This blog documents the restoration, and conversion, of a 1965 Humber (Singer) Vogue to a fully electric vehicle. The Vogue will be powered by an 11kW(modified), 3 phase industrial AC motor, controlled by an industry standard Variable Speed Drive (VSD) or Inverter. To be able to produce the 400 volts phase to phase the VSD will need about 600 VDC of batteries. A big thanks to the contributors on the AEVA forum:

Friday, May 3, 2013

Driving my thougths to Vibration

While driving the Vogue every day this week, I seldom go for more than a minute without thinkout about my driveline vibration issue. For the time being, I have found ways to and from work that allows me to keep the speed below 55 km/h except for an approximately one kimometer stretch. I can pull in and let traffic go past then keep speed down here as well - usually. Curiously this makes my 25-30 minute commute about 30-35 minutes. Not a substantial difference but no-one likes to travel slowly when they can legally go faster - and it's frustrating because the Vogue's power curve makes it way more fun at higher speeds.

Anyway my thoughts during this drive waver around in the following direction.
Back when I orginally identified that I had a driveline vibration, my first impulse (after tailshaft
balance) was to think that it was caused by the differntial pinion angle. Essentially a Universal jointed
tailshaft will vibrate a lot if the flanges on either end of the drive system are not at the same angle
with respect to the line of the driveshaft.

We thought we had dispelled this theory by temporarily altering the pinion angle using axle stands and a jack, and moved on to removing the motor, dismantling it and having the rotor balanced.
All to no avail - apparently...

Well, looking back I note in the blog (my reference source for all thing EVogue), that at the time
Laurel (wife) thought it improved but "I was looking for a complete cure". It was after that we balanced
the motor's rotor and didn't see any improvement.

What if there are two problems? What if we have fixed one which was masking the other?

My intuition, and elimination of just about everything else, tells me it just HAS to be diff. pinion angle. Add to this that the Vogue originally had this problem before conversion.
A few weeks ago I was put off this theory when told that up to 3 degrees is fine. But in retrospect, the
fella who told me that is a speedway driver. More investigation yields comments like "3 degrees for up to 400 HP, 5 degrees for up to 800 HP". Hmmm. What out normal street travel? I have dug up many references since then that you should strive for under 1 degree difference - preferably 1/2 a degree. This from lowered car folk who run big sound systems and object to their bass being supplemented by driveshaft wobble.

What it boils down to is that you really have to try it.

With that in mind, I have ordered a pair of 2 inch wide, 2 degree wedges from a 4WD online seller in the
USA. They should be here in less than a week.

I'll install them then make the decision of whether to have a new driveshaft made using CVs.
A CV driveshaft will be vibration free but have slightly more loss than a UJ shaft. Changing the pinion angle will help a keep losses lower in a CV driveshaft anyway.

So, watch this spot - or listen subsonically....

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