Thread Tools
Oct 20, 2019, 02:02 PM
Registered User
Thread OP
Help!

ESM Producing Spitfire CG Problem/Challenge


I recently completed the build of a ESM Producing (Chinese Co.) 1/6th scale Spitfire ARF. It is powered with a VVRC 25cc gas engine which runs beautifully. I'm wondering however if it will ever fly. Based on the limited documentation it states the CG is 107mm from the leading edge.
However unless I put a ridiculous amount of weight against the firewall (we are talking in pounds not ounces) I cannot get the plane to balance at 107mm..?? To add to the confusion I noticed the retractable landing gear on this tail dragger is located behind not forward of the specified CG. I cant help but feel the specified CG is wrong or there was a misprint in the instructions. Does anyone have any experience with this particular ARF or have any suggestions on finding the proper CG for this elliptical wing?
Sign up now
to remove ads between posts
Oct 22, 2019, 09:37 PM
Registered User
radfordc's Avatar
World War One Spitfire?
Latest blog entry: Assembling a Spandau kit.
Oct 23, 2019, 06:43 PM
Registered User
WWII has been described as a continuation of the political climate that produced WWI. So…. a Spit might be considered LATE WWI...????

IIRC, Spit's wing geometry is defined around the tip to tip straight line 25% location of the main spar. That would have any airfoil section, occurring along the span, as having it's 25% of chord, all occurring on that spar line. ALL conventional configured aircraft have to be balanced within 25-33% of an aircraft's Mean Aerodynamic Chord. On a scale Spitfire the math and location for balance are almost a no brainer given.... That is, of course, if your model's wing has a scale geometry. and not something invented by the model's designer.
Oct 25, 2019, 12:59 PM
An itch?. Scratch build.
eflightray's Avatar
Outzone has at least a couple of Spitfire plans, (Mk1 and Mk9), showing the CG location, you could look at the plan online and scale the chord and CG location to suit your model.

.
Nov 06, 2019, 10:06 AM
Lori, hey, you're home early
CarreraGTSCS's Avatar
Quote:
Originally Posted by Larry Lute
I recently completed the build of a ESM Producing (Chinese Co.) 1/6th scale Spitfire ARF. It is powered with a VVRC 25cc gas engine which runs beautifully. I'm wondering however if it will ever fly. Based on the limited documentation it states the CG is 107mm from the leading edge.
However unless I put a ridiculous amount of weight against the firewall (we are talking in pounds not ounces) I cannot get the plane to balance at 107mm..?? To add to the confusion I noticed the retractable landing gear on this tail dragger is located behind not forward of the specified CG. I cant help but feel the specified CG is wrong or there was a misprint in the instructions. Does anyone have any experience with this particular ARF or have any suggestions on finding the proper CG for this elliptical wing?
Larry,

Very likely there have been more than a few discussions here on RCGroups about this. At the top right of this page you'll see a "Search" button. Click on that and enter "ESM Spitfire" and submit. You should get more than a few results. That'll give you an idea of how to search here and narrow down the results. You're unlikely to find your answer here on what is specifically a WW1 forum.

From personal experience with many Spitfires over the years once dialed in on CG they are one of the best behaved models you can fly. Very gentle stall. One important thing of note: Follow control throw recommendations for the ELEVATOR to exactly what is called for. In the case of the Spitfire more elevator throw is deadly (causes an instant snap). I have a Spitfire, maybe 60" span, and the elevator throw is something like 10mm up and down. Same on my small ones.

Good luck.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Need CG for 89 in. ESM Spitfire Fastandlow Fuel Warbirds 3 Mar 25, 2019 08:39 AM
Discussion Esm p-51b cg erospawn Fuel Warbirds 13 Jan 25, 2018 04:29 PM
Discussion We intend to produce ESM FW-190 rear landing gear fimon Scale Fuel Planes 0 Jan 12, 2011 02:16 AM
Scorpio Spitfire CG problem TheRedBaron Foamies (Kits) 12 Nov 09, 2001 08:13 PM