Topic: Grumman Avenger Build

Right lads, the next project is a bit of a change for me, as I am teaming up with Tiger to build a Grumman Avenger. This is a pretty big build and will take some time, especially as i have to build my new workshop first  , so onto the specs:

The plan is by Charles Kellogg from the US, to 1/6th scale, 108"w/s 80” long fuselage for a 70cc upwards. I have already purchased the plans, cowl, ball turret and canopy moulding from Charlie. I have been looking at this model and talking to Charlie for some time but the main stumbling block to this model for me, were the retracts which are specials from Sierra at $650 for the mains and $165 for the tailwheel + airkit, which is pretty good considering the work in those legs but this was a big hit to the modelling wallet, so it was shelved.

Then along came my bud tiger who's an engineering wiz, autocad guru and all round good guy (enough Andy  ), so he has taken over design and production of the u/c which will be closer to scale than the sierra offerings.  Hopefully he can include the thoughts and build of these units on another thread as there will be some good info. The drawings for the new retracts are nearly finished and look the dog's doodad's, once they are complete we can then get onto the actual build.

As i said this will be a long term build so I will keep popping updates into this thread as they occur, next step is to acquire an engine 

Steve

WOW slurp,  watching with interest

Have fun guys, I know I will(from the sidelines)

Steady mate, I can stop your uploads you know 

Shouldn't you fly the one you already have, first..........

double slurp.......... .....NICE

Just you wait until I come over for inspection ::cc

why do you want inspecting selleri???

What a nice initiative  It's gonna be a very interesting build... Now you just get cracking....

  Johan

Shouldn't you fly the one you already have, first..........

 :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:

lozza

why do you want inspecting selleri???

I've been having this strange itch        ...in my building fingers 

Then along came my bud tiger who's an engineering wiz, autocad guru and all round good guy (enough Andy  ), so he has taken over design and production of the u/c which will be closer to scale than the sierra offerings.  Hopefully he can include the thoughts and build of these units on another thread as there will be some good info. The drawings for the new retracts are nearly finished and look the dog's doodad's, once they are complete we can then get onto the actual build.

Steve, a couple of Q's about this gear

1. are you having functional side braces on it
2. will it use the same mountings as Sierra?

Mark.

Mark,

This is the thread where I will be covering the build of the undercarriage.............http://www.rcmf.co.uk/4um/index.php/topic,35934.0.html

To answer your questions....

Yes, we are hoping for functional side braces, for increased strength advantages.

The retract unit side/mounting plates will be made from 90 deg ally angle sections as most others.

Do I detect some first hand experience here?......        

Tally Hooooooooooooooooooo

Andy

The retract unit side/mounting plates will be made from 90 deg ally angle sections as most others.

Do I detect some first hand experience here?......        

Andy,

Thanks for the link

I think having the sway braces is a very good idea they take a lot of the sideways torsional load off the mounts

I didn't phrase the second question very clearly I meant the mounting size and method, (or will they fit the bearers shown on the plan ).

Not first hand experience, more 'very interested' as I haven't got the Sierra ones yet


Mark.

p.s. I'll keep any further questions/comments in your u/c thread, rather than clutter Steve's up

I didn't phrase the second question very clearly, I meant the mounting size and method, (or will they fit the bearers shown on the plan.

Not first hand experience, more 'very interested' as I haven't got the Sierra ones yet.

Mark,

Yep, they're being designed to fit the mounting rails as shown on the plan.

Are you building one too?.............    

Tally Hoooooooooooooooooo

Andy

Andy,

I've had the plans for a while and I'm going to order the kit from PCK his month, but my apartment out here is too small to build it :( and I need to build a new workshop at home after SWMBO and daughter have declared Anshluss on my garage


Mark.

Hi,
I flew the Avenger while on active duty with the U S Navy. I also flew the F6-F Hellcat and the F8-F Bearcat. All of these Grumman aircraft were a delight to fly, and quite easy to land aboard the carriers.
Attached is a photo taken recently at an air museum here in Texas. I stand 6', so as you can see, the Avenger is a good-sized hunk!
Best of luck with your build,
hookem


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Okay, change of plan after I received an email from Charlie.

So, a full wood kit and the rest of the plastic/glass parts have been ordered   I'm just waiting for Charlie to get all the bits together and post it to me

I think the first part I'll build when the bits arrive is the ball turret, as I've got a 1/48th Trumpeter plastic kit that I'm building, and the detail in the turret on the model is incredible, (and it doesn't take up a lot of room ) and the stab/elevators, and rudder.  Another idea I've had, which is following the method used by Joe Huntley, and that's to make a 'dummy fuselage section' using something like depron, and design and make the cockpit inside it


Mark.

Mark,

Very interesting, will you please post some pics of the wood kit when it turns up. I do like the idea of the 'dummy fuselage section' to build the cockpit.

T H

Andy 

Latest news ::cc ::cc

Charlie shipped my boxes yesterday, he says 7-10 days.

He's sent me piccies of the boxes with my name on them  and a couple of the contents.  I can't post them here though, as the internet cafe won't let me d/l them


Mark.

Hi,
I flew the Avenger while on active duty with the U S Navy. I also flew the F6-F Hellcat and the F8-F Bearcat. All of these Grumman aircraft were a delight to fly, and quite easy to land aboard the carriers.
Attached is a photo taken recently at an air museum here in Texas. I stand 6', so as you can see, the Avenger is a good-sized hunk!
Best of luck with your build,
hookem

Wow, thats quite a list, no Wildcats then!! Really love the Wildcat

Any more types on the list Hookem?

Ian.

glad someone picked up one this ian, WOW indeed!!!!

Hi Ian,
Yes, actually, in flight training both the Stearman 'Yellow Peril' biplane and considerable time in the North American SNJ. In the SNJ our training included aerobatics, instruments, gunnery, and carrier qualifications.
My final training, leading to the award of my wings, was in Martin 'Mariner' PBM flying boats. I flew PBMs in Pacific fleet squadrons in Japan and China. It was after this duty that I checked out in and flew the Grummans, with some of the Avenger time in Korea.
I spent most of the day reading the long file of  the various posts of 'chaps' building/flying the YT Hurricane. The use of the RCV 91CD seems to be less than popular, tho I understand that you, Ian (?), rather like the choice for your 'Hurri'. Also, lots of space is devoted to problems with the YT-provided retracts.
I am saddened by the recurring at Americans slams that I read on this site :( I know we had tax differences a number of years ago , and more of us on your island than many of you liked more recently, but I thought that the wonderful memorial at Duxford sort of said-'hey, its ok'
Enough, already.
Be well,
hookemut

Hi All,

Have you guys thought about folding wings? Just found this site & thought it might interest you ::cc
http://home.comcast.net/~rich2001/osa/WINGMAN.html

TTFN,
Neil

Dear Hookemut
Sorry you feel like that regarding the so called anti American feeling on this site.
I can only say that here in east Anglia where I live the country side is littered with memorials to the American airman who gave so much on our behalf.

East Anglian's have fond memories of the American airman who gave parties for the children and gave them chocolate etc.
The library in the forum building in Norwich has a complete section given over to the second air division. We still have two American stations in the county of Suffolk
they are lakenheath and mildenhall, putting millions of pounds into the local economy.

I think our two nations are so closely linked with language and history that some times we are like brothers, who quite often disagree with one and other.
But who will always remain brothers.

And for your own exploits, I for one salute you.

Regards Phil Goff
Coltishall UK.

Good morning Phil,
Thank you for your comments, if I were still mobile, I would once again visit England and hope to meet you in person.
hookemut

Hookemut,

I would like to echo Phil's comments...............with regard to any anti-American comments........

I wonder if perhaps you may have mis-interpreted some of the British sense of humour..............we can be very scathing at times but deep down the majority of us don't mean it.

Well those of us in the best part of England, home of Gods Wonderful Railway, don't.

I can't speak for those turkey fanciers on the east coast, the 'yam yams' in the midlands. The heathen hoards to the North of the border and those in the extreme south west, who don't even know what day it is most of the time. The Welsh, don't get me going, by mentioning the Welsh.

Ohhhhhhhhhhhhhhh hang on............Steve's origins are South Wales..................

Great people the Welsh.................          

That leaves the Americans......................as I said on one of your compatriates introduction posts............

"We were pleased to see you in the 'forties and, in my book, I am pleased to see you here"

We can NEVER repay the debt, we owe you..........................

Tally Hooooooooooooooooooooooooooooooooooooooo

Andy

PS.......... Now, if you were French?          

Have you guys thought about folding wings?

Neill, of course I have  

There's a few problems though....
1. not knowing the correct angle to use where the hinge angles from the vertical :(  
2. how to tie the machined parts of the hinge into the spars, (1 of which needs moving, or an extra one adding, as the spars are staggered on the full size, but not on the model)
3. how to operate the triangular door on the underside of the centre section, that covers a hole in the outer wing.
4. how much extra weight would the wing fold would add
5. there's 2 hinge points but only 1 locking point per side, which leaves a bit too much room for slop getting into the system, unless you have very good fits on all the hinge/locking bolt assemblies.

Mark.

Hi All,

Have you guys thought about folding wings? Just found this site & thought it might interest you ::cc
http://home.comcast.net/~rich2001/osa/WINGMAN.html

TTFN,
Neil

Yeeeeeaaaaaaah, we thought about it too...............      

As Mark says................all good reasons.

Mark,

Very interesting, will you please post some pics of the wood kit when it turns up.

okay, I'll try, (these are the pics that Charlie sent to me on Saturday).... hope this works







Mark.

Coooooooooooooooooorrrrrrrrrrrrrrrrrrr, that looks fantastic.................I can hardly wait.............     

Coooooooooooooooooorrrrrrrrrrrrrrrrrrr, that looks fantastic.................I can hardly wait.............     

How do you think I feel then 

I dunno................tell me......      

BTW Steve's away, hence, the lack of comment.....................

Keep it coming, buddy.................

T H

Andy

Like doing this probably.............. ::cc ::cc...........thats a mighty fine lookin stack a timber you have comin your way.

Hookemut.

Having spent 25 yrs living in 'Bomber Country' (East Anglia)...............and spending many an enjoyable day at several of the now disused, but restored US WW2 bases...........I too will echo Phil's & Andy's comments. Things would be a little different round here if it weren't for the odd yank with an inordinate number of 'Big Green Planes'

Phil

I can't speak for those turkey fanciers on the east coast.

And what is wrong with fancying turkeys.
Once you get used to the feathers its not to bad.
Regards Old Bernard.
PS. The wood pile looks lovely.

  I came across an interesting pic of the Avenger fuse, showing details of the port wing root and mating wing section. Also, shown is one of the landing gear legs. Really cool when that huge wing swung into place!!
hookemut 

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Hookemut,

That's a really good picture, ole buddy..............thanks a million.

We should be able to make a start on the build in a few weeks time, Steve's 'shop is just about finished.............

He has another model to build first, but I'll let him tell you about that one...............it breaks me up, just to think about it.....    

I expect he'll be along later....................until then.......

Tally Hooooooooooooooooooooooooooooo

Andy

As Andy said I have another model to finish first (of german origin ), then it's Avenger time. The good news is that the Cut Kit has arrived from the US and looks pretty good.

Pics to follow

Steve

We've been doing a few sums...............  

After lots of discussion and dimensional checks, we have finally decided on the engine for this project. We were hoping for a five cylinder radial but the one that was the right capacity will not fit in the cowl. We couldn't find a twin that would fit either. So we are going to use a ZDZ80RV.
This engine is supposed to develop 8 HP......................
The design weight of the model is 38 lb, we have had a quick look at the cut kit and there is some opportunity for a bit of weight saving. By remaking some of the components in balsa or lite ply and drilling a few holes here and there. Early days yet though.........We intend to finish this model as best we can with quite a high level of detail so that will add some weight. Our target at the moment is 40 lbs..............

Phil (P51/P47) has just published some guidelines on the Skyraider build and this inspired us to have a look at the important criteria for this project.

Next is the wing loading the total span is 108" of which, the centre section parallel chord is 30" span x 24" chord. The fuselage is 10" wide, I subtracted the section of wing under the fuselage from my wing area??? The outer wing panels, double tapered are 39" span with a 24" chord at the root and 9 - 7/8" chord at the tip, there are two of these. . So according to my sums we are looking at 12.5 sq ft of wing area

Firstly............if we can keep to our 40 lb AUW and the CZ horses are as powerful as British ones, then we have 5lb per HP.........

Secondly........ If my sums are correct we will have a wing loading of 3.2 lb per sq ft...............

This looks very good indeed and should provide sparkling performance in the true spirit of the makers of the full size aircraft.     

Or have we I dropped one somewhere?.................please feel free to comment   

Tally Hoooooooooooooooooooooo

Andy

Andy,

Your sums look okay to me

Which radial were you looking at?

There's a guy on rcu just maidened his, and it weighed in at 49lbs   that's 10+lbs over design weight


Mark.