# RC Corsair Exhaust



## epanzella (Mar 30, 2020)

I'm converting a radio controlled Corsair from electric power to an internal combustion glow fuel engine. Since there is no commercially available exhaust system for this application I had to make my own out of aluminum billet.  The engine will be mounted inverted with twin pipes pointing down out of the cowl. I still have a lot of control cable and motor mount work to do before the engine is installed but I had to finish the exhaust system first to determine clearances.


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## pontiac428 (Mar 30, 2020)

You don't see a lot of electric to glow conversions these days.  Nice looking exhaust, you got a good, compact fit.


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## Superburban (Mar 30, 2020)

Great job, love the plane.


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## Dhal22 (Mar 30, 2020)

pontiac428 said:


> You don't see a lot of electric to glow conversions these days.  Nice looking exhaust, you got a good, compact fit.




Correct,  mostly i/c to electric conversions these days.


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## Dhal22 (Mar 30, 2020)

Be careful with weight.   The plane MUST balance.   I've built rc planes since the early 80's,  happy to help here if I can.


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## Dhal22 (Mar 30, 2020)

I like them big.


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## epanzella (Mar 30, 2020)

It's a big heavy plane that came with a 4 cell brushless outrunner. Not nearly enough power. I replaced the motor with the most powerful 4 cell I could find and it still limps around the sky. I don't want to go to 6 cell. I've got a bunch of 60's so, what the hell, I'm going for it! Ha, did I mention the plane is foam? Should be interesting.  And yeah, it's gonna take some tailweight. The 5000 mah batt was heavy but it's closer to the CG than the glow 60.


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## 7milesup (Mar 30, 2020)

Dhal22 said:


> I like them big.


Looks like a Yak...


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## epanzella (Mar 30, 2020)

7milesup said:


> Looks like a Yak...


AIRFIELD F4U Corsair 1450mm.


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## Dhal22 (Mar 31, 2020)

7milesup said:


> Looks like a Yak...




Sukhoi.  Thread derailing though.


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## Dhal22 (Mar 31, 2020)

epanzella said:


> It's a big heavy plane that came with a 4 cell brushless outrunner. Not nearly enough power. I replaced the motor with the most powerful 4 cell I could find and it still limps around the sky. I don't want to go to 6 cell. I've got a bunch of 60's so, what the hell, I'm going for it! Ha, did I mention the plane is foam? Should be interesting.  And yeah, it's gonna take some tailweight. The 5000 mah batt was heavy but it's closer to the CG than the glow 60.




I saw the foam, yes it will be interesting.  It will sound SOOO much better though.  I do not like electric power.


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## 7milesup (Mar 31, 2020)

epanzella said:


> AIRFIELD F4U Corsair 1450mm.



Sorry, I was referencing Dhal22's post (picture actually).

Curious though how you made the actual exhaust stacks.  Did you use a rotary table for each one with the center of axis over the table, or how did you do that?  

I don't have any glo or gas left.  I went to all electric.  Just love the convenience and cleanliness of it.  To me, the glow or gas don't sound like the real airplane anyhow, unless you have a Moki in it.


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## 7milesup (Mar 31, 2020)

I got into large scale helicopters a few years ago.  Really enjoy that.  All electric of course.


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## epanzella (Mar 31, 2020)

7milesup said:


> Curious though how you made the actual exhaust stacks.  Did you use a rotary table for each one with the center of axis over the table, or how did you do that?


While the block was in the mill I laid out the center location of the two stacks and center drilled them. Next step was to mill two square stacks. Then I used the 4 jaw in the lathe to line up the center of each stack using a wiggler with a ball end. Turn the square stack round. Drill the stack thru to the expansion chamber. Move to the other stack and do it again. I could have used my RT on the mill but since I've been turning for 30 years and only have a mill for a few months, I was much more comfortable using the lathe. With all the hours I have in this little part I didn't want to screw it up on the last step!
PS: I put a plastic block on one jaw of the of the lathe chuck to minimize the imbalance of asymetrical turning.


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## Weldo (Mar 31, 2020)

Cool project!  And nice work!  At first glance I was wondering why you chose to use an aluminum block instead of some kind of tubing, but since you need to incorporate an expansion chamber your solution is probably the most compact design possible.


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## 7milesup (Mar 31, 2020)

epanzella said:


> While the block was in the mill I laid out the center location of the two stacks and center drilled them. Next step was to mill two square stacks. Then I used the 4 jaw in the lathe to line up the center of each stack using a wiggler with a ball end. Turn the square stack round. Drill the stack thru to the expansion chamber. Move to the other stack and do it again. I could have used my RT on the mill but since I've been turning for 30 years and only have a mill for a few months, I was much more comfortable using the lathe. With all the hours I have in this little part I didn't want to screw it up on the last step!
> PS: I put a plastic block on one jaw of the of the lathe chuck to minimize the imbalance of asymetrical turning.



Very nice.  Thank you for the explanation.


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## Dhal22 (Mar 31, 2020)

7milesup said:


> To me, the glow or gas don't sound like the real airplane anyhow, unless you have a Moki in it.




Kavan 50cc gas/glow, OS Pegasus 320 glow, and modern Kolm or Valach AND Mokis.  All are very real sound.

We just need an RC plane forum.............


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## Dhal22 (Mar 31, 2020)

Weldo said:


> Cool project!  And nice work!  At first glance I was wondering why you chose to use an aluminum block instead of some kind of tubing, but since you need to incorporate an expansion chamber your solution is probably the most compact design possible.




Agree.


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## Weldo (Mar 31, 2020)

Dhal22 said:


> We just need an RC plane forum.............



Hey man, you could start one!  There's an R/C Model section in the "Things that move on their own" forum.  Not much traffic but if you and some other guys start posting it will liven up!  I'd lurk around such a forum for sure.  I find R/C aircraft super amazing, but also very very intimidating.

A guy over on the Rocketry Forum makes these incredible rocket gliders but they are not for the novice.  I've been considering buying a trainer and seeing what happens.

@epanzella consider starting a thread in the R/C section to chronicle your project, there's a handful of us who would be excited to follow along!

Also @7milesup, those helicopters are unbelievable!  I had no idea they were scale til I noticed the human in the first photo!


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## epanzella (Mar 31, 2020)

Hey, I didn't know there was an RC section! I've got lots of pics on changes and evolution of the corsair and other planes. It would be great to get an active RC forum going. I think I'll visit there next. Shout out to 7 mile; AWESOME BIRDS!


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## 7milesup (Mar 31, 2020)

Dhal22 said:


> Kavan 50cc gas/glow, OS Pegasus 320 glow, and modern Kolm or Valach AND Mokis.  All are very real sound.
> 
> We just need an RC plane forum.............



Yeah, forgot about the Kolm.  Those are awesome sounding too.  I had purchased a Nick Ziroli P-40 kit from a guy with the hopes of putting an inline Kolm in it but life got in the way.....


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## 7milesup (Mar 31, 2020)

Weldo said:


> Also @7milesup, those helicopters are unbelievable!  I had no idea they were scale til I noticed the human in the first photo!



Yeah, they are rather large.  The pads that they are sitting on are 1 foot square.  They weigh at least 20 lbs ready to go.   Usually makes my knees shake when I fly them.  LOL


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## epanzella (Mar 31, 2020)

I put a post in the RC section. Not too much going on but maybe we can revive it!


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## Dhal22 (Mar 31, 2020)

epanzella said:


> I put a post in the RC section. Not too much going on but maybe we can revive it!


I'll post as well.


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## Weldo (Mar 31, 2020)

Right on!


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## Dhal22 (Mar 31, 2020)

7milesup said:


> View attachment 318843
> View attachment 318844
> 
> 
> I got into large scale helicopters a few years ago.  Really enjoy that.  All electric of course.




Are those arf's or kits?


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## 7milesup (Apr 1, 2020)

Dhal22 said:


> Are those arf's or kits?



They are Roban models.  I guess you could call them arf's, although there are no electronics in them at all and the mechanics need to be put together.  Here is  a link to the manufacturer's website.   Roban Helicopters
Motion RC is now the US distributor (Used to be a RC Aerodyne in Seattle).   Motion RC linky <<<<

My intent on the AS350 is to completely scale it out since I have a Prusa 3D printer and access to a Formlabs SLA printer too.  Also going to repaint it eventually.  ugghhhh.... so many things to do; so little time.


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## Weldo (Apr 1, 2020)

Hey @7milesup I spent some time looking around Roban's website but perhaps you could educate me a bit.  What does ARF refer to?  Also what is the difference between all the models?  They have 470 - 800 ARF then the TREX kits.  Is it just the size that separates the model lines?

Also how difficult is it to fly an R/C helicopter?  The need for less space than an airplane appeals to me.


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## 7milesup (Apr 1, 2020)

ARF is Ready To Fly or Almost Ready to Fly.  Usually it means that all of the big pieces (fuselage, tail, wings for example) are already put together.  You would still have to add all of the electrics and do some finish work.  Receiver, Electronic Speed Control (ESC), Motor, Servos, gyro system, etc would need to be added.  
The numbers represent the size of the rotor blades.  A 470 is 470mm for each blade.  800 is 800mm for each blade (so a little over 31 inches plus the center hub distance).  
The helicopters I have are not anything like the "drones" you see flying around.  Certainly not something that is controlled by an app (sorry, not sure of your level of experience).  Even though I have a system to make  it much easier to fly, it is still like balancing a basketball on top of a beach ball.  If one is going to get started in RC helicopters, I would recommend a 550 size or go completely the other way and get a micro.  Horizon Hobby micro helicopters
The best chance of success is find a club and someone that can mentor you to get started.  You can search for clubs here.. https://www.modelaircraft.org/club-finder


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## Weldo (Apr 1, 2020)

Thanks for the info!  My experience level is near zero.  I flew a paper airplane once!


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## 7milesup (Apr 1, 2020)

Weldo said:


> Thanks for the info!  My experience level is near zero.  I flew a paper airplane once!



Oh man...  LOL
Well, I did that too once before I started flying the aircraft in my avatar.  Pretty much the same concept.  LOL


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## Weldo (Apr 1, 2020)

Airplanes are so super cool!  There's just something about 'em that fires up my sense of romance!  I've always been interested in R/C airplanes but found it very intimidating to get started.  I've dabbled in R/C cars before but it never really kept my interest.  I feel that someday I'll get into planes.

BTW kudos on the professional pilot thing!  I'm sure you have lots of fun getting paid to fly that jet around!  Very cool!


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## Driveslayer45 (Apr 1, 2020)

using a 4 jaw for the stacks is a great idea, i was thinking after you cut the square stacks and got each on center in the mill you used a boring head turn out the stacks on the milling machine..


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## Flyinfool (Apr 1, 2020)

I have been addicted to RC anything that will fly for over a half century now. I have a semi current build thread of a pulse jet in the RC forum.

That poor pulse jet has got put on hold by life so many times I feel sorry for it. I know people that have built full size aircraft faster than I am getting this model together.

If you are thinking of getting in, the first step is to find a local club and talk to some fliers, they will steer you in the right direction of a good trainer to learn on and more important teach you how to fly it. With proper instruction you will not crash until you get to be a much better pilot and start taking chances.


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## Hawkeye (Apr 1, 2020)

To get through the winter, I built 5 planes following plans from Flite Test and made of dollar store foam board ($1.25 a sheet). I've got electric power and computerized RC in 4 of them. Just waiting for the spring winds to die down to try them out.


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## epanzella (Apr 2, 2020)

Driveslayer45 said:


> using a 4 jaw for the stacks is a great idea, i was thinking after you cut the square stacks and got each on center in the mill you used a boring head turn out the stacks on the milling machine..


Yeah that would work but I don't have a boring head.


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