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Old Oct 29, 2008, 10:11 PM
more balsa please!
dcloin's Avatar
Princeton, In
Joined Jul 2007
793 Posts
Flight report.

I got to fly my mini sticks and EZB tonight. After a few tries and different motors, I finally got my ministicks to climb. Before it would only slowly loose elevation. The longest flight was 2min, 20 sec. I made some more adjustments and launched it again, after 1min 3 seconds, it was hit by a parkzone vapor. Needless to say, that ended the flight and the plane. Guess I should have waited till I had the gym alone.

The EZB never got trimmed out correctly. I had a bad prop wobble. I need a new prop hook I think.

I'm excited about the mini sitcks flight and going to build a new one. Everyone in my club was amazed. they had never seen an indoor duration plane fly before. That says a lot that they were impressed since one of our club members brought his 6" RC Apache helicopter. It's full scale and very, very impressive. I still think they were more mesmerized with the ff.

One of our club members had a camera, hopefully I can post a picture soon.

Darvin
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Old Oct 30, 2008, 12:10 AM
Torn 'twixt buildin' and flyin
TheNightowl's Avatar
United States, TX, Austin
Joined Oct 2007
7,220 Posts
Quote:
The EZB never got trimmed out correctly. I had a bad prop wobble. I need a new prop hook I think.
Are you sure it is the prop wobbling? If the plane has a "tail wagging" motion when you try to fly it, the chances are that you have the blades set at slightly different pitches. The most common cause of a prop actually "wobbling" isn't so much the shaft as whether or not the blades are perpendicular to the shaft, and how much slop there is in the bearing. What kind of bearing are you using?

Nightowl
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Old Oct 30, 2008, 09:58 AM
more balsa please!
dcloin's Avatar
Princeton, In
Joined Jul 2007
793 Posts
First flight, it flew fine, but would not climb. After adding a larger diameter motor, I believe that there was too much torque on the motor and it is very loose on the prop hook. Maybe wobble is not the correct work. Let me see how I describe this. It's not straight, so the left prop blade is forward of the right, so when it spins, it looks sort of like a figure 8 when viewed from the top. Probably one blade is 1/2 to 3/4 in front of the the other. Not sure what happened between the flights. I was thinking that the glue holding the prop hook on had weakened and allowed the wire to move on the prop shaft.

Darvin
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Old Oct 31, 2008, 12:22 AM
Foamy Season is here! MX2#1
pitviper51's Avatar
Elizabethtown, Kentucky
Joined Nov 2005
3,406 Posts
glad you like the pics darvin, after messing around with that stuff last night im temped to get a kit, that mini stick was cool! easy to transport to! its to bad it had the midair with the vapor you were going for a record... heheh
mike
ps , may have to get you to mix a batch of glue for me soon..
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Old Dec 17, 2008, 10:35 PM
more balsa please!
dcloin's Avatar
Princeton, In
Joined Jul 2007
793 Posts
Quote:
Originally Posted by TheNightowl
Are you sure it is the prop wobbling? If the plane has a "tail wagging" motion when you try to fly it, the chances are that you have the blades set at slightly different pitches. The most common cause of a prop actually "wobbling" isn't so much the shaft as whether or not the blades are perpendicular to the shaft, and how much slop there is in the bearing. What kind of bearing are you using?

Nightowl


Turns out you were right, I should have listened. I got a pitch gage from Tim at A2Z and checked the blade angles. There was about 9 degrees difference between the two, quite a difference. Thanks for the input.


I've made the prop so that it has adjustable blade angle now and will be able to set them the same. I've not gotten to fly it since then though.

Darvin
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Old Dec 18, 2008, 02:27 PM
Registered User
USA, CA, Aptos
Joined Jul 2005
1,115 Posts
Man I love this thread, you guys are doing some awesome stuff.

I've built a couple of porky Hangar Rats, they're probably 50% overweight but they get 2:15-2:30 in the Armory at UofI. One of them was on track for a PB when it got shredded by a Trex doing some ridiculous flippy thing.... :-(

But am inspired to build better stuff and just spent bunch of money at PP on supplies. Am looking forward to the learning.

Craig.
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Old Dec 18, 2008, 02:42 PM
Free Flight rubber flyer
jwfinn's Avatar
United States, GA, Warner Robins
Joined Mar 2005
506 Posts
Craig, what weight are your Rats? Most of the ones I've seen are in the 5-6 g range. I did get one under 4 g, but that involves using 3.5 lb balsa for most of the parts and results in a really fragile plane. Still, getting a Rat to do 3:30+ under a 31' ceiling is an amazing experience.
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Old Dec 18, 2008, 04:07 PM
Registered User
USA, CA, Aptos
Joined Jul 2005
1,115 Posts
They're 8-9g without rubber, but that's with commercial wheels, scrap balsa off the rack, ribs of 1/16 rather than 1/32 and heavy tissue. I know I can get down to the 5-6g range, probably without too much effort.

They're my first real free flight experience, and still amaze me. Getting to 5 and 10 minutes with better stuff is going to blow my mind.



Quote:
Originally Posted by jwfinn
Craig, what weight are your Rats? Most of the ones I've seen are in the 5-6 g range. I did get one under 4 g, but that involves using 3.5 lb balsa for most of the parts and results in a really fragile plane. Still, getting a Rat to do 3:30+ under a 31' ceiling is an amazing experience.
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Old Dec 19, 2008, 07:29 AM
Free Flight rubber flyer
jwfinn's Avatar
United States, GA, Warner Robins
Joined Mar 2005
506 Posts
Ditching those plastic wheels in favor of balsa or 1/64" ply wheels will save you at least a gram.
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Old Dec 19, 2008, 04:39 PM
Registered User
USA, CA, Aptos
Joined Jul 2005
1,115 Posts
Yes, I think there are a few grams I can save quite easily. Hopefully can build a couple more soon and see how they go.

I have a question about the hand wound pigtail thrust bearings, have been trying to figure out exactly how they work, without success. I have Ron's book coming, which I presume will clear it up, but if anybody wants to help me out...
Mostly am wondering the sequence in which the prop shaft is installed, and how props are removed and changed?

Craig.



Quote:
Originally Posted by jwfinn
Ditching those plastic wheels in favor of balsa or 1/64" ply wheels will save you at least a gram.
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Old Dec 21, 2008, 08:40 PM
more balsa please!
dcloin's Avatar
Princeton, In
Joined Jul 2007
793 Posts
Craig,

I've only made my own thrust bearing once. It turned out okay, but I've decided that it's easier to buy one, and a better product than I made.

With mine, I could thread the hook from the prop into the front of the bearing, then the wire was flexible enough to gently bend it while putting it through the rear of the bearing. this is probably not the correct way, but it worked. This was on a mini-sticks so the wire was "very" small and flexible. Hope this helps.

Darvin
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Old Dec 28, 2008, 08:10 PM
more balsa please!
dcloin's Avatar
Princeton, In
Joined Jul 2007
793 Posts
I got a chance to fly my EZB today after I adjusted the prop pitch. I'm still experimenting with motor size, but it looks good so far. It flies nice and slowly. I just have a hard time getting it to turn and adjusting the angle of the wing to get it to climb. I keep working with adjusting the incidence and wing angle and trying to twist the tail boom a little to help it turn. Someone should write a book on trimming. I have Ron Williams, Lew Gitlow's and Don Ross's but I'm still struggling.

Darvin
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Old Jan 20, 2013, 09:11 PM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,476 Posts
long time since this thread was active

well, i know this thread is old, but its the biggest ezb and general indoor thread, and that's what i'm working on.

i'm not new to light weight building, but not too much freeflight rubber powered models under my belt. lightest rc model to date is 1.9 grams. on a few i have used polymicro film for covering and got a very good slow flyer from.

i'm mainly getting into this as there will be a gym sanctioned for free flight at an upcoming indoor event, and i'd like to encourage others to join in on it, so am trying to get a fleet of them built before the event.

anyways, so far i have a decent prop and bearing assembly. it's probably too small for a legal size ezb, so i will likely make another few closer to full size (11 inches if i recall right)
this prop is 8.25 inches diameter and 0.2 grams including the bearing and shaft.
for the curve, i soaked the blades in water and windex (ammonia in it helps the bending) then rinsed in fresh water, and baked on a soda can at about 200 degrees. the blades on this prop are about .018-.016 thick, so that could be thinner next time as well.

so anyone else that is doing indoor should post up your models, i'd love to see more!
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Old Jan 21, 2013, 07:47 AM
TheyreComingToTakeMeAway!
derk's Avatar
USA, ID, Coeur D'Alene
Joined Dec 2003
5,476 Posts
alright, i did a lot of building, and am pretty much done with this plane for the time being. it needs some real test flights as my apartment is too small and crowded.
span is 13 inches chord is 3 inches, tail span is 9.75 and 2 inch chord.

total weight minus rubber on my crummy scale is 0.5 grams!

i tried it with a short 5.5 inch length of .040 rubber and maybe 150 turns, and to my surprise it started to climb slowly across the living room until it met the blinds
so i will try and save it for the next indoor flying session, unless i can get the fans turned off at work for a while
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Last edited by derk; Jan 21, 2013 at 08:02 AM.
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Old Jan 21, 2013, 10:59 AM
Editor - Flying Models
United States, CT
Joined Aug 2003
2,442 Posts
Looks good Derk! FWIW, I don't think there is a minimum size for EZB. My understanding was the span restriction was max size. I could be wrong though. It has been too long since I paid attention to the indoor FF rules.
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