Today's Message Index:
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0. 12:34 AM - Make Sure You're Listed! List of Contributors Published in December! (Matt Dralle)
1. 04:30 AM - Comment on Reaming vs. Drilling (TRACY SMITH)
2. 05:07 AM - Re: Zenith-List Digest: XL upgrade video (MacDonald Doug)
3. 09:19 AM - Re: Re: Zenith-List Digest: XL upgrade video (Paul Mulwitz)
4. 03:35 PM - Re: Comment on Reaming vs. Drilling (FLYaDIVE)
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| Subject: | Make Sure You're Listed! List of Contributors Published |
in December!
Dear Listers,
The List of Contributors (LOC) is just around the corner! In December I post a
list of everyone that so generously made a Contribution to support the Lists.
Its my way of publicly thanking everyone that took a minute to show their appreciation
for the Lists.
Won't you take minute and assure that your name is on the upcoming LOC? Tell others
that you appreciate the Lists. Making a Contribution to support the Lists
is fast and easy using your Visa, MasterCard, or Paypal account:
http://www.matronics.com/contribution
Or, drop a personal check in the mail to:
Matt Dralle / Matronics
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USA
I would like to thank everyone that has so generously made a Contribution thus
far during this year's List Fund Raiser! Remember that its YOUR support that
keeps these Lists running and improving! Don't forget to include a little comment
about how the Lists have helped you!
Thank you!
Matt Dralle
Matronics Email List Administrator
Message 1
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| Subject: | Comment on Reaming vs. Drilling |
Gentlemen:
I was reading yesterday's comments on drilling & reaming holes and thought
I'd add a comment or two:
Reaming is a precision cutting operation where the accuracy is determined b
y the size of the reamer and the skill of the operator using it. It is a f
inishing operation.
Most drilling operations will produce an oversize (to the order of a couple
of tenths) out-of-round hole. Mind you, I'm talking VERY small amounts he
re - and reaming puts the hole back to the intended dimensions: accurately
sized and perfectly round.
With regard to the 'pulling vs. pushing' discussion, is it possible the rea
mer chucked in the drill motor is sharper at the shaft end - maybe due to l
ack of cutting oil when reaming, or maybe trying to ream too much material?
Maybe the shaft acts to help the operator center the reamer in the hole,
making the operation much easier?
Just a few thoughts - no criticism or negativity implied.
Regards,
Tracy Smith
Zenith 601/651
Message 2
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| Subject: | Re: Zenith-List Digest: XL upgrade video |
Paul, I'm not sure how much time you have in the 601/650 (or how the 601/65
0 flys for that matter as I have a 701).- I found that in early test flyi
ng in my 701 the ball was often not centered.- By the time I had 25-30 ho
urs on the plane, I was used to the odd feeling rudder and I had developed
a sense of how co-ordinated flight should feel.- Now with over 100 hrs on
my plane, co-ordinated flight is a non-issue.=0A-=0AIf this is a recentl
y completed plane and/or you have limited time on type, you might want to p
ut a few hours on it before deciding on any modifications.- Generally spe
aking, once pilots are used to them, most people don't have any issues with
how Zenith aircraft handle.=0A-=0ADoug MacDonald=0ACH-701 from Scratch
=0ANW Ontario, Canada=0A-=0ADo Not Archive=0A-=0ATime: 08:25:44 AM PST
US=0AFrom: Paul Mulwitz <psm@att.net>=0ASubject: Re: Zenith-List: Re: XL up
grade video=0A=0A=0AHi Tommy,=0A=0APulling the reamer does sound like a goo
d idea.- Still, step drilling =0Awith small increments also produces a ve
ry nice hole.- Drills naturally =0Ago straight and this is really true wh
en taking a small amount of metal =0Afrom a relatively large hole.=0A=0AI t
oo am glad to have finished building and upgrading my XL.- It flies =0Apr
etty well now, but still has a way to go to finish flight testing.- =0ATh
e issue I am working on right now is a lack of yaw stability.- It is =0Ae
asy to see when you look at the design that there is nothing making it =0Af
ly straight except possibly the nose wheel centering mechanism in the =0Alo
wer gear column bearing.- This doesn't work well on my plane, and I =0Asu
spect the same is true on many others.- The full flying rudder is nice
=0Afor control but has no natural "Straight ahead" position like planes =0A
with a fixed vertical stabilizer.- I am going to try adding strakes next.
=0A=0APaul
Message 3
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| Subject: | Re: Zenith-List Digest: XL upgrade video |
Hi Doug,
Thanks for the comments. Indeed I only have around 20 hours in type. I
am sure you are correct that with enough experience I could fly the
plane just fine, but I am the kind of perfectionist that I don't want to
deal with this obvious shortcoming in the design that way. I did do
some work adjusting the cables so the nose wheel --> rudder pedals -->
rudder position in flight allows for a centered ball without standing on
one of the rudder pedals all the time (I needed left rudder pedal
pressure to get it centered on initial flights.).
There are several reasons I want to fix this problem. First is the fact
I have problems landing the plane so the nose wheel doesn't get jerked
around when it hits the ground. I also like to touch down with the main
gear already aligned with the runway. I have fixed that problem by
putting a stripe on the top engine cowl that shows which way is forward,
but that will go away if I ever paint the fiberglass cowl. Another
issue is I will not be the only person flying this plane. My wife wants
to fly it too, and she has a lot less pilot experience than I do. Also,
I just want it to be nice to fly.
I have been discussing this issue with a very experienced pilot and
builder on my field. We both agree that this is a typical design
problem for all airplanes. It is very common for initial designs to be
short of vertical stabilizer. This is usually fixed in subsequent
design versions by increasing the vertical stabilizer size. In some
designs strakes are added to help with this issue. My friend pointed
out that this lack of yaw stability is always a problem when floats are
added to a land plane. Apparently the shape of the floats puts enough
forward bias to the "Center of pressure" that yaw stability is ruined.
His opinion is this is usually fixed with strakes.
The issue is worse than usual with the Zodiac XL since there is no
vertical stabilizer at all. The Heintz planes (all?) use the same full
flying rudder and the XL has no sides on the fuselage that run parallel
to the line of flight. Rather, the top down view of the whole fuselage
is a diamond shape. This means there simply isn't any natural yaw
stability in this design. There is a small attempt to add some with the
v-block design of the nose gear lower bearing, but this doesn't work at
all on my plane. I spoke to Caleb at ZAC about the v-block issue and he
suggested filing down the sides of the V to make it less steep. I'm
confident this will make it even less functional in the yaw stability issue.
I considered adding a vertical fin as has been done on lots of planes.
This is the kind of feature that extends the full length of the fuselage
behind the cockpit to the previous front of the vertical stabilizer.
When I looked at the structure of the fuselage top I decided it was not
rigid enough for this kind of addition. I did not want to face
strengthening the whole fuselage design to support this kind of change.
Adding strakes is a lot more straight forward. Using a very simple
design that has both strakes connected by a flat plate in the middle the
flat plate can be riveted to the existing holes in the bottom longerons
and skin. I think this will actually strengthen the fuselage design
rather than putting more stress on it. I don't have formal drawings or
photos right now, but I have formed the basic part and will install it
when I get a burst of energy and the hangar temperature is a little bit
warmer than usual for this time of year.
I don't expect a lot from my strakes. I do expect them to add a bit of
yaw stability to the design so when the plane is flown with no rudder
input it will tend to fly straight. This is actually a requirement of
the ASTM LSA standard that the Zodiac XL was designed to meet.
Unfortunately, I don't think it ever did meet this requirement. I also
expect this to give a little control over landing approach angles with a
little bit of forward slip (like most planes). This whole area of
interest started when another list member pointed out that slips have no
impact on the approach angle. I concluded this is true for small slips
but after the nose is offset by 11 degrees from straight ahead then a
slip will add drag.
Paul
Camas, WA
XL 20 hours into flight test.
On 11/13/2011 5:05 AM, MacDonald Doug wrote:
> Paul, I'm not sure how much time you have in the 601/650 (or how the
> 601/650 flys for that matter as I have a 701). I found that in early
> test flying in my 701 the ball was often not centered. By the time I
> had 25-30 hours on the plane, I was used to the odd feeling rudder and
> I had developed a sense of how co-ordinated flight should feel. Now
> with over 100 hrs on my plane, co-ordinated flight is a non-issue.
> If this is a recently completed plane and/or you have limited time on
> type, you might want to put a few hours on it before deciding on any
> modifications. Generally speaking, once pilots are used to them, most
> people don't have any issues with how Zenith aircraft handle.
> Doug MacDonald
> CH-701 from Scratch
> NW Ontario, Canada
> Do Not Archive
> Time: 08:25:44 AM PST US
> From: Paul Mulwitz <psm@att.net <mailto:psm@att.net>>
> Subject: Re: Zenith-List: Re: XL upgrade video
>
>
> Hi Tommy,
>
> Pulling the reamer does sound like a good idea. Still, step drilling
> with small increments also produces a very nice hole. Drills naturally
> go straight and this is really true when taking a small amount of metal
> from a relatively large hole.
>
> I too am glad to have finished building and upgrading my XL. It flies
> pretty well now, but still has a way to go to finish flight testing.
> The issue I am working on right now is a lack of yaw stability. It is
> easy to see when you look at the design that there is nothing making it
> fly straight except possibly the nose wheel centering mechanism in the
> lower gear column bearing. This doesn't work well on my plane, and I
> suspect the same is true on many others. The full flying rudder is nice
> for control but has no natural "Straight ahead" position like planes
> with a fixed vertical stabilizer. I am going to try adding strakes next.
>
> Paul
>
>
> *
>
>
> *
Message 4
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| Subject: | Re: Comment on Reaming vs. Drilling |
Tracy & Gaggle:
Pull out a Machinist Handbook and look up Drilling & Reaming.
>From statements, I am gathering that people are doing both operations using
a Hand Drill. If so the quality and accuracy of the Reamer will be (guess
factor number here) only a 50% improvement over Drilling. Drilling is used
to remove large quantities of material while Reaming removes
smaller quantities. Reaming can be done with 3, 4, 6 or more flutes. The
more flutes the less is removed on each pass but the smoother and more
uniform the hole. PRICE of the reamer goes up with the number of flutes.
To obtain a proper ream it should not be done with a hand drill.
Most Reamers have a LEAD-IN at both ends. Sharpness is NOT an issue, at
one end or another. The flutes do the cutting. All your tools should be
sharp! One of the longest things to learn in a machine shop is how to
sharpen your tools. Really you never stop learning that.
There are many things that determine if you push or pull the reamer.
Direction of chips.
Access.
Length of stroke.
Direction of oil feed.
Tools being used to operate the reamer - MANY a HAND DRILL can not be used
in the PULLING operation due to cheap-ass design <--- I learned that the
expensive way. They are to be used pushing only. DRILL BITS
are designed for pushing only. <--- Don't think I really needed to say
that ;-)
What one must consider in the tool is the quality. Today you do NOT get
what you pay for. The steels coming from china are extremely poor. And
finding good tools are becoming harder and harder. I have tools from 50
years ago and they hold an edge and take an edge very well. Brand new tools
today - Well, we are a throw away society and the tools reflect that.
Barry
Machine Shop 101
On Sun, Nov 13, 2011 at 7:27 AM, TRACY SMITH <crvsecretary@aol.com> wrote:
> Gentlemen:
>
> I was reading yesterday's comments on drilling & reaming holes and thought
> I'd add a comment or two:
>
> Reaming is a precision cutting operation where the accuracy is determined
> by the size of the reamer and the skill of the operator using it. It is a
> finishing operation.
>
> Most drilling operations will produce an oversize (to the order of a
> couple of tenths) out-of-round hole. Mind you, I'm talking VERY small
> amounts here - and reaming puts the hole back to the intended dimensions:
> accurately sized and perfectly round.
>
> With regard to the 'pulling vs. pushing' discussion, is it possible the
> reamer chucked in the drill motor is sharper at the shaft end - maybe due
> to lack of cutting oil when reaming, or maybe trying to ream too much
> material? Maybe the shaft acts to help the operator center the reamer in
> the hole, making the operation much easier?
>
> Just a few thoughts - no criticism or negativity implied.
>
> Regards,
> Tracy Smith
> Zenith 601/651
>
> *
>
> *
>
>
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