Official FMS 1500mm P-47D Razorback Thread

[Davegeee]

Just a quick followup for resuming flying my FMS 1500mm heavily modified P-47D bubbletop model. I took it up this morning for two test flights, with "insurance" pins inserted, two at the front of the canopy, one on either side, and one in the back of the canopy. Did some aerobatic flying and fast flying to see if that shook up the canopy at all, but it was rock solid all the way through. Danger Dan and I might come up with a canopy bow printed piece that might help secure it better to keep it from departing the airplane in flight, but even if we don't, the three simple pins keep it nice and solid until removed on the ground for demonstrating the powered canopy, which works great.

Ten flights on it so far. I'll continue to fly it sparingly, but for the most part, I'm satisfied with this little experiment. It is an ode to my original 1/6 scale Aerotech P-47D that I flew over 20 years ago and has been in the Kalamazoo Air Zoo museum since 2006. Also, attached is a pic of the real Hairless Joe taxiing for a combat mission in 1944.

Cheers

Davegee

[Davegeee]

Davegee,
Since you're getting the only 2 canopies available for the FMS I guess I will have 2 make my JEM-CO P-47 into a P-47M. I have the plans showing the bubble conversion from JEM-CO for the conversion , all these years later. Bought kit in 1980.
Best Regards, Rex

Hi Rex: I'm sorta spooked after the mishap with the canopy a couple of weeks ago. I did do two test flights this morning with a pin inserted in the front at two places and one in the rear of the bubbletop canopy. Flew like a champ, although I learned that especially with this plane it seems, don't get it slow. I wasn't anywhere near a stall with it, but it definitely is in the groove going fast and downhill, especially with the big V3 FMS Corsair prop on it! No adverse issues with the canopy whatsoever with the three "insurance" pins installed just for flying. Afterwards, when you pull them out, the canopy operates perfectly in static display. You can scarcely see where the pinholes are in the canopy.

So, a total of 10 flights on Hairless Joe so far, and I will be keeping it flying very occasionally, mostly for display.


I'll add a separate short entry on today's flight separate from this.

I'm getting ready to pull the trigger on the Flightline P-51D. I'm very glad I made the heavily modified experimental Hairless Joe. It was a lot of work and some challenges, but I learned a lot on this project.

Does your bigger Jemco P-47 have a bubbletop canopy? What scale is it? An M model would be awesome in a larger scale plane. I did that one that you have seen in Florida, but I don't know if many (if any?) who have done a large M model before. I know the pilots loved it, even though it had some teething problems and came out near the end of the war. My late friend Russ Kyler used to tell me while flying the M model:"If anything comes up to attack us at 25,000 feet or higher, they're DEAD MEAT!"

Cheers

Davegee

[jetfool]

Davegee,
Since you're getting the only 2 canopies available for the FMS I guess I will have 2 make my JEM-CO P-47 into a P-47M. I have the plans showing the bubble conversion from JEM-CO for the conversion , all these years later. Bought kit in 1980.
Best Regards, Rex

[Grossman56]

Get out the leaf blower and hit it, see what happens!

Dan

[Davegeee]

Thanks, Dan. We can look into that. I almost went flying this afternoon for a test flight with the new replacement canopy, but it started raining and wasn't going to let up. I'll try early tomorrow or Monday.

For the near term, I have installed three ball-head pins: one for the aft tail of the canopy, and one on each side that goes through the windscreen and canopy lip, to secure those in place for flying. It feels very sturdy when I shake it gently with my hand. I want a couple of flights like that just to prove that the airplane can fly great and keep the canopy on for the whole flight. After that, we can work on some sort of frame to make sure the canopy can't blow off in flight! The pins are easily removable on the ground, enabling the demonstration of the powered canopy.

I talked with James and he is going to sell me the last two plastic canopies that the fabricator made from his mold. Then, I'll have extras for any unexpected developments during testing of ths thing.

Cheers

Davegee

[Elbee]

Dave, we can fix it! We just need to come up with the forward canopy frame and add a lip to slide under the windshield. It can be done!

Dan

Dan,

For me, that was easier said than done.

I eventually designed a good fit.

Best, LB

[Davegeee]

Davegeee,

I would agree with jetfool about a thicker plastic would add some stiffness to the canopy assembly.

Whether that is enough to prevent an unscheduled departure of the canopy is a matter of trial and error.

I might add that the canopy bow should be quite solid and any supporting rail structure should attach to the bow solidly.

The clear canopy should be the added stiffness not the sole means of support.

I surmise any modification like this at 1/8th or smaller scale, we suffer from materials not being up to the task when trying to adhere to scale proportions and yet fly in 1:1 air at above scale speeds.

Also, the bubble canopy of your P-47 doesn't allow much air to escape 'through' it and theoretically then just catches the air.

Obviously, this becomes a force of resistance and either the canopy lives through that or it does not.

I've only flown my Corsair once with the same mod and I didn't open it.

I had no issues, but again it is a completely different type of' bubble' canopy, if it can even be accurately called a 'bubble' canopy.

The Corsair has the turledeck that keeps the air flow along the fuselage and not trying to lift the canopy in flight.

I am certain you will find solution, Dave.

Best, LB

Thanks, Elbee. Great points.

I have two points of attachment in the front on either side which consist of a small bass block with a brass rod drilled into the bottom of each block that is in-turn glued to the lower front sides of the canopy. There are corresponding holes drilled into the sliding or carriage brass square tube mechanism that rides in a slightly larger brass square tube with a lengthwise channel cut through the top side. So, the servo moves this whole carriage back and forth through those brass tubes mounted on the sides of the cockpit. The brass rods glued to the blocks in the canopy are in turn glued into the holes drilled into carriage mechanism listed above.

There is a third, temporary connecting point at the back of the bubble canopy that has a tiny hole drilled through it and I place a long pin with a round ball on the top through the hole in the canopy and all the way into the foam fuselage as far as it goes. It seems to keep the rear of the canopy firmly in place.

For the first 6 flights, I had zero problems with this method. Once I got back on the ground, I could just remove the pin in the rear of the canopy and the canopy could be operated for demonstration purposes all I wanted to.

Still some work to do to make sure that this canopy will stay on the airplane consistently. I'm sure there is a solution there.

Best,

Davegee

[Grossman56]

Dave, we can fix it! We just need to come up with the forward canopy frame and add a lip to slide under the windshield. It can be done!

Dan

[Elbee]

Grossman56,

Great catch, Dan.

1:1 have similar, as you know.

Best, LB

[Grossman56]

As just a thought, my FMS P51D had a sliding canopy. There was a lip that slide under the windshield when it was closed, probably for that exact reason, to stop the air from getting under it and removing the canopy. Something like that may help. Have you asked James if he would be interested in selling you the mold or at least letting you have access to it to print up a few extras?

Dan

[Elbee]

Davegeee,

I would agree with jetfool about a thicker plastic would add some stiffness to the canopy assembly.

Whether that is enough to prevent an unscheduled departure of the canopy is a matter of trial and error.

I might add that the canopy bow should be quite solid and any supporting rail structure should attach to the bow solidly.

The clear canopy should be the added stiffness not the sole means of support.

I surmise any modification like this at 1/8th or smaller scale, we suffer from materials not being up to the task when trying to adhere to scale proportions and yet fly in 1:1 air at above scale speeds.

Also, the bubble canopy of your P-47 doesn't allow much air to escape 'through' it and theoretically then just catches the air.

Obviously, this becomes a force of resistance and either the canopy lives through that or it does not.

I've only flown my Corsair once with the same mod and I didn't open it.

I had no issues, but again it is a completely different type of' bubble' canopy, if it can even be accurately called a 'bubble' canopy.

The Corsair has the turledeck that keeps the air flow along the fuselage and not trying to lift the canopy in flight.

I am certain you will find solution, Dave.

Best, LB

[Davegeee]

Davegee,
Might try contacting the manf. that made the canopy, they might work with you on a thicker canopy. If it was Park Plastics I'm sure they would work with you. Just my .02.
Best regards, Rex

Thanks, Rex. I think James has the mold he made and is required to make more of them. I don't think he is interested in printing up more of these due to low interest by modelers doing the same thing. I think I'm stuck with what I have. Good thought, though. I think I can buy the last two canopies he has to use as spares/replacements in case another canopy departs and I can't find it in that field. I walked probably a couple hours looking for it looking for a glint coming off from the sun, but whenever I came up to that spot, it was always and old beer can!



Cheers

Davegee

[jetfool]

Davegee,
Might try contacting the manf. that made the canopy, they might work with you on a thicker canopy. If it was Park Plastics I'm sure they would work with you. Just my .02.
Best regards, Rex

[Davegeee]

A small Earth Magnet might be in order.

Dan

I'm looking into that now. The complications are that I have designed and built a motorized sliding canopy, and have taken pains to keep it as scale as possible. Unfortunately, that design is not as robust, say, if I just glued on the whole canopy/windscreen instead of the motorized unit. I'll give it a few more flights before I decide to do anything like the magnets. I don't really want to remove the powered canopy as that is an interesting demonstration on the ground, but the canopy itself is pretty flimsy and would better be made with a slightly thicker plastic. That would probably be a big help
Research continues...

[Grossman56]

A small Earth Magnet might be in order.

Dan

[Davegeee]

Davegee,
Sounds like Hairless Joe had a harry flight. Can you fix a small cable to canopy so it can't leave the plane and not be noticeable? Rex

Hi: Rex: Yes, it was a challenge, especially when I didn't even see the canopy depart the aircraft (being mostly clear plastic) and was wondering why this airplane was acting so crazy. Fortunately, I was able to bring it in for a safe landing. I've already got my backup canopy installed on the cockpit, and am looking at various protections to make sure it doesn't happen again. I"m not sure I can fix a cable to the canopy, but it is one of several ideas I have on it. The other 7 flights before it the canopy has stayed on beautifully, and I might have been lulled into complacency thinking it wouldn't come off like that. Well, that wasn't the case, as I found out.

I still plan on flying it again next week, and then it will go to the back of the rotation since this won't be an everyday flyer for me. I'll start working into getting the new Flightline P-51D for a new project, which should fun.

Cheers

Davegee

[jetfool]

Davegee,
Sounds like Hairless Joe had a harry flight. Can you fix a small cable to canopy so it can't leave the plane and not be noticeable? Rex

[Davegeee]

I am finishing up painting and weathering the 150 gallon printed drop tank that Dan and I have been working on. After a very succesful flight and drop test yesterday, I painted and weathered the tank today. I can still change out this tank for the foam 108 gallon tank that comes with the model. That one has been tested almost 10 times now, using three different P-47s equipped with the E Flite drop tank mechanism. I have added some additional scale dtetails like the transfer and venting tubes from the tank to the airplane. They can be inserted into aluminum tubes that fit flush with the fuselage for static display, or set just next to the tubes on the fuse to look like they are attached but aren't so they come off cleanly during the drop. You might see one tube has a clear tube running through the middle part of the black tubing. That was so if for some reason the tank did not come off when dropped by the pilot, the glass tube would break and ensure that the tank separates cleanly from the plane.

I'll probably fly this rig next week to do another drop test, and hopefully it will come out as well as yesterday's test went.

Cheers

Davegee

Got two more flights on Hairless Joe today. The dropping of the completed, painted, and weathered 150 gallon drop tank went flawlessly. Totally undamaged from the fall. Unfortunately, somewhere in the mix my canopy departed the aircraft, which made the airplane do some funky moves,not knowing that the canopy was gone until I landed the plane. But fortunately, I had a spare and have been preparing it for use on a future flight.

Cheers

Davegee

[Davegeee]

I'm happy to report that the idea of a scratchbuilt large, scale 150 gallon drop tank was successfully flown this morning from my testbed Hairless Joe. This larger tank was crucial in allowing Thunderbolts to penetrate deeper into enemy territory on bomber escort and other interdiction of German fighters, railroads and trains, and other valuable targets. A big shout out to Danger Dan for designing the stl and making it something from being on a computer screen to the actual part on a model airplane. I do a little small project work on my Prusa Mini, but this was too large for my skills and printer, so we had a professional outfit make up the parts that Dan designed.

I wasn't really planning on necessarily flying this first iteration of a drop tank, and it was pretty thick but hollow construction. The entire thing unpainted and unfinished like today's test flight, weighs close to 8 ounces, which concerned me. But the overall plane ready to fly without the tank weighs 10 pounds. so I figured it could probably take it ok. I put the E Flite attach bracket in a slot I cut at the CG of the tank. And then the tank attached to the E Flite release mechanism, which is also at the CG of the airplane. When I tested it with the tank attached, it was absolutely perfect on CG, so I figured I had that going for me.

Took off this morning, I think I have the throws and Expo dialed in to my liking and it took off beautifully and very scale. Did about 3 passes to check for security of the tank, and then on the next pass dropped it as it passed me. As usual, it went unstable immediately and spun end over end until it hit the ground about 150 feet from my position. It did land with an audible "THUD!" which surprised me slightly but this drop tank is built like A Sherman Tank, and just had a bit of dirt on it.

So, this completes the testing I wanted to do for this airplane model project. I think the scale 150 gallon tank is probably unique to my knowledge on a foamie fighter. I made a larger one for a 1/5 scale gasser P-47M about 20 years ago that the tank dropping was part of the routine we used in competitive flights.

I'll give Hairless Joe the weekend off, now with 6 flights on it. I'll start working on the tank, doing more sanding, filling, and eventual painting to complete it in a Neutral Gray color.

I"ll attach a few pics from this morning. The one of the tank in the field is where it landed and looking back at our clubhouse where I was standing about 150 feet away.

Cheers

I am finishing up painting and weathering the 150 gallon printed drop tank that Dan and I have been working on. After a very succesful flight and drop test yesterday, I painted and weathered the tank today. I can still change out this tank for the foam 108 gallon tank that comes with the model. That one has been tested almost 10 times now, using three different P-47s equipped with the E Flite drop tank mechanism. I have added some additional scale dtetails like the transfer and venting tubes from the tank to the airplane. They can be inserted into aluminum tubes that fit flush with the fuselage for static display, or set just next to the tubes on the fuse to look like they are attached but aren't so they come off cleanly during the drop. You might see one tube has a clear tube running through the middle part of the black tubing. That was so if for some reason the tank did not come off when dropped by the pilot, the glass tube would break and ensure that the tank separates cleanly from the plane.

I'll probably fly this rig next week to do another drop test, and hopefully it will come out as well as yesterday's test went.

Cheers

Davegee

[davegee]

I hear you, I just thought that it was cool that your research was shown on the model. Great job!
I've been looking for reference pics for Shangri La as well, which is something I never thought I'd be doing! (Never say never)
So far, these have shown up...


Amazing what you can find.

Dan

Those are great reference photos, Dan. Those can help you determine accurately how the airplane looked during its combat tour. With photos you can often make the right decisions how your plane looks.

cheers

davegee