Date: Mon, 25 Oct 2004 16:00:57 -0400

Author: sampere

Subject: Re: VDG - one more time

Post:

Machele,

From McMaster-Carr, order some 1/16" pure gum rubber. Get a foot or so
of the 36" width. Also order some Loctite 416 (I think), it's high
viscosity super glue.

Using a wheel cutter (order one of those if you don't have one, it's a
handle with a very sharp wheel attached, perhaps you have one for
sewing), cut a straight side on the rubber. Next, cut a parallel line
2-7/8" from the first cut, i.e. make a strip of rubber with parallel sides.

Now you need to know how long your belt should be. Measure the distance
between the pulley axles and multiply that by 0.75. That's the length
of your belt.

Lay something hard on top of the belt and lop the two ends over each
other, keeping them as parallel as you can. Think this part through
first, it's easy to make the belt too short now. When you have it all
set, make a diagonal cut using a straight edge. Try to keep the blade
vertical as you do this.

Now you have your blank. Apply a thin film of superglue along one edge
and carefully 'smooch' the 2 edges together. Slow is ok, you want to
get good adhesion along that whole length. Hold it for about a minute
and let it cure overnight (sorry it's so long). Perhaps you can get
away with less time, I've never tried that.

As long as your VdG is apart, thorougly clean all parts. I use
methanol, yup, even on the plexi. Never had a problem. If I did, I'd
just have the shop make a new one - it's cheap!

Good luck,

Sam

cablem wrote:

> Well, the belt on my VDG just ripped. Of course, this was when I was
> testing it for a class that starts NOW and it's my BOSSES class. I
> have a CENCO model P41055, but of course, it's no longer carried by
> Sargent-Welch, since they have their own model. So, here's my rather
> dumb questions:
>
> Is there any hope that VDG belts are universal, so that if I order the
> replacement belt for the S-W model, it'll fit my CENCO?
> If not, does anyone happen to have the manual for this model that they
> can fax me some details fast?
> Or, is my best bet to measure my old belt, subtract a few millimeters
> for stretching and then make my own?
> If so, what material is best for the belt? The same kind of rubber or
> is a vinyl or poly blend better?
>
> Fortunately, I can sew and I have a machine that will stitch thick
> stuff if I go slow, so I CAN make one if I have to. This semester just
> hasn't been good on my demos...I've had severe failures on the cloud
> chamber, jensen steam engine, Wimshurst and now the VDG. I got the old
> Wimshurst working (the belts I ordered didn't fit the new one, but
> they did fit the old one), I'm waiting for the cloud chamber to
> dehumidify a bit and I just got the part for the steam engine. Busy,
> busy me...but hey, where else do we get to play with cool toys???!!!
>
> Chele
>
From sampere@physics.syr.edu Mon Oct 25 12:52:57 2004

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