Official FMS 1500mm P-47D Razorback Thread

[Grossman56]

How about this Dave?

https://rcdrone.top/products/jx-servo-23kg-digital-airdrop?currency=USD&variant=45766788972768&utm_source=google&utm_medium=cpc&utm_campaign=Google%20Shopping&stkn=677f40c1dee9&gad_source=2&gad_campaignid=22916176319&gclid=Cj0KCQiAtfXMBhDzARIsAJ0jp3AD9SIQRmQv1Z2aTvDM57J77EZDLbe7I1aFU1J8CQHYPWvHLkQw7n8aAq2PEALw_wcB

Dan

[Elbee]

Do you know of a servo bomb drop mechanism that is available commercially that would work in the belly of the P-47?

Davegee

Dave,

As I recall Chris Wolfe has added Tank Drops and/or bomb drops to many of his builds.

You might check out his channel https://www.youtube.com/results?sear...y=The3+RC+Geek and see what he is doing for that.

Also, there might be something on "Thingiverse" of some other 3DP repository the you could print.

Found this on Prusa Printables in about 0.5 seconds...https://www.printables.com/model/132...pper-mechanism

I had/have an old Dave Brown bomb release around somewhere, might check to see if any of those are still available.

And there's always DIY: https://studyquiz.blog/rc-plane-bomb...echanism-guide

Best, LB

[davegee]

Dave,

IMHO, a servo actuated sliding canopy mod should be designed and implemented ahead of any fuselage work in a foamie.

In the case of my Corsair, the cockpit section was cut open and I performed various 'foam surgeries' as the design advanced.

Having NOT done this before and then adding the difficulty that EPO often presents, several iterations were made 'on the fly' as it were.

For me, any major mod like this should be sorted out first.

The same was true for me with the 'cowl flap' mods where the only way was to cut off the Corsair's nose.

Ya gotta break some eggs to make an omelette.

Best, LB

Yeah, I'll be thinking about doing the mods on the canopy and possible belly drop tank. I think I really need to have access to the cockpit with some sort of sliding canopy, whether I make it powered or not.

Do you know of a servo bomb drop mechanism that is available commercially that would work in the belly of the P-47?

Davegee

[Elbee]

I like the idea of using a worm drive or your rack and pinion to allow the canopy to open and close. I just don't want to do something that would ruin all the hard work James has done!

Davegee

Dave,

IMHO, a servo actuated sliding canopy mod should be designed and implemented ahead of any fuselage work in a foamie.

In the case of my Corsair, the cockpit section was cut open and I performed various 'foam surgeries' as the design advanced.

Having NOT done this before and then adding the difficulty that EPO often presents, several iterations were made 'on the fly' as it were.

For me, any major mod like this should be sorted out first.

The same was true for me with the 'cowl flap' mods where the only way was to cut off the Corsair's nose.

Ya gotta break some eggs to make an omelette.

Best, LB

[davegee]

davegee

That's beautiful work, Elbee. The P-47 wouldn't be all that different using a similar rack/pinion idea.

davegee

Thanks.

I moved my response over here to the FMS P-47 thread.

If I were building one of these, I'd consider it, too.

A worm-drive would be the smoothest, like jetfool wrote, and probably easiest to fit in a small space.

I chose the rack/pinion as I could adjust the rack length to my canopy open/close measurement for simplicity's sake.

Also, I knew I wanted the mechanism in the battery cover for ease of maintenance, if it all went sideways.

The other real trick for my build was designing a carriage (for lack of better term) that was robust enough to stay square in squishy/flexible EPO foam.

The x-axis tolerance was a tight fit in the tapered fuselage, so install fitment was critical to keep it all running smoothly in repeated cycles.

I ran the cycle function with a servo tester for more than 100 cycles before closing up the fuselage and it still 'snaps' tight in both directions.

All in all for me it was a mod worth the time and effort for a model as beautiful as the FlightLine Corsair.

Best, LB

I like the idea of using a worm drive or your rack and pinion to allow the canopy to open and close. James wrote me yesterday that he is concerned that cutting into the new areas that he just added to make it a bubbletop might damage and make a mess out of things. Not having seen the new fuselage yet, I'm reserving judgement to see it myself and come up with some sort of plan. I do know this, though: I defnitiely want to have the canopy slide back and forth or at the very least have it removable and held both closed and open with magnets or something. I did do that on one of my FMS razorbacks for simplicity. The canopy holds tight in the closed position using tiny reare earth magnets, with over a dozen test flights on it so far. For static display, I simply slide the canopy back by hand onto a magnetic strip and other magnets further back in the cockpit to have it stay in the open position. I think I could do that, at a minimum, but still would like to see if I could employ something like what you did with your Corsair. Once I get the model in-hand soon, I can start making decisions which way to go. I just don't want to do something that would ruin all the hard work James has done!

Cheers

Davegee

[Elbee]

davegee

That's beautiful work, Elbee. The P-47 wouldn't be all that different using a similar rack/pinion idea.

davegee

Thanks.

I moved my response over here to the FMS P-47 thread.

If I were building one of these, I'd consider it, too.

A worm-drive would be the smoothest, like jetfool wrote, and probably easiest to fit in a small space.

I chose the rack/pinion as I could adjust the rack length to my canopy open/close measurement for simplicity's sake.

Also, I knew I wanted the mechanism in the battery cover for ease of maintenance, if it all went sideways.

The other real trick for my build was designing a carriage (for lack of better term) that was robust enough to stay square in squishy/flexible EPO foam.

The x-axis tolerance was a tight fit in the tapered fuselage, so install fitment was critical to keep it all running smoothly in repeated cycles.

I ran the cycle function with a servo tester for more than 100 cycles before closing up the fuselage and it still 'snaps' tight in both directions.

All in all for me it was a mod worth the time and effort for a model as beautiful as the FlightLine Corsair.

Best, LB

[davegee]

Sounds good Dave. A droppable tank would really set the flying apart from others. You could 3d as many tanks as your sorties allow. A thought! I wonder if a jack screw retract servo would give enough motion to open/close the canopy. Might need a fulcrum setup underneath to give the desired movement. Just my .02.
Been working all day on the Phantom, parts everywhere but feels like I'm making headway.

Best Regards, Rex

Thanks, Rex. I might bend your ear for your opinion on things when I get to that point of wanting to make a motorized canopy. That would be cool! One of the drop tanks they used a lot was a 215 gal. "flat tank" wich looked sorta like a rectangle and the aft edges angled in to a smaller tail area. I made one of these for my Fire Ball. We dropped it in testing and later in competition. was really cool Went unstable immediately after release and tumbled down the ground without damage.

[Grossman56]

Wow, this should be sent to FMS, maybe they'll create a bubble top!?

Dan

[Elbee]

The back turtle deck is nearly complete , some minor filler and we are done, I even added the back panel line .. the hatch needs minor work, both should be ready to ship back to Dave, in a week, then full attention to the canopy plug finish work.

Vrosi,

That is Master Class level work, Sir.

Just amazing.

Best, LB

[jetfool]

Nice craftsmanship vrosi 1963

[vrosi1963]

The back turtle deck is nearly complete , some minor filler and we are done, I even added the back panel line .. the hatch needs minor work, both should be ready to ship back to Dave, in a week, then full attention to the canopy plug finish work.

[jetfool]

Sounds good Dave. A droppable tank would really set the flying apart from others. You could 3d as many tanks as your sorties allow. A thought! I wonder if a jack screw retract servo would give enough motion to open/close the canopy. Might need a fulcrum setup underneath to give the desired movement. Just my .02.
Been working all day on the Phantom, parts everywhere but feels like I'm making headway.

Best Regards, Rex

[davegee]

Davegee,
Designer Dan is really turning these things out fast. He and Elbee are the go-to 3d GURU's. So, your fine with your 3d parts and don't need me to send any? You and he should start designing the structure behind the cockpit seat turtle deck. believe there is some sort of canopy structure that is exposed.
Best regards Rex

Hi Rex: with the breakthrough of Dan's 3D printing prowess, I think I'm all set. Thanks for your explaining the casting part to me. I am still going to experiment with that since I made a tool which is very close to the size you made and the clay for making impressions to fill to make cast parts. I think I even have a bit of turtlewax in the garage somewhere to coat the clay so the part will come out. I'd like to see how it looks versus the 3D printed parts.

So, yes, I guess I've got everything I need right now, and you don't need to send anything. I certainly appreciate your helping explain this stuff to me, though. It's great that we as modelers can help each other out. Back when I competed in Scale Masters and Top Gun, there were a lot of great guys on the flightline that were happy to help out, as we were for anyone else. I had heard in the more elite divisions, the guys were pretty cutthroat, and I was happy to be with my homies on the warbird flightline.

I do plan on making the back turtledeck for the Hairless Joe bubbletop underway, and I'd really like to see if I can get a small servo to open and close the canopy like most of the bubbletops had. Another thing I'd like to add is a scale large rectangular belly drop tank that I might jettison during the flight. Those would be cool additions for this plane. This is probably the last Jug that I do, so I want it to look and fly great!

Cheers

dave

[jetfool]

Davegee,
Designer Dan is really turning these things out fast. He and Elbee are the go-to 3d GURU's. So, your fine with your 3d parts and don't need me to send any? You and he should start designing the structure behind the cockpit seat turtle deck. believe there is some sort of canopy structure that is exposed.
Best regards Rex

[Grossman56]

Here's the file I just sent to Dave so you can print 6 at a time.



[ATTACH]n444567[/ATTACH]

Dan

[davegee]

Thanks, Rex. Dan just emailed me the STL for these parts. I printed them up and I don't think I could improve on them! I still would like the exercise of making these the "old school" way that you did and that I will attempt from my end on the part I carved last night. I still think some uses of the this method are a good way to go for certain parts. I know this technique has been around for a Long time...

Thanks again!

I'll post some pics of what Dan made up on my Hairless Joe.

Cheers

Davegee

Hi Rex: Dan just sent over the STL and I printed a bunch to use on at least one of my airplanes. I will still experiment with the "old school" way of using the clay molds and epoxy, which I think are still good to use in certain cases when 3D printing doesn't work out for some parts. I think it's good to keep a skill like this alive for some parts.

I'll attach a couple pics I took of the covers on one of the wings. One of the pics has a 1/48 scale Tamiya P-47M model to use as a gauge for placing the pieces on the larger airplane.

Thanks for your help. I can barely remember doing this method over 20 years ago with the P-47M that I was working with about 2004 or so.

Cheers

Davegee

[davegee]

Davegee,
Good ole car Turtle wax. I'm cheap
I will make some up and send to you.
Best Regards, Rex

Thanks, Rex. Dan just emailed me the STL for these parts. I printed them up and I don't think I could improve on them! I still would like the exercise of making these the "old school" way that you did and that I will attempt from my end on the part I carved last night. I still think some uses of the this method are a good way to go for certain parts. I know this technique has been around for a Long time...

Thanks again!

I'll post some pics of what Dan made up on my Hairless Joe.

Cheers

Davegee

[jetfool]

Davegee,
Good ole car Turtle wax. I'm cheap
I will make some up and send to you.
Best Regards, Rex

[Grossman56]

Got the dimension pic and I'll tinker around with it this morning.
Cool project!

Dan

[davegee]

Hi Rex: thanks so much for the great explanation about the molds for the aileron covers. The only question is what do you use for the wax for the clay impressions from pressing the shaped wood parts to easily remove them from the clay? Otherwise, I think I’ll be ready to go after a trip to Walmart!

If you wouldn’t mine making up maybe six of these parts the way you are comfortable doing it and sending to me, I’d like to study and use yours along with the ones I will make and possibly if Dan can make a STL of them so I can print some up to see how they all look when finished. I’m going to put all these on my four P-47s to learn more about this technique. I did do some machine gun belts for the wings of an earlier P-47 that came out pretty well but that was over 20 years ago and had mostly forgotten how I did that!

Your dimensions and mine were very close, almost “dead nuts on” between yours and my dimensions

Thenks again!

Dave