TL;DR version: I'm looking for tips/tricks/"try this instead"/"you're
not doing THIS"/"you should be doing THAT"/etc, with respect to my
scratch stock technique which I'm about to describe, along with the
corresponding problems I seem to be having. Link to some pics are at
the end.

I've got a scratch stock for a simple 1/8" side bead, made from an LV
mini scraper (.4mm / .016", RC48-52)... my holder is a 1 1/2" square
by 5" long piece of oak, with the kerf that holds the stock in the
middle of the holder, ie: perpendicular to the length of holder... I
think this simple type of holder is pretty standard?

Anyways... I've seen numerous videos of people effortlessly scratching
a simple profile (like this small bead) into a workpiece with a
similar setup... my attempts are not effortless, to say the least.
Couple issues:

1) I keep getting deep spots in the profile, in which the stock sticks
on subsequent strokes and exacerbates the issue (ie: stops cutting
when it hits the deep spot, thus only making it worse)...

2) It feels & sounds like I'm losing 'traction' or 'stability' when I
get to the end of the piece, if that makes sense... ie: towards the
end of the 'cut', it's like the scraper stock is flexing a bit and/or
the holder is de-registering against the workpiece, which may be
happening, but I'm not sure... feels almost like the workpiece is
splintering away from me out the bottom, I get that nasty 'bendy'
feel, even though it's not.

3) I'm not sure how to approach the ends. The end nearest me, while
scratching, is covered by issue #2 above and if/when I solve that,
then the near end of the profile should turn out fairly clean... it's
the far end (ie: beginning of stroke) that I'm unsure of. The far end
always ends up messier and/or 'banged up' a little due to the
following: Altering the attack angle *only* at the beginning of the
stroke, so that the scratch stock is angled towards me more than the
rest of the stroke, seems to work OK, as the angle lets me 'slide'
onto the profile before moving to a more vertical scraping angle. The
almost-vertical attack angle seems best all around, but makes is
*much* more difficult to start unless you get the scraper hitting the
workpiece initially at *just* the right depth... which is tough
without a depth stop, heh.

Explanation of my 'technique': I still haven't figured out the best
angle of attack/amount of pressure, but 90 degrees to the workpieces
or slightly less (angled towards me a touch) seems to work best so
far, and seems correct as that's the same angle you'd normally use
with a regular scraper, is it not? As for pressure, although it's
counter-intuitive it seems that reducing pressure results in a better
scrape - I'm applying what I'd describe as 'half' pressure as straight
downwards as I can and trying to keep the scraper angle as
consistent/steady as possible. The actual stroke I've figured out so
far involves trying to keep the scratch stock holder registered flat
against the side of the workpiece, obviously. Side pressure seems to
be almost (?) more important than the downward pressure, similar to
holding the fench of a plow/moving filister against the workpiece... ?
As I mentioned, the stock-holding-kerf is centered in my holder, so
I'm trying to alter the location of the side pressure as the stroke
progresses, ie: keep pressure in front of the stock at the beginning
of the stroke and gradually shifting that to having the main pressure
being applied rear of the stock (with respect to the direction of the
stroke) as I get to the end of the stroke... ie: to try and keep the
holder registered as the scratch blade itself leaves the workpiece.
The idea being the same as altering pressure through a plane stroke,
pressure in front at beginning through to pressure being on the back
at the end of the stroke, etc.

I have a feeling a large part of the 'losing traction' issue comes
down to unsuccessful pressure application, ie: I'm not actually doing
what I just described, at least not well enough... ? I also have a
feeling that the actual scratch stock is too thin... these mini
scrapers are ideal/convenient for making scratch stock size-wize, but
I think they perhaps flex too much due to being too thin... I'm going
to experience with a heavier stock after the next trip to LV
(today?)...

I also have a hunch re. the 'deep spots', which is poor scratch
pressure consistency combined with too-soft wood for attempting crisp
profiles (yes, I'm still messing around with Doug Fir for this
project... I'm stubborn, what can I say? When this is finally done I
think I'm gonna switch to some hard stuff for a while... I think...).

Since we all love pictures around here, a link to some pseudo-relevant
pics, and some not so relevant (but they're all in-progress pics of
the same project)... the prototype for the box feet, seen in the
latter pics, is what I'm using the scratch stock for...

https://www.dropbox.com/gallery/67483493/1/jewellery%20box%20-%20IN%20PROGRESS?h=e5f787#/

-- 
Rudy X. Desjardins
pgp: 96FFA628
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