efficient, due to the increased side thrust generated. Perhaps a toothed belt drive would be more practical and efficient, but motor re-location would be required. (It seems a rather high ratio, of something around 6 to one, is used to get the high motor RPM down to rear wheel RPM.-Lets see, use a BIGGER diameter, slower turning, higher torque, 350 volt motor, with an 18 inch rear wheel, and a lower ratio, helically cut gear set, with appropriate thrust bearings=quiet "Super Scooter", with 50 horsepower, 110 mph top speed, and 125 mile range, at 65 mph??-(I want one!)
Robert M. Curry
I like my noisy gears, it helps warn pedestrians of your approach. It's a really characteristic Vectrix sound.
I'm with Dan on this one! Though I did notice a slight dulling/damping of the whine when I changed the gear oil to a fully synthetic racing oil. The whine also provides feedback to the rider as to how much load the drive-train is under and in which direction (load/overrun). It's not loud enough to be offensive, just loud enough that I can be identified by pedestrians and give them a chance to say 'Wow, look at that, an electric bike!", rather than... 'You #%~@, why did you run me over?!'
Drew
Drew
With you on that one.
It seems highly doubtful that you will obtain good RELIABILITY with plastic/nylon replacements for ANY of the gears within the existing VECTRIX planetary drive, due to the size constraints and mechanical demands placed upon them! It would take considerably LARGER gears to transfer the same power with the same reliability and endurance, and this is possibly a very good reason the factory did NOT use plastic/nylon gears, as they would have very likely been less expensive AND quieter, but they are no good if they are too big, or unreliable! (Perhaps someone will find a way to change them to plastic/nylon, and then see if they last at least 15,000 miles?)- If they DO last that long, a tear down and inspection should then be performed, to evaluate them, and give an estimate of remaining life at that point.
Robert M. Curry
Hello,
Does anybody have .STL or other 3D docs about Sun, planetary and ring gears?
Not for Nylon use. To make iron worker remake them. brand new.
Thanks.