I had to get in at least one post before the end of the month. So here's the update for the Twin Rotor Project. Got my motors installed. Two Brushless outrunners - ExceedRC 370's 28-26 Kv 1360 with 8/5 props.
(First issue) Did not get counter rotating props. Test flights indicate sever torque roll issues. Was able to trim most of it out before take off but once in the air it was highly unstable.
First flights used one 3 Cell 2200 battery with one speed control (ExceedRC - Proton 25A)
(Second Issue) Needed a second speed control.
I also used a smaller 800 mAh battery for weight reasons that would produce shorter flights I'm sure but the flights never lasted that long anyway!
(Third Issue) Motor Mounts where fabricated from molded fiberglass which was reinforced with F/G cloth. On one or two hard prop hits the motor mounts failed. I think they where strong enough but the lack of a Prop Saver was the real issue.
As I said the craft was highly unstable. After much thread search and comments from my electronic mentors, I'v decided to of course get counter rotating props of the slow flyer type. I hate orange but I'll do what I have to.
I also intend to purchase two gyros and I'm going to add a six channel radio to the mix. And... just complete the package for the next go... a V-Tail mixer.
I guess that's it for now. All of this should be in and installed in the next two weeks while I'm home.
Posted by Cruiser1 |
Feb 03, 2010 @ 05:41 AM | 5,479 Views
With the help of a few of you, I've started to rethink my design a bit. No more ducted fans for me, at least not at this point. Props are the deal for me right now. Cheep and better for the prototype stage of this project. Going to keep the Brushless motors. Plan to up the number of servos to four. I want to try to give it both pitch and yaw. V-Tail mixing on right stick will take care of two of the servos... pitch/yaw. So the forward and back movement of the craft will come from right stick moving F & B. The yaw will come from the left right movement of the stick, counter rotating the craft by tilting one prop forward and the other back.
The second set of servos will control simply the sideways travel. Guessing there will be no roll in this setup. Thinking that would be hard to do without being able to adjust the motor speed independently. Or independent varriable pitch. Woooo bet that's hard.
Anyway... that's the plan I have in my head right now. Getting close to the install of the good stuff. About a week or so.
Posted by Cruiser1 |
Jan 31, 2010 @ 03:34 AM | 5,298 Views
I haven't seen anything yet on these Blogs about Lost Foam Molding. Lost foam is just that. When your finished you loose the foam. I've made molds from wax, clay plaster, and even just bondo. But with the new foam products out there, shaping is easy and the final product is smooth, strong and best of all light weight!
I started doing this years ago when I had to make a one of a kind part for a 1973 Bonneville.
I think some of you foam builders can help out here. I mean I think you have a pretty good idea what different chemicals do to foam products. So feel free to drop in a comment or two about what works for you.
I've attached two photos of this recent Dog Bowl project. The first is the foam design. It was created from a white foam cooler we got one day while I was at work. Frozen food of some kind was shipped to the boat. (work on a boat) The top was about 2 inches thick and overall about 18 x 30 inches. All flat surfaces. It was free, flat and foam.
The second photo is the foam covered with fiberglass and painted. I put down a layer of just resin and then resin and a mesh. Not fiberglass mesh! In fact it was some old curtains my wife had in the spare bedroom. I know this sounds a little strange but... they had little Bumble Bee's sewn into the cloth and I thought the texture would be cool. Turned out they were not that cool. Took a while to grind them out. Lesson learned.
The basics are... create a foam design. I don't care what it is....Continue Reading
Posted by Cruiser1 |
Jan 31, 2010 @ 02:41 AM | 4,976 Views
I'm all over this Sketch-Up program. I can't build a box without using SU. Have any of you out there used Sketch-Up? I been using it for about 4 years now and really... I can't do anything without it. I've always had a ton of ideas going through my head. I'm a mechanical drawing kind of guy and think 3-D.
I'm not an artist! We all know how long it takes to put pencil to paper and draw. Sketch-Up lets your ideas happen fast. Its easy to use and the 3-D gives you a great perspective. Did I say it was FREE! I know you Solid Works people out there will say its not even close to Solid and your right! But how much did you pay! SU is free and easy to use. Free is good Easy is good! Check out Sketch-Up
Posted by Cruiser1 |
Jan 30, 2010 @ 07:40 AM | 5,211 Views
For starter I'm blogging on an iPhone so forgive the any errors. I've built a few scratch flying things. Sail cars, beach sailers, park flyers and some other things that are too hard to describe.
About a year I built my first VTOL. Started out all foam. Home depot special. Cool design that looked like it was going to be great from the start. Wrong!
I wanted to design something that had two ducted fans, and two servos. I wanted the servos to rotate a shaft that tilted the motors forward and back. I figured the two fan motors would operate independently. I wanted V-tail mixing on the servos. You can imagine the control movements. Stick forward both fans tilt forward. Stick left - left fan moves aft, right fan moves forward.
The controls worked flawless.
Power was the issue. Little brushed ducted fans with not enough amps, provided no lift. Well it never left the ground. It did maneuver around very well. NO Lift. It did scoot around the floor pretty well. Spins like a top one way then move the stick the other way and it spins the other way.
I was hopeful!
that brings me to my next version. Photo of original Sketch-it design below. Fiberglass shell built from a lost foam process. shell is about 8-10 ozs. Openings are of course for props which I intend to use 3 bladed 5 .5 inch props. Two servos, speed control, receiver and a lypo battery.
If anyone has an idea... please respond. I would like to keep it as close to original design as possible.