FTFC'18 WWII FH-1 Phantom designed by Namactual

[Namactual]

Update:
I got a lot done here...

The only thing I really have left to do is build the other wing. (maybe tonight if I feel overly ambitious) Then it's on to the electronics. That is going to be a big job, more than it looks anyway. I am going to have to get creative with wire routing and pull tools, but after studying it for a while, it can be done without any major issues.

As you can see in the second pic, I got my new order of PLA in today. White, Silver and Black. That should keep be busy for a while.

Speaking of PLA, I am not sure the 3D printed parts will make it for the maiden flight. I do not like the extra weight. I will make that call once complete and I have done my thrust tests though. Also note, the front and rear canopy are too narrow at the top and have already been drawn proper. Those are just test prints that are just tacked on at the moment for pictures.

At this rate, this may be done by FF!
The same FF I will most likely miss.

 

[Namactual]

I just did my weight calculations and I am looking at 850grams dry. AUW will be 1100-1200 or so depending on the battery/ies used. That is about 200-300grams heavier than my first prototype. This does have a little more wing surface and should have a lot less drag as well. This also will have a TON more thrust running these new fans on 4s.

I could shed about 100-150grams losing the 3D printed parts and substituting with foam. Which I just might do.

I am going to do thrust tests with these FMS 50mm 4s fans running on 3s and see what numbers I come up with. Not just for this build, but for future projects as well. I would like to find a 50mm EDF in between the HK 18 amp 3s and the FMS 50mm 40 amp 3s. I was thinking these FMS 4s 50's might hit that sweet spot on 3s depending on the output.

We shall see...

Edit: A quick sudo test on 3s using a 2200 at storage voltage produced around 400grams of thrust @20 amps. That is far better than the HK 50mm 3s fans running 325gr @ 14amps on a full pack. I am not going to charge a battery tonight just to test. Maybe tomorrow if I can get some flying in. It all depends on the weather.

 

[foamtest]

Update:
I got a lot done here...
View attachment 109274 View attachment 109275
The only thing I really have left to do is build the other wing. (maybe tonight if I feel overly ambitious) Then it's on to the electronics. That is going to be a big job, more than it looks anyway. I am going to have to get creative with wire routing and pull tools, but after studying it for a while, it can be done without any major issues.

As you can see in the second pic, I got my new order of PLA in today. White, Silver and Black. That should keep be busy for a while.

Speaking of PLA, I am not sure the 3D printed parts will make it for the maiden flight. I do not like the extra weight. I will make that call once complete and I have done my thrust tests though. Also note, the front and rear canopy are too narrow at the top and have already been drawn proper. Those are just test prints that are just tacked on at the moment for pictures.

At this rate, this may be done by FF!
The same FF I will most likely miss.

Wait you’re going to miss FF?

 

[Namactual]

Wait you’re going to miss FF?

Unfortunately, it is looking that way.
Our family reunion was pushed back a week which landed on the 14th. There is still a slim chance I might be able to ditch work Thursday and Friday, but I would not bet on it.

Either way, I will not know until the week of which makes it hard to rent a car and hotel room.

 

[HilldaFlyer]

I have the answer.... Flight fest should be a national holiday like Chinese new year. This is such a work of art. You should be very pleased with it. I am.

 

[Namactual]

I have the answer.... Flight fest should be a national holiday like Chinese new year. This is such a work of art. You should be very pleased with it. I am.

Thanks brother, that means a lot. I really would like to see it in the air with all of the other FTFC birds.

I wish FF was a holiday. I could always ditch the family reunion too, I am sure no one would blame me for having other plans that day. I do like the majority of the family though, and I don't see a lot of them nearly enough.

Who knows, I may get lucky with work.

While I am here I will post an update:
I have designed the foamboard nosecone and canopy, the prints should be done tonight. I will be playing with Cura tomorrow at work trying to reprint the nose and the new proper canopy with a single pass wall thickness which should cut the weight of the 3D printed parts by half. The right wing prints have been attached to foam and ready to cut. I tested my wire routing from the fuse to wing servos which worked better than I dreamed so the rest of the electronics should be a breeze.

I don't want to jinx it, but next weekend she might be ready for flight?

 

[Namactual]

Short Update: still at work... ...sshhhh.
The 3D printed parts are a go, I repeat we are good to go!

I just finished my new single pass wall nose cone and I do not think a foamboard version would be much lighter. I don't know how well it would handle a nose in as I am sure it would shatter, but we can always print another one. Geeked!

I have the new front canopy printing as I type. The rear canopy will probably have to wait until tomorrow.

I am sort of torn on if I should completely paint and finish this before the maiden. Part of me wants to just make sure it flies before I put more work into it, but at the same time I would like to see it finished at least once even if it does not survive the maiden.

 

[rockyboy]

I am sort of torn on if I should completely paint and finish this before the maiden. Part of me wants to just make sure it flies before I put more work into it, but at the same time I would like to see it finished at least once even if it does not survive the maiden.

Yeah, I run into this a lot too.

My deciding factor is "will I build another one if I completely wreck this one"?

When I'm designing a plane for a build contest and have a deadline to release plans, I always maiden before the pretty. After all, if I smash it up that probably means there are design factors I need to change and test again.

When I'm doing a one time build and not likely to do another one, then I'll spend more time on the pretty stuff up front - but still not to the full extent. Maybe an 80% finish job. Cause if it flies like a set of thrown house keys, I'd like some pictures that show how awesome it looked from 5 or 10 feet away.

 

[DamoRC]

I am sort of torn on if I should completely paint and finish this before the maiden. Part of me wants to just make sure it flies before I put more work into it, but at the same time I would like to see it finished at least once even if it does not survive the maiden.

I like to finish them up before maiden if I can, just to get the trophy picture. Because I typically only fly on the weekends but build through the week, the timing also plays into the decision, i.e. if I can just about get her ready to fly before Sunday, I'll fly without the paint job but if she's not ready to fly until early the following week, then I have the week to paint her.

Can't wait to see the finished product!

DamoRC

 

[Namactual]

Very solid advice from you both.

I think I am going to finish this thing 100% before maiden. I will be sad either way, but at least I will have pictures.
I do plan on building at least one more to work out a few kinks before I release any plans, but I have no idea when that will happen.

Thanks again for the input guys.

 

[Namactual]

They say a picture is worth a thousand words...

That is one heck of a diet.

The nose cone on the right is available for anyone looking to build a bunker busting JDAM. It is guaranteed to penetrate at least 20 feet of solid concrete. It's probably even reusable.

 

[foamtest]

Just make sure none of your controls are reversed for the maiden, I have seen this ruin many perfectly good airplanes.

 

[Namactual]

Aye.

My biggest worry on a scratch build like this is CG and trim. Hand launches on typically under powered EDF's can end in disaster real quick if either of those are off a bit.

Especially if it noses up right out of your hand.

This is easily the most time and effort I have ever sunk into a single build, but at the end of the day it's only foamboard. And the hardest part, the design work, is all done. While I would be sad it if craters after 10 feet, I would just have to build a better one next time.

 

[rockyboy]

Just make sure none of your controls are reversed for the maiden, I have seen this ruin many perfectly good airplanes.

Yep - reversed aileron controls result in the most spectacular barrel roll into a lawn dart maneuver and bag based recovery. Been there, done that, posted the video

Aye.

My biggest worry on a scratch build like this is CG and trim. Hand launches on typically under powered EDF's can end in disaster real quick if either of those are off a bit.

Especially if it noses up right out of your hand.

This is easily the most time and effort I have ever sunk into a single build, but at the end of the day it's only foamboard. And the hardest part, the design work, is all done. While I would be sad it if craters after 10 feet, I would just have to build a better one next time.

My nickles worth of maiden flight reminders: Lean a little more towards the nose on the CG, a little more elevator control throws than you might expect (in case the CG is too far out of whack), and launch very hard at the horizon. I don't think test glides are as effective on jets vs props, but still a good idea to do a power off throw into the tall grass to see if it stalls or drops sharply. And best to get someone else to do the launch if you can so you have hands on sticks, but if so make sure they know it needs to be the javelin throw to win the Olympics.

And get good video so we can all enjoy either outcome

 

[Namactual]

Oh, I will record it for sure.

I am going to miss those cheater holes on the first prototype. I could really get a firm grip for a hard hand launch and it was in the perfect location for the perfect throw every time. I don't want to cut holes in the bottom of this one just for hand launches, so I might see about attaching a dual purpose grip/belly skid on the bottom.

I will see what it feels like when it's all together. That might be the only option with that huge flat belly. There is no good place to grab it.

 

[DamoRC]

With @rockyboy on the maiden, nose heavy, high elevator rates, full throttle, and throw as hard as you can. I typically aim a little higher than the horizon, maybe 10 - 20 degrees, for a maiden. Weirdly, I also like to throw them myself - basically if the throw is bad its my responsibility. Only time I didn't do this was with the Canuck maiden because it was so heavy but I launch the Canuck myself now (and its always a butt clencher). If you have someone else launch it, try to insist that they do it one handed. I have seen too many two handed throws that get messed up because of the extra hand.

You said that you think you are underpowered and I read the 400 grams on 3S results - so are you going to maiden 4S?

DamoRC

 

[Namactual]

Aye, it was around 400. It was really hard to get an accurate reading as with only one fan going it wanted to yaw off the the scale. I was trying to prop it with my hand keeping it from tipping over but not put any pressure on the scale.

I did get a solid 20amps though, so the low 400-450grams of thrust supports the results. That was on a storage voltage pack as well. 3.7-3.8v per cell.

I think I might go with the small 1550mAh 3s I used for the first prototype. I think it should be ok if I can get it to balance. This build is a tad heavier, but I am also going from 640grams to 800-900grams of thrust on 3s. I would have A LOT more thrust on 4s, but also a lot more weight.

I will know more once I get both fans wired up and can do a proper thrust test on a fresh pack.

Thanks again for the input guys.

Off topic, kind of. I noticed today while I was working on the other wing...
...I almost feel like I am dragging my feet with this build because I know I am going to have to eventually throw this thing when it's done. It's weird. Consciously I know it does not bother me if it spontaneously explodes, It's only a few dollars in foam and time. Heck, I need to build at least one more anyway. But subconsciously I really would hate to see that happen. Don't get me wrong, I am not going to be emotionally scared by this or anything. I know I would laugh it off, but there is a slight nervousness there that I usually do not have.

It's hard to explain.

 

[DamoRC]

I think I might go with the small 1550mAh 3s I used for the first prototype. I think it should be ok if I can get it to balance. This build is a tad heavier, but I am also going from 640grams to 800-900grams of thrust on 3s. I would have A LOT more thrust on 4s, but also a lot more weight.

No problems with that logic and 800 grams thrust on an AUW of ~1100 grams should be fine.

...I almost feel like I am dragging my feet with this build because I know I am going to have to eventually throw this thing when it's done. It's weird. Consciously I know it does not bother me if it spontaneously explodes, It's only a few dollars in foam and time. Heck, I need to build at least one more anyway. But subconsciously I really would hate to see that happen. Don't get me wrong, I am not going to be emotionally scared by this or anything. I know I would laugh it off, but there is a slight nervousness there that I usually do not have. It's hard to explain.

Know how you feel, and I think it's the time invested more than anything else. One thing to remember - you have flown this bird before. Sure, you have made changes and updates and improvements, but basically you have done this already with the V1. You're good to go!

DamoRC

 

[Namactual]

Your right Damo, this should be a breeze. It must be the time as you said. It seems like I have been working on this thing forever. Really I have, but the build was just a small part of it. It has been through so many design changes. Heck, really I have 3 different designs here. I just have to keep my perspective. With the design done, the next build will be a walk in the park.

Update:
The foam cutting, folding and gluing is done...

I need to reinforce a few glue joints and hinge the ailerons in yet. The wings are not glued in place yet as I have to run the servo wires and such. The heavy lifting is done though. Electronics are next.

I shed a total of 85grams with the new 3D printed parts. My new dry weight should be around 760-780grams.
New AUW estimates:
900grams - 1550 3s
1000grams - 2200 3s
1100grams - 2x 1550 4s

 

[F106DeltaDart]

Looking awesome Namactual!