RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Extreme Speed Prop Planes (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/)
-   -   CBM F-16N Retracs (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/2386897-cbm-f-16n-retracs.html)

alfplaza 11-29-2004 06:39 PM

CBM F-16N Retracs
 
Hello,

I bough my CBM F-16N almost a year ago and i sent it to a friends house in miami to pick it up, i was able to get it last weekend and when i opened the box the retracs were missing, i ordered them with the plane and never arrived.. I even wrote emails and call CBM to request them but nobody answers...

Does anyone know the exact robart retracs that i need to use, i will try to buy them separatly....

Also does anyone has any YS 45. with rear muffler?? the only one i can see is the YS 45 side muffler on Towerhobbies, but i want a much cleaner finish by installinig the tuned pipe iniside the fuselage instead of the typicall side installation... Has anyone tried to use any 45 Ducted fan engine with a 9X7 propeller???

Thanks,

Alfredo.

Razor-RCU 11-29-2004 07:12 PM

RE: CBM F-16N Retracs
 
Well I am not sure about the Robart # but as for the YS keep an eye on the swap shop and the OTHER auction site for a YS-45RE, it is THEE powerplant for this airplane-

A 9x7 would be too small on this airplane, even if you hit 19K IMHO [X(]

James

Propjet93 11-30-2004 12:06 AM

RE: CBM F-16N Retracs
 
I have 2 of these jets and would not recommend using robart (their website: www.robart.com) - used robart retracts and struts in a CBM A-10 and had problems. I used SpringAir in both with no problems (www.retracts.com).

YS.45 is a great choice (have several) but am going to try a JETT .50 this time?? Anyone have thoughts on this engine?

ljsoarinson 12-01-2004 02:42 PM

RE: CBM F-16N Retracs
 
The plans call for a Robart #607 nose retract and 605HD mains. Others have commented that the regular 605 mains are insufficient. I don't have experience with Robart pneumatics yet but will be building the CM F-16 with the above setup. I am curious to hear what problems the Robarts have that makes the Spring Air system more desirable.

I have looked into installing a Jett .50 on my model. After talking to Dubb at Jett Engineering he recommended the following: Jett .50, 10x6 APC pusher and standard performance muffler. Their results show it to be on par with the YS45 on a pipe. However, the Jett would need a 2 oz. header tank near the engine to deal with the remote fuel tanks. A MAC pipe for the Jett .50 would add another 1000 to 1500 RPM. The Jett .50 is available with a rear exhaust.

Larry

bob27s 12-01-2004 02:52 PM

RE: CBM F-16N Retracs
 

ORIGINAL: ljsoarinson


I have looked into installing a Jett .50 on my model. After talking to Dubb at Jett Engineering he recommended the following: Jett .50, 10x6 APC pusher and standard performance muffler. Their results show it to be on par with the YS45 on a pipe. However, the Jett would need a 2 oz. header tank near the engine to deal with the remote fuel tanks. A MAC pipe for the Jett .50 would add another 1000 to 1500 RPM. The Jett .50 is available with a rear exhaust.

Larry
Yeah, thats about right. Most folks that I know of with a Jett 50 mounted the main tanks back closer to the CG, and added the 2-4oz header just forward of the firewall.

CG wise, I never much liked the forward fuel tanks. Leaves you landing a plane that has an aft CG condition.

As noted, the ideal engine is a YS 45 RE with pipe back through the fuselage.

Bob

alfplaza 12-02-2004 04:50 PM

RE: CBM F-16N Retracs
 
i would love to hear the problems with the robart retracts, they are recomended by CBM and the sell them with the kit.

Thanks,

Alfredo.

Propjet93 12-08-2004 12:27 AM

RE: CBM F-16N Retracs
 
Sorry it took so long to respond - deer season.
I had problems with Robart retract durablility in my A-10. My nose gear failed on the first flight attempt (collasped - it was installed per instructions). Granted, I was flying off of a grass field but I had been done this more than 100 times with the F-16 using Spring Air retracts.
I finally decided to fly off of pavement. The first couple of flights went good then I had a semi rough landing. One of the main gear cracked and was unusable (no damage to the mount or the plane).
I have been flying propjets for many years and have an occasional bad landing like everyone else. I have had some down right slams into the runway using Spring air retracts that broke the mounting blocks and actually bent the retract mount (Spring air are metal - Robarts are plastic). I simply bent the metal back into shape and have had several hundred flights using them on another model.
To me Spring air retracts are also simpler. If a problem developes that air is lost in the tank, they come down. With Robart if you loose air - you are in trouble.

kdhpga 12-08-2004 05:17 AM

RE: CBM F-16N Retracs
 
If one use the Jett 50 and a header tank (near firewall) do you have to use some sort of pump (Perry) with the main tanks up near the nose wheel?

Kirk

bob27s 12-08-2004 08:56 AM

RE: CBM F-16N Retracs
 
The idea of using the the header tank is to avoid using the pump. A perry pump is not "regulated", and is actually affected in some ways by fuel level (head) pressure. If you pull the nose up vertical, the fuel load is now WAY above the engine, and even with the pump in line the engine will go rich. The header tank can delay this a bit, but will not prevent it.

With the fuel tanks 25-30" from the engine (and about 3 feet of fuel lines), that is a long fuel run. Its a somewhat unmanagable fuel system.

The folks I know of whom have had the best results with the Jett 50 in the F-16 have abandoned the stock fuel tanks and fuel system, and relocated the main fuel tank (or a pair of tanks) closer to the MAIN landing gear and included the 2-4oz header tank just on the other side of the firewall. Provides for a much more consistant CG in flight as a bonus.

alfplaza 12-08-2004 02:53 PM

RE: CBM F-16N Retracs
 
Hi,

Thanks for the information on the robart retracts problem...

I have another question, i found one Rossi 40 size engine, and it paks 1.93 bhp at 17000 rpm with a 10x7 prop. Would this engine perform better than the YS or the Jett, if i use a tuneed pipe it would increase the power and turn the 10x7 prop at 19000 rpm..

What do you guys think, is it a good powerplant or do i stick with the Jett50 or Y45???

thanks,

Alfredo.

CadFlyer 12-17-2004 11:49 AM

RE: CBM F-16N Retracs
 
Alfplaza,
I have a CBM F16N. I have a Rossi .60 in it with pipe and retracts. If you are interested I would sell the retracts and complete engine w/pipe, perry carb and perry pump. The retracts are complete.
Thanks
Cadflyer

[email protected]

Razor-RCU 12-17-2004 12:08 PM

RE: CBM F-16N Retracs
 
The Rossi-40 is NOT a good match here... The only way you could get 17+ is on a 9 incher, even that is a stretch!

USE A YS-45RE ;)


All times are GMT -8. The time now is 06:21 AM.


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