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Old Feb 07, 2006, 10:27 PM
Flying on Flux Capacitors
Flipper_118's Avatar
Edmonton, AB
Joined Apr 2005
1,422 Posts
Cool
My Flyweight Bladerunner

Heres my new and improved bladerunner:

Mods:
-cut the bottem off the main shaft and cut down the lenght of the tube that holds the main shaft.
-cut off all plastic except required parts
-replaced the gear/ant with a 3 legged carbon set, and just ran ant wire down the boom.
-turned circuit board level to let the heli sit lower on the ground.

After all that I came in with an AUW of 45g, but It could use a little nose balast so I may end up moving the batt a little further ahead.

My goal was to get the BR much lighter then stock so I could get some nice long flight times, and still have the motors remain cool to the touch. So far so good, I can buzz around for about 5 min with cool motors. I will take some pitch outa the blades since I dont think I need the course pitch.

Overall I like it, and it has alot more lifting power then it did before thanks to the low AUW. The only thing I would like to have is a batt holder that lets me switch batts so I can fly while my others charge.

Heatsinks are still to come, and I may make a case for it, which would make it very James Bond like.

Curt
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Old Feb 08, 2006, 05:03 PM
4000 posts?!
micro_builder's Avatar
United States, TX, Fort Worth
Joined Jan 2005
4,047 Posts
looks good, Curt. if you're adventerous, make a set of foam blades out of foam dinner plates. the stock blades are pretty heavy, and the foam blades will hold their pitch relatively well. i made a set for my DIY BR and it worked alright. you can shave quite a few grams off by doing this, but it has to be done pretty accurately or the rotors will be out of balance.

nick
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Old Feb 08, 2006, 05:39 PM
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Joined Oct 2004
79 Posts
How about a tutorial. On that mod. That would be awsome.
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Old Feb 08, 2006, 10:18 PM
Infinitisqrd
Hilo, Hawaii
Joined Dec 2004
1,210 Posts
Flipper : Did you reduce the space between the rotors of your BR ? If you did, you may lose some stability and flight time, because there is an optimum distance the rotors must have between them, for best efficiency. Spacing them at about 19 % of the rotor diameter will make the rotors' efficiency nearly the same as a single rotor.

You realize, of course, there is a reason the main rotor support shaft is so long, is to keep the mainshaft assembly more sturdy, don't you ? It may seem a picky point, but ,like so many other things on the BR, things are done the way they are for a reason, no matter whether they are obvious or not. A lot of time was spent by Petter and ITC designing this thing to be both lightweight and somewhat sturdy. You go messing with something you don't fully understand, and you might all of a sudden have just a pile of parts on your hands.

For example, one owner tried to get rid of some weight by removing the ring around the rotors, and the damned machine wouldn't fly at all ! Those rings perform a vital function on the BR other than protecting things from getting all whacked up, in case of contact at full speed. They are one of the main reasons the rotors work as they do.
Messing with them is a no-no.

But don't let me deter you from experimenting with your weight reduction. Just be aware that things usually have a puirpose.

Aloha, Steve
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Old Feb 09, 2006, 08:21 AM
Flying on Flux Capacitors
Flipper_118's Avatar
Edmonton, AB
Joined Apr 2005
1,422 Posts
Thanks Steve, but for the most part I realize what I am doing. I knew I may have lost some stability by moving the bearing mounts closer, but I took my chances. I didn't alter the blade spacing at all, but may move them a little further apart well see.I know most of the parts on the BR are built for a purpose, but I do my homework before making any major changes.

Anyway, flies really well right now So this is how she stays. As for the tutorial, I think it would take me longer to write it out, then the actual build took.

Curt
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Old Feb 09, 2006, 08:33 AM
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Joined Oct 2004
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Oh no. I know how your lightened it. Thats easy. I was saying a tutorial for the foam blades would be cool. You know what plates he used. Dimesions on cutting them and glue all that kind of stuff. I'm going to lighten by br this weekend as light as I can get it.
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Old Feb 09, 2006, 07:02 PM
4000 posts?!
micro_builder's Avatar
United States, TX, Fort Worth
Joined Jan 2005
4,047 Posts
the foam blades are as easy to make as the plastic cup blades (the cheap and easy way to have new blades). it basically just comes down to tracing one of the stock blades on just some generic foam dinner plates that you can get at just about any grocery store. there's some little tricks to get it right, as they need to be put on rather precisely or it'll be out of balance, and they do need to be tweeked more often that the stock blades, but it does shed quite a bit of weight. if i get some spare time this weekend i'll try to make a little build thread on how to do it.

i attatched a couple pictures of the rotors i did. these are modified more than just using foam blades. i cut away excess plastic and removed the hinges and replaced them with some soft foam. this is how Petters original Proxflyers were done i believe, it was a little tricky to get it right, it took a couple tries, but it works well when done properly. i cant remember off hand how much the stock rotors weight, but my modified rotors below weighs around 3.3 grams.

nick
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Old Feb 09, 2006, 08:23 PM
Infinitisqrd
Hilo, Hawaii
Joined Dec 2004
1,210 Posts
An old fart and the angels

Fliipper : One of the bad things (one of very few), about these forums, is not knowing how old a person is, what their modeling skills are, or where they live. If I know a person has a good grip on their abilities, I write advice in a much different manner than I do when I think I'm talking to someone who may not know which end of the diving board to jump off of. Sometimes it's hard to tell the difference, so I try to kind of combine my writing styles. When I know I'm addressing a person who has been around the horn a few times, I can speak technical jargon, but the youngsters need to be led by the hands most of the time. One of my weaknesses is intolerence of ignorance, no matter what age. Coming from a family of scholars and teachers, (My great-great grandfather was the first teacher in the entire Pacific Northwest, and his son was one of the founding fathers of Oregon State Unioversity,) as well as having 21 years in the military (17 years in the Army, followed by 4 years and two tours of duty of Vietnam as a Navy Anti-sniper sniper,) I tend to forget not everyone else has the education or experience I have, and I tend to talk down to some people. To those folks, I apologize - by reading my posts, you will learn the definition of a pedantic old fart.

Sorry to ramble on, but I will get back to the subject at hand - The BR diet. If you want to do something different, to REALLY lighten up your BR, just to pass a little time, try attaching one of those shiny mylar, helium-filled balloons to the top of your mainshaft (just remove the top retainer tube, run the string through it, and reinstall on the shaft. If you get the amount of helium right (just enough to make the Br light,) you can then devote all your attention to trying to set some kind of new speed or altitude record, or whatever winds up your spring. Note - it might be a good idea to tie a string to your landing gear, or the bottom of the frame, in case you hit a thermal while you're up there bothering the angels and eagles.

Aloha, Steve
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Old Feb 10, 2006, 06:52 PM
Flying on Flux Capacitors
Flipper_118's Avatar
Edmonton, AB
Joined Apr 2005
1,422 Posts
Steve - I have read many many of your posts and took no offence to any "talking down" you may have done. I hope you didn't take any offence from my previous post, as I did not intend on putting that across. I haven't lived on this earth long enough to gain experience, but I like to think I have some knowledge.

STREETRIDAZ - ok, now I understand.

micro_builder - weren't you playing with foam dapening a little while back? or was that Steve? Glad to see that you got it all worked out, because last I read, the foam dampening caused the BR to be so unstable it fell right outta the sky. I guess its tricky business trying to find foam that is of right density. BTW did you ever finish the little aero ace BR? That one would have been super light!


Curt
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Old Feb 13, 2006, 07:53 AM
Bladerunner Nut
jtyson's Avatar
Louisville, Kentucky USA
Joined Dec 2004
106 Posts
Micro Builder, Could you post a close-up photo of your foam hinges?

Thanks,
John
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Old Feb 13, 2006, 05:04 PM
4000 posts?!
micro_builder's Avatar
United States, TX, Fort Worth
Joined Jan 2005
4,047 Posts
here ya go John. its a pretty simple idea, the foam just does what the stock plastic hinges do. the foam squares have to be pretty close to identicle in size, or it'll cause it to be unballanced during flight. this is the hardest part if your cutting from a larger chunk of foam.

the foam used in the picture is the foam that is used for insulating around a door frame, or window. you can get differant flight characteristics from differant types of foam, but it mostly depends on the stiffness of the foam itself. if its really stiff, the BR will be less stable, but might be able to go forward a bit quicker.

nick
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Old Dec 13, 2012, 10:35 PM
Registered User
Joined May 2012
3 Posts
hi flipper,

great job!!! what is the gear ratio used.

thanks,
thomas.
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