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Mar 13, 2018, 03:22 PM
Registered User
PaulB's Avatar
Quote:
Originally Posted by marhar
Has anybody ever gone old-school crazy and made a balsa nutball?
Used what??? Not heard of that stuff, is it more like EPP or Depron???



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Mar 13, 2018, 03:33 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by marhar
Has anybody ever gone old-school crazy and made a balsa nutball?
Dave Reap has made one out of carbon rod and kite material .
Mar 14, 2018, 05:41 AM
Registered User
davereap's Avatar
I thought that looked familiar.... lol...
whatever they are made from they go well..
The HK foam is fine, its not as tough as depron but is far cheaper.. I now use it.. I also use a B&Q XPS board.. this is pale green and a better size
https://www.diy.com/departments/dial...rue#icamp=recs
depron and other XPS foams should have tape or laminating film as a strengthener/ stiffening material... coloured tape is ideal..
Tape will stop impacts cracking the foam

The one above was made 9 yrs ago .. 32", 150W power, 3s, it was part of trials building various night kites.
https://www.rcgroups.com/forums/show...s-night-fliers

nutball NK2 night flight2 (4 min 23 sec)
Last edited by davereap; Mar 15, 2018 at 03:51 AM.
Mar 15, 2018, 03:02 PM
Registered User
Thanks, Mr. Reap!
Mar 18, 2018, 11:33 AM
Registered User
Terry Rigden's Avatar
I made my first nutball out of a foam pizza tray, not as light or durable as depron but free.
Mar 30, 2018, 08:43 PM
Multirotor Enthusiast
Blacky's Boy's Avatar

Well my second maiden was not great but still,....


As I mentioned in the Blue Baby thread it finally got nice enough yesterday for me to take some planes out to the flying site. One of them was the 30" nutball.

The day started out not too windy but once I got there it got sort of gusty. But I was determined to take this plane up. When I did it just acted,....weird. I had to ditch it.

So I had another member fly it and he got it airborne but said it was acting weird as well. Like it didn't have enough rudder authority. He brought it down and then noticed that I had the motor rotating CCW and had a CCW prop installed. The thrust angle is meant to counteract a CW rotating prop! So I changed that out and got it airborne only to find that the previous crash made the motor loose. So I had to bring it back to the "hangar" for some repairs. I'll give it another try maybe next week.
Mar 31, 2018, 12:38 AM
Registered User
davereap's Avatar
Back to basic checks.... dihedral angles...thrust lines... Warps.....
And make sure nothing is flexing under stress.. bigger nutballs can be a bit bendy, and you dont need that
Push rods, control surfaces, also can often flex too much.. as can the fin and rudder when getting stressed..
Last of all 25% COG..
Mar 31, 2018, 03:31 AM
flyin' fool
goldguy's Avatar
How about a builder/pilot doing a maiden with the ailerons hooked up backwards on his 1:1 scale. It happened. He survived.

Had a guy today flying his multi rotor FPV and he made that fatal mistake. Took off his goggles and with out his glasses he was totally lost as to here it was. After a two hour search by six of us we gave up.

Me? Mistakes? Never!! And, if I do I can't remember anyways, so that's why at my age mistakes never count.
Mar 31, 2018, 07:32 PM
Multirotor Enthusiast
Blacky's Boy's Avatar

A unique opportunity to modify the motor mount area


Yeah, I flew it and crashed it today. Maybe I shouldn't have flown it because of the somewhat gusty conditions. But I am getting to the point where I'll have to wait until summer is over in order to get a day where it's not windy! So I decided to give it a try when the wind died down a bit.

Actually if flew pretty well the first time out. It was behaving nicely enough that I circled the field a couple of times. But I still saw that tendency to want to pitch up when going into the wind. I landed safely and then went to get the camera. That next flight was short but exiting. Frankly I think that the repairs I made yesterday were OK the first flight but managed to work themselves loose by the second. And the result was a cash that caused the fuse to break just forward of the spot I repaired yesterday . So now I have a chance to repair it and make some improvements.

As you can see in the photo the pink foam insulation cracked just aft of the point where the dowels for the firewall end. I removed the broken pieces, cleaned the area, cleaned the motor mount (firewall) and now need to make a new fuse /motor mount area. This will give me a chance to pay extra attention to the thrust angle.

But honestly, I think I need a better way to attach then foam block that is the fuse to the underside of the wing. Or I need a way to strengthen that foam up some more. The other problem I see are those dowels that I use to attach the landing gear. They make the block susceptible to breaking at the holes for the dowels. I'm thinking of making a side plate out of some kind of plastic or card stock that would reinforce this area. Any ideas?
Mar 31, 2018, 08:33 PM
flyin' fool
goldguy's Avatar
If your having issues because of the constant wind, build one of these ............................. https://www.rcgroups.com/forums/show...Simple%20Delta

Deltas laugh at the wind because of their shape and can't stall. This one is absolutely the best of the best delta designs ever. Having elevons, it's a 'yank n' bank' to fly.
Mar 31, 2018, 08:50 PM
Multirotor Enthusiast
Blacky's Boy's Avatar
Quote:
Originally Posted by goldguy
If your having issues because of the constant wind, build one of these ............................. https://www.rcgroups.com/forums/show...Simple%20Delta

Deltas laugh at the wind because of their shape and can't stall. This one is absolutely the best of the best delta designs ever. Having elevons, it's a 'yank n' bank' to fly.
Thanks for the tip about the Simple Delta. I may try building one later.

But I want to get this nutball flying because I'm sick of giving up so easily on an RC aircraft design. Last year I built and then abandoned (4) different designs after repeated crashes and failures. I'd like to stick this one out. You know, figure out what is going on and fix it.
Apr 01, 2018, 03:46 AM
Registered User
davereap's Avatar
Try EPP nose blocks for mounting the motor... layer and fix the foam with the cool melting hot glue
more flexible they take hits better and make the motor/model quieter
If you use a triangular shaped block you can also easily fit an U/C to it
Last edited by davereap; Apr 03, 2018 at 02:38 AM.
Apr 01, 2018, 06:15 AM
flyin' fool
goldguy's Avatar
Good for you, stick with it.
Apr 01, 2018, 12:11 PM
Multirotor Enthusiast
Blacky's Boy's Avatar
Quote:
Originally Posted by davereap
Try EPP nose blocks for mounting the motor... layer and fix the foam with the cool melting hot glue
more flexible they take hits better and make the motor quieter
OK, I located a place here in the states that sells EPP and was about to order a sheet or two.

Flying Foam


They have two densities listed. 1.3# and 1.9#. I imagine I'd want the denser of the two for this particular part. Correct?

I'll probably order a couple sheets in 1" thk and 1/4" thk in black (just 'cause black looks cooler!)
Apr 01, 2018, 11:40 PM
flyin' fool
goldguy's Avatar
I usually go with 1.9# X 7/8mm when I slice up my own sheets, it the most versatile for the size of models I build and about right for stiffness. 1.3# is OK for super light, but need lots of support from CF flats and rods.

I've got 1 and 2" black and white slabs, and a hot wire cutter which is mandatory for making sheets and wing cores.


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