Official Dynam 1270mm F6F Hellcat Thread

[BILLY BOY]

Just watch the hinge line if doing the flaps. The upper and lower lines don't match.

I was happy to find that flaps were installed at the factory. Also included was the navigational light controller.

[BILLY BOY]

Just watch the hinge line if doing the flaps. The upper and lower lines don't match.

I noticed that, but I noticed it before I read your post, and after I made the cut. Grrrr. I was able to add a little hinge tape and the joint seems functional. Once I give it a coat of water base sealer the hinge tape should not be visible. I sure wish I had read your post before I made the hinge cut. Oh well. No harm done.

[qmmo44]

This arrived today from MRC:


Can't wait to put this one together. Being old and a noob you know I'll put at least one decal on upside down or backwards. It is how I roll...:wacky

Building these planes is a lot more fun than building out a pedal board. Cost a whole lot less to boot!

[rifleman_btx]

And probably the best flying dynam warbird of the bunch

[rifleman_btx]

Cool, just too bad you cant ship some stuff out this way, ive heard how 2A unfriendly they are up there with alot of thinge. But yes the way they have them set up, the flaps do crease in the wings.

[rifleman_btx]

Also almost forgot, dynam retracts are not reliable or durable, i would replace with eflite 1.2m corsair retracts. I did for this one and the dynam corsair. Much better durability and reliability.

[qmmo44]

Also almost forgot, dynam retracts are not reliable or durable, i would replace with eflite 1.2m corsair retracts. I did for this one and the dynam corsair. Much better durability and reliability.

Thank you sir. I see what you did. I'm going to incorporate that with what I was thinking - I will slit the foam on the top of the wing (perpendicular to the cut you made) just over the "v" channel under the wing hopefully leaving enough foam to act as a hinge (I'll also do the cut you did to keep the wing from buckling/creasing at that point. I'll put a bead of foam-tac at the bottom of the "V" channel and will lay a strip of hinge tape in that channel if needed (I'll probably cut it too deep...cuz its me...so I'll have to order some hinge tape...). I think if I do it this way the break line on top of the wing for the flaps will be wickid clean as we say here in the Boston area. I'll post pix of the operation steps if it works out well...maybe someone else can benefit from it. If it doesn't work I'll post what not to do...

I have an E-Flite 1200mm Corsair. I'll definitely check out the differences in the retracts and will order the E-Flite ones when I see how it all goes together. Thanks for that tip...something else I would have missed (until I busted the gear up...).

My URL is qmmo.net. A simple set of web pages. I've lived here (MA) all my life. It didn't used to be like this. A real shame and sometimes a real embarrassment when I travel and people ask me where I'm from. I think back to the election in '72...the only state McGovern took was MA. Nixon took the other 49 states. Things started to get a little strange around here after that...on both sides of the aisle.

Thanks again for showing me what you did with the flaps. I'm not so sure I would have thought of that until it was too late!

[qmmo44]

Also almost forgot, dynam retracts are not reliable or durable, i would replace with eflite 1.2m corsair retracts. I did for this one and the dynam corsair. Much better durability and reliability.

You were absolutely correct about the Dynam retracts. When the model is upside down in a stand the retracts work fine. When the plane is upright, one of the gear jams when it is supposed to rotate. I have E-Flite Corsair retracts arriving on Monday. I'll swap those out and see if I can figure out what is wrong with the Dynam retract.

I've been able to slit the top of the wing for the flaps just deep enough to ensure the foam broke straight along that line. I tried running the flaps without cutting for the split flap and found all works OK...the flaps are well behaved. I'll post some pix after I get the other retracts on.

Thanks for the advice...saved me a bit of aggravation as I knew what to expect. The only real issue I had with the assembly was getting the screws into the vertical stab. Nothing lined up..just off enough to cause screws to bind to the point where one screw broke and I stripped the head on the other. I cut the screw ends off and glued the assembly on with Foam Tac. I hope it holds together. I still have to calibrate/program the ESC...it has that "stutter" at low throttle that I need to work out. Everything else works as expected (more or less).

Q

[rifleman_btx]

Sounds good, it should run great with everything set up. Looking forward to seeing it all done and ready to fly!

[rifleman_btx]

You did a great job! The extra work will reward you, as this plane is sweet flying!

[Atesvn]

Picked up a hellcat and did some mods for the flaps and Eflite Corsair retract swap. Did a split flap concept, and on the retracts, was able to swap the wheel rods out into the Eflite's so the door and length stayed the same for the wheel seating into wing. Still got some touchup to do and some Varathane. Anybody interested in the specifics feel free to ask. Looking forward to maiden her.

[rifleman_btx]

Very nice! Looks great!

[Atesvn]

Thanks Rifleman, I notice the Efites add some weight compared to the Dynams. I'm hoping to have less lead in the nose for the CG.

[rifleman_btx]

I have those and runn a 2700 4s, with no added weight flys great

[BILLY BOY]

Dynam F6F landing gear works sporadically at best. There is no rhyme or reason. Once in awhile both will deploy and retract but often only one will work. I have noticed a few posts that have also encountered the same thing. It must be a Dynam exclusive.

[OV10]

Dynam F6F landing gear works sporadically at best. There is no rhyme or reason. Once in awhile both will deploy and retract but often only one will work. I have noticed a few posts that have also encountered the same thing. It must be a Dynam exclusive.

That pretty much sums it up across all their airframes with etracts. Both my 262 and 190 were problematic.
It seems they are very susceptible to hanging up with the least amount of longitudinal twist.
Longitudinal twist I refer to is with regard to the 2 mounting surfaces that the etract engages not being in a perfect aligned flat plane of dimension.
If this condition occurs, just one of the four mounting screws being slightly more snug than the other three can cause the twist leading to the temperamental operation.
Hope this observation helps others;)

[Builda]

Picked up a hellcat and did some mods for the flaps and Eflite Corsair retract swap. Did a split flap concept, and on the retracts, was able to swap the wheel rods out into the Eflite's so the door and length stayed the same for the wheel seating into wing. Still got some touchup to do and some Varathane. Anybody interested in the specifics feel free to ask. Looking forward to maiden her.

Hey dude nice job-I modded my own hellcat but ended up using FMS P40b Retract units, some oleo struts, and some 4° shims I 3D printed up (to kick the wheels fwd more to prevent nose overs on grass). Obviously I couldn’t use the gear doors but I still have them so id bhhe interested in a full write up of what you did incl npart ynnumbers. Also I haven’t done the flaps yet (I have jservos etc to do it incl a reverse flap servo from FMS). Would be very interested in more detail around your split flap design. Also out of curiosity what motor are you running? I put a turning SK3 in my one and run a MAS prop same size as stock one-however I’m boycotting Hobbyking these days so I’m looking for alternatives that work and can handle 800-900W and 60a as my Dynam tempest runs the same power setup and naturally I want to change it to a more capable one like the hellcat. I may just have to lower my standards and go with the Hobbyking sk3 agsin as I know it works ????

[Atesvn]

Hi Builda, Thanks for the nice words on the upgrade. I'll try to be as easy and simple as I can. The parts list: (retracts) Eflite part# EFLG1590R, Small piece of 3mm craft plywood, 30 min epoxy, (2) 4D finishing nails, 12 Dubro pin style hinges, 2 Dave Brown 2 1/2" (lite flite) treaded wheels. The retracts are a simple remove and replace as they line up exactly with the Dynam mounts. After removing the stock gear before replacing the new Eflites you will need to use a good set of pliers to pull the pin on the Dynam retract ( the one that is the pivot for the rotation). I use a servo tester and stop the retract half way through cycle as its easier to get at the pin. Use a twisting motion, and the little pin will come out. At this point pull the wheel axle out and set aside. Repeat this for the Eflites as well. The Dynam axle will fit into the Eflite exactly so just swap it out and replace the pivot pin. I use some CA to make sure and tap it back in to make sure it seats well. I did have to file the pin about a 1/16 of an inch as it could bind on the Eflite mount if not done. Also watch the screw clearance at the pivot point it may need to be changed to a smaller head screw if it looks to close. After the swap you can still retain the same skirt, and wheel will still line up upon closing. I did swap out the old tires to the Dave Browns due to their being much softer and absorbing a lot of stress/hard landings better. They may need some small filing to open the hole a tiny bit to slip on the axles. As for the number plates, you can just cut the Eflites down and remount to the retracts keeping clearance for the rotation of the skirt to clear. On the flaps, I cut as many have said from the trailing edge of the foam and removed the piece and trimmed out all the wedges remaining. At the bend in the removed piece again cut the foam at the slight bend splitting the flap. I attached three pin hinges to the outboard flap first and then mounted it to the wing. ( I use a small nail and just heat it enough to melt the foam and make my holes, then epoxy them in. For the inboard flap I add three more to that flap as well and test fit to assure enough gap and clearance. I then will cut 2 small pieces of the 3mm plywood 1" x1 1/2". I then cut a notch just the thickness of the plywood into the trailing edge of inboard flap. I then epoxy that piece onto the notch I cut out. This allows it to fill in the gap and have a nice clean edge for appearance. Before I epoxy it to the wing I drill a 1/16 hole through the plywood level with the foam. Once the split flap has been done, now I attach the finishing nail to the other main flap by first holding the flaps even and with the nail through the drilled hole this is your line up point to mark the flap. I again melt a small groove in the main flap enough to recess the nail. Just epoxy the nail to the flap with about 3/8 of an inch through the plywood piece and your done. The flap works very smoothly and has no slop in it. This design allows the split effect with minimum moving parts and no binding. Note I did this before I did the complete assembly as it was easier just working on the wing. I did some touch up afterwards on the paint and the Efite number panel. I did a real close gray with a drop of dark blue mixed and decided to just brush a coat over the entire wing underside. Then 3 coats of a water-base urethane and call it a job well done. Sorry if this dragged out. Hope it helps you or others out there as well. So far I have left my powerplant stock, , but may do an upgrade when I get more comfortable with her flying tendencies. I may go with the FMS 1400 Corsair motor/prop swap I've read about. Time will tell.

[CaptAmerica]

I maidened mine yesterday and it was quite the handful. Severely tail heavy and way out of trim. Fought it for several minutes to get it somewhat trimmed out before putting it back on the ground. Going to either get larger batteries or add lead to the nose or both. On a good note I've had no issues with the retracts. Fingers crossed.

[Dewey H Lee]

It took 2 and a 1/2 ounces with a 3000 to get my cg.