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dc71(at)netspace.net.au
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 Posted: Sat Feb 17, 2007 4:29 pm Post subject: Crossbow vs Pinpoint |
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Guys, as part of the D2A recovery package from Lancair avionics, I've been offered the choice between a Pinpoint and a Crossbow 425EX AHRS (Crossbow is cheaper)
I realise that Crossbow had problems with this model, but they claim to have fixed them all
On the other hand, Pinpoint is a relatively "new" (and small?) company, with strong ties to D2A.
What are the experiences regarding installing & flying these different units?
Indran
#40228
[quote][b]
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Tim Olson
Joined: 25 Jan 2007
Posts: 2882
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| Posted: Sat Feb 17, 2007 5:35 pm Post subject: Crossbow vs Pinpoint |
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|
Indran,
You won't find much on the list yet for experiences from people flying
with pinpoints, as I think I and Vic the only ones who are, in an RV-10.
There are some other models of aircraft flying the pinpoint though.
Having flown them both, I have some experience behind both of them with
about 70 hours on the crossbow and 125 on the pinpoint. If Crossbow
has all of the bugs completely worked out, which right now I would say
still needs the test of time, then I think you could really use either.
This isn't to say that I don't trust the product, because they have
been much more forthcoming with information in recent months. I just
think we need to see it re-develop a track record...different than
the one it had previously developed. There's no reason why that
unit couldn't be acceptable. The largest more recent problems were
caused by issues with the GPS aiding that were supposedly fixed in
software, so it very well could be good now.
So, lets assume they are both good...then what?
Well, the pinpoint will be a bit easier to install and does include
some benefits as well.
1) It has a remote magnetometer which allows easier mounting in
a magnetically stable location. It is actually quite hard to
find a good location for the 425, because the best I could do
at the time was above the battery, and it doesn't really get
as far out of the area of the battery and AP servo for me to
feel as comfortable with it.
2) The pinpoint comes with its own air data computer, and its
highly accurate. It has been flown next to a known and tested
air data unit in my plane that was also accurate to within 7'
of altitude, and the airspeed on the 2 units matches perfectly
too. So even if you have a 2nd air data system, you now have
multiple systems that you can compare for data.
3) The algorithm within the pinpoint is not at all GPS dependent.
In fact, the GPS is not internally connected at all to the AHRS,
so you will never develop attitude related issues due to GPS
signal loss. I have also tested mine by disconnecting in various
ways the pitot and static lines during turning flight and that
does not upset it either, so it should be very reliable.
4) The pinpoint does have a superior mounting and alignment software
function. You can mount it oriented in any of the 4 directions,
so you're not tied to one specific installation, and in fact you
can mount it under the panel. And due to it's configuration
software on the Chelton, you don't have to be as precise in regards
to the level as others. The calibration procedure is accurate
and much easier, and can be done without a PC...all from the
screen.
The downside to the pinpoint is really the delivery. I don't
know any of the recent specifics as to shipping time, but I'm
sure you could get a Crossbow in short order, where you may
wait 30-60 days I'd suppose for the pinpoint.
As for your comment about strong ties to D2A, I won't go too
into it on this forum, but whereas the pinpoint was perhaps
strongly tied to D2A before, that's just because they were
the only distributor. In fact, today I would say that
there are no companies with "strong ties" to D2A, because
Chelton itself is distributing the pinpoint, and they are also
involved in suing D2A....so there are no warm fuzzies even
by them for the people at D2A. Products are products, and
should be judged on their product quality. Politics aren't
really things that enhance the ability to choose the right
product. There were lots of bad things happening by multiple
parties a year ago. At present, I think the real bad eggs
are now expunged and what's left is the same products being
offered, but from a more reliable source. And Crossbow has
really whipped themselves into a good playing team too...so
you really can't go too awful wrong today.
What you really should do is dig in though on the Chelton
EFIS forum at http://www.CheltonEFISpilots.com, because there
you should be able to ask these questions and get responses
from a much higher number of people who can respond with
actual in-flight experience with either. With either
system, make sure you do a real "by the book" install
and you'll likely have success. The pinpoint just makes
the job easier by it's design. Hopefully we'll eventually
see a similar unit available by another manufacturer like
Crossbow, as the design itself is much easier to work with.
For the small price difference today though, I myself
would choose the pinpoint if I was in your shoes.
Tim Olson - RV-10 N104CD - Flying
Indran Chelvanayagam wrote:
| Quote: | Guys, as part of the D2A recovery package from Lancair avionics, I've
been offered the choice between a Pinpoint and a Crossbow 425EX AHRS
(Crossbow is cheaper)
I realise that Crossbow had problems with this model, but they claim to
have fixed them all
On the other hand, Pinpoint is a relatively "new" (and small?) company,
with strong ties to D2A.
What are the experiences regarding installing & flying these different
units?
Indran
#40228
*
|
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billderou(at)yahoo.com
Guest
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| Posted: Sun Feb 18, 2007 9:17 pm Post subject: Crossbow vs Pinpoint |
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|
Last October I sat in a conference room at Crossbow and went over each problem they resolved. All of the problems were of the maturing variety and none pertained to core technical changes. I was quite puzzled by D2A "toss everything out" reactions.
I met with Crossbow face-to-face and came away comfortable with their answers and their product and choose Crossbow for my WTD Aviation Technology primary flight display product. Two of these units have been installed to date and both work flawlessly.
During 3 years of investigating and installing gyros it was apparent that the numbers you get from the gyro depends greatly on the installation. See the attached photos (yes- we turned the XBow around). By far the best location for the Crossbow is on a reinforced (stiffened) plate attached to the longerons using the same holes where the aft end of the rear shoulder harness cable connects to the longerons. In fact, the shoulder harness cable end was relocated to the plate. This location allows the gyro to be perfectly aligned with the aircraft axis and is magnetically minimized from the pitch servo and the trim servo. Don't let the small size of the trim servo fool you - it casts a magnetic field 20 inches from the unit. Note that the gyro was attached with brass screws.
Looking over the possible locations for the gyro GPS antenna its obvious that the best probable location is the forward tip of the vertical stablizer and an easy location is just under the fiberglass fuselage to vertical stab fairing. Out of curiousity, I took the easy route and it has worked without fail. The antenna was aligned with the vertical stab to minimize the RF shadow. A status on my PFD shows when the gyro has locked the GPS constellation and it locks about one minute after I start my taxi from the hanger. Once locked on it has never dropped. If it starts dropping out then I will relocate the antenna to the vertical stab forward tip.
The Crossbow gyro has the capability to calibrate its compass for hard iron interferrence. From my previous experience with gyros it was obvious that the Crossbow is very sensitive, so I included the commands necessary to begin and end this procedure into my PFD product. It is a quick and simple procedure that will maximize the accuracy.
Now when I look back at D2A they look more like a kool-aid manufacturing company than an avionics distribution company. They slammed Crossbow far beyond sanity and then elevated Pinpoint to angel status - always positioning themselves as heros. Just now, I only believe what I can see and touch on this subject. And what I have seen is that Crossbow is a very good and very serious engineering company with experience producing (in quantity) solid state gyros.
Bill DeRouchey
N939SB, Flying
billderou(at)yahoo.com
Tim Olson <Tim(at)MyRV10.com> wrote: [quote]--> RV10-List message posted by: Tim Olson
Indran,
You won't find much on the list yet for experiences from people flying
with pinpoints, as I think I and Vic the only ones who are, in an RV-10.
There are some other models of aircraft flying the pinpoint though.
Having flown them both, I have some experience behind both of them with
about 70 hours on the crossbow and 125 on the pinpoint. If Crossbow
has all of the bugs completely worked out, which right now I would say
still needs the test of time, then I think you could really use either.
This isn't to say that I don't trust the product, because they have
been much more forthcoming with information in recent months. I just
think we need to see it re-develop a track record...different than
the one it had previously developed. There's no reason why that
unit couldn't be acceptable. The largest more recent problems were
caused by issues with the GPS aiding that were supposedly fixed in
software, so it very well could be good now.
So, lets assume they are both good...then what?
Well, the pinpoint will be a bit easier to install and does include
some benefits as well.
1) It has a remote magnetometer which allows easier mounting in
a magnetically stable location. It is actually quite hard to
find a good location for the 425, because the best I could do
at the time was above the battery, and it doesn't really get
as far out of the area of the battery and AP servo for me to
feel as comfortable with it.
2) The pinpoint comes with its own air data computer, and its
highly accurate. It has been flown next to a known and tested
air data unit in my plane that was also accurate to within 7'
of altitude, and the airspeed on the 2 units matches perfectly
too. So even if you have a 2nd air data system, you now have
multiple systems that you can compare for data.
3) The algorithm within the pinpoint is not at all GPS dependent.
In fact, the GPS is not internally connected at all to the AHRS,
so you will never develop attitude related issues due to GPS
signal loss. I have also tested mine by disconnecting in various
ways the pitot and static lines during turning flight and that
does not upset it either, so it should be very reliable.
4) The pinpoint does have a superior mounting and alignment software
function. You can mount it oriented in any of the 4 directions,
so you're not tied to one specific installation, and in fact you
can mount it under the panel. And due to it's configuration
software on the Chelton, you don't have to be as precise in regards
to the level as others. The calibration procedure is accurate
and much easier, and can be done without a PC...all from the
screen.
The downside to the pinpoint is really the delivery. I don't
know any of the recent specifics as to shipping time, but I'm
sure you could get a Crossbow in short order, where you may
wait 30-60 days I'd suppose for the pinpoint.
As for your comment about strong ties to D2A, I won't go too
into it on this forum, but whereas the pinpoint was perhaps
strongly tied to D2A before, that's just because they were
the only distributor. In fact, today I would say that
there are no companies with "strong ties" to D2A, because
Chelton itself is distributing the pinpoint, and they are also
involved in suing D2A....so there are no warm fuzzies even
by them for the people at D2A. Products are products, and
should be judged on their product quality. Politics aren't
really things that enhance the ability to choose the right
product. There were lots of bad things happening by multiple
parties a year ago. At present, I think the real bad eggs
are now expunged and what's left is the same products being
offered, but from a more reliable source. And Crossbow has
really whipped themselves into a good playing team too...so
you really can't go too awful wrong today.
What you really should do is dig in though on the Chelton
EFIS forum at http://www.CheltonEFISpilots.com, because there
you should be able to ask these questions and get responses
from a much higher number of people who can respond with
actual in-flight experience with either. With either
system, make sure you do a real "by the book" install
and you'll likely have success. The pinpoint just makes
the job easier by it's design. Hopefully we'll eventually
see a similar unit available by another manufacturer like
Crossbow, as the design itself is much easier to work with.
For the small price difference today though, I myself
would choose the pinpoint if I was in your shoes.
Tim Olson - RV-10 N104CD - Flying
Indran Chelvanayagam wrote:
[quote] Guys, as part of the D2A recovery package from Lancair avionics, I've
been offered the choice between a Pinpoint and a Crossbow 425EX AHRS
(Crossbow is cheaper)
I realise that Crossbow had problems with this model, but they claim to
have fixed them all
On the other hand, Pinpoint is a relatively "new" (and small?) company,
with strong ties to D2A.
What are the experiences regarding installing & flying these different
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
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AV8ORJWC
Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"
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| Posted: Sun Feb 18, 2007 11:05 pm Post subject: Crossbow vs Pinpoint |
|
|
Bill your comments on brass hardware rather than S. steel is a great post specially for sailors. I am curious about other builders determining where the CG and CL is on their aircraft. Lycoming reports that the CG on their engine is 0.5” below the crankshaft centerline. The human torso has a CG even lower sitting on those Oregon Aero seats. Wouldn’t the cross mount to longeron actually be about 3.5” higher than perfection. And is that a determination on magnetic, ferrous and electro-magnetic neutrality?
I am considering a further aft and outboard to the starboard, battery tray and was wondering about such things. I am aware that VAN declares 112.3” aft of datum the perfect CG. That would put it right in the middle of Deems Console under his lid.
John Cox
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Bill DeRouchey
Sent: Sunday, February 18, 2007 9:16 PM
To: rv10-list(at)matronics.com
Subject: Re: Crossbow vs Pinpoint
Last October I sat in a conference room at Crossbow and went over each problem they resolved. All of the problems were of the maturing variety and none pertained to core technical changes. I was quite puzzled by D2A "toss everything out" reactions.
I met with Crossbow face-to-face and came away comfortable with their answers and their product and choose Crossbow for my WTD Aviation Technology primary flight display product. Two of these units have been installed to date and both work flawlessly.
During 3 years of investigating and installing gyros it was apparent that the numbers you get from the gyro depends greatly on the installation. See the attached photos (yes- we turned the XBow around). By far the best location for the Crossbow is on a reinforced (stiffened) plate attached to the longerons using the same holes where the aft end of the rear shoulder harness cable connects to the longerons. In fact, the shoulder harness cable end was relocated to the plate. This location allows the gyro to be perfectly aligned with the aircraft axis and is magnetically minimized from the pitch servo and the trim servo. Don't let the small size of the trim servo fool you - it casts a magnetic field 20 inches from the unit. Note that the gyro was attached with brass screws.
Looking over the possible locations for the gyro GPS antenna its obvious that the best probable location is the forward tip of the vertical stablizer and an easy location is just under the fiberglass fuselage to vertical stab fairing. Out of curiousity, I took the easy route and it has worked without fail. The antenna was aligned with the vertical stab to minimize the RF shadow. A status on my PFD shows when the gyro has locked the GPS constellation and it locks about one minute after I start my taxi from the hanger. Once locked on it has never dropped. If it starts dropping out then I will relocate the antenna to the vertical stab forward tip.
The Crossbow gyro has the capability to calibrate its compass for hard iron interferrence. From my previous experience with gyros it was obvious that the Crossbow is very sensitive, so I included the commands necessary to begin and end this procedure into my PFD product. It is a quick and simple procedure that will maximize the accuracy.
Now when I look back at D2A they look more like a kool-aid manufacturing company than an avionics distribution company. They slammed Crossbow far beyond sanity and then elevated Pinpoint to angel status - always positioning themselves as heros. Just now, I only believe what I can see and touch on this subject. And what I have seen is that Crossbow is a very good and very serious engineering company with experience producing (in quantity) solid state gyros.
Bill DeRouchey
N939SB, Flying
billderou(at)yahoo.com
Tim Olson <Tim(at)MyRV10.com> wrote:
--> RV10-List message posted by: Tim Olson
Indran,
You won't find much on the list yet for experiences from people flying
with pinpoints, as I think I and Vic the only ones who are, in an RV-10.
There are some other models of aircraft flying the pinpoint though.
Having flown them both, I have some experience behind both of them with
about 70 hours on the crossbow and 125 on the pinpoint. If Crossbow
has all of the bugs completely worked out, which right now I would say
still needs the test of time, then I think you could really use either.
This isn't to say that I don't trust the product, because they have
been much more forthcoming with information in recent months. I just
think we need to see it re-develop a track record...different than
the one it had previously developed. There's no reason why that
unit couldn't be acceptable. The largest more recent problems were
caused by issues with the GPS aiding that were supposedly fixed in
software, so it very well could be good now.
So, lets assume they are both good...then what?
Well, the pinpoint will be a bit easier to install and does include
some benefits as well.
1) It has a remote magnetometer which allows easier mounting in
a magnetically stable location. It is actually quite hard to
find a good location for the 425, because the best I could do
at the time was above the battery, and it doesn't really get
as far out of the area of the battery and AP servo for me to
feel as comfortable with it.
2) The pinpoint comes with its own air data computer, and its
highly accurate. It has been flown next to a known and tested
air data unit in my plane that was also accurate to within 7'
of altitude, and the airspeed on the 2 units matches perfectly
too. So even if you have a 2nd air data system, you now have
multiple systems that you can compare for data.
3) The algorithm within the pinpoint is not at all GPS dependent.
In fact, the GPS is not internally connected at all to the AHRS,
so you will never develop attitude related issues due to GPS
signal loss. I have also tested mine by disconnecting in various
ways the pitot and static lines during turning flight and that
does not upset it either, so it should be very reliable.
4) The pinpoint does have a superior mounting and alignment software
function. You can mount it oriented in any of the 4 directions,
so you're not tied to one specific installation, and in fact you
can mount it under the panel. And due to it's configuration
software on the Chelton, you don't have to be as precise in regards
to the level as others. The calibration procedure is accurate
and much easier, and can be done without a PC...all from the
screen.
The downside to the pinpoint is really the delivery. I don't
know any of the recent specifics as to shipping time, but I'm
sure you could get a Crossbow in short order, where you may
wait 30-60 days I'd suppose for the pinpoint.
As for your comment about strong ties to D2A, I won't go too
into it on this forum, but whereas the pinpoint was perhaps
strongly tied to D2A before, that's just because they were
the only distributor. In fact, today I would say that
there are no companies with "strong ties" to D2A, because
Chelton itself is distributing the pinpoint, and they are also
involved in suing D2A....so there are no warm fuzzies even
by them for the people at D2A. Products are products, and
should be judged on their product quality. Politics aren't
really things that enhance the ability to choose the right
product. There were lots of bad things happening by multiple
parties a year ago. At present, I think the real bad eggs
are now expunged and what's left is the same products being
offered, but from a more reliable source. And Crossbow has
really whipped themselves into a good playing team too...so
you really can't go too awful wrong today.
What you really should do is dig in though on the Chelton
EFIS forum at http://www.CheltonEFISpilots.com, because there
you should be able to ask these questions and get responses
from a much higher number of people who can respond with
actual in-flight experience with either. With either
system, make sure you do a real "by the book" install
and you'll likely have success. The pinpoint just makes
the job easier by it's design. Hopefully we'll eventually
see a similar unit available by another manufacturer like
Crossbow, as the design itself is much easier to work with.
For the small price difference today though, I myself
would choose the pinpoint if I was in your shoes.
Tim Olson - RV-10 N104CD - Flying
Indran Chelvanayagam wrote:
> Guys, as part of the D2A recovery package from Lancair avionics, I've
> been offered the choice between a Pinpoint and a Crossbow 425EX AHRS
> (Crossbow is cheaper)
>
> I realise that Crossbow had problems with this model, but they claim to
> have fixed them all
> On the other hand, Pinpoint is a relatively "new" (and small?) company,
> with strong ties to D2A.
>
> What are the experiences regarding installing & flying these different
[quote][b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
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Deems Davis
Joined: 09 Jan 2006
Posts: 925
|
| Posted: Mon Feb 19, 2007 8:51 am Post subject: Crossbow vs Pinpoint |
|
|
Bill, thanks for your post regarding Crossbow. From someone who has
researched, designed, programmed, built, debugged and flown his own
EFIS, and ADC. I appreciate your perspective. I have always been
suspicious of the, as yet undetermined ownership, of Pinpoint
particularly with regards to the ditching/slamming of Crossbow. Perhaps
during the D2A lawsuits that will follow the 'rest of the story' will
get told.
Deems Davis # 406
Finishing - ( A Misnomer ! )
http://deemsrv10.com/
do not archive
Bill DeRouchey wrote:
| Quote: | Last October I sat in a conference room at Crossbow and went over each
problem they resolved. All of the problems were of the maturing
variety and none pertained to core technical changes. I was quite
puzzled by D2A "toss everything out" reactions.......................
|
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http://www.matronics.com/Navigator?RV10-List |
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billderou(at)yahoo.com
Guest
|
| Posted: Mon Feb 19, 2007 4:07 pm Post subject: Crossbow vs Pinpoint |
|
|
John-
Its impossible to locate the gyro at the CG of all axis [fuel & people variances?] so the consideration that I use is what is the best location that the unit will provide excellent information. "Perfectly aligned" as I used the phrase is meant to be parallel with each axis. It may be offset from the origin but should not so far to affect the numbers in a meaningful way.
So, I recommended the aft gyro location based upon the following criteria and in the following priority:
1. Location that can be "aligned" (parallel) to all three axis as close as possible.
2. Minimum offset from roll axis (Roll axis moves fastest and distance from this
origin will create large errors. IE: not out on wing)
3. Area where the magnetism is constant (not near baggage area)
4. Minimum surrounding magnetic fields
5. No strobe, battery, nor navigation wires
The value of setting the plate on the longerons is an immediate 2 axis alignment - pitch and roll. By running a string through the length of the cabin yaw orientation can be easily determined. All internal Xbow sensors are aligned physically and by calibration to the mounting holes. A much more difficult mounting would be some inches lower that would align with origin of the roll axis. However, the gain is small compared to the effort - and it now allows the other two axis to vary.
Deems-
I think you have "pinpointed" the missing piece of the D2A story. Were they making purely emotional decisions? Were they technically clueless and thinking solid state gyros are a commodity? Were they motivated from themselves or another influential third party investing in Pinpoint and it was all a cleverly planned ruse?
Yep. When this information becomes public then we will have the whole story.
Bill DeRouchey
N939SB, flying
billderou(at)yahoo.com (billderou(at)yahoo.com)
"John W. Cox" <johnwcox(at)pacificnw.com> wrote:
[quote] Bill your comments on brass hardware rather than S. steel is a great post specially for sailors. I am curious about other builders determining where the CG and CL is on their aircraft. Lycoming reports that the CG on their engine is 0.5” below the crankshaft centerline. The human torso has a CG even lower sitting on those Oregon Aero seats. Wouldn’t the cross mount to longeron actually be about 3.5” higher than perfection. And is that a determination on magnetic, ferrous and electro-magnetic neutrality?
I am considering a further aft and outboard to the starboard, battery tray and was wondering about such things. I am aware that VAN declares 112.3” aft of datum the perfect CG. That would put it right in the middle of Deems Console under his lid.
John Cox
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Bill DeRouchey
Sent: Sunday, February 18, 2007 9:16 PM
To: rv10-list(at)matronics.com
Subject: Re: Crossbow vs Pinpoint
Last October I sat in a conference room at Crossbow and went over each problem they resolved. All of the problems were of the maturing variety and none pertained to core technical changes. I was quite puzzled by D2A "toss everything out" reactions.
I met with Crossbow face-to-face and came away comfortable with their answers and their product and choose Crossbow for my WTD Aviation Technology primary flight display product. Two of these units have been installed to date and both work flawlessly.
During 3 years of investigating and installing gyros it was apparent that the numbers you get from the gyro depends greatly on the installation. See the attached photos (yes- we turned the XBow around). By far the best location for the Crossbow is on a reinforced (stiffened) plate attached to the longerons using the same holes where the aft end of the rear shoulder harness cable connects to the longerons. In fact, the shoulder harness cable end was relocated to the plate. This location allows the gyro to be perfectly aligned with the aircraft axis and is magnetically minimized from the pitch servo and the trim servo. Don't let the small size of the trim servo fool you - it casts a magnetic field 20 inches from the unit. Note that the gyro was attached with brass screws.
Looking over the possible locations for the gyro GPS antenna its obvious that the best probable location is the forward tip of the vertical stablizer and an easy location is just under the fiberglass fuselage to vertical stab fairing. Out of curiousity, I took the easy route and it has worked without fail. The antenna was aligned with the vertical stab to minimize the RF shadow. A status on my PFD shows when the gyro has locked the GPS constellation and it locks about one minute after I start my taxi from the hanger. Once locked on it has never dropped. If it starts dropping out then I will relocate the antenna to the vertical stab forward tip.
The Crossbow gyro has the capability to calibrate its compass for hard iron interferrence. From my previous experience with gyros it was obvious that the Crossbow is very sensitive, so I included the commands necessary to begin and end this procedure into my PFD product. It is a quick and simple procedure that will maximize the accuracy.
Now when I look back at D2A they look more like a kool-aid manufacturing company than an avionics distribution company. They slammed Crossbow far beyond sanity and then elevated Pinpoint to angel status - always positioning themselves as heros. Just now, I only believe what I can see and touch on this subject. And what I have seen is that Crossbow is a very good and very serious engineering company with experience producing (in quantity) solid state gyros.
Bill DeRouchey
N939SB, Flying
billderou(at)yahoo.com
Tim Olson <Tim(at)MyRV10.com> wrote:
--> RV10-List message posted by: Tim Olson
Indran,
You won't find much on the list yet for experiences from people flying
with pinpoints, as I think I and Vic the only ones who are, in an RV-10.
There are some other models of aircraft flying the pinpoint though.
Having flown them both, I have some experience behind both of them with
about 70 hours on the crossbow and 125 on the pinpoint. If Crossbow
has all of the bugs completely worked out, which right now I would say
still needs the test of time, then I think you could really use either.
This isn't to say that I don't trust the product, because they have
been much more forthcoming with information in recent months. I just
think we need to see it re-develop a track record...different than
the one it had previously developed. There's no reason why that
unit couldn't be acceptable. The largest more recent problems were
caused by issues with the GPS aiding that were supposedly fixed in
software, so it very well could be good now.
So, lets assume they are both good...then what?
Well, the pinpoint will be a bit easier to install and does include
some benefits as well.
1) It has a remote magnetometer which allows easier mounting in
a magnetically stable location. It is actually quite hard to
find a good location for the 425, because the best I could do
at the time was above the battery, and it doesn't really get
as far out of the area of the battery and AP servo for me to
feel as comfortable with it.
2) The pinpoint comes with its own air data computer, and its
highly accurate. It has been flown next to a known and tested
air data unit in my plane that was also accurate to within 7'
of altitude, and the airspeed on the 2 units matches perfectly
too. So even if you have a 2nd air data system, you now have
multiple systems that you can compare for data.
3) The algorithm within the pinpoint is not at all GPS dependent.
In fact, the GPS is not internally connected at all to the AHRS,
so you will never develop attitude related issues due to GPS
signal loss. I have also tested mine by disconnecting in various
ways the pitot and static lines during turning flight and that
does not upset it either, so it should be very reliable.
4) The pinpoint does have a superior mounting and alignment software
function. You can mount it oriented in any of the 4 directions,
so you're not tied to one specific installation, and in fact you
can mount it under the panel. And due to it's configuration
software on the Chelton, you don't have to be as precise in regards
to the level as others. The calibration procedure is accurate
and much easier, and can be done without a PC...all from the
screen.
The downside to the pinpoint is really the delivery. I don't
know any of the recent specifics as to shipping time, but I'm
sure you could get a Crossbow in short order, where you may
wait 30-60 days I'd suppose for the pinpoint.
As for your comment about strong ties to D2A, I won't go too
into it on this forum, but whereas the pinpoint was perhaps
strongly tied to D2A before, that's just because they were
the only distributor. In fact, today I would say that
there are no companies with "strong ties" to D2A, because
Chelton itself is distributing the pinpoint, and they are also
involved in suing D2A....so there are no warm fuzzies even
by them for the people at D2A. Products are products, and
should be judged on their product quality. Politics aren't
really things that enhance the ability to choose the right
product. There were lots of bad things happening by multiple
parties a year ago. At present, I think the real bad eggs
are now expunged and what's left is the same products being
offered, but from a more reliable source. And Crossbow has
really whipped themselves into a good playing team too...so
you really can't go too awful wrong today.
What you really should do is dig in though on the Chelton
EFIS forum at http://www.CheltonEFISpilots.com, because there
you should be able to ask these questions and get responses
from a much higher number of people who can respond with
actual in-flight experience with either. With either
system, make sure you do a real "by the book" install
and you'll likely have success. The pinpoint just makes
the job easier by it's design. Hopefully we'll eventually
see a similar unit available by another manufacturer like
Crossbow, as the design itself is much easier to work with.
For the small price difference today though, I myself
would choose the pinpoint if I was [quote][b]
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Mike@Crossbow
Joined: 28 Nov 2006
Posts: 8
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| Posted: Mon Feb 26, 2007 2:51 pm Post subject: Re: Crossbow vs Pinpoint |
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I just wanted to poke my head in here and provide a couple of pieces of information for those that are considering mounting a NAV425EX in their aircraft.
1) You do NOT have to mount the unit at the CG of the aircraft as has already been stated in this forum. We recommend in our installation manual that our customers mount the unit as close as possible to the CG, however given the size and nature of RV's/Lancairs a better location is aft of the baggage area. The intent of mounting at the CG is to prevent any "lever affect", however this really doesn't occur in such small aircraft.
2) Please note that we are currently recommending an external mount GPS antenna (TSO'd) be used with all installations. I understand that this causes some heartache for builders, however please note that there isn't one certified GPS antenna made for internal installations. We believe and our testing has proven that there is a reason for this. In theory composite aircraft should be transparent, however our experiences have shown this to not hold completely true. We urge all of our customers to consider the Antcom 2G15A-XS-1 antenna or a suitable alternative called out in our service bulletin.
Sincerely,
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_________________
Michael Smith
Application Engineer Inertial Systems
Crossbow Technology
msmith@xbow.com |
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