Foamboard F-22 EDF

[JustPlaneChris]

If they work, can you share the STL/Cad files? Looks awesome.

Absolutely! Now that they are halfway printed, I thought to measure the outlet area and it's only 60% FSA. I've redrawn the exits to get 80% FSA and will print just those bits later. It will require enlarging the holes in the last former, but I'm concerned that 60% FSA exhaust area may be restricting performance and/or increasing current draw.

Chris

 

[JustPlaneChris]

Test fit looks good! Pay no attention to the mutilated formers, I had to do surgery to get the paper pants out. I had to do a tiny bit of trimming to the opening in the wing, since the printed ducting flares out a bit more than the paper. These are still the stock diameter exits, the larger ones are on the printer now. I may not be able to use them, there's very little meat around them in that last former. We'll see.

The paper version weighed 18.5g, printed weighs 25.5g. Since I've read this tends to run nose heavy, that's an extra 7g where it needs it.

Chris

 

[Michael9865]

So I did a thing this morning. For no real reason other than "because I can" I drew up a pair of plastic pants to replace the paper pants in the F-22. It's on the printer now, but I'm not going to cut out the already-installed paper ones until I'm sure I like the plastic version.

If they work, can you share the STL/Cad files? Looks awesome.

+1

 

[Michael9865]

Test fit looks good! Pay no attention to the mutilated formers, I had to do surgery to get the paper pants out. I had to do a tiny bit of trimming to the opening in the wing, since the printed ducting flares out a bit more than the paper. These are still the stock diameter exits, the larger ones are on the printer now. I may not be able to use them, there's very little meat around them in that last former. We'll see.

The paper version weighed 18.5g, printed weighs 25.5g. Since I've read this tends to run nose heavy, that's an extra 7g where it needs it.

Chris

They/it looks great.

 

[JustPlaneChris]

OK guys and gals, now that I'm satisfied these fit, here are the STL files!

NOTES:

• As you can see in the photo below, the outlets that are enlarged to ~85% FSA pretty much obliterate former 7. I'm going to make it work, but it won't be beautiful.
• File F22Exhaust2-originalsize will fit in the stock former 7, and basically duplicate the paper ones in outlet area. Obviously that outlet area works, but I can't leave anything alone.
• F22Exhaust1 is the portion that slips over the fan housing. It's not a super tight fit, you'll want to tape it on.
• Print two copies of F22Exhaust2. They have a flange that lets them slip over the ends of Exhaust1.
• DO NOT GLUE THESE IN WITH HOT GLUE! You will distort the ducts. (ask me how I know) Use tacky glue, epoxy, foam safe CA, etc.

This was printed in generic PLA. If you are interested in my printer settings (Prusa i3 Mk3s) here they are:

• 0% infill
• Brim width 4mm
• 0.12mm layer height
• 0 top and bottom layers
• 1 perimeter
• skirt height 3 layers, distance 0mm from object
• NO COOLING
• First layer temp 215c, other layers 210c
• Bed temp 60c

I've played around to come up with those settings, and it really works great. Excellent layer adhesion and very light. Any other questions, please ask!

And if I haven't already said it, THANK YOU @Grifflyer for doing all this work with the design and plans.

Chris

 

[chris398mx]

OK guys and gals, now that I'm satisfied these fit, here are the STL files!

NOTES:

• As you can see in the photo below, the outlets that are enlarged to ~85% FSA pretty much obliterate former 7. I'm going to make it work, but it won't be beautiful.
• File F22Exhaust2-originalsize will fit in the stock former 7, and basically duplicate the paper ones in outlet area. Obviously that outlet area works, but I can't leave anything alone.
• F22Exhaust1 is the portion that slips over the fan housing. It's not a super tight fit, you'll want to tape it on.
• Print two copies of F22Exhaust2. They have a flange that lets them slip over the ends of Exhaust1.
• DO NOT GLUE THESE IN WITH HOT GLUE! You will distort the ducts. (ask me how I know) Use tacky glue, epoxy, foam safe CA, etc.

This was printed in generic PLA. If you are interested in my printer settings (Prusa i3 Mk3s) here they are:

• 0% infill
• Brim width 4mm
• 0.12mm layer height
• 0 top and bottom layers
• 1 perimeter
• skirt height 3 layers, distance 0mm from object
• NO COOLING
• First layer temp 215c, other layers 210c
• Bed temp 60c

I've played around to come up with those settings, and it really works great. Excellent layer adhesion and very light. Any other questions, please ask!

And if I haven't already said it, THANK YOU @Grifflyer for doing all this work with the design and plans.

Chris

Thanks, these look great. so if I am reading correctly, these are stock size files? Are you going to post the larger ones, if they work out?

 

[JustPlaneChris]

Thanks, these look great. so if I am reading correctly, these are stock size files? Are you going to post the larger ones, if they work out?

Both are there. The stock size is F22Exhaust2-originalsize. The other is my enlarged version.

Chris

 

[chris398mx]

Both are there. The stock size is F22Exhaust2-originalsize. The other is my enlarged version.

Chris

Sorry, I was just going to delete my post. I saw that as soon as i downloaded the files and opened them in Cura. Thanks again.

 

[Ratcheeroo]

Good progress tonight, just about to solder some extensions for the motor and then the front end can go together. V-stabs are not glued in as of yet, just wanted to give a better idea of the color scheme.

 

[OliverW]

Good progress tonight, just about to solder some extensions for the motor and then the front end can go together. V-stabs are not glued in as of yet, just wanted to give a better idea of the color scheme.

View attachment 201696 View attachment 201697

I can't wait to build one of these. Yours looks amazing

 

[Ratcheeroo]

I can't wait to build one of these. Yours looks amazing

Thanks, its a good build , good plans

 

[JustPlaneChris]

Time for some update pictures! Hopefully these will help future builders. I'm not super happy with how some of the seams turned out, but I have to keep reminding myself that this isn't a Scale Masters entry, it's a $3 foam board airframe!

Chris

 

[JustPlaneChris]

More progress! All that's really left to do is the canopy / hatch. After that, it's time for a poly wipe and some spackle to fix the areas I'm not happy with (like right behind the canopy area... ugh). Overall though, it's looking OK.

Chris

 

[Ratcheeroo]

Almost there, now that I know how it goes together I want to do another one

 

[JustPlaneChris]

Looking great! Yeah, now that I know where all the pieces go I know I could do a better job on the build. While looking at it from the back I realized I put the nose on a bit crooked. Oh well, I'm sure it'll fly.

If it really flies great, maybe I'll just scale the next one up for the 80mm fan I picked up for cheap over on RCG...

Chris

 

[Ratcheeroo]

Looking great! Yeah, now that I know where all the pieces go I know I could do a better job on the build. While looking at it from the back I realized I put the nose on a bit crooked. Oh well, I'm sure it'll fly.

If it really flies great, maybe I'll just scale the next one up for the 80mm fan I picked up for cheap over on RCG...

Chris

Looking good!

 

[skymaster]

This one was actually laser cut! It definitely helps the parts fit easier. But it's not impossible to do by hand cutting. For instance this first version of the F-22 was hand cut. As long as you go slowly it's possible to get laser precision
View attachment 182153

That sounds like a challenge, but I think this plane hate me i have built a couple of them and they come out like crap. my hanger if full so maybe in the future. by the way nice design. kind of looks like pinguins rc.

 

[Ratcheeroo]

Two intake covers left, canopy needs a little bit of finesse but not too bad. Should look good with the rest of the decaling and a nice clear coat.

 

[JustPlaneChris]

Looks amazing! And you didn't glue your nose on pointing off to the left like I did.

Chris

 

[JustPlaneChris]

Almost there! Basic colors are on (two different kinds of primer). Now I just need to come up with some pseudo-markings and do some sort of hatch latch. Not perfect by any measure, but it kinda looks like a Raptor.

Chris

PS: Ignore the naked Mamba in the background, it just got de-stickerfied in preparation for some custom vinyl.