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

TopRC Corsair 93in - center of gravity?

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

TopRC Corsair 93in - center of gravity?

Old 12-19-2019, 06:37 AM
  #1  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default TopRC Corsair 93in - center of gravity?

Hi,

Has anyone already purchased the new Corsair from TopRC? Mine arrived last week, but unfortunately, there is no manual available yet. Therefore, I would like to ask if someone already figured out the correct center of gravity?

Best Regards,
Oliver


Old 12-19-2019, 09:07 PM
  #2  
spitfire66
 
spitfire66's Avatar
 
Join Date: Jun 2007
Location: Parker, CO
Posts: 505
Likes: 0
Received 5 Likes on 5 Posts
Default

Clue us in man! Where did you order from? Initial thoughts? Any pics?
Old 12-20-2019, 12:30 AM
  #3  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Over here in Europe, you can get it from bigplanes.nl or engelmt.de. However, both ship it without a manual.

I would love to share some photos. However, vBulletin tells me "You are not allowed to post URLs until you have at least 10 posts". So I have to do eight more posts before I can show something. bigplanes.nl has some nice photos.

Best Regards
Oliver

Old 12-20-2019, 06:38 AM
  #4  
BarracudaHockey
My Feedback: (11)
 
BarracudaHockey's Avatar
 
Join Date: Jul 2003
Location: Jacksonville, FL
Posts: 25,206
Received 152 Likes on 123 Posts
Default

Looks nice, this one is on my list.
Old 12-21-2019, 06:03 AM
  #5  
Craig B.
 
Join Date: Dec 2002
Location: PERTH, AUSTRALIA
Posts: 1,402
Likes: 0
Received 3 Likes on 3 Posts
Default

I received this message from the Australian dealer...

The C.G for the Corsair is 155mm from the leading edge at the mid wing root.
Old 12-21-2019, 06:05 PM
  #6  
TimD.
My Feedback: (207)
 
TimD.'s Avatar
 
Join Date: Dec 2001
Location: Jacksonville, FL
Posts: 746
Likes: 0
Received 11 Likes on 10 Posts
Default

Had my eye on this one as well. I have a brand new UMS 7cylinder 90cc ready to go. Have been putting another Zero together but may hold off a bit now that I know they are being released.
Old 12-23-2019, 01:53 AM
  #7  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Thumbs up

Originally Posted by Craig B. View Post
The C.G for the Corsair is 155mm from the leading edge at the mid wing root.
Thanks, Craig,

That sounds reasonable. My old Hangar 9 Corsair had 120 - 135 mm (4.5 - 5.3 in) with a wingspan of only 2.17 m (85.5 in). I was hoping for more since the TopRC Corsair seems to be very tail heavy. I am planning to mount a Moki S180 on it and it looks like I need to add additional nose weight even with this heavy engine. The natural fit is a Saito FG-90 or the UMS 7-90 mentioned above. However, those engines will require even more nose weight. The UMS 9-115 or the UMS 5-125 could also fit under the cowl.

Best Regards,
Oliver

Last edited by sg26565; 12-23-2019 at 01:57 AM.
Old 12-27-2019, 02:51 AM
  #8  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Today, I received the manual for the TopRC Corsair and the CG is indeed 155 mm from the leading edge of the wing root.

Thanks,
Oliver
Old 12-28-2019, 05:49 AM
  #9  
tevans55
 
Join Date: Aug 2007
Location: Louisville, KY
Posts: 1,329
Received 3 Likes on 3 Posts
Default

Do you have a diameter on the cowl yet?
Old 12-28-2019, 08:13 AM
  #10  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

The cowl is 270 mm heigh and 265 mm wide at the fuselage. To the front, it narrows down to 250 mm. A Moki S180 (255 mm) will most likely fit, as well as a Saito FG-90 (250 mm) or a UMS 7-90 (230 mm). A UMS 9-115 (260 mm) may also fit, but it may become very tight. The UMS 5-125 (265 mm) is likely too large for this cowl.

Oliver
Old 12-31-2019, 06:38 PM
  #11  
TimD.
My Feedback: (207)
 
TimD.'s Avatar
 
Join Date: Dec 2001
Location: Jacksonville, FL
Posts: 746
Likes: 0
Received 11 Likes on 10 Posts
Default

Word Is, the US will not get any till end of Feb - beginning of March. There are only a few coming in that shipment..

I have a USM 7-90 waiting for mine.
Old 01-01-2020, 11:30 AM
  #12  
warbirdfan2
 
Join Date: Jul 2012
Location: , PA
Posts: 84
Likes: 0
Received 0 Likes on 0 Posts
Default

The photos that I have seen on their website shows the bottom of the airplane painted grey. Is this right? I thought all the ones I have ever seen were white?
Old 01-23-2020, 11:29 AM
  #13  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Yes, the bottom is painted grey, which differs from the original.
Old 01-23-2020, 11:41 AM
  #14  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Some comments regarding the quality of the kit (I still can't post any photos because I need to do four more posts ):
  • In my opinion, the overall quality of the kit is very good, at least far above average compared to other kits from China.
  • The landing gear seems to be very robust. I have the landing gear from TopRC, not the one from Robart.
Old 01-23-2020, 11:47 AM
  #15  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

However, there are also some things, that I don't like.
  • The wing servos are mounted using L brackets. The same L brackets are used for the gear door servos. With two aileron, four flap and two gear door servos, we get eight in total. However, only twelve L brackets are shipped. I made four more by myself.
  • There are two different kinds of hinges for the flaps. Eight of one kind and four others. However, the manual does not tell where they should go. We asked TopRC for advice and they told us that the eight go into the center wing and the other four into the outer wings.
  • The pushrods for the gear doors are too short so that the doors don't close completely. I had to replace them with longer ones that I had laying around.
  • The springs in the oleo struts are way too hard and too long. My oleo struts did not move at all. I had to replace the springs. When I disassembled the oleo strut, I discovered that the original springs were deformed because they had been mounted using extreme force.
Old 01-23-2020, 11:52 AM
  #16  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

There are no holes for the pushrods for the ailerons and elevators. You have to cut them into the composite yourself. My result was not optimal. However, most of the time, you don't see the holes on the bottom side of the wings.
Old 01-23-2020, 11:57 AM
  #17  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

I finished the assembly of my Corsair with a Moki S180. The propeller arrived today. The plane weights app. 16 kg without fuel. Therefore, Take-off weight will be around 17 kg. This is not too far away from the 16.8 kg specified in the manual. The website talks about 13 - 15 kg, which is unrealistic. Even with a smaller engine, you need to add a lot of nose weight to achieve the correct center of gravity. I prefer to carry a larger motor instead of lead .
Old 01-25-2020, 12:45 AM
  #18  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Now that I made ten posts, I can finally share some photos. For an ARF warbird, the level of detail is very good.





Old 01-25-2020, 01:02 AM
  #19  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

As previously mentioned, I installed a Moki S180 engine. This made mounting of the cowl a bit challenging because the ply cowl frame will not move over the engine. Instead of clueing the frame into the cowl, I attached it to the fuselage and used five threaded rods to connect it to the air guide for the engine. The air guide was then glued to the cowl. Aluminum tubes ensure the correct distance.

The cowl frame and the air guide

Mounted to the fuselage without engine

... and with engine

The air will flow close to the cylinders for a good cooling effect.

The air guide was glued into the cowl. Aluminum tubes take care of the correct distance.

Everything mounted together.
Old 01-25-2020, 01:06 AM
  #20  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

As mentioned earlier, there are two different kinds of hinges for the flaps, but the manual does not tell which should go where. Here is a picture that we received from TopRC after we asked for advise.

Note: The hinges for the outer wings have small tooths.
Old 01-25-2020, 01:20 AM
  #21  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Finally, some words about the landing gear. I bought the original one from TopRC and this one looks quite robust. However, the springs in the oleo struts were a total disaster. The springs are too strong, too long and mine were already damaged.


My springs were already damaged because they were mounted with extreme force.

I had to replace the springs with softer ones. Ideally, you would take 100 mm springs with a spring rate of approximately 5 newtons per mm. However, I was not able to find springs with these characteristics. Therefore, I used two 50 mm springs for each side.

That's it from my side. I'm now waiting for better weather to take the new plane outside.

Regards,
Oliver
Old 01-25-2020, 02:56 AM
  #22  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

The manufacturer released new photos on his web site. The manual is now also on-line.

80CC F4U - Scale warbirds - TopRCModel SCALE WARBIRDS,JET, PATTERN, BOATS & MULTIROTOR
Old 01-25-2020, 06:15 AM
  #23  
marksp
My Feedback: (9)
 
marksp's Avatar
 
Join Date: Aug 2004
Location: Redmond, WA
Posts: 840
Received 7 Likes on 7 Posts
Default

Wow...you’re cowl mounting/baffle looks great!

Did you require any additional weight to balance?

Cheers
Old 01-25-2020, 08:12 AM
  #24  
sg26565
Junior Member
Thread Starter
 
Join Date: Dec 2019
Posts: 22
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by marksp View Post
Did you require any additional weight to balance?
With the Moki, it's almost on level. With a smaller engine, you would need extra nose weight.
Old 01-26-2020, 07:33 PM
  #25  
marksp
My Feedback: (9)
 
marksp's Avatar
 
Join Date: Aug 2004
Location: Redmond, WA
Posts: 840
Received 7 Likes on 7 Posts
Default

How many servos required for the build? Manual says 8, which i assume are (2) aileron, (2) flap, (2) elevator, throttle & rudder. What about gear doors? Center vs outside flaps? Are elevators standard size servos?

Cheers

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.