Red Bull Air Race Challenge!

[DamoRC]

So finally re-assembled, should be ready to test fly this bad boy later today or tomorrow. Added some to the wingspan so this craft is now rocking an 80cm wing.

BTW, where do you think the vlog/build process should be posted? The workbench?

Awesome - but is it possible you drank more Red Bull than you needed to (given the number of empty cans lying around)? Looking forward to the flight footage.

Regarding the vlog/build process, per the video and the article announcing the competition, entries are to be submitted as an article (rather than a forum post). So that is what I was planning on doing. My concern is that I think that articles have to go through a review process before they are accepted. If a lot of folks post articles at the same time this might cause a logistical issue for the FT guys.

On a related note, I PM'd @Mid7night who is on site at FF Ohio to see if he could get confirmation of a closing date for submission of the entries.

On another related note, I started Team Bull Rider's build and am having a hell of a time with the cantilevered wing (it's not straight, it wont hold the originally planned weight of the plane, and all round is just a PITA). I am close to the point where I might just stick some Red Bull stickers on a Diamond and call it done. Oh well, nothing ventured, nothing gained.

DamoRC

 

[Namactual]

NOOOOO!! don't give up on the Bull Rider! That is too much awesome to abandon!

If I may make a suggestion, just attach the wings like a normal airplane. Having the wings separated like that does look cooler, but it also creates more drag essentially creating 4 wingtips. Don't drop the design though, that thing is a work of art.

 

[DamoRC]

Thanks @Namactual !

Have been considering the conventional wing approach but even though the cantilevered wing makes no sense aerodynamically my tendency is toward cooler rather than faster (I'm such a showoff man-child ).

Part of the problem is time to fix it. In addition to traveling with my daughter for softball at the end of the month, I also want to take DamoRC Jnr on a trip to LA just before that (he's what we call a softball widow - his summer gets trashed because we travel so much with my daughter). Then right after the softball tournament there's a trip to the east coast again with my daughter for college visits. It's crazy - but its also fun once you figure out how to surrender yourself to the madness!

DamoRC

 

[Namactual]

I hear ya, I do the same thing regarding the cool factor over performance.

I hear ya on the lack of time as well.
Even if you don't complete it in time for the challenge, or even go through the trouble of making an actual article on it. That thing is just too cool not to be built.

I do see the complication though. Trying to keep the wings from twisting under load will be a challenge with such a small attachment point. You may have to cheat and use a second support rod connecting everything together. Maybe running from one leading edge through the fuse to the other leading edge?

Unless you have access to some carbon/fiber/glass sheets you could cut a "z" shape strut out of?

 

[DamoRC]

I do see the complication though. Trying to keep the wings from twisting under load will be a challenge with such a small attachment point. You may have to cheat and use a second support rod connecting everything together. Maybe running from one leading edge through the fuse to the other leading edge?

Unless you have access to some carbon/fiber/glass sheets you could cut a "z" shape strut out of?

I think I know what you mean but there are so many points where this cantilevered approach suffers from weaknesses it could be one of many.

The first frame I built was using 10mm square section CF tubes from HK with 1/8th ply pieces top and bottom at each joint which were gorilla glued and screwed in place. These ply pieces are considerably bigger than in the original sketchup model, particularly the center piece in the fuse which in the new plan will be attached to a hefty piece of foam that runs 3-4 inches longitudinally front and back of the connection center (and the ply piece matches this). This was to stop the whole frame pitching up and down under various loads - the frame itself is strong enough for this, its just the mounting point inside the fuse is still a concern and I still don't know if this is going to work.

Although the frame is pretty strong the torsional strength of the square sections is not brilliant, So apart from the "not making it properly" issue (my own doing) the wings tips will flex up and down because the tubes from the fuse to the wing are twisting under load. Before I discovered that I had misaligned the frame, I was going to just lighten the plane by approximately 1 lb by removing the 70 mm EDF in the rear from the design (the 1 lb comes from the EDF, the ESC, and the 4S 2200 mAh battery that it would need). That leaves me with the twin 50mm EDFs in the nacelles (did I say it was originally going to be a triple EDF running on 2 x 2200mAh 4 cells?). I decided on keeping the twin 50s because they are mounted on the wings rather than in the fuse. By my twisted thinking (would be good to hear input on this), although the wings have to carry the whole weight of the plane, the torsion problem I have is only due to the weight of the fuse in flight.

Anyway, I'm rebuilding the frame, this time using a jig that incorporates the bottom surface of the wing panels which I cut last night, and a center piece of foam that allows me to keep the whole thing square. Plus I am replacing the fuse-to-wing tubes with 12mm round tubes - this should give me better torsional strength. If this works, I might return to the triple EDF idea.

Thanks for the input!

DamoRC

 

[Namactual]

By my twisted thinking (would be good to hear input on this), although the wings have to carry the whole weight of the plane, the torsion problem I have is only due to the weight of the fuse in flight.

I agree.

I just did some quick 2d sketches of a few possible compromises if you can not get the torsion out with the new tubes.

The blue one is just the cheater spar. The red being a double Z strut with a slightly shallower angle.
Anyway, don't let my nonsense slow you down. I am sure you will come up with something.

I had a pretty good idea you were going to make a triple EDF out of this from the images, but I did not know the particulars. This thing is even cooler with the new details.

 

[DamoRC]

Wow! Thanks @Namactual - First the NAMA duct, then the NAMA foil, and now the NAMA Z-strut!

I think if the new frame fails I will go with the cheater spar. Got half of the new frame finished last night. It just has the top pieces of ply screwed and glued and I think it might work because it is almost as strong as the original complete frame. Will attach the lower pieces of ply today and by this evening, when the glue is set, I should know if its good.

DamoRC

 

[Namactual]

NAMA Z-strut

Haha! It almost sounds like a dance move. Maybe a Jazz song title...

Cool, I am sure what you have will work. I can not wait to see this thing though.

 

[mrjdstewart]

got the paper template converted into vector files today so i can cut with the laser. no matter what the outcome of this event, it has pushed me to learn more in the last few weeks than i have in the last year. all of these skills will serve me well.

i also think Dave is ticked to see his dream get transformed into reality. this really has been a cool event.

files were also sent to Rasterize so he could begin the work on skins. not really sure where we will go yet, but it will be vintage, it will be red bull, and it will be cool...

keep building!

me

 

[DamoRC]

got the paper template converted into vector files today so i can cut with the laser. no matter what the outcome of this event, it has pushed me to learn more in the last few weeks than i have in the last year. all of these skills will serve me well.

i also think Dave is ticked to see his dream get transformed into reality. this really has been a cool event.

files were also sent to Rasterize so he could begin the work on skins. not really sure where we will go yet, but it will be vintage, it will be red bull, and it will be cool...

keep building!

me

Agreed!

Like the look of the wing planform - was there supposed to be more (I only saw 1 page in the attachment)?

I have never tried the skin approach - I really should at some point - learning new stuff is important and part of the fun. For now I am going to stick with paint and decals.

On the Bull Rider front the new cantilever frame is way better than the original. Will it carry a triple EDF? Not sure, but what's the worst that could happen?

DamoRC

 

[mrjdstewart]

i only attached 1 of my 4 pages. don't want to give it all away.

skins are a pain, but also cannot be replicated as far as detail. Rasterize is very good @ what he does.

laters,

me

 

[DamoRC]

i only attached 1 of my 4 pages. don't want to give it all away.

Ahh - the anticipation builds....

skins are a pain, but also cannot be replicated as far as detail. Rasterize is very good @ what he does.

Yep - the detail on some of the planes in the Dat Rhino thread are incredible.

DamoRC

 

[mrjdstewart]

i need to build me one of those. i'm retired navy and worked on the F/A-18 and somehow that is the one plane i don't have in the hangar.

i need to harass Rastrize and get him to open his skins post back up. something about the new forum messed up all his formating and he hasn't had a chance yet to fix it.

laters,

me

 

[kilroy07]

i need to build me one of those.

Still waiting on ya to PM me your address...

 

[mrjdstewart]

all i got to say is, MY TEAM ROCKS!

just saying...

carry on.

me

 

[DamoRC]

all i got to say is, MY TEAM ROCKS!

just saying...

carry on.

me

Cool! - Why?

Did you fly (your original plan included the possibility of flying today, but I remember you were unwell in the last few days)?

DamoRC

 

[mrjdstewart]

no, but loudly knocking/kicking on the door. tickled pink with what we have so far. Rasterize is working on the skins and i hope to have a proof soon. i have an ETA for maiden on friday, saturday at the latest.

 

[DamoRC]

no, but loudly knocking/kicking on the door. tickled pink with what we have so far. Rasterize is working on the skins and i hope to have a proof soon. i have an ETA for maiden on friday, saturday at the latest.

Great! That is excellent progress. All going well I hope to maiden this weekend as well - gotta get it done 'cos I am out of here on Wed next for 10 days!

Anyone on the Flite Test Fans Facebook? I have requested to join the group (I am not much of a social media guy) but am still waiting for admission. Ben suggested posting the question about the closing date for entries on that page as the FT crew might be more likely to see it there.

DamoRC

 

[DamoRC]

Oops - forgot - teaser pic.... - you sharin' @mrjdstewart ?

 

[Namactual]

Man, I wish I had time to enter this.

I just might have to find time to build a Bull Rider though.

I can't wait to see what team @mrjdstewart has in store.

Any more news on the canned goods?