Re: Wimshurst machines (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 14 Nov 2003 18:36:29 +0100
From: Finn Hammer <f-h@xxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Wimshurst machines (fwd)

OK!

I have looked at the pictures some more, and found the other pictures as
well, and now I understand it alright. It is not a timing belt, but a
soft belt made out of small links, as seen here:
http://www.coe.ufrj.br/~acmq/rovc2.jpg
And the driving shaft is perpendicular to the shaft that the discs
revolve around.

The layout that I made is based on this particular layout, really.
However, since I wanted to have the ratio that is given by the classical
large drivewheels at the bottom of the machine, as well as drive the
machine from the same position as the classical one, I did this:

(no, wait a bit, it`s impossible to explain with words, I`l finish the
rendering, to make it more clear

High Voltage list wrote:

> Original poster: Steven Roys <sroys@xxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Thu, 13 Nov 2003 20:37:49 -0200
> From: Antonio Carlos M. de Queiroz <acmq@xxxxxxxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Wimshurst machines
>
> Original poster: Finn Hammer <f-h@xxxx>
>
> (This thread was in the Tesla list)
>
>
>>Wimshursters:
>>
>>I have had fine results using FR4 PCB material as disks for Wimhurst machines.
>>The prototype vas just plain PCB, home etched in ferrochloride. The next
>>batch were professionately made, goldplated sectors and soldermask, both
>>for "boy, does that look good" effect.
>
>
> Good to know that this material has enough insulation.
>
>
>>Makes it easy to have 48 exactly placed sectors. The neutralizing points
>>were small roundheaded screws,
>
>
> Screws? Wouldn't they scratch the disks? I use brushes as light as I
> can.
> The current is very small.
>
>
>>and although they promoted interdisk spark
>>formation at the low voltage end of the machine,
>
>
> Sparking close to the neutralizers always happens. The only way to avoid
> it is to mount the sectors inside the disks, accessed through small
> buttons, as in the old Wehrsen/Wommelsdorf machines. Maybe you can make
> a machine using a multilayer PCB with internal sectors using a standard
> professional PCB construction method. It's even possible then to mount
> the sectors as two interleaved sets in two plates for greater
> insulation:
> http://www.coe.ufrj.br/~acmq/wehrsec.jpg
> http://www.coe.ufrj.br/~acmq/wermov.jpg
> Made the access buttons flush with the disk surface, or they break
> the brushes too easily. PC boards seem a good method for this.
>
>
>>they started up easily,
>>and produced as much spark as the acryllic disked machines that they
>>replaced. Sectors don`t fall off these disks.
>
>
>>I also deviced a drive layout with only one long belt, which does not have
>>to be crossed at one of the disks. This saves the machine from becoming
>>covered vith rubber dust in time.
>
>
> Don't use rubber belts. You know the effect. Ozone destroys rubber.
> A classic method of using a single belt is to pass the belt through
> two pulleys at 90 degrees with the pulleys in the disk bosses, one
> fixed to an axle and another free to rotate over it:
> http://www.coe.ufrj.br/~acmq/rovc1.jpg
>
>
>>This is getting OT, so if anyone is interested in this belt layout, I`l
>>describe it in more detail on the high viltage list where it belongs.
>
>
> The thread is here now.
>
> Antonio Carlos M. de Queiroz
>
>
>