New motor and electronics balancing?

[flash875]

Hey guys just finished mounting my new brushless motor setup and I was wondering if those of you that did the same had to add weight to the front of the nose to re-balance the plane?? If so what is the best place to put the weight and what should I use?

[Dillzio]

Best stuff to use is lead, best place to put it is as far forward as possible on the inside of the cowl. I find that if you put two weights at the 8 O-clock and 4 O-clock positions it helps to keep the plane level, especially with a ROG take-off. I attach mine with one screw per weight.

[duck]

When I broke my tail off the first time, i used 2 small fishing weights inside the cowl to balance the weight of the epoxy and skewers in the tail.

When I converted to brushless, I found that just mounting the Lipo vertically at the front of the compartment was enough to get it to balance close enough for me. However, keep in mind that my motormount was made from a piece of 1"pine board, so it had some weight of its own. If i needed to add some weight to balance, id drill a hole in the motor mount and add a fishing weight or two.

My biggest problem was getting it to balance laterally. I had to add two pennies to a wingtip to keep it balanced.

[bird]

Just doing this with mine too (park 450). I recommend trying to get some sticky weights used for balancing alloy car wheels. The are scored and pre weighed at 7g/.25oz each and have an adhesive backing. I asked at our local walmart tire centre and they gave me 8 squares at no charge. Since they are meant to stick to the inside of your car rim I'm sure the adhesive is strong enough.

[flash875]

I had to use 3 pretty large fishing weights to balance my plane. I ran some fishing line through all three and wrapped it around the motor mount I will post a pics soon. How much weight do you guys usually have to add after adding a brushless motor and aluminum motor mount? I also mounted the battery vertically.

[flash875]

Here are my pics electronics and weights:
receiver is HobbyKing 6 channel 2.4
ESC
UBEC
Battery 3 cell 11.1 1500mah
2 9g servos mounted using popsicle sticks and hot glue.

[flash875]

[flash875]

esc is on left and ubec is on the right you can also see the battery sitting vertical and i have some velcro on the battery door keeping the battery from moving. I also have some excess wire from connecting the esc and motor I guess I should cut that down as well instead of bunching it all up like that..... any suggestions with how I have things??Please all are welcome

[Dillzio]

Nice looking motor flash. Can you provide the link for it please? How easy is it to replace the shaft in case it bends.

I do have a suggestion for you, and if you take it on board I think you'll be able to take a couple of ounces off your motor.

There's a law of physics about levers and fulcrums and all that cool stuff that basically states that in a "class 1 lever" such as a see-saw, or an airplane in flight that the force produced by a weight is proportional to it's distance from the fulcrum (in this case the fulcrum is the plane's center of lift(CL) ).

In plane English (plane, lol) this means that a 6 ounce weight that's 2 inches in front of your CL will have EXACTLY the same balancing effect as a 3 ounce weight that's 4 inches in front of the CL (double the distance, half the weight).

Judging by the look of your setup, you should be able to double the distance between your weights and your CL by moving the weights forward and mounting them against the very front of your cowl. This should allow you to half the amount of weight you need for balancing.

Your electronics setup looks great, I hope to have a setup like yours myself once I have a spare few hundred dollars. One thing that surprises me a bit though is the fairly small battery you have. Everything in your setup pretty much kicks arse, it's all way better than any of my stuff, except for the battery. With a setup like yours, you shouldn't have any problems chucking a 2200mah Zippy Flightmax in there. I have 3 of them and they go fine in my stock plane, it even does ROG takeoffs in grass. With a setup as powerful as yours you shouldn't have any probs carrying a heavier battery.

All in all it's a top looking little plane. I think once it's optimized you'll have a real gem!

Have you flattened out the wing for the ailerons?

[ginginho]

Flash,
Am alternative to using weights would be to move your ESC (and possibly) UBEC to inside the cowl. Apart from the weight loss and distribution benefits, you'll also get better cooling for these and unclutter the fuse a bit. Extending the battery to ESC/UBEC wires is not be a problem as you'll need around an additional 6 inches. You can just tie-wrap/velcro/double sided tape the ESC & UBEC to your mount.

[flash875]

Thanks for the input ... the motor is from Headsuprc.com and its the sport 450 and they sell replacement shafts as well Dillzio... I have never replaced one though but im sure it cant be hard.. As for my weights I might look into some stick on weights or glue some to the cowl..but I was just surprised that I had to add so many ... I guess my brushed motor and aluminum mount made the front that much lighter from the stock setup.

[ginginho]

One other thing I've just noticed which may be worth thinking about, is the battery orientation. If you mount it upside down (to how you have it now) then you should be able to connect/disconnect/change a battery without taking the wings off. A huge benefit as and when you've fitted ailerons.

[flash875]

Given my car is a 2006 Mustang GT I have to take the wing off to transport it to my flying feild anyway... and I have a way to actually fit this thing in my trunk. But I dont mind taking the extra couple minutes to put it together and check out all my trim controls plus I purchased a longer y-harness for the aileron servos making it easy to connect etc...