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-   -   Sundowner 50 Arf (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/6733354-sundowner-50-arf.html)

Herbs_007 02-16-2010 04:00 PM

RE: Sundowner 50 Arf
 
1 Attachment(s)
The 0S.95AX gives the same speed as the JETT SJ60LX, which is from 120 to 130 MPH, its very quick..And here are some pics of it installed:

Iflyglow 02-21-2010 11:09 AM

RE: Sundowner 50 Arf
 
How are you guys attaching your exhaust extensions with Jett muffler, and are you rotating the engine at all to make it fit. I have the spacer from Jett, and am just starting on the Build.:D

BIGBADBOB65 02-21-2010 11:39 AM

RE: Sundowner 50 Arf
 
I put in the Jett 56, which is the replacement for the Jett 60SLX.(same size). I put it in at 90 degrees (at 3 oclock, looking from tail to front of plane.and it worked fine. If I did it again, I might put it at maybe 93 or 95 degrees. This would leave alittle more of outside of firewall in place. Hope this helps.
Bob D

Iflyglow 02-21-2010 01:39 PM

RE: Sundowner 50 Arf
 
What are youy guys running for an extension on the outlet, and are you running the stock mount which looks a little whimpy? Are you just useing a Silocone extension, or is it aluminum? There is not alot of meat on the end of the muffler ot have anything stay on there an my pilot is a non-smoker. Oh, I am running a New Evolution .60NX (13 1/2oz) with a Jett Muffler. I am only gettng 15,500 with a 10-8 or 15,900 with a 10-7 though.[:o] It should go pretty good though.:D:D There are two of them being built in my club now, and both are Evo .60NX/Jett Combo's.
Mine has a little Clean Up Work done to it, and my friends is stock internally. Mine is about 300 rpm stronger.:D

BIGBADBOB65 02-21-2010 02:51 PM

RE: Sundowner 50 Arf
 
I'm using a Great Planes 40-60 size motor mount.Rubber deflector is a Hobbico exhaust deflector. On oneend of that goes Jetts aluminum exhaust ext.that he made for the Sundowner 50. Buy his, or make your own. 1.4" long, .3 O.D., .25" I.D.
With a raised lip at one end to keep it from sliding out of rubber ext. Lip is appox. 1/16" wide and 1/32" high. Make out of aluminum, or brass tubing..soldering, or silver soldering ring on to tube.
Bob D

BIGBADBOB65 02-21-2010 02:55 PM

RE: Sundowner 50 Arf
 
Wire clamp connections or use nylon zip ties. Be aware nylon ties may loosen/soften with heat.
Bob D

Iflyglow 02-21-2010 06:20 PM

RE: Sundowner 50 Arf
 

ORIGINAL: BIGBADBOB65

I'm using a Great Planes 40-60 size motor mount.Rubber deflector is a Hobbico exhaust deflector. On one end of that goes Jetts aluminum exhaust ext. that he made for the Sundowner 50. Buy his, or make your own. 1.4'' long, .3 O.D., .25'' I.D.
With a raised lip at one end to keep it from sliding out of rubber ext. Lip is appox. 1/16'' wide and 1/32'' high. Make out of aluminum, or brass tubing..soldering, or silver soldering ring on to tube.
Bob D

So you are just useing a Silicone defletor to get the angle, and then cutting it off shorter, and sliding the Aluminum tube into the Silocone. Are you useing a wire like aviation safety wire wrapped around the Silicone on the end of the muffler. Also, do the holes for the GP mount miss the original holes in the firewall.
I just finishing oedering a Carbon Wingtube, and makeing some aluminum axles for it. They look just like the stock axles, but are aluminum and Music wire. I use 2024-T4 3/8" bolt's and nuts, and machine them down in the lathe. The axles them self are a Interference Fit with RED Loc-Tite used for a little extra safety. Between the new axles, and the aluminum collers I use, I will eliminating 2 ounces just on the landing gear. The Wing tube only weighs 1.7 oz for a 30" section, so the cut length will be about a 3 ounce saving's there too since the stock wing tube is like four ounces.:D

BIGBADBOB65 02-21-2010 07:25 PM

RE: Sundowner 50 Arf
 
Yes, rubber deflector sets angle, sticks out the side of my plane appox. 1/8 ". Aluminum ext. sticks out appox. 1" further
Aluminum axles? are they strong enought? we are talking a 6#7 oz, or 6#14 oz plane here.
FYI: there all ready is a cutout in the side of the plane(but not through the covering), this is used for the exhaust exit.
I had to cut off right landing gear bolt flush with base to get muffler through. It is obvious once you look inside the fuse.
Rubber deflector comes with nylon tie, I think wire is better.
Bob D

Iflyglow 02-22-2010 08:46 PM

RE: Sundowner 50 Arf
 
1 Attachment(s)

ORIGINAL: BIGBADBOB65

Yes, rubber deflector sets angle, sticks out the side of my plane appox. 1/8 ''. Aluminum ext. sticks out appox. 1'' further
Aluminum axles? are they strong enought? we are talking a 6#7 oz, or 6#14 oz plane here.
FYI: there all ready is a cutout in the side of the plane(but not through the covering), this is used for the exhaust exit.
I had to cut off right landing gear bolt flush with base to get muffler through. It is obvious once you look inside the fuse.
Rubber deflector comes with nylon tie, I think wire is better.
Bob D

Only the hub of the axle is Aluminum "2024 T4", as the actual axle is 5/32 music wire. They will not break.:D I first turn the head thickness of the bolt to .094, and the drill the hole on the lathe for an interference fit. I make each set custom to allow the use of a wheel coller on the end only. They are then pressed together with a little arbor press. I used these on several planes so far. This is far stronger than the landing gear itself, and they are only half the weight.

I also stripped the gear, airfoil shaped it, and finished it with a nice polish.

earlseaholm 02-25-2010 09:19 PM

RE: Sundowner 50 Arf
 

ORIGINAL: BIGBADBOB65

I put in the Jett 56, which is the replacement for the Jett 60SLX.(same size). I put it in at 90 degrees (at 3 oclock, looking from tail to front of plane. and it worked fine. If I did it again, I might put it at maybe 93 or 95 degrees. This would leave alittle more of outside of firewall in place. Hope this helps.
Bob D

That is interesting I tried to mount the .56LX at 90 degrees, and it was obvious that I would have to take out too much material to clear the muffler. If you look close you can see that the material I removed, before I rotated the motor, is almost into the covering. The muffler was still touching the fuselage.
I wonder if these planes vary a little.
I made the trip to Central Hobbies, and picked up an adjustable mount and rotated the head down a little.
When I pushed out the blind nuts it tore up the back of the firewall a little - so I added a piece of 1/8 ply to the back.
Here is what it looks like.

http://gallery.barrymorrison.com/alb...l_DSCF0178.JPG

earlseaholm 02-28-2010 04:47 PM

RE: Sundowner 50 Arf
 
The snow finally melted enough to get the field and do a little prop testing with the .56LX.
I tried 3 props all APC a 9-8, 10-6, and a pylon 8.75-9W. The pylon prop DIDN'T work at all about as fast as a trainer. [>:]
The 10-6 was the best overall prop for yesterday. It feels close to the same speed as the 9-8, but has noticeably more thrust.
The 9-8 turns 18,000, and the 10-6 turns a little over 17,000.

The sun is shining today may need to go to the field and play again. [8D]

Iflyglow 03-01-2010 09:30 AM

RE: Sundowner 50 Arf
 
Has anyone opened up both holes in the lower prtion of the fuse? Also, is anyone having problems with the extension staying on the Jett muffler. I was just wondering since it would make a giant mess.:eek: Also, are you guys beefing up the engine box on the inside?

Iflyglow 03-01-2010 09:34 AM

RE: Sundowner 50 Arf
 


ORIGINAL: vertical grimmace



ORIGINAL: tsyssa

Has anyone taken this airframe up to 175 mph yet? I checked a while back...but nothing. I do not plan on doing turns or maneuvers at that speed, at high speed I just fly it straight as I realize that you could break it in the air easily.

I have a 30cc gasser in mine with a 14x14 prop currently and am thinking of putting a carbon fiber tuned pipe on it for more speed...this will not change the weight of the plane by more than 1 or 2 oz. This combo makes over 4 hp...I guess its just a matter of propping it correctly. It seems right now I already need more pitch...I need a 14x16 as when I punch it...it instantly comes up to top speed...seems like it needs more load. Using time clocking over a known distance (600 ft), we're getting about 138 mph.

Although it is quite fast, I am a little disappointed I cant find a prop that is 14x16 or more pitch stock.
Anyone know at what point an over-square prop becomes inefficient?

The plane weighs 1 pound exactly over recommended flying weight and flies very well with no ballast weight added.
To start with I find this one tough to believe! But, and I hate to say it, you may have to move into a 3 blade prop to get ground clearance.
I am surprised your ignition allows you to turn all of those RPM. Speaking of which, what kind of RPM are you getting?

I have watched this video many times, and there is no way that engine is turning 14,000 rpm. I take it he has never heard an engine rev that fast, since the sound is nothing like what he is running. I would say it sound more like 10-11 thousand max.

z06kal 03-01-2010 06:22 PM

RE: Sundowner 50 Arf
 
Yeah 10,000 sounds reasonable to me. 14x14 @ 10,000rpm is about 132mph pitch speed. The airplane in the video didn't look like it was doing 138 to me but you can never tell on video. If he is able to get 10,000rpm out of it with a 14x14 I don't see why it wouldn't be in the 130's.

Iflyglow 03-02-2010 08:50 PM

RE: Sundowner 50 Arf
 
What are your SD's weighing in at? Mine is looking like it will come in under 6 Lbs's with a Carbon Wing tube and EVO .60/Jett Muffler combo. I am at 5lb's 14 oz's minus the Velcro and foam for the tank.:D

earlseaholm 03-02-2010 09:46 PM

RE: Sundowner 50 Arf
 
A hair under 6.5 lbs here

bob27s 03-04-2010 11:54 AM

RE: Sundowner 50 Arf
 


ORIGINAL: earlseaholm


ORIGINAL: BIGBADBOB65

I put in the Jett 56, which is the replacement for the Jett 60SLX.(same size). I put it in at 90 degrees (at 3 oclock, looking from tail to front of plane. and it worked fine. If I did it again, I might put it at maybe 93 or 95 degrees. This would leave alittle more of outside of firewall in place. Hope this helps.
Bob D

That is interesting I tried to mount the .56LX at 90 degrees, and it was obvious that I would have to take out too much material to clear the muffler. If you look close you can see that the material I removed, before I rotated the motor, is almost into the covering. The muffler was still touching the fuselage.
I wonder if these planes vary a little.
I made the trip to Central Hobbies, and picked up an adjustable mount and rotated the head down a little.
When I pushed out the blind nuts it tore up the back of the firewall a little - so I added a piece of 1/8 ply to the back.
Here is what it looks like.

http://gallery.barrymorrison.com/alb...l_DSCF0178.JPG
Install looks good,

Yes, needs to be just past 90deg

a few folks have taken to enlarging the mount holes a bit, and it gave it just another 1-2 deg of clocking... although it is always best to do it properly :)

Bob

Iflyglow 03-07-2010 01:15 PM

RE: Sundowner 50 Arf
 
I am at the point, where I have to decide on a side outlet, or bottom outlet for the exhaust. Are you guys running the electric cutout in the rear of the fuse with the side exhasut? And if you are running bottom the bottom exhaust outlet, where are you letting the hot air out then.
Also, has anyone tried running it with both electric opening's open on the front with the internal muffler setup. The reason I ask, is that I removed it to do fuel proofing, and am trying to decide If I should glue it back in or not.;)

BIGBADBOB65 03-07-2010 03:57 PM

RE: Sundowner 50 Arf
 
I left both front openings and rear open when I ran electric.
I closed them all when I went to2-stroke. I have only about 1/8" clearance around muffler/firewall.
I didn't want any fuel residue inside fuse. I did makea cut-out under the cowling for cooling, and for excess fuelto drip out.
The inside of the fuselage, just above the muffler isbarely warmafter a flight.
I'm using the Jett 56LX.

Iflyglow 03-07-2010 07:38 PM

RE: Sundowner 50 Arf
 
1 Attachment(s)
Are you running the Jett Exhaust out the Bottom, or the side. Here is a Pic of the cowl vents that I just cut for cooling. I have done this with both of my other Pylon racers with excellent results. I have not cut the cooling cutout in the bottom of the cowl yet.;) If anyone needs a cowl vent template, give me a PM.:D

BIGBADBOB65 03-07-2010 09:34 PM

RE: Sundowner 50 Arf
 
Exhaust is out the side.
If you look on the inside of fuse, you will see where the wood is already cut out. Just cut off the covering.
I cut a semi circle on bottom of cowl for cooling.
PS.
You did a great job on cutting the "cowling gills.
Bob D

Iflyglow 03-07-2010 09:41 PM

RE: Sundowner 50 Arf
 

ORIGINAL: BIGBADBOB65

Exhaust is out the side.
If you look on the inside of fuse, you will see where the wood is already cut out. Just cut off the covering.
I cut a semi circle on bottom of cowl for cooling.
PS.
You did a great job on cutting the ''cowling gills.
Bob D

Thanks.:D I have done it on about six planes now, and have templates to do it. You use a carbide bit in a dremel.:) It takes me about 10-15 minutes to do it.

BIGBADBOB65 03-07-2010 10:04 PM

RE: Sundowner 50 Arf
 
Now take some :AERO GLOSS ..CUB ORANGE, go around the cut edges of the fiberglass, with a bit of paint on a q-tip, wiping off any that gets on the painted surface, and no one will be able to tell they were put in after manufacture.
Bob D

Iflyglow 03-09-2010 10:15 PM

RE: Sundowner 50 Arf
 
Anyone have any stab problems since it seems quite flimsy.:eek: I constructed a Solid Stab for security reasons.

BIGBADBOB65 03-09-2010 10:49 PM

RE: Sundowner 50 Arf
 
NOPE, not so far. The back-end has followed the front-end all over the sky without taking a separate course!
Bob


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