[mizlplix]

I have seen 4000 RPMs or so on my AC50 unloaded...BUT, that was from just pecking the throttle pot. It would redline if I just pressed it for 1 full second.

It was possible to get it to just tick over, but you must use the smallest throttle input you can manage. The unloaded condition lets it rev up wildly fast.

If you go into your controller and set the max rpms to what you want to test at, it would be good to go also.

The unloaded condition is not the motor killer, it is the wildness caused by no-load. Just be really careful and you can do a test.

Miz

[sabahtom]

thanks mizlplix. Before I connect up all the batteries (which are sitting on the other side of town at the moment) I thought of putting a rubber wheel on the end of my electric drill and spinning the flywheel using friction between drill and flywheel. Can I do that without harming the motor?

[DavidDymaxion]

If the bolt pattern allows it, try taking the flywheel off and bolting it back on at a new angle. Pick the angle that minimizes wobble. Then put on the pressure plate at different angles until vibration is minimized. Then you can do the John Wayland trick of adding washers to just 1 bolt (the closer to the edge of the flywheel the better) until vibration is minimized.

My flywheel wobble was about 0.002 inches, but vibrated more than I liked until I rotated the pressure plate 180 degrees. It was then smooth enough I didn't think I needed to balance the flywheel and pressure plate combo.

[sabahtom]

Thanks David Dymaxion. I spun it up to 1000rpm with my drill. Slight vibration but the motor didn't jump off the bench I tried undoing the flywheel, turning it 180 deg and bolting it on again. Exactly the same 0.13mm bump so I guess the flywheel itself is good but the hub is off centre.

I was wondering if this could be due to the weight of the flywheel pulling the spline down? Maybe it'll straighten up when the pressure plate is applied.

Seemed to be two bands where there was some harmonic and the loose tools on the bench started to rattle. Otherwise ok.

I got a fright at how much power it takes to spin that flywheel + motor! My drill is 650w and it took around 25 seconds to get to max. I'm guessing it'll use at least 4kw to spin the whole lot up to 2500 rpm in 5 seconds or so, as with normal driving.

[MemphisPapa]

I went through some of this today when I tried to get my motor connected to an 020 VW transmission. I found that since I didn't have the tool to get the clutch plate exactly in the center between the pressure plate and the flywheel, the flywheel kept bumping the bell housing. I thought it might be a problem with my hub, but then took a closer look at my adapter plate. I found that when I got the whole thing bolted together, I couldn't spin the tail shaft with the trans in neutral. I added some shims between the motor and the adapter and am now sure that my hub it too long. Very careful clutch assembly with shims on the motor face allow enough to keep the flywheel clear. I'm figuring the motor spinning CCW with the right hand rule will keep everything pushed against the motor? I'll need to come up with a plan to get my hub fixed or add a quarter inch to the adapter plate.

[Joey]

I had 0.38 mm of runout and 0.05 mm wobble on my hub adaptor, and the vibration with just the hub (4 kg) was too much for me at 2000 rpm. After a small touch up on the lathe, I measured 0.075 mm runout and 0.05 mm wobble, and the vibration was gone. Try to get the hub as true as possible. I would recommend <0.1 mm, but it does depend on rpm and spinning mass. I had the flywheel balanced at an automotive machine shop and adding the flywheel did not introduce any vibration.

[sabahtom]

Thanks Joey.

If the hub bolt holes are machined off centre then as far as I understand I can't fix it without getting a new hub made? The issue seems to be that the female spline (top of this photo, not quite visible) was machined straight, then the piece was removed from the jaw and turned around for the flywheel bolt holes to be drilled.

Other question I have is if I need Loctite or a grub screw on the two nuts to lock the thrust bearing against the back of the adapter plate? I think if I torque them down it'll be enough?

Cheers!