sysiek

My Feedback: (176)

Jim this picture shuld be a nice edition it show grate lite shadow and surface texture

rcjets_63

My Feedback: (4)

Fuel Tank Installation - Finished Pics

Here are a few pics of the completed fuel tank installation. It took a bit of work, but I'm really pleased with how this turned out. To remove the tank, I just have to remove the front two screws that are easily accessible through the main gear doors, and pull the tank forward 3/8" to release the back mounting tab. The tank is installed exactly centered on the recommended C.G.


Regards,

Jim

rcjets_63

My Feedback: (4)

Cockpit Installation

Now that the scale canopy frame & bow are molded, I thought I'd install the cockpit to see how it fit. The Airworld cockpit kit for the Gripen looks gorgeous and has lots of detail. The main pieces are the rear dorsal deck, left & right sides with consoles, floor/seat back with attached seat, glare shield with HUD, and the instrument panel. The sides and dorsal are made of thin plastic and have been laminated with .5oz glass cloth.



This is literally how it comes, right out of the box. I haven't compared it to my pics of the full-sized Gripen so I don't know how close a match it is, but even if it is semi-scale, it's rather impressive. One thing I noted was that the multi-function displays (MFD's) are in green monochrome per the JAS-39A and JAS-39B variants; I'm doing a C which has color displays so I'll likely install working MFD's if I can find some in the right size.

A few things to note for the installation:
- DO NOT glue the front former (aka "firewall") in place before you install the cockpit. Having access from the front will make it a lot easier to install the glare shield. I had glued mine in place many moons ago and had to cut it out of the model
- This is a finicky job and you need time & patience. You literally screw the pieces together inside the plane (through the holes for the removable air inlets) and there is a lot of assemble, check, disassemble, trim/sand, and repeat several times. If you are stressed or rushed, it'll drive you crazy.
- It is really handy if you have a couple of blocks of 2-3" soft foam that you can cut to size to hold the dorsal deck and glare shield in place as you are fitting the pieces.
- Remove the seat from the floor/seat back piece before installing the pieces. The seat will just get in the way until you have it all together in the plane.

I started at both ends and worked towards the middle. The glare shield was installed such that the curved flange followed the cutout for the windscreen. On the full-scale, the glare shield doesn't start even with the front of the windscreen so this is quite scale. The aft pressure bulkhead in the full scale is a bit behind the rear edge of the cockpit cutout and has a fair amount of kizmo's attached. The kit dorsal deck has a plain flat bulkhead so I positioned it (for the time being) flush with the rear edge of the cockpit cutout. The main feature of the dorsal deck is a box and I'll fine tune the position of the dorsal deck so the box matches the position on the full scale.


The glare shield slightly too wide and will interfere with the windscreen (when it is installed). Maybe this isn't a problem if you do the stock setup with the windscreen & canopy glued to the exterior of the model. The rear edge of the glare shield also needs to be trimmed to match the full-scale as the error will be pretty obvious to the judges from the side view documentation:


The cockpit sides and floor/seat back were screwed to the dorsal using #2 SHCS. I glued little pieces of 1/16" plywood to reinforce the cockpit pieces at the screw holes. The floor/seat back is intended to sit on the large wood longerons (to which the nose gear is mounted) and these had to be trimmed/sanded a bit but it really wasn't a bad fit. There is a cutout in the floor which gives access to the steering servo (after removing the pilot and seat). The control arm & linkage interfered with the bottom of the seat so I ground off about 3/8" of the seat bottom (hidden) to give the needed clearance.


The sides have molded in slots at the front which engage the glare shield thus tying the cockpit together at the front. The angled front edge of the side pieces align with the glare shield with only a bit of fore/aft adjustment and the instrument panel was laid in place. Installation of the seat completed the cockpit. Here are some pics. You have to admit, it looks pretty cool. I can't wait to see how it will look when my 1/5 scale YT International Euro Jet Pilot arrives. http://www.ytinternational.co.uk/tai...red_fifth.html


Next I'll check the model cockpit against photos of the full scale (particularly the side view for seat placement and height). Also, I will have to come up with a method to hold the individual pieces in place (particularly the dorsal deck and the glare shield) where they can be quickly/easily removed if needed during a competition if access is needed for maintenance. I'll post some pics when I figure out how to do this.

Regards,

Jim

sysiek

My Feedback: (176)

Happy and heathy new year 2015 for all and the crazy gripen enthusiasm.

rcjets_63

My Feedback: (4)

Instrument Panel Comparisons

I compared the Airworld instrument panels to pics I have of various Gripens. Cockpits are something that tend to change from variant to variant (eg A model vs C model) or even block to block as my good buddy and former F-16 driver Dave "Goose" Brawley has learned me. Also, some published "pictures" of the cockpit really are illustrations or GGI and who knows if they have been doctored. I always put most of my faith in photos.

Here are some pics of the various cockpits. I had expected the Airworld cockpit to be much like the Swede A variant.



The AW forward panel is the big disappointment. The left/right MFDs are oriented in landscape and should be in portrait. There are no gauges above these displays but only a couple of switches/indicators. The left and right side consoles were done much more accurately and are surprisingly close to the full scale though some panels are in the wrong order. AW appears to have really knocked themselves out to do a detailed cockpit; I just wish the front panel was accurate. Ah well, something else to fix.

I'm doing a C variant so I would expect there to be some custom work. I got a photo of Czech C tail number 9235 but it doesn't quite get all of the panels. I found a photo/CGI reported to be of a Hungarian C variant and it seems to match the Czech C with the exception of a single panel (Comms?) on the left front. All other panels visible in the Czech C photo match the Hungary photo. If I can't find a more comprehensive set of Czech photos, I'll copy the Hungarian with the exception of the comm panel. Hopefully I can get the All-Scale Models MFD to fit as the screens seem to be about the right size. http://www.dreamworksrc.com/catalog/...rizon-Portrait

Regards,

Jim

rcjets_63

My Feedback: (4)

I got some photos of the finished rims that Thomas White (invertmast) is having making for myself and Roy. I'm really looking forward to getting them onto the model.

Regards,

Jim

rcjets_63

My Feedback: (4)

Nose Cone Installation

The Gripen has a removable nose cone much like the Skymaster or BVM F-16. A wooden structure beneath the cone provides support and serves as a mounting platform for batteries, fill valves, etc. The cone is held in place by the pitot tube which screws into a nut or insert glued to the front of the wooden structure. While the F-16 has a cruxiform structure with both horizontal and vertical plywood, the Gripen has only a vertical cone-shaped piece of 1/4" lite ply. The back end has a series of notches that fit into the "firewall" former.

To install the "firewall" former, you have to do some serious grinding on the massive fiberglass fillet at the front of the fuselage, or grind the former, or both. Then it can be glued in place. I forgot to take a pic of this so here is one from Radek Suk (Czech Republic) taken from inside the cockpit opening and looking forward. You can see the carved up former at the front of the plane and the vertical row of cutouts into which the plywood nose structure is fitted.


I had installed the firewall former a long time ago and hadn't considered access to the fuselage interior between the cockpit and the firewall. As you can see in Radek's photo, it's a great place to install radio and other equipment. Once you glue this former in place, you can only access the area by removing the cockpit :-( I learned this lesson the hard way and had cut out my firewall former to improve access when installing the cockpit glare shield.

As such, I decided to re-engineer the area to create a removable front former and nose cone support. Not only would this give access to the fuselage interior, removing the ply nose structure for shipping would shorten the crate by at least 14" (in addition to the 6-1/2" savings from the removable tail cone). A new 1/4" plywood "ring" former was created with a 4" H x 3-1/4" W bolt pattern fitted with 8-32 blind nuts and glued into the nose.


A mating removable former was also cut from 1/4" ply and I also cut a new vertical plate which was slightly larger (top/bottom) than the kit plate. When cutting the slots in the removable former, I made the fit snug enough that the two parts would stay together without glue and made the slots a bit too long. This enabled the pieces to be bolted onto the fuselage and the position & angle of the vertical plate to be fine tuned (by trial fitting the fiberglass nose cone) before gluing the former and plate together.


The big openings at each side allow plenty of room to run wires from any batteries mounted on the vertical plate and by simply removing the four SHCS holding the former/plate in place, the opening in the fuselage is large enough to give two handed access to the interior.

Regards,

Jim

RCISFUN

My Feedback: (44)

Jim
That's a great idea!
Keeping it simple but very effective... will work great for access when charging your batteries.

roydefiant

Perfect I will replicate that on my Gripen

Roy

rcjets_63

My Feedback: (4)

Mounting of Air Intakes:

The air intakes are molded separate from the Gripen fuselage. This is similar to the C-ARF Hawk, but unlike the Hawk, the Gripen intakes are not glued to the fuselage. The intakes are intended to remain removable for access to the fuselage interior ahead of the main wheel wells as seen in these Airworld photos:


I traced the outline of the fuselage at the intakes and made intake formers out of 1/8" plywood. Three 1/8" holes were match drilled with the fuselage for aluminum pins that are glued to the formers. The intake is then positioned and glued to the former with epoxy. This secures the back of the intake.


Roy and I ordered inlet ducts from Airworld. Installing inlet ducts tends to be finicky work and these were no exception with a lot of trimming, sanding, grinding necessary to have them fit at the intake and clear the cutout in the fuselage side and formers but eventually I got them to fit. Here is the photo of them prior to shipment from Airworld.


To secure the inlet at the front, you might be tempted to simply put a screw at the front of the ramp behind the splitter plate as was done in the example kit - See photo below with screw hole circled in red. The issues with that are:
- the screw is quite far forward and would be easily visible (rather than being at least partially hidden inside the inlet duct) during static judging of the side view
- the front of the ramp where the screw hole is located should actually be cut away for the auxiliary air inlet as seen in the photo of the left air intake below. The full scale also has an aux air inlet on the right side too.


Installing a screw from the inside of the fuselage isn't practical as the cockpit would have to be removed to get to the screw. As such, I secured the front of the inlet by a similar method to that shown in the photo above but moved the hole back to 3-1/4" behind the front of the splitter plate. This puts the screw far enough into the intake that it isn't visible from the side (the screw comes into view at 30 degrees off axis) but is far enough forward that you can reach into the inlet with a screwdriver bit to loosen/tighten the #4 screw. A socket head countersunk screw would be even better.


Regards,

Jim

marc s

Lots of work here Jim, remember the days when I was doing this sort of build, gets the brain thinking

I know its done now but an option might have been to fit a canopy type latch to the intake section where you have the ply brace, mount on the fuselage mating section a plate for the hatch pin to engage and run a wire or thread from the latch via a snake back to a suitable opening (under the main hatch) where a simple pull ring would allow you to release the hatch pin and allow the intake to be removed.

PS your CAT will ship this week.

marcs

rcjets_63

My Feedback: (4)

Marc,

That's a really great idea; I wish I had thought of it. D-oh. I could have mounted a hatch latch on the inboard side of the plywood plate glued to the fuselage at the inlet cutout and connected it to a "pull rod" routed forward through the ring former in the nose. Once the nose cone is removed, the rod could be pulled to release the intake. Don't be surprised if this is redone in time for Germany. I hope to see you there!

Many thanks to you for your support of Jet Team USA!

Regards,

Jim

rcjets_63

My Feedback: (4)

Nose Cone Installation - Retaining Hardware

Similar to the SM F-16, the nose cone is held on the front of the plane by a threaded "bolt" or simulated pitot tube. In the case of the Gripen, the nose cone has a 6mm hole/tube formed into the fiberglass tip. Unfortunately, the kit does not come with a pitot tube so I'll have to make one. It's tough to get a good photo of a pitot tube, but I was in luck.


Since I have to make a pitot tube anyway, I thought that I'd go all out and make it both scale and functional. I use a Jeti DC-16 radio system which has a variety of very useful sensors including the MSpeed airspeed sensor. The unit comes with a pitot tube that has both the dynamic and static pressure ports which makes the installation a lot easier for the user. In order to make it scale, separate static and dynamic pressure ports are required. The static port is reasonably easy; one merely has to connect air fitting nipple to a small vented cavity on the side of the model.


To do the dynamic pressure, an air fitting will have to be internally connected to the pitot tube. I did this by cutting the end off an old Robart fill valve and Hysol'ing it to a 6mm threaded coupler from Ace Hardware. The assembly was fitted into a tight slot in the nose cone plate and checked for the 5 degree pitch down and correct alignment by using a brass tube and threaded stud (also from Ace) before being Hysol'd in place.


The 6mm thru-hole in the nose cone was molded in at about 7 degrees of pitch down but a dowel file sorted that issue out and some 1/32 & 1/64 ply shims were added behind the removable front former to align the threaded coupler perfectly with the hole in the nose cone. A standard 6mm SHCS will be used to keep the nose cone in place except when flying (and static judging) when the more easily damaged pitot tube will be used.


The strakes on either side of the nose in the above photo were molded in at about 9 degrees of pitch down. You can clearly see in the 3rd photo of this post that the strakes should be in line with the pitot tube (5 degrees pitch down). As such, they will have to be cut off and replaced with G-10 cut to the scale shape (seen in 2nd photo of this post).

Regards,

Jim

roydefiant

great progress

Roy

rcjets_63

My Feedback: (4)

Cockpit Installation and Canopy Release

There are probably a million ways of installing the cockpit pieces. I wanted to be able to remove any panel (without having to first remove another panel), and have all the screws hidden so I put a fair amount of thought and effort into it. Perhaps these pics may be useful to any other folks who build this kit.

Dorsal Deck -


Side Panels -

Floor/Back Panel -

Glare Shield -


Canopy Release (left side, right side not shown) - v


Regards,

Jim

rcjets_63

My Feedback: (4)

Back to work today after a 12 day Christmas break of Gripen building. I didn't manage to get too much done tonight but I did finish off the canopy release and pins at the back of the canopy frame (see edited post above). Then I thought I'd put it all together for some motivation.



Regards,

Jim

rcjets_63

My Feedback: (4)

I finished off the initial cockpit installation last night and added the scale side guards and blended the canopy frame ledge. It should look great when painted black and some scale details added. Here's a comparison of the model and the full scale.


I did notice that the shape of the Airworld ejection seat is wrong. They molded the seat based on the front seat from a -39B/D rather than the seat from a -39A/C (same as the rear seat in a -39B/D). This is best explained with pictures though you may have to look closely.


Regards,

Jim

smchale

My Feedback: (67)

Jim, I appreciate your efforts but frankly I'm still not seeing the seat you describe??

smchale

My Feedback: (67)

Maybe instead of you and Andy presenting the model to the judges you hire some static judging girls to have the same effect on the judges? I'm sure there are worse ideas.

rcjets_63

My Feedback: (4)

Sean,

That's an interesting idea. Static shouldn't be a problem but I am worried about my flight scores because, well, you've seen me fly so you understand. Maybe I should see if Karolíně Jonákové is available to be my caller/helper during the flying rounds. With her Gripen experience, she may be able to give me some tips. She'd have her back to the judges but I doubt that they would mind.


Regards,

Jim

sysiek

My Feedback: (176)

So after the gripen of my arrived damaged I'm going to do so repair uploads and programs .The jet have some damage doing the travel by forward air the list of damage .broken canard multiple gellcote cracks damaged wing lots off scratches ripped gear doors .cracked nose broken exhaust nozzle .I did fixed some things started with glue the canard nose some gellcote cracks and fixing the nozzle. The gripen it's a old aviation design prototype line it's about 98" long .no pictures the rcu acting up again.

sysiek

My Feedback: (176)

Ok the pictures upload works now so the new history of this jet shipping damadge 1.and little repair progress 2the nozzle it's fixed and painted it took some time.so this is it for now.

rcjets_63

My Feedback: (4)

Here are the dimensions (in millimeters) of the pitot tubes on the fin and nose of the full scale Gripen.


Regards,

Jim

rcjets_63

My Feedback: (4)

I fitted the Details 4 Scale drop tanks to the inboard pylons using BVM EZ Hangers. The hanger is installed in the aft slot of the pylon and the "eye screw" is positioned such that the front of the pylon is 11-7/8" behind the front of the tank. This puts the front of the tank 8-1/2" behind the fuselage/inlet split which is the scale position.


Regards,

Jim

rcjets_63

My Feedback: (4)

I was having a bit of trouble confirming the if features that had been molded into the fin (vents, probe mounts, maneuvering lights, etc) were actually in the scale location. I realized a great way of checking would be to use the sabre-tooth tiger skull and claw markings as they have a lot of detail and would easily allow me to see if everything lines up as it should.

The sabre-tooth tiger skull and claw graphics on the fin (as well as the tiger eye graphics on the canard) were not painted on the full scale Gripen 9245. They were actually printed onto film which was applied to the aircraft. Here are some pics of the techs applying the film to the plane in preparation for the 2010 NATO Tiger Meet.




I made electronic files for the model using Photoshop. By scaling major features I took a "informed guess" at the size and printed out some fit-check prints on paper. All in all, the model graphic seems to be a very good match for the full scale if you take into account that the light grey shades tend to get swamped out by the black ink on paper; the vinyl prints will be better.


By comparing the paper graphic installed on the fin to the corresponding photo of the full-size, we can see the good (in green) and the bad (in red)


By comparing the model to the full scale, we can see:
The good:
- the upper and middle rudder hinges match quite well and the 3rd finger in the claw lines up well with the hinge line
- the horizontal panel line that bisects the "2" in "211" lines up quite well
- the upper left corner of the "2" in "211" is the right distance from the leading edge of the fin.

The bad:
- The bottom of the "211", the jaw teeth, and the tip of the 4th claw is too close to the fin/fuselage junction as is the 4th finger tip in the claw
- The 4th fingertip of the claw is too far behind the hinge line
- The skull opening for the nasal cavity doesn't line up with the fairing

Obviously the graphic is too big since it lines up well at the top but not the bottom. While the molded-in horizontal panel line goes through the "2" at the right location, it would be too low when the size of the graphic is reduced which means that the panel was molded in the wrong place. Although it can be easily seen that the graphic is too big, as it turns out, it is only about 3% oversize. It will be easy enough to change the scale factor and print out another set tomorrow.

Regards,

Jim