Go Back  RCU Forums > RC Airplanes > RC Warbirds and Warplanes
Reload this Page >

New CARF P-51D Project

Notices
RC Warbirds and Warplanes Discuss rc warbirds and warplanes in this forum.

New CARF P-51D Project

Old 10-03-2017, 08:15 AM
  #101  
bentwings
 
Join Date: Dec 2001
Location: St.Paul, MN
Posts: 474
Likes: 0
Received 4 Likes on 3 Posts
Default

Scale exhaust

ive made a number of scale exhaust systems for my Ziroli Corsair, P 51 and the 118" B 25.
ive used Stainless steel, 4130 steel tubing, copper tube fittings and totally fabricated from sheet Stainlees steel. All are relatively time consuming to build.

I like your P 51 system and the heat wrap. It sounds really cool.

With the two cylinder system as you have even though yours runs very well, I found that the multi engine (twin like yours) needed equal length pipes for each cylinder. Not really as " tuned pipes" but to provide equal exhaust flow for each motor/cylinder. It was quite pronounced on the big bomber. Even though I had to add a full 180 deg turn to equalize the length on the short side it improved performance of that motor so we could balance the speeds.

While yours seems to run very well it may help equalize temps on both cylinders to balance the pipe lengths. Just a thought.

The single cylinder P 51 had a 5.8 cu in 2 stroke motor. On this one I split the manifold at the exhaust port into two ports then and made two individual equal length pipes to the exit manifolds. This worked pretty well but we felt that it was a bit too heavy as we had to insulate both pipes as you did. It's very difficult to get tight bends in SS or steel so I made a single pipe to a smooth flowing " Y " and fabricated SS manifolds. This was all done with .028" sheet SS. I do TIG welding on hotrod stuff as well as for work but even so it was really difficult to weld this as it had to be back purged to make good welds. This system worked very well and was much lighter even with the heat wrap.

The Corsair was much easier as it needed considerable balance weight in the nose so weight wasn't an issue. I simply used copper tube fittings and for the " Y " pipe I sectioned a pair of elbows and welded them together. This gave a smooth and equal flow to both pipes. I never did add the smaller pipes as the radial has but that was the next step. This plane flew for 13 years without exhaust problems.

byron
Old 10-04-2017, 12:38 PM
  #102  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

I've been thinking of a design for a three into one header that's pretty basic. From each head up to a common larger tube then a flexible connection out to each side of the nose. Scale pipes optional but at least two working, one per side.
Like car manufacturers it would be great to tune the sound to get as much bass and rumble possible.
Old 10-04-2017, 01:20 PM
  #103  
bentwings
 
Join Date: Dec 2001
Location: St.Paul, MN
Posts: 474
Likes: 0
Received 4 Likes on 3 Posts
Default

That would be ok too. The hard part is getting flex tubing that fits the header close enough for a good weld. TIG welding flex tubing is very difficult as it is usually really thin. .015-.. 020". Fit has to be nearly ..0 It takes a very small electrode and .020 -.035 SS wire. It can be silicone bronze welded....TIG braised but even that is very tricky.
Old 10-07-2017, 07:53 AM
  #104  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

@Flypilot
How much vibration did you experience when running your engine?
Are you planning to use the supplied dampening mounts?
Old 10-07-2017, 02:56 PM
  #105  
bentwings
 
Join Date: Dec 2001
Location: St.Paul, MN
Posts: 474
Likes: 0
Received 4 Likes on 3 Posts
Default

We tried the dampening mounts but the motor simply moved around too much. It worked best to just solid mount it. I made aluminum replacements for the urathane soft mounts. I still used a slip joint in the headers however.

we also tried them on the B 25 but there was just too much moving around. So we solid mounted the motors. They actually ran smoother however I think there was just a different sound. The rpm remained the same.

byron
Old 10-08-2017, 02:37 PM
  #106  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Chris Nicastro
@Flypilot
How much vibration did you experience when running your engine?
Are you planning to use the supplied dampening mounts?
There is some vibration but not excessive I would say. I will hardmount it directly to the fuse in my plane..

I also found the engine to be very easy to start so I will not be using the starter, that way I will save about 1.5kg on the flying weight...maybe add it later when I get to know the plane..

H
Old 11-06-2017, 03:17 AM
  #107  
Ixtrim
 
Ixtrim's Avatar
 
Join Date: Nov 2014
Location: Austria
Posts: 447
Likes: 0
Received 11 Likes on 11 Posts
Default

Mustang and Kolm IL150 ???? I´m in :-)

thanks to norway for the link!

Tom
Old 11-08-2017, 10:03 AM
  #108  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

My prop just arrived, gonna be great...

Old 11-08-2017, 10:13 AM
  #109  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Also after a good tip from my friend Salte I made an access hatch to be able to service the engine without taking it out of the model...
Attached Thumbnails Click image for larger version

Name:	20171108_140318.jpg
Views:	568
Size:	441.9 KB
ID:	2244108  
Old 11-08-2017, 10:58 PM
  #110  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

I've considered doing the same but I'd rather work on the engine alone on the bench. It's very heavy and has many covers to seal. I can take out the engine very easily.
I'll be getting back to the project soon. I want to start the engine and see how it vibrates.
Old 11-14-2017, 11:15 PM
  #111  
Ixtrim
 
Ixtrim's Avatar
 
Join Date: Nov 2014
Location: Austria
Posts: 447
Likes: 0
Received 11 Likes on 11 Posts
Default

Originally Posted by Chris Nicastro
I've considered doing the same but I'd rather work on the engine alone on the bench. It's very heavy and has many covers to seal. I can take out the engine very easily.
I'll be getting back to the project soon. I want to start the engine and see how it vibrates.
Awesome work so far Chris!
the hatch downside will make it possible to check the valves wihout removing the engine. but when you say ist easy , no Problem. looking Forward to see more :-)
Old 12-15-2017, 11:12 AM
  #112  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

What do you think? Necessary or no?

Old 12-16-2017, 09:13 PM
  #113  
BobH
My Feedback: (2)
 
Join Date: Mar 2003
Location: Springfield, VA,
Posts: 8,049
Received 21 Likes on 21 Posts
Default

Only Necessary if you are going to use it for cooling.
Old 12-17-2017, 06:04 AM
  #114  
bentwings
 
Join Date: Dec 2001
Location: St.Paul, MN
Posts: 474
Likes: 0
Received 4 Likes on 3 Posts
Default

Gotta have it! The full size did. Make it scale.
Old 12-17-2017, 08:42 AM
  #115  
BobH
My Feedback: (2)
 
Join Date: Mar 2003
Location: Springfield, VA,
Posts: 8,049
Received 21 Likes on 21 Posts
Default

The full scale has a lot of things models don't have lol.
Seems like you already made the cooler door so you may as well keep them. It'll be another thing people won't notice unless you point it out lol
Old 12-19-2017, 02:03 PM
  #116  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Yeah, plan on using it in conjuction with the temp sensor measurments for the two aft cylinders to control the opening, should be easy to make functional with my awsome Jeti radio

Things are coming togheter and I am starting to mount togheter the major bits to complete the plane...
Old 12-22-2017, 08:14 AM
  #117  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

The working door is nice and yes if you’re actually ducting air thru the fuselage like mine then it will work. Have you made a duct tube like mine? If not then let me know and I could make one for you.
I plan to make a servo mount that goes on top of the duct with a control linkage to operate the door. I was not happy with the shape of the door, it’s too round, so I’m also modifying the door to look correct.
There is a company that makes a thermal controller for servos to move cowl flaps. I’ll post the info. It’s temp driven and can be controlled by the Tx.
I was debating on making the door operate based on throttle position or temp depending on how the engine ends up running.
Old 12-22-2017, 08:28 AM
  #118  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

Oregon Scale Aviation made the controller called Thermacowl but the website is not working.
Im using temp telemetry on my TF Corsair with the DX18 but I haven’t tried to see if I can make a mix to open the door when a certain temp is reached.

Last edited by Chris Nicastro; 12-22-2017 at 08:31 AM.
Old 12-22-2017, 03:34 PM
  #119  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Chris Nicastro
The working door is nice and yes if you’re actually ducting air thru the fuselage like mine then it will work. Have you made a duct tube like mine? If not then let me know and I could make one for you.
I plan to make a servo mount that goes on top of the duct with a control linkage to operate the door. I was not happy with the shape of the door, it’s too round, so I’m also modifying the door to look correct.
There is a company that makes a thermal controller for servos to move cowl flaps. I’ll post the info. It’s temp driven and can be controlled by the Tx.
I was debating on making the door operate based on throttle position or temp depending on how the engine ends up running.
Thanks appreciate the offer, I have made a duct similar to your out of fiberglassed depron so I am going to try that out first, it should be plenty strong for the purpose. I agree that the shape is a bit round but not too wooried about that as its not a competition machine..
Old 12-23-2017, 09:51 AM
  #120  
Maschar
 
Join Date: Jun 2017
Location: Schnelldorf
Posts: 36
Received 0 Likes on 0 Posts
Default

One gorgeous Carf Mustang from Germany. Found the photos on FB.
Attached Thumbnails Click image for larger version

Name:	21641240_1677309665682629_1709900961_n.jpg
Views:	483
Size:	81.6 KB
ID:	2248493   Click image for larger version

Name:	21754629_1677309642349298_606799727_n.jpg
Views:	539
Size:	82.5 KB
ID:	2248494   Click image for larger version

Name:	21763687_1677309815682614_1154036782_n.jpg
Views:	489
Size:	202.5 KB
ID:	2248495   Click image for larger version

Name:	22141038_1692732064140389_1687229839736124697_n.jpg
Views:	477
Size:	73.3 KB
ID:	2248496   Click image for larger version

Name:	22851950_1724946637585598_3798653974176069862_n.jpg
Views:	496
Size:	253.1 KB
ID:	2248497  
Old 03-06-2018, 05:17 AM
  #121  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

How are you guys solving getting the wing on without splitting it, I am planning on making this whole piece removable to be ab to lay the wing on in one piece without splitting it... what do you guys think?
Attached Thumbnails Click image for larger version

Name:	IMG_20180306_140113.jpg
Views:	402
Size:	667.9 KB
ID:	2257842  
Old 03-06-2018, 07:20 PM
  #122  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

I’m getting back to this project very soon.
The wing on my project will be two piece so I’m not sure how it affects the fuse to be one piece. My plan is to have it assembled and split as it’s placed on the fuse, then pushed together.

If you have the space to live with a huge wing then that’s cool.

I would suggest some additional tabs or keys to align the the scoop as well. Part of the design of the fuse in that area is to lock the wing in place. Now you have to carry that load into the fuse another way not just with the wing screws.
Old 06-29-2018, 03:19 PM
  #123  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Had my second flight this afternoon, starting to get used to it anddialing in the engine and radio settings. Will be painting her this winter, fall...once all the bugs are removed and things are working nominally....

Old 06-29-2018, 05:34 PM
  #124  
Chris Nicastro
Thread Starter
My Feedback: (3)
 
Chris Nicastro's Avatar
 
Join Date: Oct 2005
Location: Coeur d'Alene, ID
Posts: 3,146
Received 24 Likes on 22 Posts
Default

Very nice!
What do you think of the Vario Prop?
It looks very good installed.
Old 06-30-2018, 05:24 AM
  #125  
flypilot
 
flypilot's Avatar
 
Join Date: Jul 2004
Location: NORWAY
Posts: 217
Likes: 0
Received 2 Likes on 2 Posts
Default

Hi, Yes I like ramoser props very much but they will of course not be as effecient as a two blade, a two blade will give you more speed and be more powerful, but for me its the whole package thats important, therefore I think the airplane needs a fourblade.... Ramoser is good quality and ok priced spare blades if you are unlucky and chips one..also a very nice guy

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.