Figured out a way over "The Sticky spot"!

[carlprad]

Can anyone please tell me what the material and purpose of the material he attaches to the V-GATE in this video:

http://www.youtube.com/watch?v=8Eyp_j0_-7o

In other words, what is the logic in attaching that piece to the gate?

Also, why did he never finish it? It seemed to work on the "sticky spot" he placed it over.

Thanks everyone.

[Floor]

It may be,  that a second one of the (steel ?) pieces would also change the magnetic field of the next (the second) V, and so recreate a new set of "sticky spots"  ?

[gyulasun]

Hi carlprad,

The material he attaches to the V gate must be made from soft ferromagnetic material I believe (like say transformer lamination) so that it has a minimum remanence magnetic property.

The logic in using such V shaped soft iron piece is to "bridge" over the sticky spot somehow by changing the fields around the spot. You have surely noticed that on the cylinder rotor there is a sticky spot in-between the two 'series' gates without the soft iron piece and the rotor stops at the spot. However, when the piece is attached, the rotor goes through the spot by its inertia powered by the initial momentum gained during the acceleration from the startup. Notice that there is still a sticky spot there but its distribution must have been changed by the soft iron piece as member Floor has figured also above.

You can see the effect of such iron piece on the sticky spot in his (a bit earlier) linear motor version in which the two V gates' meeting point is overlapped (bridged) by the iron piece: http://www.youtube.com/watch?v=n2yHsVqA5Po 

Probably the "father" of this V gate principle is Robert Calloway (if I am not mistaken), here is his site: http://www.callowayengines.com/

An interesting variant of this V gate principle in a rotor is here by Dietmar: http://www.youtube.com/watch?v=N0pctDW00hU

rgds, Gyula

PS  you asked why he had never finished it: well, he would be the best to answer it... 

[carlprad]

Gyulasun

Thank you for the explanation and the link to Dietmar's video.

I'm A little confused thought; why does Dietmar continuously prevent his v-gate from completing the full rotation?

In the video it looks like the rotor was going to continue until Dietmar places his hand on it?

Thanks

[gyulasun]

...
I'm A little confused thought; why does Dietmar continuously prevent his v-gate from completing the full rotation?

In the video it looks like the rotor was going to continue until Dietmar places his hand on it?

Hi carlprad,

My impression from Dietmar's video is that he seems to give a small but definite push to the rotor by his fingers approximately at the 8 o'clock rotor position to start the rotor (video time 0:27) and there seems to be a sticky spot at the 9 o'clock position, this latter is defeated partially by the extra force from his hand-push. I say this because he starts the rotor nearly in the middle part of the V gate involved between 6 and 9 o'clock positions: this is strange for me because in the middle of a V gate there is normally no problem for the rotor to pass,  sticky spots normally show up at the entrance and at the exit of V gates but not neccessarily in the middle. 
So I think there are at least 4 sticky spots in his setup, these are where the curved V gates start and end i.e. at 12, at 3, at 6 and at 9 o'clock positions and the starting force for the rotor given by his fingers helps the rotor going through the 9 o'clock sticky spot.
Watching carefully the rotor, you can see moments it wants to go back towards the 9 o'clock spot (0:31-0:33) just after his fingers captured it at the 8 o'clock position, just having made a full circle.
I accept that the rotor was able to complete an almost full circle by not giving any hand-push to it but the 4th sticky spot surely stopped it.  Dietmar placed his hand on the rotor to prevent it going backwards to the 9 o'clock attraction spot. Perhaps using a ferromagnetic V shaped plate across the 9 o'clock sticky spot would help reduce the strength of the attraction force like it is shown in the other video?

rgds, Gyula