BIG F-14 Tomcat scratch build project

[Elios000]

Originally Posted by invertmast

To complicated and un necessary. The real thing didnt start to sweep the wings until Mach .95. But on the other hand, it would be a cool indicator of how fast your going.

i was thinking set to scale speed

[xspare]

Originally Posted by Slyster

Excellent update. How fast do you think this thing will top out at? Will it do past mach 1 (to scale of course)?

I'll be surprised if this thing can't hit over 200 mph in real life. Mach 1 is 768 mph for full scale, at sea level and 20 Celsius, and a mere 109 mph at the 1:7 scale of this model, so she might hit Mach 2 in model space.

[invertmast]

I got home early so it was time to do something productive. First up I sanded the primer in both slats. There are just a few small little spots to fill in before i can flitemetal and detail the slats. Soooo....i popped the first slat off and cut/sanded it to shape to give i nice fit to the wing panel. Here is a shot with it on the wing and the "raw" slat for the other wing.





Once the slats are cut to the proper dimensions, the trailing edges are sanded to a nice thin edge so they seat as close to perfect fit to the wings. They arent perfect, but they are pretty dang close and I am happy with that!

Top:


Bottom:


And here is a shot of the backside of the slats. This area will also be molded into the slat bc i feel this is a very important part of keeping "smooth" airflow going through the slat.

[invertmast]

Since the pancakes are on Hold due to landing gear (story of my life... Or lack of!). I l have done some more work on the Tomcat.

I was never happy with the canopy frame mold, so i pulled the plug back out, stripped off the litho plate, repaired it and redid all the detailin with flite metal.



Then made up a new set of parting planes.

[URL=http://s.photobucket.com/user/Flamed04R6/media/F-14%20build%20stuff/2B3118E7-8E84-4E0D-B32E-4953A1F528D2_zpshchvnrax.jpg.html][/URL

And remolded it. So far only the top half is done, ill do the bottom tomorrow. I also molded one half of a fuel tank as well.




I am still waiting on my special metal filled surface resin and epoxy dough, so i cant do the slat molds till i get that stuff... Once these molds are done I am really stuck as i wont have anything major to do for awhile. So it'll be back to body work on the parts already done i guess.

[invertmast]

The canopy frame halves are layed up, then left to to green for an hour. Them the overhang is trimmed on the actual frame mold. The base mold the glass layers are carefully cut to the proper size and placed on the mold aligning the edge or the fiberglass with the grey edge on the mold. The halves were then bolted together while still green. This is something new i am trying as with the last mold it was very difficult to get the two portions of the mold together perfectly if the glass was oversize at all (it didnt help how that mold was messed up either). By clamping the molds together while the glass is still green, i am hoping the flanges will help compress the layup enough to get a perfect seam.



The inside corners where the two layups meet then had two strands of 50k carbon tow stuffed tightly into them. These are going to provide some bending resistance and join the two layups together.

[invertmast]

Mold surface closeup:




Canopy frame out of the mold prior to cleaning any flashing.



Closeup of the detail in the canopy frame:



And test fit to the airplane. I am happy to say that this canopy frame fits the fuselage perfectly:

[CrashDavis]

Amazing!

[*Bushwacker]

Pretty dang impressive. Mind if I ask about what your into this project so far money wise and what is the projected cost when completed?

[invertmast]

About $15k... Probably $30-35k when done

[*Bushwacker]

Thats serious brother. Not really sure how I would feel when it came to do the maiden flight or any flight come to think of it. Mostly the maiden though. Of course if you fly as good or better than you build, then it will probably just be that first one that's gonna rack your brain.

Cant wait to see this monster get airborne.

[invertmast]

I popped the mold apart, pulled the plugs out, cleaned it all up and prepped it for layup. Im not happy with how the back side mold turned out and actually have a revelation on how I should of done it to eliminate the problems i have with it. So for the time being, im going to abandon the back mold segment until the epoxy dough arrives.

So i laid up the leading edge slats. 2 layers of glass, 1 layer of carbon, some 1.2mm airex core, some more carbon in the slider and servo mount locations and then a final layer of glass. The entire thing is thrown in the vacuum bagged with The Industrial Suck on it. This time i reduced the vacuum from 26" like i had been using to 20" to try and eliminate some resin lean issues i have had on a few parts in areas.

I also took a panelling nail and perforated the airex core. I have noticed air bubbles trapped between the glass and the airex core on one part that i am attributing to the prewetting of the airex core before placing in the layup and the air bubble being unable to escape. The perforations should fix that.






This is Officially the LAST mold for the airframe of this project. From here on out, i can produce kits of a flying model. Everything to come after this is just detail parts, like cockpit components, missle pylons, drop tanks, bombs, missles, etc.

Tomorrow after work im planning to pull the slats from the molds and start the installation of them to the wing panels.

[Elios000]

Wow grats on the mile stone
cant wait to see this thing in the air

[invertmast]

And here we have the slats fresh from the molds. I painted these silver since the vast majority of the slat is unpainted on the real thing.



Then the slider rail holes and pushrod linkages were cut in the wings and the entire assembly mocked up with the sliders in place.







Then i adjusted the slat sliders where they glue to the slat so the slat closes tight and flush with the wing leading edge. It was all tack glued together and verified it all slid together nicely. Im happy to say that the slider ribs are perfectly aligned and the slat moves Very easily!

Then i made up the pushrod linkage rib for the slat. Unfortunately i didnt get many pictures of this as it was lots of adjusting and test fitting to get it all to fit perfect when up and down.

Here it is with the torque tube linkages and all hooked up.







The deflection forward and down is not alot, but it should be sufficient, the next set of wings i do, i will make a slight change to the torque tube position and place a lightning hole in the sheer web so the torque tube arms can move a bit more. I believe with these two changes i should be able to get another 1/2-1" of movement from the slat.

Overall, all of the fears i had were for nothing as this system is extremely easy for a servo to manipulate the slat, even when pressure is placed on the slat by hand. Later tonight ill do the other wing and go hysol all the slat and spoiler hinge parts. Tomorrow ill prime the spoilers and put it all back together and start installing servos, flap linkages, etc since wing construction is essentially Done!

[CrashDavis]

Amazing, sir. I've been following for a while and just have say how impressive this all is. I, too, cannot wait to see her all together and in the air! Thanks for keeping such a great journal!

[silas3d]

Originally Posted by CrashDavis

Amazing, sir. I've been following for a while and just have say how impressive this all is. I, too, cannot wait to see her all together and in the air! Thanks for keeping such a great journal!

+1 this has been my favorite subscribed thread by far! Keep it up

[invertmast]

While waiting on epoxy to dry on the pancakes, i decided to do some work on the F14.

First up was determining slat servo placement:


Then since the forward servo mount is impossible to get to, a 3/8" aircraft ply "U" shaped bracket was hysol'd to the backside of the wing sheer web and a maple block to the wing skin and slat servo plate.


The servo grommets are a tigh push fit into the U bracket and once the BVM 90* flish mount servo mount is screwed into the rear maple block, the entire assembly is very tight and will have no problems over the life of the model (there is no load in the servo linkage or servo when fully up and down due to the over-centering of the mechanism).

Then the servo is installed for the next to the last time (im probably going to replace these servos with a different version, these (JR ST126MG) dont seem to like 6v). Plugged into the matchbox and the linkage adjusted and installed.





The wing wiring harness was also made using Hd servo wire and 6 pin ashlock connnectors:



The flaps were up next and the inboard control horn slots were cut into the flap at the propee notch of the inboard spoiler panel. Unfortunately my G10 flap hinge assemblies are Just barely out of position (i'll update the CAD files to correct this) so the linkage wont fit down the slot, but its not to big of an issue.

Flaps up:


Flaps Down:

[DominicD]

Grab some video of the flap in action Tom.

[invertmast]

Originally Posted by DominicD

Grab some video of the flap in action Tom.

I will, i need to get the flap servos installed and hooked up first. It'll be a week or two though as i need to get some work on the pancakes done now.

[invertmast]

The 3D printer arrived yesterday.. After some upgrades and a little bit of tweaking, i've got it working out pretty good.. Here is a shot of the throttle quadrant at 200 micron layers, Once all the tweaks are done, i'll be doing all the cockpit parts at 40-60 microns.

[invertmast]

While i took the family to beach today, the printer was busy printing some F14 landing gear parts. Attached are two photos of essentially a complete right main gear mockup. Ive already found a few mods to make to the gear (change the pivot attachment for the down locks, reposition the forward pivot boss for the down lock braces down and forward on the mount itself, reposition the retraction cylinder mount tabs on the backside of the mount, move the gear mount plate towards the center of the airplane, etc etc). Thats a 12" rule Btw.