My brushless mod

[mikejbb]

parts:
from hobbycity:
TP2409-18 www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5112 Brushless Outrunner TowerPro2409-18 1000kv / 180w
TP18A_BESC www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=656 TowerPro n18A Brushless Speed Controller
AM1033A www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2116 Deans Style T-Connectors 10 Pairs
HXT900 www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=662 HXT900 9g / 1.6kg / .12sec Micro Servos
HX8080 www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2055 hexTronik Balancer/Charger Dual Channel
GW/WH01/76 www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5210 GWS Ultra Light Wheels (2pc 76mm)
from cwtco on ebay:
360035335333 cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360035335333 2400mAh 15C 11.1v LiPo Li-Po Rechargeable Battery RC

After reading every post re this mod I decided to use a thin wood firewall epoxy'd to foam directly. So I removed original plastic firewall, which was broken in a couple of places and not attached very well. When removing the orig motor, I noticed the 2 screws holding the motor in were very loose. I'd recommend everyone do an engine check every so often and tighten everything.

Next I shaped a 3/4" piece of wood as a spacer. I weighed everything before and after and this wood plus putting the esc in front under the motor kept the weight the same and the cg in the same place. When I attached this spacer I put a nut between it and the firewall at the top and sc's left side to make the thrust angle the same as it was.

Finally I shaped a 1/2" piece of wood and attached the motor to it after drilling out the 3 holes in the metal motor mount so a wood screw would fit. You have to take the mount off the motor to attach it and use a screw with almost no head to put the motor back into the attached mount. Or mount from behind, which was not an option for me.

Then I mounted the wood motor mount to the spacer. I used wood screws for all wood to wood fastening. That way I can redo any part of this that is screwed up.

I soldered all electical connections and soldered on deans for the battery.

front view from above:



top view looking straight down:



view from below showing the esc is straping taped on:





old futaba 7ch receiver:
esc control wires are attached to servo 3 which is the throttle in this receiver.
tail servo is attached to servo 1
elevator servo is attached to servo 2
when I add ailerons, they will both be attached to servo 4, one regular and one reversed. I only have a 4 ch tx.



servos are gorilla glued in. The orig servo's came out last week way up high and caused a real bad crash, lots broken. So glue in original servos.



I put the lipo thru the battery holder by melting thru the plastic until it fit. It is very secure.



finally I put a power switch outside the fuse so I can leave the wing on. I also keep an extension of the lipo balancing charging cable outside on the other side to charge without removing battery or wing. I only have 1 battery now, with orig sc motor I got 20+ mins in air ;D We'll see what happens with brushless.

You can also see the result of the servo's coming loose way up high, the fuse was very broken and now gorilla glued and packing taped. Seems secure. I did notice the fuse is not exactly straight now because I didn't hold it together long enough for the glue to set. I should have taped it instead of holding it.



My workshop, the kitchen. So now you see that my wife is very sc friendly. This mess was here in the kitchen for over 24 hours.



Mess cleaned up. The final product with independent kite string struts looped over the orig strut screw for easy wing removal and knots glued to stop untying. Also my 3" very thin wheels. They work great in the rough grass I take off in, but they've been hot glued at the hub because a spoke on each wheel broke loose, so I'm not so sure they are the best choice. However if the hot glue holds, then they will become recommended, once again, we'll see. The wing has the front and side edge covered with 2" packing tape. I also used packing tape to attach 2 carbon fibre strips under the wing for extra strength. The wing snaped in half at the end of the very bad crash caused by loose servos.



So that's it. It's not as pretty as some, but it almost hovers now in the house with a 10-4.7 prop. I ran it full throttle for a minute and nothing got too hot, battery cool, esc warm, motor warmer. It did it again for 2 minutes, same result so It seems the prop is not drawing too much power. I really should order the watt meter.

Oh, I added a prop saver. Not sure if it's a good idea or not, it was recommended here so I thought I'd try it.

One nice thing about this motor, it's 3mm shaft I think instead of 4mm of orig motor so the props I use don't have to be drilled out any more

Mike

[flydiver]

Over 100W is pushing it one prop savers. Use double bands or you can easily throw the prop. I prefer bands cut from latex tubing. The O-rings are not designed for stretch.
Make the shaft as short as possible. It's REALLY wimpy soft. Have spares on hand for replacement.

Other than the wheels may not hold up it looks pretty good.

fly

[mikejbb]

Thanks fly.

I agree about the wheels, we'll see, I'm not recommending them unless they hold up under more landings.

re latex tubing, how do you do that? Just cut at 90degree to the tubing and use as is or something else? The tubing I have is only 1/3" wide.

Mike

[flydiver]

I got some 1/2" OD tubing with about 1/8" thick walls at an ACE hardware. I use sharp scissors to cut-pinch it flat, cut 90 degrees. I've heard of using a razor blade but haven't tried that. You can vary the thickness depending on need. I think they are clearly superior to O-rings.

Those look like slow stick wheels. I've had them crack spokes on the much lighter SS. I've got big 3" foam on mine. Much better in grass, and hard for that matter.

[flyinghigh]

Have you flown it yet? I'm curious to hear how the motor,esc,battery combo works out.

[mikejbb]

No I live near Chicago and today the wind was 25mph+ with gusts 35mph+ and tonight nasty but short T-storms so far.

But as far as combo, I've run it full throttle for 1 min then 2 min plus other less than full to test it out. Battery cool, exc warm, motor warmer, but didn't seem to hot to me. All with a 10-4.7 prop.

But the proof will be when I take off. Tomorrow's forcast is 10-20mph so a little better. Hope the weather man doesn't know what he's talking about. Or maybe early it won't be too bad.

Mike

[mikejbb]

I finally got to fly on Sat late just before sunset. My sc flew great. It took right off from the ground and jumped into the air up high. It flew great, very fast climbs etc. It was very windy, weatherunderground said it was 12mph to 20 gusts. I've flown in 10+mph before, but with stock so my sc was very slugish against the wind. Well now it just goes. But with that wind I did have throttle almost wide open against the wind.

Well I guess the wind was really worse that I thought. And my depth perception isn't the greatest when it starts to get a little dark so my sc was way further away than I thought and as I was turning around to come back I guess a gust took it out of radio range because it did not respond to any commands. It just went off cross wind and descended nicely. So you can only guess how bad the crash was. Well I didn't even get to see the crash. So I ran to my car and went looking.

I went down 3 streets beyond the park boundaries and did not see it. I watched the descent carefully to be sure I'd see where it went. When low and behold a house jumped between me and my sc. I was shocked because that house was so far away. Thus the claims of my bad depth perception in less than full lighting.

I decided that it was in one of the yards with a fence that I couldn't see it from my car. I was right, it was in the yard with the tallest fence, of course. It was just sitting in the corner of the yard looking ready for takeoff. However, when I got closer I noticed the firewall was ripped off. The esc was complaining that the transmitter was off too.

Well all is fixed and ready for takeoff. I do need to get another shaft as mine didn't bend, but broke off completely. I put in my one spare and it still runs just fine.

Mike

[mikejbb]

I was getting ready to go flying tonight and found just one minor problem, my radio combo, which worked just fine after the crash, is no longer working? The esc thinks the tx is off. So I tested the tx and rx without the esc by using the nitro battery on the rx and NOTHING! So debugging will continue tomorrow after my friend gets home from work. He has many tx's and rx's so I should be able to figure out which one is failing and then go from there.

Mike

[mikejbb]

I borrowed a tx rx combo from a friend and found that my rx was dead. The ch15 crystal was fine so I bought another rx and put my crystal in and reassembled my sc.

The rx may have been the problem in the first place.

Mike

[mikejbb]

I packed the new rx in foam for shock protection in case of a crash and moved the battery to lie flat against the battery box to move the cg back a bit.

ROG in rough grass just fine, up up and away. Flew my Flight plan at 2/3 throttle incl inside loops, outside loops, and level inverted flying. The outside loops only got 3/4 of the way around even with full power because my sc would "fall" out of the final climb. Probably pilot error.

I did 2 nice low powered landing in the grass. I keep power to keep the nose up although I think the prop will break easier if I keep power, but a way nicer landing. The grass is really rough.

I brought her down after 20 minutes. I could hear the motor doing less rpm's even at wot and I wanted a good final landing.

I checked all the temps and they were good.

So my brushless mod can be called a great success.

Next is ailerons.

Mike