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Old Aug 02, 2011, 02:54 PM
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I'm quite a distance from a hobby shop and low on funds. What else could be used in place of the CF spar? What about a 3/16" wooden dowel? They're about 25 cents at Walmart.
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Old Aug 02, 2011, 05:06 PM
JOHN 3:16
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Central Ohio
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Originally Posted by chris1379 View Post
I'm quite a distance from a hobby shop and low on funds. What else could be used in place of the CF spar? What about a 3/16" wooden dowel? They're about 25 cents at Walmart.

You can get a c/fiber'ish arrow from Walmart for $3-4 that should work...
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Old Aug 02, 2011, 05:27 PM
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Chris,

I think Sammy's advice is good. I've never thought about other CF items like that. There are really all kinds of things that you could do and I would suggest that any of them is butter than nothing at all. My first Funbat's wings folded up like a cheap suit though it was probably due to the larger (heavier) 2.2 Ah battery.

I've been flying on a laminate I made from balsa strips and gorilla glue with excellent results. My son likes to use the popsicle stick you can get in the craft section.
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Old Aug 02, 2011, 06:37 PM
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United States, IL, Marion
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I built and flew one of the funbats. I had four good flights on it till my battery came loose, and my CG went full aft. Now I need to build a new one
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Old Aug 02, 2011, 08:49 PM
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I know the feeling all too well Willie. Whenever I blow off the basics (checking control surfaces, cg) it almost always bites me in the butt. You can glue foam blocking to confine the batt to one spot or use some heavy duty velcro or both.
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Old Aug 03, 2011, 04:42 PM
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You can get a c/fiber'ish arrow from Walmart for $3-4 that should work...
I looked at them too but aren't they too thick to fit between the layers of 5mm Readiboard? Maybe I could put it behind the step like the Blue Funder?
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Old Aug 07, 2011, 05:39 PM
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New Funbat

Finally just completed my funbat which is my first scratchbuilt plane. I don't think I picked the best battery for the plane as I had to add 5oz of weight to the front of the plane to get it balanced. The plane seems pretty heavy but does fly.

Any feedback/suggestions about my battery? Here's what I have

- GraysonHobby 2200mAh 11.1V 15C / 20C Lithium Battery Pack
- ParkJet Combo 2212-06 V2 Super-Sonic Brushless Combo (Combo-Sonic)
- Add a Prop Add an APC 6x4
- Speed Controller Options GrayonHobby 30Amp ESC

Quite a change from the HZ Super Cub and what a thrill to see the darn thing actually fly when I was done!
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Old Aug 07, 2011, 05:55 PM
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Originally Posted by chris1379 View Post
I looked at them too but aren't they too thick to fit between the layers of 5mm Readiboard? Maybe I could put it behind the step like the Blue Funder?
I use .26" CF arrows, on the kits I was selling I would bevel a slot in both halves of the wing and fit the arrow shaft there, But I have a CNC machine to cut mine perfect lol. it would work to put it right behind the step though.

Jon
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Old Aug 07, 2011, 06:00 PM
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Originally Posted by jathef View Post
Finally just completed my funbat which is my first scratchbuilt plane. I don't think I picked the best battery for the plane as I had to add 5oz of weight to the front of the plane to get it balanced. The plane seems pretty heavy but does fly.

Any feedback/suggestions about my battery? Here's what I have

- GraysonHobby 2200mAh 11.1V 15C / 20C Lithium Battery Pack
- ParkJet Combo 2212-06 V2 Super-Sonic Brushless Combo (Combo-Sonic)
- Add a Prop Add an APC 6x4
- Speed Controller Options GrayonHobby 30Amp ESC

Quite a change from the HZ Super Cub and what a thrill to see the darn thing actually fly when I was done!
That set up sounds like almost exactly the same as I used, but it sounds like you didn't place the battery or servos far enough forward. The 2212-06 has plenty of power for the weight, but it will reduce what glide rate this plane has. I would try moving things forward, its much better to use the battery and other gear to get CG rather than adding dead weight. I have used several difrent motor and lipo combos on this plane and have not had to add lead yet to get CG.

I am working on a version 2 with a bit of sweep to the LE of the wing in hopes of moving the CG back a bit, it will make the build a little more complicated (which was not the purpose of the original design) but getting CG a little further aft will make balancing the plane much easier.

Jon
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Old Aug 07, 2011, 06:10 PM
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Thanks for the info. Hmmm... I think I placed the servos I used in the same positions as in the plan. I used some pretty thick pushrods (2mm) and I used elmers foam board with packing tape around all edges for a little better crash protection. The receiver is behind the furthest servo from front and both the battery and esc are just behind the motor mount. I have to be missing something to need so much weight. To balance, I measured the point for cog on the edges of the wing and balanced on my fingers. Had to add 5oz behind the motor to get it to lean slightly forward.

I have to be mising something obvious....

Sent from my SPH-D700 using Tapatalk
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Old Aug 07, 2011, 06:32 PM
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Here are a few pics before the first 2 crashes. Let me know if anything looks obviously wrong to cause the weight issue.

Thanks!!!!
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Old Aug 07, 2011, 06:46 PM
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ahh, I think its the Elmers board I use Dollar Tree Redi Board. Its much lighter. Redi Board is covered in heavy paper, Elmers board is covered in poster board. I have built in both and the planes come out about 5oz heavier in elmers board on average, and on this plane it would all be on the tail.

that would be a big difference, if you have a dollar tree somewhere close, try that foam next time you build in it, it is also about 1/3 the cost.

Jon
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Old Aug 07, 2011, 08:05 PM
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For foam I use the blue "Fan Fold" foam that you can get from Home Depot or Lowe's. Home Depot sells the pink Pink Panther Foam and Lowe's sells the blue stuff made by Dow. Both are 1/4" thick which works with plans calling for 6mm foam. It costs between $35-$40, but you get 25 sheets that are 2'x4' each which means you pay only about $1.60 for each sheet, not a bad deal. Each sheet is enough to build a whole FunBat and then some.

You seem to very close attention to detail as your build looks very clean. Even using the materials you used I don't think that was your cause for failure unless they flexed and collapsed, which I doubt was it.

I hope you did put some reinforcement in the wing as per the instructions. My 1st FunBat did well until I flew it with my 1800mAH and then the wings gave out after a couple diving moves. I prefer my much lighter 1050mAh batteries since they put much less stress on the airframe and allow for more life. Even still, I think you should be able to make it work with your 2.2AH.

The biggest factor you need to be sure about where to balance this. I recommend some heavy duty velcro to give yourself a little bit of room for adjustement. If you have a nearby field with tall weeds or hay that would be an ideal place to work out the balance issue. But I found that the directions have you right where you need to be whith the balance line 1 3/4 inches back from the leading edge of the wing.

One other thing I would HIGHLY recommend is a prop saver which was not on the plane in your pic. If you are unfamiliar with these, they are a type of hub that allows the prop to spin as normal but if the prop collides with anyting it flexes instead of breaking. They only cost about 3 bucks and will save you in what you will likely spend in breaking props. And when you go this route, always double up on rubber bands so that if one fails you have another keeping things together. When you hear a funny buzz, check those rubber bands.

I tried building a bigger fuselage version to keep the prop away from the ground but that made the flight handling much worse and I still broke props.
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Old Aug 07, 2011, 10:09 PM
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I like the FFF too, but the up front cost has stopped me from using it recently. Its also a bit less durable. I personally have grown quite fond of the Readi Board. It seems to hold up much better than the blue core, but both are great building materials. I however tend to stay away from elmers board both because of weight first and cost second.

Just my experience, everyone has their preferences.

Jon
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Old Aug 08, 2011, 12:47 AM
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Originally Posted by jhtitan View Post
ahh, I think its the Elmers board I use Dollar Tree Redi Board. Its much lighter. Redi Board is covered in heavy paper, Elmers board is covered in poster board. I have built in both and the planes come out about 5oz heavier in elmers board on average, and on this plane it would all be on the tail.

that would be a big difference, if you have a dollar tree somewhere close, try that foam next time you build in it, it is also about 1/3 the cost.

Jon
Are you leaving the paper on the Rediboard?
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