Greater Southwest Aero Modelers Chat Forum

Scale Aircraft => Warbirds => Topic started by: dlabby on February 20, 2020, 09:29:08 PM

Title: F6F-3 Hellcat Build
Post by: dlabby on February 20, 2020, 09:29:08 PM
After several months of debating with myself and doing research, I decided to order the TF 86" Hellcat "Ready To Cover". That was right after Christmas. I already had a DLE 61. Due to light schedule and very little flying, I have put in many hours so far. I'm using Robart air retracts.
The large naked balsa pieces were in good shape. Using the newer Hytec D645MW servos throughout. In the way of upgrades I fabricated a new wood tail wheel cover to replace the overlapping ill-fitting plastic one. I ordered rotating drive system components (IRF Machine Works) for the ailerons. The elevator connecting rods and horn will be hidden and the rudder pull-pull system almost hidden. Mark Fuess fabricated a couple of custom horns for rudder and elevators. The ARF systems were ugly and too visible. The flaps controls will be sticking out. Ughh. Equipment installed to date: tail wheel/air hoses/steering; air tank/fill valve; all servos except flaps; air control valve; gas tank/plumbing/fill valve; 3 LiFe batteries/3 switches; nav lights; engine stand-offs; cowl mounting blocks.
Air control valve is in the wing which minimizes the wing to fuse connections. The wing is one piece; the ARF style outer wing securing bolts are light weight. The dummy engine is assembled, painted and installed in the cowl. My WW II pilot is from Warbird Pilots and the compact Pitts wrap-around muffer is from JTEC.The rudder and elevators are covered with Koverall, doped, and primed. Rib stitching is added; trim tabs are cut out. Hardwood blocks had to be installed in the rudder and elevators for control horn insertsIMG_0125.jpgIMG_0128.jpgIMG_0131.jpgIMG_0131.jpg. The fuse and wing and assorted pieces are glassed with 3/4 oz cloth  with 3 coats of Z-Poxy. The last few days have been spent priming and more sanding.
I don't have many photos but here is what I have:

IMG_0124.jpg
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on February 20, 2020, 09:34:00 PM
Well, I pretty much messed that up. Been a long time since I added pictures. Do better next time....maybe.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on February 21, 2020, 08:49:09 PM
Good progress Darrell! Looking forward to getting to mine one day.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on February 24, 2020, 08:49:20 PM
Took a few more pics today. I'll see if I can upload them right this time. I opened the 4 upper cowl flaps; this will increase the exit air opening a little. I'm not sure what the lower cowl openings are but I opened both just slightly to match the 3-view. Also have trimmed out for the exhaust stacks and added another cowl bulge on each side. At the very rear I added the tail tie-down bracket, cut opening in the very back to accommodate the end of the tail hook so it is in the retracted position. There is a large upper hatch in front of the canopy so I placed the 3 switches, fueling port, and air fill valve there. It is easy on and off but I need a small homemade tool. Also a shot of tail wheel hatch. TF did not include the window just aft of the canopy; my F6F-3 that I'm doing has the window so I cut those out today. I am going to box in the inside and paint it black. Not sure what is supposed to be in there; probably radio gear. The fuel tank is mounted on a removable ply tray; access to that is in the wing opening. That will also give access to throttle and choke servos and batteries. The rudder and elevator servos are also on a removable tray. Most everything is in some stage of priming.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on February 28, 2020, 09:28:07 AM
Darrell, cowl flaps look good. That hatch up front is handy, no need to cut a hatch into the side of the fuselage. Lane
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on March 19, 2020, 10:20:12 AM
Absolutely correct! Making good use of it. I cut a very small slot at the rear and made a little 'hook' to insert and lift rear of hatch off of the magnets.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on March 23, 2020, 07:21:01 PM
This shelter in place stuff translates into many hours in the workshop the last 9-10 days working on details added to the primer coat. This includes several panels, exhaust openings on fuse bottom, nav light lens, rear window glass, and a few thousand rivets. Haven't found a good nomenclature guide; I do have some more labels ordered from Callie since I think her 1/6 print is too large. Every day I think it is ready to start painting then I find another day of things that can be done. Here are a few pictures but the details don't show up very well.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on April 08, 2020, 09:32:13 AM
Painting on the Hellcat is mostly done. Perhaps some touch-up later. The Pasche air brush works very well with this Behr acrylic; not as easy to disassemble and clean as the old one. All control surfaces are now mounted; not real happy with the rudder/tailwheel performance. I had to fabricate a conglomerated double servo arm since both are pull-pull (no picture yet). Receiver and all hook-ups are done. Working on retracts and air system. At first the gear and pressure pump wouldn't work right and I was afraid of a major leak. Fortunately, the problem was the connector on the air pump; for some reason it had stopped up or just gone bad so that was an easy fix. Now the up/down is backward which is a fairly easy fix since the air assembly tray in the wing is removable.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on April 09, 2020, 08:29:16 AM
Good job on the colors! I like the way you laid on the three colors too. She's going to look great all assembled.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on April 09, 2020, 09:06:48 AM
Thanks, Lane. Got the pneumatic gear working good; only remaining thing here is to adjust valves to slow down the rates. Here's a picture of the rudder/tailwheel servo arm. Can't really put a separate servo off to the side when both are pull-pull. I should have converted the tailwheel to one connecting rod, then it could have been off to side. Used D645MW servos throughout. I wasn't happy that HiTec changed arm spline count on these new servos. Also a pic of removable air assembly tray. Wing to fuse connections are 3 and 5 banger servo connectors and 3 air connectors. The powder coated Robart retracts and wheels sure are pretty when they are new and clean. I will do some detailing before bolting on the heavy engine/ignition. It's already kinda hard to manipulate. And I don't think I have a transporting rack for this one. Ugh.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on April 10, 2020, 11:30:10 AM
Darrell, I see an electronic engine kill lurking in there. Each to their own ways, but that's just another point of failure ready to go wrong. I bet your Tx has an APP to kill the engine. My DX-18 has one. Ask Barry about those kill units. ha

Also on your Robart valve, add a drop of RC-56 white glue or light thread-locker under that jam nut to keep it from coming undone. Yes, they can come undone! Happened on my Spitfire.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on April 11, 2020, 09:22:46 AM
Yes, I am familiar with Barry's 'kill' failures. Right now I can't remember that brand but I have never had a failure of this 'Smart Fly' brand or heard of a failure. All I know about on my 14 channel Futaba Tx is the throttle kill which I use on smaller planes. All it does is idle down the throttle servo making the engine die. I will check the manual though.
I will definitely secure the locking nut. I think this used Robart valve is out of my old P-40.
Thanks for the tips. Happy Easter.
Title: Re: F6F-3 Hellcat Build
Post by: Steve Rogers on April 14, 2020, 03:16:35 PM
The kill switch that has a high failure rate is the DLE or Rcexl Opto Gas Engine Kill Switch. I've seen at least 10 of them fail at the field.

I've been using the Tech Aero Ultra IBEC which has a regulator and kill switch, also it eliminates the need for a separate ignition battery. I have never had a Tech Aero module fail.

I always use two batteries with two ON/OFF switches to power the receiver, servos and ignition module for my gas planes.

LiFe Dual Battery Receiver and Ignition Setup.pdf
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on April 14, 2020, 08:23:27 PM
Question to all or any. If your Tx has the kill option, then why have the electronic version? Both will stop the engine in the air or on the ground.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on April 17, 2020, 10:33:24 AM
Lane, if we all did the same thing, what fun would that be? ha-ha. As you know, if we have 10 members together, there will 12 different opinions.
Well, I got the Hellcat together, right side up on her feet yesterday for some photos. Still a lot to do but at least she looks like a warbird now. First thing I noticed was the fact that, even after cutting the exhausts, the drop tank is going to be a mess from the exhaust. Waiting for some new graphics, still lot of detailing, and of course, the cockpit which will take couple of weeks at least.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on April 17, 2020, 10:36:03 AM
Oops.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on April 17, 2020, 12:31:59 PM
A very "clean" build, Darrell! Nice.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on May 12, 2020, 12:14:27 PM
To honor Mother's Day the Hellcat got assembled in the backyard for Nancy to take some photos and an engine run. No, I can't find any Mother's Day connection, either. The engine run went very well. Total weight is 30 lb 15 oz which includes 1 lb 15 oz added to the engine standoffs. Here are a few cell phone shots; haven't got Nancy's photos yet.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on May 25, 2020, 10:07:22 AM
The 2 pound weight from divers-supply.com was just shy of 2 lb which worked perfect. It is now secured to the upper engine stand-offs. Need to do a final balance check, then she is ready to go to the field. But the runway is closed so it may be awhile. bummer.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on May 25, 2020, 10:19:34 AM
Here is the "Hellcat Hero Picture". No 3-blade scale prop yet.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on May 25, 2020, 11:17:25 AM
She turned out real nice Darrell! I like that paint scheme. Same one Lawrence had on his late Hellcat. When will the field be open?
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on May 26, 2020, 07:36:42 AM
My best guess is several weeks. I think we have to do the grass seeding again.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on June 14, 2020, 08:21:13 PM
Yea! Runway 16-34 opened yesterday and IMHO it is quite a bit flatter and much improved. Over 2 days I watched a lot of takeoffs, landings, and touch-goes and even the smaller planes are not bouncing up. I have seen one spot and will be fixing that. It will continue to improve as the grass fills in.
So I flew the Corsair twice today to check runway and get warmed up for the Hellcat. So if all goes well, we'll give it a go around 11 am Monday 15th.
Title: Re: F6F-3 Hellcat Build
Post by: dlabby on June 22, 2020, 12:26:12 PM
For the NON-Facebookers: Maiden take-off was a 9.5. Brian dialed in a ton of down elevator. It flew solid; engine sounded strong and reliable. Flap deployment seems to have little pitch effect (will revisit that). Runway is about 20% dirt/sand so I landed in one of those spots with too high of descent rate so she nosed over. Broke prop and toed out the wheels. No other damage. Post inspection revealed 171 units of elevator "sub-trim". I don't know how but that was the trim problem. She's ready to go again.
Title: Re: F6F-3 Hellcat Build
Post by: Lane C. on June 22, 2020, 06:08:47 PM
Glad she suffered only minor damage Darrell. Flight looked good! She really went up after lift off. Lots of power. And she'll score well in static judging. Good job! Lane