After putting a deposit on a Vectrix last year I finally got a call from a dealer who said they had my Vectrix put together and ready to go. I have been lurking around here for a couple of months and was really questioning if I should go through with the purchase or not. I have looked at all the posts on this forum and it really helped me to make an informed decision. I decided to take a ride on their demo unit before trying the new unit that was to be delivered to me. I really enjoyed the ride and operation of the Vectrix. The demo unit ran perfectly. The gearbox (which was a problem I noticed from the first time I heard it on a youtube video and confirmed on this forum) was very quiet and smooth. Just before I was ready to sign the papers, I asked to ride the unit that I was purchasing. Boy, I am sure glad I did. The gearbox sounded like the ring gear was about as eliptical as an oval racetrack. I tried every Vectrix the dealer had set up and none were as quiet as the demo unit. So-----I bought the demo instead. I really thank everyone on this forum whose input helped me really look over this scooter and know what I might be in for. I have driven electric for a number of years including a couple of Chevrolet S10e's, a Grumman Kurbwatt, and a Rav4 EV which I still own and drive. I can live with the range of the NiMH Vectrix by planning my trips. I would have liked to have the LiIon option, however the NiMH technology is fairly mature with a proven long life cycle. With a somewhat reduced range, the old S10's are still plugging along with 10 year old first generation Cobasys batteries and the six year old Rav4 batteries show no change in range since new. I'll keep lurking here and if I have anything to offer, I'll post. I already took copies of Mr. Mik's pictures of his gearbox to a company in town who makes gears and just from the pictures came up with a number of problems going on in the geartrain. At least these guys told me that they can make all of the parts in the planetary gearbox in a couple of days to proper tolerances and hardness. If desired to really get it quiet, they could cut a helical set for me. Time will tell.
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What are they doing at the assembly factory? They test drive the new scooters for aprox. 35km and they don't notice the gearbox noise?
Hallo everyone: pushed by the hot days we are experiencing now, I took out my old open helmet with goggles (no fun if you don't play clown every now and then...): boy is the drivetrain loud! Anyway the noise is quite even so I hope I'll have no major problems with that.
AFAIK the "problem" with helical set of gears is that it chews up more power than a system with "stright theeth".
Regards
Great! Thank you for reading and putting the stuff to good use! That makes it worth the effort.
A few questions if I may...
Does the regen breaking capability (causing a reversal of the forces in the gear box) make a difference to helical cut gear options?
About the RAV4EV: Any insights into why those batteries still keep going, and how to replicate the experience in the Vectrix?
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
That makes me wonder if maybe I have heard more of the noise than others, because I have a helmet designed for installation of speakers (Nolan N102).
The ears are "free" inside the shell, rather than being squished against foam as in many other helmets.
That does however not explain uneven noise from wonky ring gears...
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Yes, helical gears have a slightly greater power loss then spur gears for a couple of reasons. First, because of the helix angle, the gear face and contact area is larger then that of a spur gear of the same thickness. In addition, there is contact of more then one tooth at a time in a helical gear. Additional losses occur because the tooth slides along the helix angle and does produce a side load on the geartrain relative to torque input. However, the helical set can carry more torque and runs with much less noise then a spur gear set. Almost all vehicles built today run with helical gears including the planetary reduction in my Rav4 EV which was built to minimize frictional loss. In the other electrics I have, two different approaches were taken to reduce losses in the geartrain. The Rav4 is a single helical planetary reduction that is running in a dry sump. The geartrain is lubricated with pressurized oil sprayed on to the gears by a small oil pump. The oil used is standard ATF which works well in the planetary transmissions in just about every automatic transmission in the world. The Chevrolet S10e (and EV1) used a special oil in the reduction gear oil bath that was of a very low viscosity and had a very low ability to cling to the gears thus reducing power loss caused by the drag from the oil (sort of an anti "Lukas" oil). This stuff is really expensive and I don't know if it is even available anymore. I do have a couple of pints of the stuff and it might end up in an unnamed scooter gearbox. Regarding Mr. Mik's question---yes, side thrust takes place in all helical gearsets but the loads shouldn't be enough to cause a problem in the Vectrix. Overrunning loads (re-gen) would be opposite of driving loads. If you want the features of a helical gear without any thrust load, you cut a "V" shaped gear known as a herringbone gear. The costs to make such a gear would be high and not really necessary in the Vectrix. A quick note---my gear guys say that from the pictures of Mr. Mik's gears they looked at, the plant gears are failing. The pitting on the gear faces show overload failure. Their opinion is that the plant gears might not be hardend enough compared to the ring gear. Also, if the ring gear is out of round, it could place some very high loads on the plant gears. They also wondered about the damage to the teeth on one side of each plant gear and questioned if there is interference in the gearbox when it is running or if this is assembly damage. Nothing for sure, just from a quick look at the pictures.
Spur gears is the word! Now I know :)
This should be where Citroen has its logo from, BTW ;)
Planet's orbits are never round, anyway I ask to myself if the guys at Vectrix should revise the tolerances they allow for the ring gear (or control that the manufacturer is compliant with the drawings!).
I also received mine not long ago, and it seems that the gearbox whining slowly reduces by time. It might be subjective, I haven't measured or recorded the noise, but I'm pretty sure it's reduced or at least lower pitch now after 500 km. The noise was indeed high-pitch and aggressive initially, like a circular saw or grinder.
It's an alternative explanation to why siai's demo is less noisy than brand new bikes.
Mine also doesn't have much of that oscillating sound that mr Mik has recorded. It's there, but only at certain loads and speeds, mostly not perceptible. The noise level never reached those of mr Mik's recordings either.
I was thinking that too, that the gearbox has to break-in.