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Re: 1/4 Inch Tube



Original poster: "huil888" <huil888@xxxxxxxxxxxx>

Jared -

I'll bet you have never actually tried the "drop it down from above"
technique for winding a spiral primary, using the coiled tubing directly
from the box. It does take four hands, but a 50 foot primary can be wound,
cosmetically perfect, in less than ten minutes using this technique. There
is no relationship between the diameter of the raw coil of tubing and the
primary you are trying to wind; a primary with a 5" ID (for a 3.5" dia
secondary) is just as easy to wind as a primary with a 12" ID (for a 10" dia
secondary).

I guarantee this is MUCH easier then straightening an entire coil of tubing
(with a mallet!!??), re-winding on a 32" drum, then re-re-winding onto the
primary form. Also, ANY cold working (bending, straightening, re-winding,
etc) of soft copper tubing significantly work-hardens it and makes any subsequent
forming much more difficult, with a distinct tendency to generate "kinks"
and non-uniform bend radius.

Try it .....

Scott


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, March 29, 2007 3:53 PM
Subject: 1/4 Inch Tube


Original poster: "Jared Dwarshuis" <jdwarshuis@xxxxxxxxx>

Jared -

You've got it backwards. Type "L" tubing is not refrigeration tubing.

Regards,
Scott Hanson

.............................................................................................................


Hi Scott:

You are right, I mixed up refrigeration tube with plumbing tube. Included
are the dimensions of type L:

We wind everything on to a 32 inch drum and straighten out the tube first
(using soft rubber mallets with very light blows). Dropping tube directly
from the box to the brackets only works if the form is roughly equal to
the dimensions of your box of tubing. You will find it much easier (and
get better results) if you wind from a large uniform diameter coil to a
smaller intermediate form, where it can be straightened out further before
placing in brackets. (Pancake style primary can be wound between stiff
sheets of plywood with spacers.)


Rigid Tube, Type L

Specifications:

Diameter

Nominal

Outside Diameter

Wall Thickness

Average Weight per Section


Actual

Maximum

Minimum

Actual

Maximum

Minimum


6.35 mm

1/4"

9.525 mm

0.375"

9.550 mm

0.376"

9.500 mm

0.374"

0.762 mm

0.030"

0.838 mm

0.033"

0.686 mm

0.027"

1.143 kg

2.521 lb

9.5 mm

3/8"

12.700 mm

0.500"

12.725 mm

0.501"

12.675 mm

0.499"

0.889 mm

0.035"

0.991 mm

0.039"

0.787 mm

0.031"

1.798 kg

3.963 lb

12.7 mm

1/2"

15.875 mm

0.625"

15.900 mm

0.626"

15.850 mm

0.624"

1.016 mm

0.040"

1.118 mm

0.044"

0.914 mm

0.036"

2.585 kg

5.700 lb