Notices
PST Jets Direct support for PST Jets Turbines.

FOD screen

Old 04-26-2006, 07:46 AM
  #1  
Thread Starter
My Feedback: (1)
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,672
Likes: 0
Received 26 Likes on 16 Posts
Default FOD screen

I really need a proper FOD screen on my J600. I have a home made screen but it isn't sealed to the engine case at the back of the screen and I have noticed that two compressor blades have tiny impact chips on their leading edge. Is PST not going to make a proper FOD screen, and if not is their a screen from another brand that fits properly?

Harry
Old 04-26-2006, 07:57 AM
  #2  
My Feedback: (135)
 
Meesh's Avatar
 
Join Date: Jan 2003
Location: Dracut, MA
Posts: 2,798
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

Harry,

Todd at Dreamworks RC http://www.dreamworksrc.com

has one advertised for a JetCat P70 that fits my PSTJ600R perfectly.

You could also try putting a little Silicone RTV between the homemade screen and the turbine housing. I did this on the PST in my Boomerang Intro and it works fine.
Attached Thumbnails Click image for larger version

Name:	Xv63806.jpg
Views:	87
Size:	43.5 KB
ID:	451382  
Old 04-26-2006, 09:49 AM
  #3  
Senior Member
 
Join Date: Jul 2002
Location: Bangkok, THAILAND
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

Over-sized FOD screen should give adequate protection if it enclosed the engine front. We don't recommend a silicone sealant as this can come loose overtime and will be sucked into the engine. On my engine, I don't seal the back of the FOD screen against the engine cover. I use FOD screen that is about 1-2 cm larger than the engine diameter and just let it sits centered over the starter. When the turbine is running, the suction will pull the screen tight against the engine cover.

Keep it simple and make sure that the mesh is not too fine. Remember that if you reduce the intake air volume, you will raise the EGT and decrease the thrust output.
Old 09-06-2006, 08:54 AM
  #4  
My Feedback: (6)
 
limeybob's Avatar
 
Join Date: May 2003
Location: Rockwall, Tx, TX
Posts: 1,008
Likes: 0
Received 1 Like on 1 Post
Default RE: FOD screen

Made a FOD from a tea strainer, $1.00 at "Dollar General", fitted another make turbine perfectly, 3.75" O.D. . I also worried about the reduction in air due to the mesh, so decided to measure.
The mesh wire is .006, the mesh centers are .032, calculating shows a 67% air to mesh ratio.
The total available surface area of the mesh is 16 Sq in, take away the area of the starter and you are left with approx 15 sq in.
The available air entry is 15 x .67 =10 sq in . The area of the the compressor is approx 3.14 sq in.
So is the 3:1 ratio sufficient?
Thanks
Bob
Old 09-06-2006, 09:33 AM
  #5  
Senior Member
 
Join Date: May 2002
Location: Cornelius, OR
Posts: 624
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

You forgot the turbulence that round makes in airflow.
Darryl
Old 09-06-2006, 10:04 AM
  #6  
My Feedback: (6)
 
limeybob's Avatar
 
Join Date: May 2003
Location: Rockwall, Tx, TX
Posts: 1,008
Likes: 0
Received 1 Like on 1 Post
Default RE: FOD screen

Darryl, OK, so whats the answer?
Regards
Bob
Old 09-06-2006, 11:22 AM
  #7  
Senior Member
 
Join Date: May 2002
Location: Cornelius, OR
Posts: 624
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

Do not know, but real ones ice up with the right conditions.
Darryl
Old 09-06-2006, 12:24 PM
  #8  
Senior Member
 
Join Date: Jul 2002
Location: Bangkok, THAILAND
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

Bob,

Your calculation is correct for area ratio. However, the intake and compressor designs assume zero restriction or infinite area ratio to the surrounding. If we take this as 100% air volume available at the intake to the compressor, then any restriction you placed in front of the intake will reduce the air volume accordingly. From your information, you are restricting or reducing the intake air volume by 33%. What this means is that you are reducing the intake area by 33% and this will have direct effect to increased EGT and reduced thrust output. From experiment, an average FOD screen with 25% restriction will reduce thrust by about 10-15%. With higher restriction, engine ramping is also affected and you may experience hesitation or flaming during acceleration if ramping value is not changed.

Regards,
Kraivuth S.
PST Jets



Old 09-06-2006, 06:16 PM
  #9  
My Feedback: (6)
 
limeybob's Avatar
 
Join Date: May 2003
Location: Rockwall, Tx, TX
Posts: 1,008
Likes: 0
Received 1 Like on 1 Post
Default RE: FOD screen

Kraivuth S. , many thanks, great info.
So whats the optimum FOD, we have got to have something, right?
Regards
Bob
Old 09-06-2006, 10:59 PM
  #10  
Senior Member
 
Join Date: Jul 2002
Location: Bangkok, THAILAND
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

I would use FOD screen with 25% restriction or less. Sink drain filter works best. Tea strainer is too fine. I find these sink filter at kitchen or plumbing accessories section.

Have fun,
Kraivuth S.
Old 09-10-2006, 08:51 AM
  #11  
 
speedbrake's Avatar
 
Join Date: Jan 2006
Location: Fort Valley, GA
Posts: 476
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

I would like someone to answer HarryC's question. Is PST going to provide/manufacture a FOD screen for the 600R?

I looked at the screens provided by Dreamworks and there were none for the P70. They advertise screens for the P80 and up.

I've looked for a sink screen and can't seem to find one that meets the expert's criteria. I think there is a market for a screen for the 600R, I'll buy one if somebody decides to make them.

Speedbrake
Old 09-10-2006, 09:53 AM
  #12  
Senior Member
 
Join Date: Jul 2002
Location: Bangkok, THAILAND
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

PST Jets will produce the FOD screen for J600R and J1300R. Production takes time so I did a quick search on the internet and this is a sample of filters that can be used. They usually come in 60,70,90, and 110 mm sizes. 90mm is perfect for J600R while 110mm will fit the J1300R.

http://www.wholesalecentral.com/eagl...6catid%3D69077

Regards,
Kraivuth S.


Old 05-02-2007, 02:32 PM
  #13  
Senior Member
 
tahfiet's Avatar
 
Join Date: Mar 2002
Location: RaesfeldNRW, GERMANY
Posts: 463
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

Hi speedbrake!

Go for Tamjets FOD guard for a P-60. We use one on the J-600R in the reaction R54 and it a) works great, b) does look professional and c) ain't that expansive compared to a new compressor and/or turbien wheel. It comes with a big O-Ring to hold it on the starter. Both ends are "framed" and they provide short pieces of 3/4mm tube and two Festo-connectors.

Best regards,

David
Old 05-03-2007, 06:23 AM
  #14  
Senior Member
 
Join Date: Jul 2002
Location: Bangkok, THAILAND
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default RE: FOD screen

We now have FOD screen available for both J600R and J1300R. We are at the Top Gun 2007 in Florida and I will post the price and pictures here asap.

Cheers,
Kraivuth S.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.