Mpizpilot

My Feedback: (45)

Thanks for updated and notated pictures, really explains a lot.

I ran into a bit of an issue when fitting my retracts and wheels. (Sierra,5.5").

I had to cut the rear spar for the wheel to clear. Pretty much shows the same thing on the drawings. Not too happy about that. I added a 2nd spar to make up for it.

If I'm stepping too much on your thread, please let me know.

DaleCS

Found a nice video of a Hellcat and Zero together in a demo flight:

https://www.youtube.com/watch?v=HLMvH-0dOz4

Noticed that the Hellcat doesn't have the plate behind the pilots head. I'm wondering if this plate is a -3 versus -5, or 'has side windows behind cockpit' vs. 'no side windows' feature. As I'm doing a -5, without the side windows, maybe I don't need to add this detail.

DaleCS

No problem - I appreciate the company, though with my pace, you will probably finish before me.

I had to cut the rear spar, also. I braced the longest bit, before cutting - kind of like bracing a car body before cutting it in order to maintain its dims. The center section's main spar is built like a tank, so I'm not worried about the rear spar cut. Grumman was known for its tank like durability, thus the nickname "Grumman Iron Works" - and Ziroli's F6F center section design appears to live up to the reputation.

DaleCS

Outboard flaps framed and hinged. The rib count and spacing were taken from a 1/72 scale drawing from a book. Basically, these are built like small wings, using D-box construction to give each flap torsional rigidity. In the picture, above, the D-box is incomplete. The bottom sheeting, cap strips are in place, as well as the sheer webbing. I'll mount, fit the flaps to the wing and finalize their length. Last step will be to install the top front sheeting and top cap strips.

I'm swinging back to using just two flap servos, utilizing the pin between the inner and outer flaps to actuate the outer flap. Main reason is time - two less servos to mount. Would still like to see this fly by Sept 2017, if not earlier.

DaleCS

Left outer flap hinge blocks installed in wing, grooved to accept hinges.




Left outer flap temporarily mounted to check rough fit with inboard flap. In bottom view, I've sheeted just enough to cover the hinges. Next, I'll mount the last, outer rib, setting the length of the flap and apply the top sheeting and cap strips. Then finish the right outer flap, then start cutting parts for ailerons.

DaleCS

Outer rib on outer flap installed, square to aileron bay/LE. Note: "square to aileron bay/LE" is not "square to flap LE" as the aileron LE and flap LE do not run parallel to each other.


Top sheet to complete the D-box and top cap strips installed - torsional rigidity is excellent. Flap TE has developed a warp despite all the effort to clamp to flat surface while building, gluing. Working on removing warp. Between sessions of wetting, weighting and waiting (to dry), have started fit, hinging of right outer flap.

Chad Veich

My Feedback: (60)

That's nice work Dale, sure to be a real attention getter at the flying field. I'm working down my "to do" list as fast as possible and will get to your items as soon as circumstances allow. Merry Christmas and Happy New Year to you and yours.

DaleCS

Thanks, Chad. Merry Christmas to you, also and to all following this build.

DaleCS

Left aileron started. Sketched up shape for inboard and outboard ribs, cut and checked against wing. Using same D-box technique I used for outboard flaps, but these will use offset hinges.

DaleCS

Left aileron framed and rough fit. Still need to install top spar, sheer webs, top sheeting and top cap strips. Before doing these, will work on mounting hinges.

DaleCS

A small bit of progress Using offset Robart hinge points would have been easier, as used on the flaps, but I think I've got a mounting configuration that will work for these Tamjet offset hinges. 5 more to go - 3 per aileron. Will be a tight fight on the outboard end, needing to trim the hinge tabs to fit within the thickness of the aileron. A bit tedious, but now that I have it figured out, I think I can go quicker, neater on the next 5.

Chad Veich

My Feedback: (60)

Dale, I can laser cut G10 up to 1/16" thick which works well for making hinges such as those found on the Hellcat's ailerons. If you need something custom made to suit your build just say the word.

DaleCS

Chad - do you have any pics you can post or email?

Chad Veich

My Feedback: (60)

Nothing Hellcat specific but if you check out the thread link below you will see some that I cut for a P-47 project. A bit different aileron actuator but very similar overall execution. It would not be any problem to simulate the Hellcat hinges with G10.

http://www.rcuniverse.com/forum/kit-...e-build-5.html

DaleCS

Chad - I think the Hellcat's hinges are a bit different. Picture, here, shows that the hinge arms are hanging below the aileron and wing, not just the hinge point as on the P-47.


So far, based on what I've been able to find, the two planes had the same off set hinge concept, but different implementations.

Chad Veich

My Feedback: (60)

The Hellcat hinge is definitely of a different style but they could be made from G10 in the same fashion as those on the P-47. They are simple in design and I plan to do them on my 1/6th scale Hellcat but simply have not got that far yet. If you would like to draw up a scale hinge for your Hellcat I would be happy to laser cut them for you.

DaleCS

Excellent picture. The Tamjet hinge is the closest thing I could find off the shelf that functions like this and sorta/kinda looks like this.

What do think about flipping the G10 parts around - putting the 3-ply assembly on the aileron so that the "U" it forms exits the bottom of the aileron, and then one would have the single ply 'arm' would extend from the TE of the wing as shown in your full-scale pic? Would the single ply of G10 have the strength/robustness to do the job? If yes, then the cut-out slots in the aileron could be one ply wide rather than three.

If not, I may stay with my Tamjet hinges, as I'm about half done - though I'm not thrilled with the wide cutouts required for them in the ailerons - as they too have the 3-ply component mounted to the wing. If we could get the one ply on the wing, reducing the cutout width, then it may be worth the trouble of redoing the work I've completed so far.

For a drawing, what do you need? Scanned drawing?

Chad Veich

My Feedback: (60)

I think your solution sounds perfect Dale. Just like the real deal really, no need to change it as I think the design of the full size will work fine scaled down. May have to beef up where the hinge pin passes through just to make sure there is enough "meat" there that it does not break out but that would be the only change I think. A scanned drawing of what you want is all that I would need.

DaleCS

Alright - let me see if I can dust off my old drafting skills. Will get drawing to you before Jan 28th.

I see TonyBuilder used 1-72 round socket head screws. Was thinking about going a bit bigger, to 2-56 - can find easier and, if threads on hinge stripped, there are nylock hex nuts available - could do a field repair easily. See that I can get taps, tap/clearance drills from Micro-Mark for 1-72 or 2-56. I'm assuming that from P-47 diary that you did the laser cutting and that TonyBuilder did the drilling/tapping - correct me if I'm wrong.

What do you think of going with 2-56?

Chad Veich

My Feedback: (60)

Nothing wrong with 2-56 so long as you are happy with the finished appearance. I think it will be fine on a model this size. As for the drilling/tapping I simply bored a pilot hole with the laser and let Tony finish it out to the proper size for his hardware.

DaleCS

Chad - will be at least a couple weeks before I get to this. Other stuff on priority list.

Chad Veich

My Feedback: (60)

No problem Dale. I am so busy right now I have to look up to see the bottom!

DaleCS

Back. Expect to get some progress made on Saturday. Have been out of town for two weeks (Steamboat, CO) then busy with work upon return.

DaleCS

Hi Chad,

My first CAD drawing, ever. The portion of the hinge that hangs from the wing, extending back to the aileron, I know is not drawing exactly to the scale shape. However, not knowing G10's properties, elected to stay a bit beefier (also, still learning this CAD software). The tabs that glue into the aileron, wing - this dims are roughly based on the Tamjet hinges. The 0.475" dim is high for the ailerons - should fit without trimming on the inboard end of aileron - the middle and outboard hinges will need to be trimmed to shape of ribs at those points.

What do you think? If good enough, will send DXF file to you.

Dale

Chad Veich

My Feedback: (60)

Looks like it should work just fine Dale. Send along the CAD file whenever you're ready.