Re: Funnels as supports for secondary winding jig.

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Original poster: "Scott Hanson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <huil888-at-surfside-dot-net>

John -

I have used matching sets of opposed plastic funnels for several years as a
means of supporting and centering small to medium sized secondaries on a
motorized winding jig.

My winding jig consists of a variable-speed right-angle DC gearmotor driving
an arbor consisting of a 30" long piece of heavy-wall stainless steel tubing
supported in ball bearings. I have several different sets of funnels that
slip over the tubing that can accommodate secondary form diameters from
about 3/4" ID to 4" ID. One funnel is located axially on the arbor by a
fixed shaft collar, the other funnel has a compression spring between the
funnel and a second shaft collar. This acts like a "slip-clutch", so by
varying the compression on the spring, I can "set" the torque at which the
secondary form starts to slip on the funnels. This is necessary when you are
using small gage wire (30 and smaller) to prevent a broken wire if there is
an "oops" anywhere in the winding process like a snag or a kink in the wire.

For winding 3" or larger secondaries, I use funnels that have a
polycarbonate disk glued in the large end (obviously with a 1/2" central
hole) to better support the funnel against the side load caused by the
tension in the magnet wire.

Secondaries larger in diameter than about 4" generally need more physical
support than can be reliably provided by plastic funnels. For larger
secondaries, I use hubs of  3" diameter Delrin round stock, cut to about
1.5" long and drilled and tapped to accept four hex bolts at 90 degrees,
like spokes. This allows me to use any length bolts as required to match the
diameter of the form I'm winding. The bolts can be individually adjusted to
perfectly center the secondary, and provide enough "grip" so that it doesn't
slip. A fifth tapped hole in the hub provides a means of locking the hub to
the arbor using a set screw. I've wound 4", 5", 6" and 8" secondaries using
these adjustable hubs, and they work great.

I'll post photos tomorrow at http://surfboard.surfside-dot-net/huil888/winder1.j
pg, winder2.jpg, etc.

Scott Hanson

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, December 22, 2002 6:54 PM
Subject: Funnels


 > Original poster: "John Richardson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jprich-at-up-dot-net>
 >
 > Hello,
 >
 > This is another one of my barely relevant ideas, but here goes.  The
recent
 > thread on secondary winding techniques got me thinking:  Instead of having
 > end caps turned to fit each secondary pvc pipe, why not obtain two large,
 > identical plastic funnels, the ones with a smallish hole in the middle,
but
 > with a large taper.  I have seen them for sale for as low as a buck
apiece,
 > and with one on each end of your homemade "threaded rod" winding jig, it
 > would be an easy matter to adjust back and forth for varying lengths.  The
 > taper of the funnel would also allow different size secondaries to be
 > "chucked up", and the funnels taper guarantees that the pvc is centered on
 > the jig.
 >
 > John Richardson
 >
 >
 > ---
 > [This E-mail scanned for viruses by SURFSIDE INTERNET]
 >
 >

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