21 Jul 2003 09:42:12
Neil Wallace
Concept 2 gates inserts again

Hi

At Lucerne, I spoke to a nice chap on the C2 stand who claimed that....

1. all the blades that leaves there factory are pitched to an accuracy of
0.1 degrees.

(!)
and

2. he had never heard of inserts being used in half unit combinations.. i.e.
a "4" and "5" in one gate to make 4.5 (approx). I understood this was common
practice. furthermore, he raised concerns about whether this was likely to
stress or distort the gate during the stroke.


Comments?

Cheers

Neil





21 Jul 2003 11:56:56
Geoffrey Lloyd
Re: Concept 2 gates inserts again

I have never heard of this practice, and a quick think makes me believe it
would put stress on the gate.

The way an insert works is to provide an angled path through the gate support.

If the angle at one end is different from the angle at the other something
has to bend, and i reckon it will be the gate.

Just one other thing, who wants a pitch of 4.5 degrees??? And who has the
faciility to measure it that well. I have never known a pitch gauge to be
that precise!!


Neil Wallace (rowing.golfer@NOSPAM.virgin.net) wrote:
: Hi

: At Lucerne, I spoke to a nice chap on the C2 stand who claimed that....

: 1. all the blades that leaves there factory are pitched to an accuracy of
: 0.1 degrees.

: (!)
: and

: 2. he had never heard of inserts being used in half unit combinations.. i.e.
: a "4" and "5" in one gate to make 4.5 (approx). I understood this was common
: practice. furthermore, he raised concerns about whether this was likely to
: stress or distort the gate during the stroke.


: Comments?

: Cheers

: Neil




--

Geoff



21 Jul 2003 13:06:44
Neil Wallace
Re: Concept 2 gates inserts again


"Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk > wrote in message
news:bfgke8$9m$1@news.ox.ac.uk...
Snip
> Just one other thing, who wants a pitch of 4.5 degrees??? And who has the
> faciility to measure it that well. I have never known a pitch gauge to be
> that precise!!
>

At the top level (not me!), I'm assuming a difference in pitch of 0.5
degrees would be totally unacceptable.

So if your blades are out by that amount, what options do you have? Removing
and resetting the sleeve or planing it down?

Neil




21 Jul 2003 13:16:37
Geoffrey Lloyd
Re: Concept 2 gates inserts again

I see, you were talking about the top level. Well I guess, although am no where
near that level so couldnt say for sure, that if it was that important they may
have inserts that allowed 0.5 degree differences. It wouldnt be too hard to
make a set of 4.5 inserts if it was absolutely essential.


Neil Wallace (rowing.golfer@NOSPAM.virgin.net) wrote:

: "Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk > wrote in message
: news:bfgke8$9m$1@news.ox.ac.uk...
: Snip
: > Just one other thing, who wants a pitch of 4.5 degrees??? And who has the
: > faciility to measure it that well. I have never known a pitch gauge to be
: > that precise!!
: >

: At the top level (not me!), I'm assuming a difference in pitch of 0.5
: degrees would be totally unacceptable.

: So if your blades are out by that amount, what options do you have? Removing
: and resetting the sleeve or planing it down?

: Neil



--

Geoff



21 Jul 2003 14:45:06
Carl Douglas
Re: Concept 2 gates inserts again

Neil Wallace <rowing.golfer@NOSPAM.virgin.net > writes
>
>"Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk> wrote in message
>Snip
>> Just one other thing, who wants a pitch of 4.5 degrees??? And who has the
>> faciility to measure it that well. I have never known a pitch gauge to be
>> that precise!!
>>
>
>At the top level (not me!), I'm assuming a difference in pitch of 0.5
>degrees would be totally unacceptable.
>
>So if your blades are out by that amount, what options do you have? Removing
>and resetting the sleeve or planing it down?
>

Mmmm. I'm very surprised to hear it suggested that half a degree here
or there is unimportant.

We'd never market a pitch gauge which could not give better than the
nearest degree. However, I've seen pitch being measured in ways which
may explain how such attitudes gain prevalence.

For instance, how can you measure pitch accurately by slapping a gauge
onto the curved spoon of an oar held by someone else in a maybe slack
oarlock at what they think is the correct depth with the boat rocking on
trestles?

The correct way to set pitch is:
1. Set stern & lateral _pin_ pitches, with the boat rigidly held. Use a
common reference point in the boat for all measurements. Usually you
want the pin set vertical for stern pitch & between vertical & 1 degree
outward for lateral pitch. You can only measure these pitches on the
bare pin.
2. If the pin/rigger setup is non-adjustable for pin pitch you have a
problem, but please don't kid yourself that changing oarlock pitch will
make it OK, because it won't.
3. Independently measure the pitch of every oar by placing it
horizontally & face up with the sleeve on a reference edge, & then
setting the gauge on the edge of the end of the spoon, in each case at
the same position.
4. Fit oarlock inserts such that the sum of the pitch on the blade just
measured & the oarlock pitch add up in each case to the same value -
usually 3 or 4 degrees of overpitch.

The flexibility of the insert material on C-II oarlocks is IME
sufficient to allow you to set oarlock pitches to the nearest 1/2 degree
by the expedient of using mixed insert bushes - e.g. 4 & 5 to give 4.5 -
without any perceptible distortion of the oarlock in use. The oarlock
might be a touch tighter on the pin, but generally nothing serious
(especially if the pin is slightly worn).

Cheers -
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



21 Jul 2003 14:36:54
Neil Wallace
Re: Concept 2 gates inserts again


"Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk > wrote in message
news:bfgt11$4vs$1@news.ox.ac.uk...
snip
> I was merely saying, why choose 4.5 when 4 is so mcuh easier to set, given
the
> correct use of inserts and the fact that pitch guages (however accurate)
are
> easier to use if you choose an integer pitch.
>

Believe me, I would love to have everything symmetrical, and nice round
integers, but if 1.5 degrees seems to produced the best draw under dynamic
testing (pitch gauges are crap IMHO... our canal is dead level and more
accurate than any).

So impossible to be even both sides :o(

BTW - oarlocks are very low tech aren't they. Why can't we have some kind of
precision bearing system to allow the sleeve to square and feather. Much
quieter and smoother.... do FISA not allow it?




21 Jul 2003 09:34:56
Carl Boon
Re: Concept 2 gates inserts again

> 1. all the blades that leaves there factory are pitched to an accuracy of
> 0.1 degrees.

I would suggest that this is about 10 times more optomistic than
reality!
They seem to vary by about 1 degree either way. That's why some oars
in a set feel slightly different when used in the same boat position.


> 2. he had never heard of inserts being used in half unit combinations.. i.e.
> a "4" and "5" in one gate to make 4.5 (approx). I understood this was common
> practice. furthermore, he raised concerns about whether this was likely to
> stress or distort the gate during the stroke.

This is entirely possible, though we've never tried it. We have
noticed that Concept's gates & inserts have become a slightly sloppy
fit in recent years, which suggests that their factory mould/dies are
becoming slightly worn. It may only be a few fractions of a
millimetre, but it shows up. Anyway, if the mixed inserts fit on the
pin without undue force, there should not be a problem in the medium
term. Longer-term, the inserts may wear a bit quicker than normal, but
it's only a 5 min task to change them.

CarlB.


21 Jul 2003 16:49:47
Walter Martindale
Re: Concept 2 gates inserts again

Hi,
Whenever purchasing blades - check that they're set the way the factory
claimed... Either rest the "major surface" of a Smoothie on a spirit
level and check that your pitch-gauge says "-3", or get a jig made up
like the one C2 uses and check with that. Small differences from spec.
can be scraped off the "high" side with a sharp knife - scraped - hold
the knife so that the edge is perpendicular to the wear plate (like you
were going to cut through the shaft) and draw it along the high side of
the wear plate to scrape off thin bits of the plastic. Check frequently
the pitch. - if it's only out by .5 degree you can easily fix it this way.

However, pins vertical, 3 or 4 degree pitch inserts in the gates, and
everything kept in fairly good repair seems to give rowers and scullers
the most comfort.
I have used the "mixed up pitch inserts" method to quickly get .5
degrees here or there, but don't like to do it because the holes are,
after all, made through at an angle.
Walter

Neil Wallace wrote:

>Hi
>
>At Lucerne, I spoke to a nice chap on the C2 stand who claimed that....
>
>1. all the blades that leaves there factory are pitched to an accuracy of
>0.1 degrees.
>
>(!)
>and
>
>2. he had never heard of inserts being used in half unit combinations.. i.e.
>a "4" and "5" in one gate to make 4.5 (approx). I understood this was common
>practice. furthermore, he raised concerns about whether this was likely to
>stress or distort the gate during the stroke.
>
>
>Comments?
>
>Cheers
>
>Neil
>
>
>
>
>



21 Jul 2003 23:08:48
Henning Lippke
Re: Concept 2 gates inserts again

"Neil Wallace" schrieb:

> Believe me, I would love to have everything symmetrical, and nice
> round integers, but if 1.5 degrees seems to produced the best draw
> under dynamic testing (pitch gauges are crap IMHO... our canal is
> dead level and more accurate than any).

So if you are aiming for the perfect set up, you have to keep in mind
that 'the machine', your body, is not at all that symmetrical. We were
talking about rigging to match the rowers proportions some weeks ago.
How does that find an entry in the measurements?

-HL


22 Jul 2003 08:17:57
John Yeatman
Re: Concept 2 gates inserts again

FWIW I have never heard anyone talk half degrees in terms of pitch in over
20 years.
I thought Carl's contribution a very useful bit of 'revision'.
JY

"Carl Douglas" <Carl@carldouglas.co.uk > wrote in message
news:SOwmDXEi5+G$Ew3e@rowing-cdrs.demon.co.uk...
> Neil Wallace <rowing.golfer@NOSPAM.virgin.net> writes
> >
> >"Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk> wrote in message
> >Snip
> >> Just one other thing, who wants a pitch of 4.5 degrees??? And who has
the
> >> faciility to measure it that well. I have never known a pitch gauge to
be
> >> that precise!!
> >>
> >
> >At the top level (not me!), I'm assuming a difference in pitch of 0.5
> >degrees would be totally unacceptable.
> >
> >So if your blades are out by that amount, what options do you have?
Removing
> >and resetting the sleeve or planing it down?
> >
>
> Mmmm. I'm very surprised to hear it suggested that half a degree here
> or there is unimportant.
>
> We'd never market a pitch gauge which could not give better than the
> nearest degree. However, I've seen pitch being measured in ways which
> may explain how such attitudes gain prevalence.
>
> For instance, how can you measure pitch accurately by slapping a gauge
> onto the curved spoon of an oar held by someone else in a maybe slack
> oarlock at what they think is the correct depth with the boat rocking on
> trestles?
>
> The correct way to set pitch is:
> 1. Set stern & lateral _pin_ pitches, with the boat rigidly held. Use a
> common reference point in the boat for all measurements. Usually you
> want the pin set vertical for stern pitch & between vertical & 1 degree
> outward for lateral pitch. You can only measure these pitches on the
> bare pin.
> 2. If the pin/rigger setup is non-adjustable for pin pitch you have a
> problem, but please don't kid yourself that changing oarlock pitch will
> make it OK, because it won't.
> 3. Independently measure the pitch of every oar by placing it
> horizontally & face up with the sleeve on a reference edge, & then
> setting the gauge on the edge of the end of the spoon, in each case at
> the same position.
> 4. Fit oarlock inserts such that the sum of the pitch on the blade just
> measured & the oarlock pitch add up in each case to the same value -
> usually 3 or 4 degrees of overpitch.
>
> The flexibility of the insert material on C-II oarlocks is IME
> sufficient to allow you to set oarlock pitches to the nearest 1/2 degree
> by the expedient of using mixed insert bushes - e.g. 4 & 5 to give 4.5 -
> without any perceptible distortion of the oarlock in use. The oarlock
> might be a touch tighter on the pin, but generally nothing serious
> (especially if the pin is slightly worn).
>
> Cheers -
> Carl
> --
> Carl Douglas Racing Shells -
> Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
> Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
> Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
>




22 Jul 2003 13:26:02
Neil Wallace
Re: Concept 2 gates inserts again


"Henning Lippke" <usenet@my-boathouse.com > wrote in message
news:bfhrq0$fal3m$1@ID-122207.news.uni-berlin.de...
> So if you are aiming for the perfect set up, you have to keep in mind
> that 'the machine', your body, is not at all that symmetrical. We were
> talking about rigging to match the rowers proportions some weeks ago.
> How does that find an entry in the measurements?
>
> -HL

Are you telling me my boat is off-set because I "dress to the left"?

BTW if you can understand that, your English is far too good.

Neil




22 Jul 2003 17:40:05
Ewoud Dronkert
Re: Concept 2 gates inserts again

On Tue, 22 Jul 2003 13:26:02 +0000 (UTC), Neil Wallace wrote:
> Are you telling me my boat is off-set because I "dress to the left"?

Just keep the bidon (big one 75 cl, right?) at port.



22 Jul 2003 16:28:57
Neil Wallace
Re: Concept 2 gates inserts again


"Ewoud Dronkert" <me@privacy.net > wrote in message
news:88nqhvgktfs1s94v7r8ab4761iim3rhrk1@news.cis.dfn.de...
> >HOWEVER (sorry Ewoud),

> what did I say?

I was just apologising for shouting, one of your (many) pet hates?

Neil




22 Jul 2003 18:09:20
Carl Douglas
Re: Concept 2 gates inserts again

Geoffrey Lloyd <lloyd@physchem.ox.ac.uk > writes
>Firstly, I wasnt suggesting that a difference of half a dgree here or that was
>unimportant, and secondly I am very capable of setting the pitch of the pin and
>oarlock.
>
>I was merely saying, why choose 4.5 when 4 is so mcuh easier to set, given the
>correct use of inserts and the fact that pitch guages (however accurate) are
>easier to use if you choose an integer pitch.
>
>And if indeed your blade pitch is out, then at the top levbel I ma sure
>you get
>it fixed, rather than squashing a couple of inserts to 'get' 4.5 degrees.
>

Geoffrey -
I wasn't preaching to you on pitching. In this world-wide group replies
are for the benefit of all readers, some of whom appreciate the odd
informed digression into the underlying technicalities of our sport as
opportunity presents.

As for why we might need for half-degree pitching:
You would, e.g., choose 4.5 degrees for an oarlock when one blade had
zero pitch & the other had -0.5. I think you'll agree that that
situation precludes selection of integer pitch for both?

Next:
How many of us would send an oar back for professional re-pitching when
we need to use it today? Especially if we've just learned how, by dead
simple cheating, to get the correct pitch. Sure, at 'top level' it may
be that one has only to snap one's elegant fingers for minions to come
running. But how many of _us_ are in so exalted a position?

As for "squashing" the inserts:
The misalignment in each insert due to a 1/2 degree mismatch is but 1/4
degree. That generates a mere 0.025mm (= 1/1000 inch) of run-out at top
& bottom of each insert. In a thermoplastic of such moderate hardness
that really is peanuts. It is far less than the wear you often find on
pin or insert. Indeed, it is less than the dimensional changes due to
water absorption & temperature changes which oarlock components take
easily in their stride.

You don't, surely, think I'd advocate doing something either unsound or
likely to slow you down - do you? ;^)

Cheers -
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



22 Jul 2003 20:01:23
Ewoud Dronkert
Re: Concept 2 gates inserts again

On Tue, 22 Jul 2003 16:28:57 +0000 (UTC), Neil Wallace wrote:
> I was just apologising for shouting

Nah, you were just adding some dynamic to the conversation.



22 Jul 2003 18:38:18
Neil Wallace
Re: Concept 2 gates inserts again

Carl (Kirk?),

thanks for the posting below, very informative. All done on the back of an
envelope too, I'd wager.

For those interested, I took some photos of my attempt to measure the pitch
on my blades.
They are here....
http://www.invernessrowingclub.co.uk/personal/bladepitch.html

Can anyone spot the deliberate mistake??

Cheers

Neil



"Carl Douglas" <Carl@carldouglas.co.uk > wrote in message
news:HGpjRZFA$WH$Ew9v@rowing-cdrs.demon.co.uk...
Snip
> As for why we might need for half-degree pitching:
> You would, e.g., choose 4.5 degrees for an oarlock when one blade had
> zero pitch & the other had -0.5. I think you'll agree that that
> situation precludes selection of integer pitch for both?
>
> Next:
> How many of us would send an oar back for professional re-pitching when
> we need to use it today? Especially if we've just learned how, by dead
> simple cheating, to get the correct pitch. Sure, at 'top level' it may
> be that one has only to snap one's elegant fingers for minions to come
> running. But how many of _us_ are in so exalted a position?
>
> As for "squashing" the inserts:
> The misalignment in each insert due to a 1/2 degree mismatch is but 1/4
> degree. That generates a mere 0.025mm (= 1/1000 inch) of run-out at top
> & bottom of each insert. In a thermoplastic of such moderate hardness
> that really is peanuts. It is far less than the wear you often find on
> pin or insert. Indeed, it is less than the dimensional changes due to
> water absorption & temperature changes which oarlock components take
> easily in their stride.
>
> You don't, surely, think I'd advocate doing something either unsound or
> likely to slow you down - do you? ;^)
>
> Cheers -
> Carl
> --
> Carl Douglas Racing Shells -
> Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
> Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
> Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
>




22 Jul 2003 21:23:22
Walter Martindale
Re: Concept 2 gates inserts again

This is a multi-part message in MIME format.
--------------090504090801050902000709
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit

I'll try with this deliberate mistake... I see that you "zero" your
pitch gauge on the surface that is supporting your blades, but was that
"level" - it appears you've perhaps got the "weight" level, (not enough
res. to tell), but it looks from the outside that you're not zero-ing
your gauge on a known level surface...
Didn't pay much attention to the spotting of the gauge on the blade,
Is the Care pitch gauge meant to be used upside-down or does it matter?
Walter

Neil Wallace wrote:

>Carl (Kirk?),
>
>thanks for the posting below, very informative. All done on the back of an
>envelope too, I'd wager.
>
>For those interested, I took some photos of my attempt to measure the pitch
>on my blades.
>They are here....
>http://www.invernessrowingclub.co.uk/personal/bladepitch.html
>
>Can anyone spot the deliberate mistake??
>
>Cheers
>
>Neil
>
>
>
>"Carl Douglas" <Carl@carldouglas.co.uk> wrote in message
>news:HGpjRZFA$WH$Ew9v@rowing-cdrs.demon.co.uk...
>Snip
>
>
>>As for why we might need for half-degree pitching:
>>You would, e.g., choose 4.5 degrees for an oarlock when one blade had
>>zero pitch & the other had -0.5. I think you'll agree that that
>>situation precludes selection of integer pitch for both?
>>
>>Next:
>>How many of us would send an oar back for professional re-pitching when
>>we need to use it today? Especially if we've just learned how, by dead
>>simple cheating, to get the correct pitch. Sure, at 'top level' it may
>>be that one has only to snap one's elegant fingers for minions to come
>>running. But how many of _us_ are in so exalted a position?
>>
>>As for "squashing" the inserts:
>>The misalignment in each insert due to a 1/2 degree mismatch is but 1/4
>>degree. That generates a mere 0.025mm (= 1/1000 inch) of run-out at top
>>& bottom of each insert. In a thermoplastic of such moderate hardness
>>that really is peanuts. It is far less than the wear you often find on
>>pin or insert. Indeed, it is less than the dimensional changes due to
>>water absorption & temperature changes which oarlock components take
>>easily in their stride.
>>
>>You don't, surely, think I'd advocate doing something either unsound or
>>likely to slow you down - do you? ;^)
>>
>>Cheers -
>>Carl
>>--
>>Carl Douglas Racing Shells -
>> Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
>>Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
>>Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
>>URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
>>
>>
>>
>
>
>
>

--------------090504090801050902000709
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >
<html >
<head >
<meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1" >
<title ></title>
</head >
<body text="#000000" bgcolor="#ffffff" >
I'll try with this deliberate mistake... I see that you "zero" your
pitch gauge on the surface that is supporting your blades, but was that
"level" - it appears you've perhaps got the "weight" level, (not enough
res. to tell), but it looks from the outside that you're not zero-ing
your gauge on a known level surface...<br >
Didn't pay much attention to the spotting of the gauge on the blade,<br >
Is the Care pitch gauge meant to be used upside-down or does it matter?<br >
Walter<br >
<br >
Neil Wallace wrote:<br >
<blockquote type="cite" cite="midbfk0ap$b5c$1@hercules.btinternet.com" >
<pre wrap="" >Carl (Kirk?),

thanks for the posting below, very informative. All done on the back of an
envelope too, I'd wager.

For those interested, I took some photos of my attempt to measure the pitch
on my blades.
They are here....
<a class="moz-txt-link-freetext" href="http://www.invernessrowingclub.co.uk/personal/bladepitch.html"color=#0000FF> >http://www.invernessrowingclub.co.uk/personal/bladepitch.html</a>

Can anyone spot the deliberate mistake??

Cheers

Neil



"Carl Douglas" <a class="moz-txt-link-rfc2396E" href="mailto:Carl@carldouglas.co.uk" ><Carl@carldouglas.co.uk></a> wrote in message
<a class="moz-txt-link-freetext" href="news:HGpjRZFA$WH$Ew9v@rowing-cdrs.demon.co.uk" >news:HGpjRZFA$WH$Ew9v@rowing-cdrs.demon.co.uk</a>...
Snip
</pre >
<blockquote type="cite" >
<pre wrap="" >As for why we might need for half-degree pitching:
You would, e.g., choose 4.5 degrees for an oarlock when one blade had
zero pitch & the other had -0.5. I think you'll agree that that
situation precludes selection of integer pitch for both?

Next:
How many of us would send an oar back for professional re-pitching when
we need to use it today? Especially if we've just learned how, by dead
simple cheating, to get the correct pitch. Sure, at 'top level' it may
be that one has only to snap one's elegant fingers for minions to come
running. But how many of _us_ are in so exalted a position?

As for "squashing" the inserts:
The misalignment in each insert due to a 1/2 degree mismatch is but 1/4
degree. That generates a mere 0.025mm (= 1/1000 inch) of run-out at top
& bottom of each insert. In a thermoplastic of such moderate hardness
that really is peanuts. It is far less than the wear you often find on
pin or insert. Indeed, it is less than the dimensional changes due to
water absorption & temperature changes which oarlock components take
easily in their stride.

You don't, surely, think I'd advocate doing something either unsound or
likely to slow you down - do you? ;^)

Cheers -
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: <a class="moz-txt-link-abbreviated" href="mailto:carl@carldouglas.co.uk" >carl@carldouglas.co.uk</a> Tel: +44(0)1784-456344 Fax: -466550
URLs: <a class="moz-txt-link-abbreviated" href="http://www.carldouglas.co.uk"color=#0000FF> >www.carldouglas.co.uk</a> (boats) & <a class="moz-txt-link-abbreviated" href="http://www.aerowing.co.uk">www.aerowing.co.uk</a>(riggers)

</pre >
</blockquote >
<pre wrap="" ><!---->

</pre >
</blockquote >
</body >
</html >

--------------090504090801050902000709--



22 Jul 2003 23:19:13
Carl Douglas
Re: Concept 2 gates inserts again

Walter Martindale <wmartind@SPAMSTOPPER??telusplanet.net > writes
>I'll try with this deliberate mistake... I see that you "zero" your pitch gauge
>on the surface that is supporting your blades, but was that "level" - it
>appears you've perhaps got the "weight" level, (not enough res. to tell), but
>it looks from the outside that you're not zero-ing your gauge on a known
>level surface...
>Didn't pay much attention to the spotting of the gauge on the blade,
>Is the Care pitch gauge meant to be used upside-down or does it matter?
>Walter

Should be OK, Walter, as long as:
1. Neil did set his arbitrary zero on the "Workmate" with the scale set
at zero & the bubble then brought to neutral.
2. when measuring the blade pitches he rotated the gauge without
touching the bubble until the bubble returned to neutral

>Neil Wallace wrote:
> Carl (Kirk?),
>
> thanks for the posting below, very informative. All done on the back of
> an
> envelope too, I'd wager.
>
> For those interested, I took some photos of my attempt to measure the
> pitch
> on my blades.
> They are here....
> http://www.invernessrowingclub.co.uk/personal/bladepitch.html
> Can anyone spot the deliberate mistake??
>
The mis-spelling of the word "Gauge", perhaps?

;^)
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



23 Jul 2003 12:24:11
Neil Wallace
Re: Concept 2 gates inserts again


"Carl Douglas" <Carl@carldouglas.co.uk > wrote in message
news:zYhOWzLhhbH$Ewqe@rowing-cdrs.demon.co.uk...

> > http://www.invernessrowingclub.co.uk/personal/bladepitch.html
> > Can anyone spot the deliberate mistake??
> >
> The mis-spelling of the word "Gauge", perhaps?
>

Whoops - not deliberate that one.

Actually, doing the web page brought home a nasty truth to me.

1. I am sure there is a pitch difference in the blades.
2. That pitch difference would be the opposite of what I would have
expected, given my sculling problems.

Explanation. If I have a "neutral" rig. I go very deep starboard, and can't
keep my port blade buried. This has been rectified by my 1.5 degree
difference in pitch inserts....

I assumed the inserts were neutralising the oar pitch...
However, looking at the blade pitches as measured, it looks as if I actually
have 2.5 degrees difference in the set up.

Bugger!

I am confused as, to me at least, my hands appear level throughout the
stroke.
Last night I had a nice 16km scull after work on which to ponder... I now
think it is little old me that is the problem. I think my weight
distribution is all to pot. All the weight on my left side. Using a spirit
level in the boat, it appears I've got used to pulling the thing along at an
angle!

I now have a dilemma. Should I reset everything to neutral, and have
numerous frustrating outings trying to re-learn my posture, or carry on
regardless (I have been getting much quicker and more relaxed with my
"Sparkys magic piano" rigging).

I think the answer is obvious.

Sod it.

Neil




23 Jul 2003 14:51:15
Walter Martindale
Re: Concept 2 gates inserts again

Neil,
How old are your smoothies? If they're from the 90's, you may consider
this... Last year at the 2002 Canadian Henley, the Concept 2 service
team that were re-sleeving and doing other repairs to blades mentioned
that for a while, their blades were being assembled with the pitch as
ordered, but that the shafts were continuing to cure after delivery,
twisting in the same direction (causing the blades to pitch themselves
positive on one side, negative on the other) because the shafts are all
wrapped with carbon fibre in the same direction..
.
I understand from my chat with them that they've overcome this, perhaps
by baking the shafts for a little longer before assembly.

Possible Solutions:
1 - replace the sleeves if you have the bits, pieces, and skill.
2 - scrape down the high side, again if you....
3 - take them to someone who can do this for you
4 - take them to the Concept 2 rep nearest you for this repair.
I would do 1 or 2, but I've also earned what little keep I earned for a
couple of years by fixing boats and oars..
Walter


Neil Wallace wrote:

>1. I am sure there is a pitch difference in the blades.
>2. That pitch difference would be the opposite of what I would have
>expected, given my sculling problems.
>
>Explanation. If I have a "neutral" rig. I go very deep starboard, and can't
>keep my port blade buried. This has been rectified by my 1.5 degree
>difference in pitch inserts....
>
>
>



23 Jul 2003 16:17:33
Neil Wallace
Re: Concept 2 gates inserts again


"Walter Martindale" <wmartind@SPAMSTOPPER??telusplanet.net > wrote in message
news:DhxTa.26359$xn5.4350364@news0.telusplanet.net...
> Neil,
> How old are your smoothies?

6 months.

>If they're from the 90's, you may consider
> this... Last year at the 2002 Canadian Henley, the Concept 2 service
> team that were re-sleeving and doing other repairs to blades mentioned
> that for a while, their blades were being assembled with the pitch as
> ordered, but that the shafts were continuing to cure after delivery,
> twisting in the same direction (causing the blades to pitch themselves
> positive on one side, negative on the other) because the shafts are all
> wrapped with carbon fibre in the same direction..


A good point.
Is that why it is recommended to keep them out of the heat/sun also?




24 Jul 2003 12:30:52
Nick Suess
Re: Concept 2 gates inserts again

I agree with Carl that there's absolutely no problem with the 4.5 degree
system. The plug inserts achieve the predetermined pitch angle essentially
through the excentricity of their holes in relation to the axis of the
barrel of the gate. Whilst the holes are made to the appropriate angle (or I
assume so), if the pin is half a degree off this angle, the plug can
accommodate this by sitting on one side a fraction of a millimetre proud of
the top or bottom of the gate.

But none of this is worth a hill of beans unless the pin pitch is set
accurately in the first place. How many of us have seen the old
length-of-steel-pipe system of adjusting pin pitch. Does that give
half-degree resolution? This may sound like a promo for Axior pins, and
you'll wonder how many pints Carl has bribed me, but in fact it's more the
observation of an old bloke that there's a lot of Emperor's New Clothes
stuff about rigging, and the engineering notion of establishing a proper and
stable datum and referring everything back to that is all too often not
observed, even by people who are prepared to devote masses of time to
tinkering around with plug inserts and pitch gauges.

I'm also far more dubious that oar pitch is routinely set to that level of
accuracy. I have at times seen oar sleeves being fitted "in the field" where
a very coarse setting of pitch, probably to the nearest degree at best, is
possible. It was always an easier task when our oars had symmetrical spoons,
and the datum chord of this would be parallel to the tip. With cleavers and
all other asymmetric designs, the oar maker must define a datum chord, and a
proper measuring jig must then be used to set up this chord so that the
sleeve angle is correctly set with reference to that.

Nick


"Carl Douglas" <Carl@carldouglas.co.uk > wrote in message
news:SOwmDXEi5+G$Ew3e@rowing-cdrs.demon.co.uk...
> Neil Wallace <rowing.golfer@NOSPAM.virgin.net> writes
> >
> >"Geoffrey Lloyd" <lloyd@physchem.ox.ac.uk> wrote in message
> >Snip
> >> Just one other thing, who wants a pitch of 4.5 degrees??? And who has
the
> >> faciility to measure it that well. I have never known a pitch gauge to
be
> >> that precise!!
> >>
> >
> >At the top level (not me!), I'm assuming a difference in pitch of 0.5
> >degrees would be totally unacceptable.
> >
> >So if your blades are out by that amount, what options do you have?
Removing
> >and resetting the sleeve or planing it down?
> >
>
> Mmmm. I'm very surprised to hear it suggested that half a degree here
> or there is unimportant.
>
> We'd never market a pitch gauge which could not give better than the
> nearest degree. However, I've seen pitch being measured in ways which
> may explain how such attitudes gain prevalence.
>
> For instance, how can you measure pitch accurately by slapping a gauge
> onto the curved spoon of an oar held by someone else in a maybe slack
> oarlock at what they think is the correct depth with the boat rocking on
> trestles?
>
> The correct way to set pitch is:
> 1. Set stern & lateral _pin_ pitches, with the boat rigidly held. Use a
> common reference point in the boat for all measurements. Usually you
> want the pin set vertical for stern pitch & between vertical & 1 degree
> outward for lateral pitch. You can only measure these pitches on the
> bare pin.
> 2. If the pin/rigger setup is non-adjustable for pin pitch you have a
> problem, but please don't kid yourself that changing oarlock pitch will
> make it OK, because it won't.
> 3. Independently measure the pitch of every oar by placing it
> horizontally & face up with the sleeve on a reference edge, & then
> setting the gauge on the edge of the end of the spoon, in each case at
> the same position.
> 4. Fit oarlock inserts such that the sum of the pitch on the blade just
> measured & the oarlock pitch add up in each case to the same value -
> usually 3 or 4 degrees of overpitch.
>
> The flexibility of the insert material on C-II oarlocks is IME
> sufficient to allow you to set oarlock pitches to the nearest 1/2 degree
> by the expedient of using mixed insert bushes - e.g. 4 & 5 to give 4.5 -
> without any perceptible distortion of the oarlock in use. The oarlock
> might be a touch tighter on the pin, but generally nothing serious
> (especially if the pin is slightly worn).
>
> Cheers -
> Carl
> --
> Carl Douglas Racing Shells -
> Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
> Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
> Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
>