HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 02, 2014, 05:50 AM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Sad isn't it when someone makes what is basically a good unit then gets some of it so wrong

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 02, 2014, 12:17 PM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Spitfire CG

CG in the instructions says 25 – 28 % of Mac. With 3 lbs in the nose and the plane on its wheels it is quite bouncy and will be okish as it is now on the ground but would easily tip onto its nose if not good on the elevator. (Retracts as designed position no added tilt forward which I can still do.)

In the pic the black mark is at 26 % and I am balancing at 10 mm behind it which is 145 mm which is 28 %. but looking at the pic it looks quite forward. to move it forward by 10 mm to the black mark I have got to add another 1 lb (blinking spitfires) which would make it worse on the ground. Do you know what percentage yours is at. I generally like nose heavy so would prefer it at the lower (26) end but this will give me jip on the ground.

Do you measure along the curve of the wing or on the flat ?

Bottom line is do you think I should add more nose weight. Overall weight is not a problem as it is a huge wing

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 02, 2014, 12:33 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
My CG is going to be as Kahlog has suggested. He has already flown it and did mention that 6" was a bit touchy but that 5.5" locked it in.

I measure linear.. from the front to the mark. Dont follow the curve in other words

Adding another pound is no big deal.. from what ive read your still 2lbs under everyone else!
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 02, 2014, 12:36 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
Why are your Decals on upside down....LOL More Quality control I see
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 02, 2014, 12:49 PM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Quote:
Originally Posted by vettster View Post
Why are your Decals on upside down....LOL More Quality control I see
Yes more quality control. It took you quite a while to spot that one lol. I kind of like it as it is a talking point particularly as I am not a person to fly inverted very often

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 02, 2014, 12:51 PM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
I had another few hours messing with the retracts with a friend who had some new O rings I have changed them out and with the Jetronics valve they now go up and down lovely and hold air for ages (1 hour and still plenty) That will do for me

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 02, 2014, 12:51 PM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Quote:
Originally Posted by vettster View Post
My CG is going to be as Kahlog has suggested. He has already flown it and did mention that 6" was a bit touchy but that 5.5" locked it in.

I measure linear.. from the front to the mark. Dont follow the curve in other words

Adding another pound is no big deal.. from what ive read your still 2lbs under everyone else!

I think I will add another 3/4 of a pound and maybe cant the wheels more forward then that will do for me

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 02, 2014, 12:51 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
LOL I guess I didnt realize because your fues was always on the stand up side down
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 02, 2014, 03:55 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
my Spinner showed up today.. No doubt is the from the same company that supplies HK with their CF spinners. Only difference is that this one came with the prop holes already cut AND was free shipping

So far today I finished the other wing(minus paint)

Next up will be to install the motor and cooling duct for the cylinder head. Im using loovers for the low pressure area at the rear of the cowl. I was SO close to being talked into using the rads on the wings as low pressure areas to draw the heat and exhaust out of the cowl. This means there would be no exhaust hole in the cowl..but that it would just vent into the fues as my buddy does on his giant warbirds. BUT I just couldnt bring myself to doing that and chickened out
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 02, 2014, 04:24 PM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Quote:
Originally Posted by vettster View Post
my Spinner showed up today.. No doubt is the from the same company that supplies HK with their CF spinners. Only difference is that this one came with the prop holes already cut AND was free shipping

So far today I finished the other wing(minus paint)

Next up will be to install the motor and cooling duct for the cylinder head. Im using loovers for the low pressure area at the rear of the cowl. I was SO close to being talked into using the rads on the wings as low pressure areas to draw the heat and exhaust out of the cowl. This means there would be no exhaust hole in the cowl..but that it would just vent into the fues as my buddy does on his giant warbirds. BUT I just couldnt bring myself to doing that and chickened out
I am hoping that mine will vent ok through the hole in the bottom I cut for the exhaust. There is next to no air going in though. I might have to make a small slot in the front of the lower part of the cowl. Going to test run it first.

I am very pleased with my retracts now

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 02, 2014, 05:44 PM
Registered User
kahloq's Avatar
Fort Collins, Colorado, USA
Joined Dec 2005
7,821 Posts
CG.....do NOT fly at 6" back. You will probably lose the plane. 5.5" is good though......5.75" is tolerable.

I did shim the back retract rails with about 1/8" ply just to cant the gear forward some. My plane had zero tendency to nose over. Very stable on the ground and flew very solid in the air.
My friend had is also at 5.5", but did not shim his gear and he did have his start to over rotate.
kahloq is offline Find More Posts by kahloq
Reply With Quote
Old Jan 02, 2014, 06:17 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
Dennis you absolutely must put a hole in the lower front of the cowl to get cooling air!!

My buddy told me that most of the spits would take the last letter on the side of the fues and put it directly under the prop on the cowl. So just cut a large letter H for your cool air intake. But make sure its not upside down LOL
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 02, 2014, 06:30 PM
"Take Off" eh!
vettster's Avatar
Canada, ON, Beeton
Joined Aug 2008
2,944 Posts
Here's louvers I got from Thunderbolt RC. They are pre curved to fit the cowl.

My build it coming to a halt for a while. I need to finish painting my Angel Jet so I can put her up for sale. Just need to do the wings.. but its going to take at least 2 days.

Selling the Angel for $4500 if anyone local is interested
vettster is online now Find More Posts by vettster
RCG Plus Member
Latest blog entry: Im selling my 220mph jet
Reply With Quote
Old Jan 03, 2014, 03:24 AM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
Air in

Well I did not want to cut the cowl more but I kind of knew I needed to get some air in so this is what I have done. Not pretty but it will have to do. My cutting skills are not up to cutting a letter (the right way up or indeed upside down).

Now where am I going to find a place for this extra 1 lb of lead

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Old Jan 03, 2014, 04:41 AM
Keep building, buying,fly
Bigplumbs's Avatar
Suffolk, In the UK
Joined May 2004
2,598 Posts
That spinner looks good and a very nice fit

Dennis
Bigplumbs is offline Find More Posts by Bigplumbs
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Hobbyking Spitfire MkIX 89" EP Conversion & Build Blog? Scott Cuppello Electric Warbirds 225 Feb 24, 2014 04:46 AM
Build Log F-16 70mm - Tian Sheng (from HobbyKing) - Build Log PeterVRC Foamy EDFs 30 Aug 26, 2013 10:34 PM
Discussion I have spitfire-itis. only curable by building a spitfire! dcwwcp Electric Warbirds 52 May 31, 2013 06:54 PM
Help! ESC for Hobbyking Spitfire Mk IXc 650mm BigIron357 Electric Plane Talk 7 Apr 11, 2013 12:31 PM
Help! First BUILD Mini Yak 54 from HobbyKing perschek Scratchbuilt Indoor and Micro Models 5 Apr 07, 2011 06:57 AM