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-   -   Gruman Ag-Cat (https://www.rcuniverse.com/forum/giant-scale-aircraft-general-467/1156153-gruman-ag-cat.html)

RandyL 11-02-2007 08:27 PM

RE: Gruman Ag-Cat
 
I used wood dowels on the upper wing panels, much like the lower wing. It is very sturdy as it is. The dowels go through the upper center section per plans. I then put is 1/8th ply pieces ahead and behind each wood dowel to box them in. ( more if intersted ). I worked on the wing panels until they would slide in and out easily, like they should....then used a long 1/16 bit and drilled from the rear to the front through each 1/8th ply plate and dowel until there is a hole through the mounts and dowels.
I then used 1/4 x 20 machine screws, drilled a hole in them and soldered 1/16th music wire into the screws... ( about 6 inch piece of music wire )
I slide the wings in, push the 1/16th wire through the dowels to lock the panels to the center section...and then screw the machine screws into the center section to lock it all together. A scetch would explain it all................but it is light and the wings a pinned in very well.

anothercrashpilot 11-03-2007 02:10 PM

RE: Gruman Ag-Cat
 
.............:D............WOW ! ! ! !..........PAGE 2............. We might get somewhere yet ! ! ! ! ........................ Pretty good Idea RANDY and I'll probably do something like that when the time comes . But most likely run a tube All the way across the top and then use Dowels or a smaller tube inside . I have aluminum tubes now ,but the Fit doesn't seem Good Enough ! I'll see how Dowels Fit them . ...Not ready for them Yet ,But I'm just Getting all the problems out of the way before I get to them ! ! ! ...........And YES , I'm interested in ANY help /Ideas you have ! ............................ STILL no kit .........But last contact the guy will be cutting mine at 120", Someone elses at 128", and another at 140"or so ! ! ...................I did order A COUPLE MORE BOX's of wood Again ! ! ! .......And there's some DUST in the air , BUT , nothing OFFICIAL YET ! ! ! .............. I got a new chip for our camera,But never tried doing photos on the computer , So I'll need practice on that TOO ! ! ................. LATER .............;)

RandyL 11-03-2007 06:56 PM

RE: Gruman Ag-Cat
 
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I'm kinda like you... I sort problems out long before I encounter them when possible.

To keep things going I will post a pic of my tail wheel. As I recall, It is a CB Associates that comes with multiple leaf spring and you use what you need. Looks Like I used 2 of the leafs. The 2 blind nut / screws also hold on small brass strips that the tail wires connect to. Probably not in scale spacing for the wires but my cows don't care... : ) At least they don't complain to me!

Randy

anothercrashpilot 11-04-2007 03:25 AM

RE: Gruman Ag-Cat
 
Thanks for the reminder on the lower wires, I'll have to make sure the plywood is ran far enough out. ,,,,,,,,,I burned the computer about out one day looking through any tailwheel set up I could find ! I have an extra large leaf spring type from Sig or Sullivan ? But it's still small and only takes like a 2 1/2" wheel . The enlarged plans show more like a 3 1/2" wheel and alot Taller /longer spring setup. I may have to make this too. unless I can find parts from another . I was going to make one like on the plans, but didn't want to have to make up the Bearing/guide part. ..........................Didn't get to do much these last three days, since staying up till 2-3 AM every night has kinda wore me out ! Tommorrow I'll attempt to cut out the formers. .................... It's already 1:30 AM again............[:o]

outacontrol41 11-04-2007 08:36 AM

RE: Gruman Ag-Cat
 
You're going to attempt to scratch build? Big kit not there yet?

RandyL 11-04-2007 03:28 PM

RE: Gruman Ag-Cat
 
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A little more of the controls at the tail. The rudder is a direct angle to the servo. The two elevator servos are connected through Hobby Lobby bellcranks. They make for a clean setup.

Randy

anothercrashpilot 11-04-2007 11:42 PM

RE: Gruman Ag-Cat
 
Well that's the bellcrank and control horn I had been cosidering and wondered how it might look !. now I know ! Nice, I didn't want the big plastic ones ,and was also wondering about the threaded /adjustable type . ......... Didn't get much done again today, As the wife wanted to go shopping ,And I lite the B-B-Q pit when we got back [X(] .................................................. ..OUTACONTROL ,,,,,,,,,,, NO KIT YET ! ! ! ! Last report he was getting back on tract and finishing up on the list he already had .!...... And YES, I'm TESTING the waters in the meantime ! ! BUT that's why I haven't made the Official announcement .........I want to see how it goes ! So far I've got the Basic frame boxed up ,went ahead and ran a sheet of 1/16 ply down the frame sides , made up the front firewall assy ,using 3/8" ply up against the front of the frame ,with a 3/8" box using 3/8" on the end along with a 1/4" disc to shape the firewall . (makes 5/8" thick) Put lightening holes in it , But with the landing gear mount And plywood boxing it in , I can say it's built like a Tank but It 's also starting to weigh like one ! ! ! I got a little anxious and wanted to see how it looked with the front gear, wheels and engine/prop, and WOW ! I can say BIG! ! ! ! Has the potential to be AWSOME ! ! ! And again that GT-80 REALY added some weight ! ! [X(] I am taking pictures as I go ! .............Tommorrow is another day ! ...............

anothercrashpilot 11-05-2007 12:08 AM

RE: Gruman Ag-Cat
 
HEY, RANDY ......Do you have a shot of the radio installation ,Fuel tank etc .? ........I still have time and none of the parts , But I don't want to get too far ahead of myself and close off any access I need for Installation ! ! .......THANK'S................................

outacontrol41 11-05-2007 12:25 AM

RE: Gruman Ag-Cat
 
acp....yup! Gotta take pictures. This is my next project in a couple of months so it's nice someone else got a jump on me. What are you framing...the big version or the standard 90'' ws version? GT80 will only fit in big one.;)

anothercrashpilot 11-05-2007 12:39 AM

RE: Gruman Ag-Cat
 
:D.........! ! ! ! ! THE BIG ONE ! ! ! ! ..........I've never done Scratch , But if this part turns out O.K. then maybe I'll use the wings from the kit , If it gets here ! ......................................... One of my concerns about doing this so late in the year is that I'm basicely working out in a tiny detached garage with NO HEAT and the doors don't shut very tight to keep out the moisture ! .........BUT , Around here it doesn't rain much or get TOO cold very often ! ! ;)

outacontrol41 11-05-2007 12:57 AM

RE: Gruman Ag-Cat
 
It never rains in California but acp don't they warn 'ya..when it rains, man, it pours. You got it made in CA. Here in MD we deal with very hot or very cold. The days in between are a blessing. I'm putting an O.S. Sirrus 5 cylinder four stroke on my Agcat and I'm going to scale her up real good. Just not sure at this point what spray or dusting system I'll use. Oh, well. I've got plenty of time to think about it.:)

anothercrashpilot 11-05-2007 01:54 AM

RE: Gruman Ag-Cat
 
Weatherwise ,They don't now how to forcast it since they don't know what it is ! ! I Can tell you I'm a Misplaced TEXAN and back home they can usually tell Exactly how much and for how long ! ! !,,,,,,,,,,I REALLY missed the Rain when I first moved here around 19 years ago ! ! ! WOW ! ! ! Long time from HOME ! ! ............................... I couldn't find a radial engine that was bigger than the firewall ! ! RCS was only around 11" or something like that . ..................I made up a dummy that looks pretty decent at about 15" O.D. , Haven't glued it yet And have painted it about 6 times trying to get it to cordinate with the engine ! But as I mentioned earlier there won't be much holding it together once I cut it out for the Engine ! ! I'll take a picture of it mounted before I hack it up and destroy it ! ![:o]

RandyL 11-05-2007 07:38 AM

RE: Gruman Ag-Cat
 
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I use standard BB servos in mine. One on each elavator half and one for throttle, one for rudder, and now one for smoke...which was not installed when this pic was taken.
The fuel tank is a B&B tank that is banded onto an L shaped bracket mounted to the rear side of the firewall. The rest of the forward area is lightly packed with foam rubber to dampen egine vibrations.
The smoke tank is a B&B tank as well and it is now resting free in a cutout of that large foam in the nose.
Fill and vent fittings are, again, B&B. They will show in future pics ( I think )... Randy

The radio rec is inside the gray foam in center of airplane...battery is as far forward as possible, under the front foam.

outacontrol41 11-05-2007 09:28 AM

RE: Gruman Ag-Cat
 
Thanks, Randy. Finally a look inside your creation. Become a shutter-bug. More, more, ...MORE!!:D

RandyL 11-05-2007 08:49 PM

RE: Gruman Ag-Cat
 
1 Attachment(s)
Here is a shot of the underside of the lower wing. I installed a "1/4 scale" servo out the bottom of each lower wing panel which drives the lower aileron...then a 4-40 threaded pushrod drives the upper aileron. The 4-40 pushrod has streamlined tubing epoxied to it to stiffen the pushrod and make it look better.
A lot of testing was needed to find the correct place to connect the 4-40 pushrod to the lower aileron and the upper aileron to make them work smooth and properly.
2 servo screws hold the servo the the ply servo plate. The other 2 servo screws go through the servo and the plate...and attach to the wing frame. Sort of looks like there are no mounting screws holding the front of the plate to the wing. Randy

D.R.BOWERS 11-14-2007 01:48 PM

RE: Gruman Ag-Cat
 
Hi, to all
I am Dale. I have a set of AG-CAT from Bill Northrop plane that I bought in 1992. I have lost the building article and need to get another copy. I think I could build it without it, but it would be nice to have.

Thanks
Dale

outacontrol41 11-14-2007 04:25 PM

RE: Gruman Ag-Cat
 


ORIGINAL: D.R.BOWERS

Hi, to all
I am Dale. I have a set of AG-CAT from Bill Northrop plane that I bought in 1992. I have lost the building article and need to get another copy. I think I could build it without it, but it would be nice to have.

Thanks
Dale

Sent you a reply on cropduster thread.

anothercrashpilot 11-16-2007 03:17 AM

RE: Gruman Ag-Cat
 
OUTACONTROL.......................I had to take a break !.........................But for the sake of conversation, I don't know if you've taken the time yet to go Through the pictures on Agplane.nl ,,,,,and I know it 's difficult starting off, But in the later shots there are some good ones that actually show some useful Scale Details and Construction ! ! And there are a couple pictures from the rear showing the REAR FIN running OFFSET and along the fuse side!. Like the plans show !.......................................former #4 still doesn't work right .YET ,.And I need to rework a couple side formers to get the stringers to Lay right ! (Not to bow in after D and then out after E ! ![:o]) ...................One other thing, is that I found a guy on eBay that had the DECEMBER 1978 ISSUE of Model Builder ,Which of course I Had To Have ! :D ,And it's NICE seeing the Construction Article in ORIGINAL Magazine form ! ! even though the pictures aren't much better than the Copies .........

outacontrol41 11-16-2007 07:17 AM

RE: Gruman Ag-Cat
 
ACP.........Yea, I've had them for a while and have seen them all. I'm gonna build the AgCat with the rear fin offset....probably needed to help fly straight.
I've got a copy of the article, and it's interesting, but lacks in any real help in building the model. The real help would be to check out the build pictures on Randy Linderman's website....low res...but what the hey, still useful.
-
-Also...there's a full scale agcat down the road from here, and for scale detail I'll be using it as well.;)

RedTwilight 11-17-2007 09:57 PM

RE: Gruman Ag-Cat
 
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Well you can't tell from this picture but the vertical Stabilizer does appear to be offset. Maybe I'll go take another pic or two and find out for sure.

RedTwilight 11-19-2007 12:45 PM

RE: Gruman Ag-Cat
 
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Went and took a closer pic and the full scale is off center. So there ya go. Not only are you building it by the plans but your also building it scale.;)[&:]

outacontrol41 11-19-2007 12:52 PM

RE: Gruman Ag-Cat
 
Kind of unusual for a plane...but there you go...hard evidence. Thanks for posting.;)

gjmjoe017 11-19-2007 01:21 PM

RE: Gruman Ag-Cat
 
Wow.I grew up watching Ag Cats fly and even had a friend in Arkansas who owned three of them and never knew the vertical stab was off center and that much!!!Must be a hellva lot of tork!!

outacontrol41 11-19-2007 03:07 PM

RE: Gruman Ag-Cat
 
600 H.P. will blow your cap off......! Mine's gonna have two pilots, a full payload and still hang on the prop. LOL[sm=tongue_smile.gif]

RedTwilight 11-19-2007 08:39 PM

RE: Gruman Ag-Cat
 
Even though it probably doesn't make a difference; the pics are of the turbo prop version. Prob still the exact same though on the radial version. I don't know if they changed things to the stab when going from the radial to the turbine.


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