[simpits-tech] Gsuit-Aircompressor-F4
Craig Rochester
simpits-tech@simpits.org
Sun, 15 Jun 2003 10:33:00 -0400
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Re: [simpits-tech] Gsuit-Aircompressor-F4Hi Marv,
Do you mean a ball check valve? I tried that first, but couldn't get it to work. A quick exhaust valve(QEV),
is a 3-way valve where the exhaust flow moves a seat(usually a rubber disk/seal) like this:
http://www.polyconn.com/pdf_files/quick_exhaust_valves.pdf I use these in my work for big pneumatic control
valves that would take to long to exhaust through the solenoid valve. They work great for higher pressures in
the 0-100 psi range. I tried the one in the above link on my rig, but the friction in the seat was too much.
I had some pneumatic cylinders I bought on ebay. I used a 1.5" piston with two cup seals in a PVC plumbing
fitting(has a bit larger ID than 1.5").
http://pages.zdnet.com/johncraigrochester/sitebuildercontent/sitebuilderpictures/new_qev.jpg The larger
cylinder ID and dry graphite lubricant yielded the desired sensitivity and exhaust capacity. But... I had
problems with the cup seals sticking open when exhaust was complete. In the pic the cup seal nearest the check
valve slide over the exhaust holes. The cup seals would stick on the edges of the holes. I tried a bunch of
thing to stop this; beveled edges, staggered, drilled on angle... Finally I changed to an "O" ring against a
metal seat design, which finally worked.
The performance from the QEV rig really made the difference between a cool feedback for the magnitude of the
G-force vs.. an even better real-time feedback of small force changes. Quantitatively, the regulator without
the QEV --> a 1/4 psi reduction in pressure takes about 1 second to exhaust. With the QEV the exhaust is
almost immediate(faster than I can measure). This feels much different in the suit. Without the quick
response, the small changes aren't as noticeable; it takes about 1 psi change to perceive the reduction. With
the quick exhaust small changes in stick position(=small G-force changes) are felt in the suit. It's like the
way a motion platform uses "wash out" to return to neutral force, only we don't want the wash out.
Craig R.
-----Original Message-----
From: simpits-tech-admin@simpits.org [mailto:simpits-tech-admin@simpits.org]On Behalf Of Marv De Beque
Sent: Sunday, June 15, 2003 8:33 AM
To: simpits-tech@simpits.org
Subject: Re: [simpits-tech] Gsuit-Aircompressor-F4
Craig,
Have you considered a ball valve for the exhaust port?
On 6/15/03 8:08 AM, "Craig Rochester" <johncraigroch@msn.com> wrote:
Hi Albert,
Cautionary note: working with compressed air is inherently dangerous, as there's a lot of stored energy.
I bought the regulators and servos on eBay for about $45US. There's another $15 in miscellaneous
materials. You'd need a lathe to make the piston for the "quick exhaust valve(QEV)". The servo controller
I'm using costs $54US and is a "no-brainer" to use with the program written by the guy in Norway.
I use a nail gun compressor @ 100 psi supply pressure. I've tested down to 40 psi. You need the
compressor at a higher pressure to ensure fast response. One of the Norway guys is using an old refrigerator
compressor. He says it is very quiet and has the required capacity. If it were me, I'd go for the free
compressor and run a long air hose to the computer.
I've been struggling with the QEV design. I've made a couple and they're being tested. When the design
is proven reliable, I'll post construction details. I don't intend to make the rigs for sale.
Craig
-----Original Message-----
From: simpits-tech-admin@simpits.org [mailto:simpits-tech-admin@simpits.org]On Behalf Of Albert
Sent: Sunday, June 15, 2003 4:16 AM
To: simpits-tech@simpits.org
Subject: Re: [simpits-tech] Gsuit-Aircompressor-F4
G'day Craig,
Good to hear from you. The concept of the servo pushes down on the diaphragm of a pressure regulator
make sense to me. How it is constructed is something I am not too sure at this stage. However, I am
researching and evaluating whether its a thing to do to my own project. After reading on the simpit forum
link. I wonder how much will a normal regular/ exhaust valve be worth? Like yourself, I have never work with a
servo previously, but I am slowly coming to terms with what it does :) Judging from the amount of PSI required
to inflat the Gsuit... will something like a small compressor typical for airbrushing be good for the purpose?
A mate was going to give me a 50PSI air compressor (for nail gun) but when I told him the most I will
need from a compressor is only about 10 PSI. He asked me what on earth am I doing with it? YOu should have
seen the guy trying hard to understand what on earth I am trying to do :) Judging by your experience, it
sounds like it really only need 4psi to do the job. So I thought something small will hopefully be cheaper and
also quieter compared to a larger louder compressor.
Similar to the problem of trying to cool down my cockpit previously with an active cooling system. (At
the moment, the canopy is not on the pit yet. I use a normal household rotary fan blowing air in from the
location of the rudders) Space and noise will be an issue I have to take into consideration. Did I mention
budget as well :)
Thanks for sharing your insight with us Craig.
Cheers,
Al
Sydney, Oz
----- Original Message -----
From: Craig Rochester <mailto:johncraigroch@msn.com>
To: simpits-tech@simpits.org
Sent: Sunday, June 15, 2003 3:12 PM
Subject: RE: [simpits-tech] Gsuit-Aircompressor-F4
Hi Al,
I've been working with a couple of guys in Norway on this(I'm in US). We use the "shared file" in
Falcon4 to get the G data. One of the other guys wrote a small program that runs in the background with
Falcon. The program takes the G data and drives a servo. The servo pushes down on the diaphragm of a
pressure regulator that controls the pressure to the suit.
The max pressure in high G maneuvers(real jet) is about 10 psi. The military uses this in simulators at
about 5 psi max. I use mine at 4 psi max as 5 psi is starting to hurt.
I use mine more as a motion cue device than a simulation of the G-suit function. I've added a component
to increase the speed and sensitivity of the exhaust part of the regulator. By having immediate response,
changes in G feel like real motion(inertial forces).
I locate my compressor 50' away in another room. The rig makes a fair amount of hissing a farting; I
wrap a towel around it and reduce most of the noise.
There's info here:
http://www.simpits.org/forums/viewtopic.php?topic=55&forum=1&28
<http://www.simpits.org/forums/viewtopic.php?topic=55&forum=1&28>
http://forums.frugalsworld.com/vbb/showthread.php?s=&threadid=20800
<http://forums.frugalsworld.com/vbb/showthread.php?s=&threadid=20800>
Craig R.
-----Original Message-----
From: simpits-tech-admin@simpits.org [mailto:simpits-tech-admin@simpits.org]On Behalf Of Albert
Sent: Saturday, June 14, 2003 7:30 PM
To: simpits-tech@simpits.org
Subject: [simpits-tech] Gsuit-Aircompressor-F4
I think someone has already been using a air compressor controlled by a computer to inflat a Gsuit for
their flight simulator?
My Gsuit is coming in on Wednesday (Thanks to Sukit from Thailand) and I was wondering how the setup
is. What kind of computer, software and compressor are used and if it can be used in conjunction with falcon
4?
My other concerns are the noise factor from the compressor...as well as the pain factor :)
Thanks in advance,
Al
Sydney, Oz
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<DIV><SPAN class=3D968034513-15062003><FONT face=3DArial>Hi=20
Marv,</FONT></SPAN></DIV>
<DIV><SPAN class=3D968034513-15062003><FONT =
face=3DArial></FONT></SPAN> </DIV>
<DIV><SPAN class=3D968034513-15062003><FONT face=3DArial>Do you mean a =
ball check=20
valve? I tried that first, but couldn't get it to work. A =
quick=20
exhaust valve(QEV), is a 3-way valve where the exhaust flow moves a =
seat(usually=20
a rubber disk/seal) like this: </FONT><A=20
href=3D"http://www.polyconn.com/pdf_files/quick_exhaust_valves.pdf"><FONT=
=20
face=3DArial=20
color=3D#000000>http://www.polyconn.com/pdf_files/quick_exhaust_valves.pd=
f</FONT></A><FONT=20
face=3DArial> I use these in my work for big pneumatic control =
valves that=20
would take to long to exhaust through the solenoid valve. They =
work great=20
for higher pressures in the 0-100 psi range. I tried the one in =
the above=20
link on my rig, but the friction in the seat was too =
much.</FONT></SPAN></DIV>
<DIV><SPAN class=3D968034513-15062003><FONT =
face=3DArial></FONT></SPAN> </DIV>
<DIV><SPAN class=3D968034513-15062003><FONT face=3DArial>I had some =
pneumatic=20
cylinders I bought on ebay. I used a 1.5" piston with two cup=20
seals in a PVC plumbing fitting(has a bit larger ID than =
1.5"). =20
</FONT><A=20
href=3D"http://pages.zdnet.com/johncraigrochester/sitebuildercontent/site=
builderpictures/new_qev.jpg"><FONT=20
face=3DArial=20
color=3D#000000>http://pages.zdnet.com/johncraigrochester/sitebuildercont=
ent/sitebuilderpictures/new_qev.jpg</FONT></A><FONT=20
face=3DArial> The larger cylinder ID and dry graphite lubricant =
yielded=20
the desired sensitivity and exhaust capacity. But... I had problems =
with=20
the cup seals sticking open when exhaust was complete. In the=20
pic the cup seal nearest the check valve slide over the exhaust =
holes. The=20
cup seals would stick on the edges of the holes. I tried a bunch of =
thing to=20
stop this; beveled edges, staggered, drilled on angle... Finally I =
changed to an=20
"O" ring against a metal seat design, which finally =
worked.</FONT></SPAN></DIV>
<DIV><SPAN class=3D968034513-15062003><FONT =
face=3DArial></FONT></SPAN> </DIV>
<DIV><SPAN class=3D968034513-15062003><FONT face=3DArial>The performance =
from the=20
QEV rig really made the difference between a cool feedback for the =
magnitude of=20
the G-force vs.. an even better real-time feedback of small force =
changes. =20
</FONT><FONT face=3DArial>Quantitatively, the regulator without the=20
QEV --> a 1/4 psi reduction in pressure takes about 1 =
second to=20
exhaust. With the QEV the exhaust is almost immediate(faster than I can=20
measure). This feels much different in the suit. Without the quick =
response, the=20
small changes aren't as noticeable; it takes about 1 psi change to =
perceive the=20
reduction. With the quick exhaust small changes in stick =
position(=3Dsmall G-force=20
changes) are felt in the suit. It's like the way a motion platform uses =
"wash=20
out" to return to neutral force, only we don't want the wash=20
out.</FONT></SPAN></DIV>
<DIV><SPAN class=3D968034513-15062003><FONT =
face=3DArial></FONT></SPAN> </DIV>
<DIV><SPAN class=3D968034513-15062003><FONT face=3DArial>Craig=20
R.</FONT></DIV></SPAN>
<DIV><FONT size=3D2><SPAN =
class=3D968034513-15062003></SPAN></FONT> </DIV>
<DIV><FONT face=3D"Times New Roman"><FONT size=3D2><SPAN=20
class=3D968034513-15062003> </SPAN>-----Original Message-----<SPAN=20
class=3D968034513-15062003><FONT face=3DArial color=3D#0000ff> =20
</FONT></SPAN><BR><B>From:</B> simpits-tech-admin@simpits.org=20
[mailto:simpits-tech-admin@simpits.org]<B>On Behalf Of</B> Marv De=20
Beque<BR><B>Sent:</B> Sunday, June 15, 2003 8:33 AM<BR><B>To:</B>=20
simpits-tech@simpits.org<BR><B>Subject:</B> Re: [simpits-tech]=20
Gsuit-Aircompressor-F4<BR><BR></DIV></FONT></FONT>
<BLOCKQUOTE><FONT face=3DVerdana>Craig,<BR><BR>Have you considered a =
ball valve=20
for the exhaust port?<BR><BR><BR>On 6/15/03 8:08 AM, "Craig Rochester" =
<johncraigroch@msn.com> wrote:<BR><BR></FONT>
<BLOCKQUOTE><FONT color=3D#0000ff><FONT size=3D2><FONT face=3DArial>Hi =
Albert,<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial><B><U>Cautionary =
note:=20
</U></B>working with compressed air is inherently dangerous, as =
there's a=20
lot of stored energy.<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR></FONT><FONT color=3D#0000ff><FONT size=3D2><FONT =
face=3DArial>I=20
bought the regulators and servos on eBay for about $45US. =
There's=20
another $15 in miscellaneous materials. You'd need a lathe to =
make the=20
piston for the "quick exhaust valve(QEV)". The servo =
controller I'm=20
using costs $54US and is a "no-brainer" to use with the program =
written by=20
the guy in Norway.<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR></FONT><FONT color=3D#0000ff><FONT size=3D2><FONT =
face=3DArial>I=20
use a nail gun compressor @ 100 psi supply pressure. I've =
tested down=20
to 40 psi. You need the compressor at a higher pressure to =
ensure fast=20
response. One of the Norway guys is using an old refrigerator=20
compressor. He says it is very quiet and has the required =
capacity.=20
If it were me, I'd go for the free compressor and run a long =
air hose=20
to the computer.<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial>I've been =
struggling with the=20
QEV design. I've made a couple and they're being tested. =
When=20
the design is proven reliable, I'll post construction details. =
I don't=20
intend to make the rigs for sale.<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR></FONT><FONT color=3D#0000ff><FONT size=3D2><FONT =
face=3DArial>Craig<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR> <BR> <BR></FONT><FONT size=3D2><FONT=20
face=3D"Times New Roman">-----Original Message-----<BR><B>From:</B>=20
simpits-tech-admin@simpits.org =
[mailto:simpits-tech-admin@simpits.org]<B>On=20
Behalf Of</B> Albert<BR><B>Sent:</B> Sunday, June 15, 2003 4:16=20
AM<BR><B>To:</B> simpits-tech@simpits.org<BR><B>Subject:</B> Re:=20
[simpits-tech] Gsuit-Aircompressor-F4<BR><BR></FONT></FONT>
<BLOCKQUOTE><FONT size=3D2><FONT face=3DArial>G'day=20
Craig,<BR></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT =
size=3D2><FONT=20
face=3DArial>Good to hear from you. The concept of the servo =
pushes down on=20
the diaphragm of a pressure regulator make sense to me. How it is=20
constructed is something I am not too sure at this stage. However, =
I am=20
researching and evaluating whether its a thing to do to my own =
project.=20
After reading on the simpit forum link. I wonder how much will a =
normal=20
regular/ exhaust valve be worth? Like yourself, I have never work =
with a=20
servo previously, but I am slowly coming to terms with what it =
does :)=20
Judging from the amount of PSI required to inflat the Gsuit... =
will=20
something like a small compressor typical for airbrushing be good =
for the=20
purpose? <BR></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT=20
size=3D2><FONT face=3DArial>A mate was going to give me a 50PSI =
air compressor=20
(for nail gun) but when I told him the most I will need from a =
compressor=20
is only about 10 PSI. He asked me what on earth am I doing with =
it? YOu=20
should have seen the guy trying hard to understand what on earth I =
am=20
trying to do :) Judging by your experience, it sounds like it =
really only=20
need 4psi to do the job. So I thought something small will =
hopefully be=20
cheaper and also quieter compared to a larger louder compressor.=20
<BR></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT =
size=3D2><FONT=20
face=3DArial>Similar to the problem of trying to cool down my =
cockpit=20
previously with an active cooling system. (At the moment, the =
canopy is=20
not on the pit yet. I use a normal household rotary fan blowing =
air in=20
from the location of the rudders) Space and noise will be an issue =
I have=20
to take into consideration. Did I mention budget as well :)=20
<BR></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT =
size=3D2><FONT=20
face=3DArial>Thanks for sharing your insight with us=20
Craig.<BR></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT =
size=3D2><FONT=20
face=3DArial>Cheers,<BR><BR>Al<BR>Sydney, =
Oz<BR></FONT></FONT><FONT=20
face=3DVerdana>----- Original Message ----- <BR><B>From:</B> Craig =
Rochester=20
<mailto:johncraigroch@msn.com> <BR><B>To:</B>=20
simpits-tech@simpits.org <BR><B>Sent:</B> Sunday, June 15, 2003 =
3:12=20
PM<BR><B>Subject:</B> RE: [simpits-tech]=20
Gsuit-Aircompressor-F4<BR><BR></FONT><FONT color=3D#0000ff><FONT=20
size=3D2><FONT face=3DArial>Hi Al,<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR></FONT><FONT color=3D#0000ff><FONT =
size=3D2><FONT=20
face=3DArial>I've been working with a couple of guys in Norway on =
this(I'm=20
in US). We use the "shared file" in Falcon4 to get the G =
data.=20
One of the other guys wrote a small program that runs in the =
background with Falcon. The program takes the G data and =
drives a=20
servo. The servo pushes down on the diaphragm of a pressure=20
regulator that controls the pressure to the=20
suit.<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial>The max pressure =
in high G=20
maneuvers(real jet) is about 10 psi. The military uses this =
in=20
simulators at about 5 psi max. I use mine at 4 psi max as 5 psi is =
starting to hurt.<BR></FONT></FONT></FONT><FONT=20
face=3DVerdana><BR></FONT><FONT color=3D#0000ff><FONT =
size=3D2><FONT=20
face=3DArial>I use mine more as a motion cue device than a =
simulation of the=20
G-suit function. I've added a component to increase the =
speed and=20
sensitivity of the exhaust part of the regulator. By having=20
immediate response, changes in G feel like real motion(inertial=20
forces).<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial>I locate my =
compressor 50'=20
away in another room. The rig makes a fair amount of hissing =
a=20
farting; I wrap a towel around it and reduce most of the=20
noise.<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial>There's info=20
here:<BR></FONT></FONT></FONT><FONT =
face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT=20
=
face=3DArial>http://www.simpits.org/forums/viewtopic.php?topic=3D55&f=
orum=3D1&28=20
=
<http://www.simpits.org/forums/viewtopic.php?topic=3D55&amp;forum=3D=
1&amp;28>=20
=
<BR>http://forums.frugalsworld.com/vbb/showthread.php?s=3D&threadid=3D=
20800=20
=
<http://forums.frugalsworld.com/vbb/showthread.php?s=3D&amp;thread=
id=3D20800>=20
<BR></FONT></FONT></FONT><FONT face=3DVerdana><BR></FONT><FONT=20
color=3D#0000ff><FONT size=3D2><FONT face=3DArial>Craig=20
R.<BR></FONT></FONT></FONT>
<BLOCKQUOTE><FONT size=3D2><FONT face=3D"Times New =
Roman">-----Original=20
Message-----<BR><B>From:</B> simpits-tech-admin@simpits.org=20
[mailto:simpits-tech-admin@simpits.org]<B>On Behalf Of</B>=20
Albert<BR><B>Sent:</B> Saturday, June 14, 2003 7:30 =
PM<BR><B>To:</B>=20
simpits-tech@simpits.org<BR><B>Subject:</B> [simpits-tech]=20
Gsuit-Aircompressor-F4<BR><BR></FONT><FONT face=3DArial>I think =
someone=20
has already been using a air compressor controlled by a computer =
to=20
inflat a Gsuit for their flight simulator?<BR><BR>My Gsuit is =
coming in=20
on Wednesday (Thanks to Sukit from Thailand) and I was wondering =
how the=20
setup is. What kind of computer, software and compressor are =
used and if=20
it can be used in conjunction with falcon 4? <BR> <BR>My =
other=20
concerns are the noise factor from the compressor...as well as =
the pain=20
factor :)<BR> <BR>Thanks in =
advance,<BR> <BR>Al<BR>Sydney,=20
Oz<BR></FONT></FONT></BLOCKQUOTE></BLOCKQUOTE><FONT=20
face=3DVerdana><BR></FONT></BLOCKQUOTE><FONT=20
face=3DVerdana><BR></BLOCKQUOTE></FONT></BODY></HTML>
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