Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Incompatibility with CAT air trap and Kingtech/Jetcat engines?

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Incompatibility with CAT air trap and Kingtech/Jetcat engines?

Old 01-22-2016, 10:04 PM
  #1  
dubd
Thread Starter
 
dubd's Avatar
 
Join Date: Aug 2007
Location: Bay Area, CA
Posts: 4,313
Likes: 0
Received 2 Likes on 2 Posts
Default Incompatibility with CAT air trap and Kingtech/Jetcat engines?

I heard Kingtech and Jetcat do not recommend using CAT air traps with their engines. Can either company, their reps, or someone who knows for certain verify this information?
Old 01-23-2016, 03:30 AM
  #2  
BlueBus320
My Feedback: (57)
 
Join Date: Mar 2002
Location: Rockville Centre
Posts: 1,674
Received 3 Likes on 2 Posts
Default

I've never heard that. Thanks for posting, I planned on picking one up.
Subscribed, Jay
Old 01-23-2016, 06:35 AM
  #3  
Midas D.
 
Join Date: Apr 2013
Location: holland, NETHERLANDS
Posts: 474
Likes: 0
Received 0 Likes on 0 Posts
Default

Had one on the K140, and going to get one as we speak on the K45.Works flawless, don't know where this comes from ??
Old 01-23-2016, 06:45 AM
  #4  
Jannica
 
Join Date: Jun 2008
Location: Borlange, SWEDEN
Posts: 251
Received 23 Likes on 20 Posts
Default

Sounds like a hoax. I would not care.

Jannica
Old 01-23-2016, 07:02 AM
  #5  
dubd
Thread Starter
 
dubd's Avatar
 
Join Date: Aug 2007
Location: Bay Area, CA
Posts: 4,313
Likes: 0
Received 2 Likes on 2 Posts
Default

I hope it's not true as I have many CAT air traps and never had a problem.
Old 01-23-2016, 08:27 AM
  #6  
Helijet
 
Join Date: Jan 2002
Location: Kamloops, BC, CANADA
Posts: 1,023
Received 9 Likes on 8 Posts
Default

???? I would be very interested to hear how this came about.
Someone have a gripe with them???

Dean w.
Old 01-23-2016, 08:49 AM
  #7  
vinnyjet
My Feedback: (39)
 
vinnyjet's Avatar
 
Join Date: Dec 2001
Location: brooklyn, NY
Posts: 1,295
Likes: 0
Received 0 Likes on 0 Posts
Default

I am sure john and barry will post here
Old 01-23-2016, 08:53 AM
  #8  
jws_aces
My Feedback: (33)
 
jws_aces's Avatar
 
Join Date: Jul 2002
Location: Salem, Va
Posts: 1,048
Received 1 Like on 1 Post
Default

I have the Cats in my first Hawk and my current one. I had over 160 flights on the first one with no Issues. I use the Cats on both the engine and the smoke.

The only gripe I have is the orings. On my first one I mounted them hanging down. I finally ended up using rubber bands to hold them. The second one I mount them upright and no issues. I guess the G's got the orings

I have kingtech for power. I have run both 180g and the 210g with the cats.
Old 01-23-2016, 09:46 AM
  #9  
FenderBean
 
FenderBean's Avatar
 
Join Date: Feb 2006
Location: Huntsville AL
Posts: 7,135
Likes: 0
Received 77 Likes on 51 Posts
Default

I had a conversation with D at KT the other day he gave me some info on this very subject, if I remember correctly it was certain size that has an issue. Being so efficient now in a smaller package, I am pretty sure this was what he referred to but give him a call. Its the 210 size

Last edited by FenderBean; 01-23-2016 at 10:00 AM.
Old 01-23-2016, 09:52 AM
  #10  
mr_matt
My Feedback: (10)
 
mr_matt's Avatar
 
Join Date: Dec 2001
Location: Oak Park, CA,
Posts: 10,446
Likes: 0
Received 12 Likes on 10 Posts
Default

I have been using a 130 ml CAT on a 210+N JetCat and the pump voltages are fine. I would have went with the bigger one but no room. FWIW
Old 01-23-2016, 03:38 PM
  #11  
marquisvns
 
marquisvns's Avatar
 
Join Date: Oct 2005
Location: Pasadena, CA
Posts: 1,816
Received 3 Likes on 3 Posts
Default

Between myself and Dirk, we've had troubleshot over a dozen complaints of flame outs, with pump limit reached and speed low message display on these ECU, after exhausted all possibilities, all came down to the same solution - change out the CAT UAT. A customer based in Florida Dirk was supporting went as far as cutting it open and found much debris in the canister.

I myself never owned a CAT UAT until the 1/5 F-16 from Scott Marr since last October. 15 or so flights went by without a problem, and at Jets over Lake Havasu, after one landing the GSU displayed pump limit reached at 500, (the limit was set at 350 and full throttles at 300) I increased pump limit under RUN menu but the next flight engine flamed out with speed low message. After Havasu, I did nothing but swapped out the UAT to our own, all subsequent flights were flawless with normal pw values.

For kicks, Dirk cut the CAT open, also found debris inside the CAT, not enough to cause a resistance to the core of the UAT. Subsequent pressure testing of the pleated paper filter core checks out fine with no abnormal resistance, so the only possibility that I could think of is during fueling that the debris may have flushed from the bottom and gotten well stuck into the port and caused a high resistance.


Kris Gunter or Gunradd received a PM from overseas on another thread also concerning the CAT by a reputable member in this community "....... but we have the same thing, I know a lot of people used the CAT had flame outs and then changed to ...... and had no further problems changing nothing else."


We have been holding back on this matter with caution to damage the reputation of CAT, but ultimately, I suppose revealing facts that has direct impact to safety is always important.


Regards,
Barry
Attached Thumbnails Click image for larger version

Name:	10715.jpeg
Views:	1406
Size:	470.1 KB
ID:	2143040   Click image for larger version

Name:	11050.jpeg
Views:	1599
Size:	1,003.8 KB
ID:	2143041   Click image for larger version

Name:	11052.jpeg
Views:	1652
Size:	794.3 KB
ID:	2143042   Click image for larger version

Name:	11046.jpeg
Views:	1617
Size:	526.2 KB
ID:	2143043  

Last edited by marquisvns; 01-23-2016 at 03:46 PM.
Old 01-23-2016, 05:08 PM
  #12  
FenderBean
 
FenderBean's Avatar
 
Join Date: Feb 2006
Location: Huntsville AL
Posts: 7,135
Likes: 0
Received 77 Likes on 51 Posts
Default

I think interairco is on to something with the clear hi flow uats and fuel filters. I found some things already when I defueled that I would never have found with a regular style. Nice being able see trash in it.
Old 01-23-2016, 08:04 PM
  #13  
Helijet
 
Join Date: Jan 2002
Location: Kamloops, BC, CANADA
Posts: 1,023
Received 9 Likes on 8 Posts
Default

So, it appears that the CAT filter /air trap is working as advertised. It actually is capturing crap like any other filter.
I guess I don't understand as to how it is problematic? It does not loosen around a neck as do other brands, It does not expand and contract with filling.
If the filter gets dirty, flush it or replace it - isn't that the idea????

Please enlighten me as to why I should not use this product over the BVM or MAP UAT?

D.W.
Old 01-23-2016, 08:25 PM
  #14  
gunradd
My Feedback: (9)
 
gunradd's Avatar
 
Join Date: Aug 2008
Location: Springhill, FL
Posts: 3,426
Received 50 Likes on 43 Posts
Default

Originally Posted by Helijet
So, it appears that the CAT filter /air trap is working as advertised. It actually is capturing crap like any other filter.
I guess I don't understand as to how it is problematic? It does not loosen around a neck as do other brands, It does not expand and contract with filling.
If the filter gets dirty, flush it or replace it - isn't that the idea????

Please enlighten me as to why I should not use this product over the BVM or MAP UAT?

D.W.
Not really sure what the problem is but on several different aircraft they had flameout issues with the CAT and changed it out and no problems after.
Old 01-23-2016, 08:48 PM
  #15  
Ragz
 
Ragz's Avatar
 
Join Date: Dec 2001
Location: Nagpur, INDIA
Posts: 2,609
Likes: 0
Received 4 Likes on 3 Posts
Default

I have owned and used almost 6-8 CAT's. Been happy so far. The customer service is second to none and Marc takes that extra effort to answer every single question.
Old 01-23-2016, 09:59 PM
  #16  
Boomerang1
 
Boomerang1's Avatar
 
Join Date: Jun 2005
Location: Sydney, AUSTRALIA
Posts: 2,960
Received 20 Likes on 10 Posts
Default

Did you check the CAT was full following any flame outs?

Any fuel weeping on the outside body of the CAT?

The outer tube of these tanks is quite delicate, it only takes a slight compression to cause tiny
cracks in them. A friend has an Xcalibur & the guy who built it jammed the CAT in the nose
above the wheel well moulding causing a tiny crack in it. Only a very slight weep of fuel but
the fuel pump suction drew in more than half a CAT full of air after a few minutes stopping the
engine.

John.
Old 01-23-2016, 10:02 PM
  #17  
dubd
Thread Starter
 
dubd's Avatar
 
Join Date: Aug 2007
Location: Bay Area, CA
Posts: 4,313
Likes: 0
Received 2 Likes on 2 Posts
Default

I've also has nothing but success with the CATs, which is why I'd like to know if this is a real issue or not.
Old 01-23-2016, 11:47 PM
  #18  
marquisvns
 
marquisvns's Avatar
 
Join Date: Oct 2005
Location: Pasadena, CA
Posts: 1,816
Received 3 Likes on 3 Posts
Default

Originally Posted by Helijet
So, it appears that the CAT filter /air trap is working as advertised. It actually is capturing crap like any other filter.
I guess I don't understand as to how it is problematic? It does not loosen around a neck as do other brands, It does not expand and contract with filling.
If the filter gets dirty, flush it or replace it - isn't that the idea????

Please enlighten me as to why I should not use this product over the BVM or MAP UAT?

D.W.
The function of an UAT is to trap air from the surface tension of the fuel from the filter media. Normally an UAT is not designed to be back flushed.

A filter filters the fuel. This is why it's typically plumbed right before the engine and it isn't eliminated by the presence of an UAT.

Barry
Old 01-24-2016, 12:02 AM
  #19  
marquisvns
 
marquisvns's Avatar
 
Join Date: Oct 2005
Location: Pasadena, CA
Posts: 1,816
Received 3 Likes on 3 Posts
Default

Originally Posted by Boomerang1
Did you check the CAT was full following any flame outs?

Any fuel weeping on the outside body of the CAT?

The outer tube of these tanks is quite delicate, it only takes a slight compression to cause tiny
cracks in them. A friend has an Xcalibur & the guy who built it jammed the CAT in the nose
above the wheel well moulding causing a tiny crack in it. Only a very slight weep of fuel but
the fuel pump suction drew in more than half a CAT full of air after a few minutes stopping the
engine.

John.
John, the CAT was full and with no leaks. Based on the shape and size of the debris seemed had to be from within.

Perhaps we could look into reconfigure the plumbing of any UAT. Cap off one of the upper ports and use a T fitting to plumb a fill/defuel line from the other. This way the UAT would not be back flushed during filling.

Regards,
Barry
Old 01-24-2016, 01:13 AM
  #20  
olnico
 
olnico's Avatar
 
Join Date: May 2007
Location: Houston, Texas.
Posts: 4,120
Likes: 0
Received 15 Likes on 9 Posts
Default

Originally Posted by marquisvns
The function of an UAT is to trap air from the surface tension of the fuel from the filter media. Normally an UAT is not designed to be back flushed.
.

Barry
Wrong and wrong.

Modern air traps are not designed to eliminate cavitation but to reduce the likeliness of it by reducing the suction drag they create. However:

The primary function of an air trap is to work as a complement to the non perfect clunk.

As a reminder, air gets sucked into the system while performing maneuvers. No clunk system is perfect and no matter what, it will get into an empty portion of the tank at some point and pickup air.
When this happens, air is sent into the system downstream the tank and will be trapped by the air trap. The more aerobatics, the stiffer the clunk line, the more air will be sent into the system, especially towards the end of the flight. This is normal and cannot be avoided.

So it is essential to be able to back flush your air trap to refill it between each flight.

Otherwise, after a few flights, the air trap will be empty.

Also, there is a big mis-conception with the latest air trap. People believe that it is so good at trapping cavitation, that they do not need to have a big air trap volume in there. Once again, cavitation trapping is a secondary function of the air trap. The primary function is to block the air that is being sucked by the clunk and offer continuous flow to the engine. The main advantage of CATs or similar is to offer a various buffer volumes. Large volumes are important for big engines and I recommend chosing an air trap that offers 30 seconds of buffer at full thrust.

Down sizing an air trap is a big mistake and most system that I have seen getting people flame outs where either because of a drastic restriction in the system ( creating a cavitation condition ), wrong clunk line plumbing ( clunks blocking against a wall or stiff line due to hardening tygon ) and very small air trap buffer capacity.
Old 01-24-2016, 01:44 AM
  #21  
olnico
 
olnico's Avatar
 
Join Date: May 2007
Location: Houston, Texas.
Posts: 4,120
Likes: 0
Received 15 Likes on 9 Posts
Default

Originally Posted by marquisvns

Perhaps we could look into reconfigure the plumbing of any UAT. Cap off one of the upper ports and use a T fitting to plumb a fill/defuel line from the other. This way the UAT would not be back flushed during filling.

Regards,
Barry
Nope. This will invariably lead to a flame out after 2 to 3 flights because the air trap will be empty.
It is absolutely essential to ensure that the air trap is re-filled after each flight.

It must be back flushed after each flight
.
Old 01-24-2016, 01:49 AM
  #22  
marc s
 
marc s's Avatar
 
Join Date: Jan 2007
Location: farnborough, , UNITED KINGDOM
Posts: 3,294
Likes: 0
Received 1 Like on 1 Post
Default

Hi guys, thought I might chime in here as I make the CAT products - every one by hand, by myself using cnc machined parts from the UK and filters from one of the largest US filter companies!

The first I heard of the 'Kingtech' issue was via a customer of mine who indicated Barry may have had some clients with issues, I hasten to say I did not hear from Barry direct, which would have been nicer. Anyway I contacted and had an email conversation with Barry asking for the detail, replied to this feedback and then heard nothing back.

The CAT is a simple device using a pleated paper fuel filter as the pickup and filter, as said these are sourced from the USA and shipped to me direct, the cases are hand made by me on mandrels and are made of 8 layers of two different glass cloths using West resins, the end caps are black FR4 (G10 to the US guys), the barbs are machined to my own design here in the UK by an RC friend who has a large business machining parts for the oil industry, these brass barbs are now also chromed to make them more durable, the internal filter standoff is machined by the same company from high grade aluminium, these are bonded to the filters with Hysol following a process of keying and cleaning so NO debris is present when manufacture is completed.

Each CAT is pressure tested to a minimum of 30psi, which is what most of our modern day car tyre pressures are inflated to, so the case and bonding is strong, naturally jamming it into spaces is not ideal nor recommended as first you should be able to see the CAT to enable observation of fuel/air issues and second it could cause damage. I make the cases from glassfibre and epoxy and the ends from FR4 (epoxy/glass board) so that the materials being bonded are of the same family making the bond the strongest, bonding different materials for many adhesives can result is reduced bond strength.

Some 5 years ago Cranfield University here in the UK were working with NASA and Boeing on development of the X-48 and they contacted me to ask if they could test the CAT as they were looking for an air trap to use in the project, I shipped them 4 and following 6 months of testing they confirmed these were the best performing air traps they had tested, (I was not privy to the other brands tested) and the result was they were used with both Jetcat and AMT Titan turbines in the project and performed without issues. I would expect the testing followed some fairly well documented and tried processes.

I appreciate that this does not provide a guarantee, but it does prove the system and concept have been tested by authorities who have undergone lab and field testing to a very high level.

The filter in the CAT is designed to act as a filter, and I would expect it to do so, debris is going to get trapped in it on occasion and this would highlight potential issues with fuel, pre-filtering or something else. The filter size is very large when compared to many other UAT products and this provides a huge surface area for filtering but also allowing fuel to freely flow through it. All filters will gather debris, in sintered types the debris embeds itself in the honeycomb of the filter making observation difficult and not easy to detect until restrictions build up and something then results.

The CAT does have one issue, the O ring fixing system. It is one area that I am reviewing to improve, O rings are easy to replace however, available from me or Todd at Dreamworks and cheap as chips, even if they need replacing every 3 months its only going to cost you a few $ a year. If there is a problem with the extra $ then email me with your address and CAT size and I will send you some FOC

The CAT may not be the solution for everyone, the choice you have is much bigger now, I remember back to the days when the good old BVM air trap was being widely used and some loved it and others did not, many still use them and love them, many don't, there is no right way or wrong way but I know the CAT does what its designed to do, its been tested at the highest level and I know each one is made exactly the same way as every one before it, I do not outsource any assembly processes, apply the Hysol myself, tap each barb hole, layup each tube, cnc each mounting base myself and test and package each too.

Finally I have had no direct feedback or comment from Jetcat, in fact I would be surprised if there was, one top German kit manufacturer who sells a huge jet kit supplies a custom 450ml CAT to them to use as these jets are mainly powered by the P400 turbine. BF turbines also recently purchased 450ml CAT's for use with the B500 turbine following testing.

If anyone has a problem or a comment or a suggestion around making the CAT better please get in touch, I'm very happy to provide help, suggestions and learn from your experiences.

Safe flying.

marcs
Old 01-24-2016, 05:42 AM
  #23  
Vincent
My Feedback: (61)
 
Vincent's Avatar
 
Join Date: Dec 2001
Location: Arizona
Posts: 5,014
Received 20 Likes on 16 Posts
Default

In one of the pics Barry posted it looks like some fiberglass fibers sitting on a wire mesh screen. Is that screen inside the cats paper filter element??
Vin...
Old 01-24-2016, 07:41 AM
  #24  
RCFlyerDan
My Feedback: (54)
 
RCFlyerDan's Avatar
 
Join Date: Apr 2002
Location: SWFL
Posts: 2,004
Received 68 Likes on 51 Posts
Default

Originally Posted by vinnyjet
I am sure john and barry will post here
When you have an issue, why not call and get it from the horse's mouth? Instead of posting on here? If I have an issue with a product, I always call the company, instead of getting "SWAG's" on here.
Old 01-24-2016, 08:05 AM
  #25  
David Gladwin
 
David Gladwin's Avatar
 
Join Date: Feb 2002
Location: CookhamBerkshire, UNITED KINGDOM
Posts: 3,913
Received 141 Likes on 90 Posts
Default

Originally Posted by marc s
Hi guys, thought I might chime in here as I make the CAT products - every one by hand, by myself using cnc machined parts from the UK and filters from one of the largest US filter companies!

The first I heard of the 'Kingtech' issue was via a customer of mine who indicated Barry may have had some clients with issues, I hasten to say I did not hear from Barry direct, which would have been nicer. Anyway I contacted and had an email conversation with Barry asking for the detail, replied to this feedback and then heard nothing back.

The CAT is a simple device using a pleated paper fuel filter as the pickup and filter, as said these are sourced from the USA and shipped to me direct, the cases are hand made by me on mandrels and are made of 8 layers of two different glass cloths using West resins, the end caps are black FR4 (G10 to the US guys), the barbs are machined to my own design here in the UK by an RC friend who has a large business machining parts for the oil industry, these brass barbs are now also chromed to make them more durable, the internal filter standoff is machined by the same company from high grade aluminium, these are bonded to the filters with Hysol following a process of keying and cleaning so NO debris is present when manufacture is completed.

Each CAT is pressure tested to a minimum of 30psi, which is what most of our modern day car tyre pressures are inflated to, so the case and bonding is strong, naturally jamming it into spaces is not ideal nor recommended as first you should be able to see the CAT to enable observation of fuel/air issues and second it could cause damage. I make the cases from glassfibre and epoxy and the ends from FR4 (epoxy/glass board) so that the materials being bonded are of the same family making the bond the strongest, bonding different materials for many adhesives can result is reduced bond strength.

Some 5 years ago Cranfield University here in the UK were working with NASA and Boeing on development of the X-48 and they contacted me to ask if they could test the CAT as they were looking for an air trap to use in the project, I shipped them 4 and following 6 months of testing they confirmed these were the best performing air traps they had tested, (I was not privy to the other brands tested) and the result was they were used with both Jetcat and AMT Titan turbines in the project and performed without issues. I would expect the testing followed some fairly well documented and tried processes.

I appreciate that this does not provide a guarantee, but it does prove the system and concept have been tested by authorities who have undergone lab and field testing to a very high level.

The filter in the CAT is designed to act as a filter, and I would expect it to do so, debris is going to get trapped in it on occasion and this would highlight potential issues with fuel, pre-filtering or something else. The filter size is very large when compared to many other UAT products and this provides a huge surface area for filtering but also allowing fuel to freely flow through it. All filters will gather debris, in sintered types the debris embeds itself in the honeycomb of the filter making observation difficult and not easy to detect until restrictions build up and something then results.

The CAT does have one issue, the O ring fixing system. It is one area that I am reviewing to improve, O rings are easy to replace however, available from me or Todd at Dreamworks and cheap as chips, even if they need replacing every 3 months its only going to cost you a few $ a year. If there is a problem with the extra $ then email me with your address and CAT size and I will send you some FOC

The CAT may not be the solution for everyone, the choice you have is much bigger now, I remember back to the days when the good old BVM air trap was being widely used and some loved it and others did not, many still use them and love them, many don't, there is no right way or wrong way but I know the CAT does what its designed to do, its been tested at the highest level and I know each one is made exactly the same way as every one before it, I do not outsource any assembly processes, apply the Hysol myself, tap each barb hole, layup each tube, cnc each mounting base myself and test and package each too.

Finally I have had no direct feedback or comment from Jetcat, in fact I would be surprised if there was, one top German kit manufacturer who sells a huge jet kit supplies a custom 450ml CAT to them to use as these jets are mainly powered by the P400 turbine. BF turbines also recently purchased 450ml CAT's for use with the B500 turbine following testing.

If anyone has a problem or a comment or a suggestion around making the CAT better please get in touch, I'm very happy to provide help, suggestions and learn from your experiences.

Safe flying.

marcs
Dont worry, marcs there absolutely nothing wrong, and everything right, with the CAT which is why so many of us, including myself, use them with complete success. It's the OPERATORS who are getting it wrong by improper and/or insufficient fuel filtration. Rather like those who blame Festo filter leaks, which are designed for gaseous vacuums, because they leak occasionally leak when improperly used under fuel pressure !!

Following fullsize practice I filter fuel multiple times BEFORE it gets into the aircraft so that its clinically clean and the final filters including the last chance filter present on some engines. should have, and don't have, anything to do.

Some advice:

Obtain fuel from a known, clean source, you'd be surprised how dirty some fuel is from GA airfields. Kerosene from UK hardware stores such as B +Q is incredibly clean.

When transferring fuel to your bowser use a MR Funnel filter.

If there is ANY trace of water or debris repeat until clean and without water. Mr Funnel may not remove all water at first pass.

Use a filter on the entry side of the bowser, field, pump, and another after the pump in the line transferring it to the model.

Use an onboard filter in the refuelling line feeding the UAT, CAT or other header tank,and on to the main tank.

Use a very fine filter on the inlet side of the pump. JetCat metal filters are perfect (but must be tested under pressure before installation)

Result, perfectly pure fuel to the tanks and on to the engine and in jet aviation, (fuel) cleanliness is next to godliness !

All of my jets are configured this way and the filters in my two BobCats, my high time models, have been installed for about 13 years and hundreds of flights without replacement.

Of course the guys who replaced the CAT with another brand after it became blocked with debris, had no problems, the CAT had precleaned the system for him !

Enjoy the CAT, ( a far from delicate device when installed and used properly !

(Lets not abuse it !)

David.

PS for Fenderbean its INTAIRCO not Interairco, and that trap is also excellent.

Last edited by David Gladwin; 01-24-2016 at 08:46 AM.

Thread Tools
Search this Thread

Contact Us - 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.