Re: Re: Stripping Rubber - caution, long and tedious

From: LeRoy C Cordes <lcordes_at_juno.com>
Date: Thu, 27 Apr 2006 11:38:15 -0500

Nice description of stripper use, Steve.

LeRoy Cordes
AMA 16974
Chicago, IL

On Thu, 27 Apr 2006 16:04:51 -0000 "Steve Brown" <rtxc_at_yahoo.com> writes:
> --- In Indoor_Construction_at_yahoogroups.com, "barrysholder"
> <barry_at_...> wrote:
> > I just received Harlans rubber stripper and I can't quite figure
> it out...
>
> Rubber is sold in widths of 1/8, 3/16 and 1/4 inch. Any of these
> will work. I'd buy 1/8 or 1/4 if I were buying new. The supplier is
>
> FAI Model Supply. Either Tan Sport or Tan Super Sport is more than
> adequate when learning to fly indoor duration or scale models. Tru-
> Weight rubber seems to be best suited to sport models.
>
> One pound of rubber is a *lot* for indoor - often a multi-year
> supply. For model classes where rubber weight is unlimited
> (Ministick, EZB, Int. Stick, etc.) it is often best to just strip
> rubber to a few likely widths and then tie motors to length at the
> flying site once you determine appropriate loop lengths thru
> testing. For classes like F1d and F1m it's best to pre-make (and
> weigh) motors at home. In other words, don't strip the entire one
> pound box all at one time.
>
> I'll walk you thru a visualization of the Harlan stripper:
>
> With the crank on the right and the cutters at the back you have two
>
> knobs, one on the left and one on the right. The two knobs control
> the two overlapping blocks or "rubber guide". Rotate the knobs to
> open the width of the slot in the guide as well as to vary the
> position of the entire rubber guide left/right in relation to the
> cutters.
>
> The slot should fit the rubber strip width closely but still allow
> the strip to move forward and backward freely. The slot width
> adjustment is critical and typically the best way to set it is to
> reduce the size of the slot until the rubber can't be moved and then
>
> back off until it is just moveable.
>
> The width of the cut rubber is determined by turning both knobs to
> position the 1/8 or 1/4 inch(or whatever size)rubber strip in
> relation to the cutters. I usually adjust it so the strip that is
> being cut to the desired width is on the right or crank side of the
>
> rotary cutters and the remainder is on the left.
>
> With scissors, cut a few 4" - 5" long pieces of your rubber strip to
>
> use for setting up the Harlan stripper. Don't just feed in a piece
> of 1/8 or 1/4 and try to adjust the cut "dynamically"...it's harder
>
> to do and you end up with the remainder strip (the one on
> the "left") of varying width.
>
> It is almost impossible to then use the remainder because there is
> no way to determine which edge is variable. Variances in strip width
>
> cause uneven drag thru the rubber guide and the result is inaccurate
>
> cutting. Avoid this whole problem by setting up the stripper with
> short sample strips and then cutting 8-10' or more of rubber all to
>
> the same size.
>
> Push the sample strip into the slot until it meets the rotary
> cutters and turn the handle. You will feel it catch and draw the
> strip into the rotating cutters and through.
>
> You will need a tool to measure the width of the resulting cut. A
> dial thickness gauge is preferred by most flyers (Mitutoyo 7300 or
> similar. Check Ebay, much cheaper. Other brands are OK too such as
> Peacock, SPI, Teclock, Chinese knock-offs, etc.) The Ebay search
> keys "dial thickness gage" or "dial thickness gauge" will produce a
>
> listing of gages that are available.
>
> An alternative is a dial caliper. Not as user-friendly but will work
>
> fine. Insert the cut strip and measure. You want the pressure of the
>
> caliper jaws to be enough to generate a very slight "tug" but not
> significant compression of the rubber. Cut rubber edges are often
> slightly concave and the slight "tug" will compress just the edges
> enough to produce a true measurement of the strip width. Hold the
> sample strip in the caliper jaws up to a light to better visualize
> the measurement.
>
> Adjust both dials on the Harlan stripper to reposition the "rubber
> guide" left-right as needed and cut another sample. The dials are
> calibrated in .001", but much depends on the pressure of the jaws,
> and the strip thickness (which varies on Tan usually from .038-
> .045").
>
> Always cut and tie rubber dry, never lubed. The lube will often
> cause the knot to slip. Many people, including me, wash the talc off
>
> the rubber and blot/air dry before cutting but that isn't a
> requirement. The main reason is to keep the cutter blades clean and
>
> sharp.
>
> On the Harlan stripper the trick is to learn to move both dials to
> move the 1/4" strip left/right. That is where the paper calibration
>
> marks come in handy. By moving them both the same you can move
> the "rubber guide" in relation to the cutters without changing the
> drag on the rubber (by varying the opening size).
>
> The Harlan stripper, because of its design, is vulnerable to nicks
> on the blades so be careful not to bump them.
>
> Small or thin rubber will gain a static charge as it exits the
> cutters on the back side of the stripper and will cling to the
> rollers. It then tends to get pulled back into the cutters. Keep an
>
> eye on the out-spooling of the rubber and don't allow it to get
> pulled back in.
>
> Rubber in hobby stores from Peck Polymers seems to be Tan Sport from
>
> FAI, repackaged. Sig's rubber is probably also Tan Sport.
>
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> Yahoo! Groups Links
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LeRoy Cordes
AMA 16974
Chicago, IL
Received on Thu Apr 27 2006 - 13:33:43 CEST