Canadair CL-415 Water Bomber (Guan Li)

[road king 97]

Originally Posted by jap71173

OK, I said i would post a picture of the setup before i actually install it... just in case anyone spots something i'm doing wrong...

I think i've got it pretty much down with the help of Jeff @ Headsuprc... but i'm debating where to solder the BEC power-in wires. Should i open up the connection at the battery t-plug and solder it there? or just tap into the +/- wire a few inches down on one side?

Curiosity question: Could i power the BEC with a small 2nd battery? And if yes, the what should be my minimum mAh/voltage?

I have my motors only on my esc and i cut the wire to my bec and put heat shrink on it . I run a second 2700 sanyo flight pack battery for my servos and reciever . This way i dont have to worry about my motor batterys shutting down my reciever or servos when low.Iam running my metal gear high tek servos on 6 volt but some like less voltage. joe

[jap71173]

Well, I've got everything setup right and tested... But one of my motors seem to be running faster than the other... By the time I back down the throttle from full to 1/4... One motor stops and the other is still spinning slowly... on top of that, once that motor stops, it wont respond to throttle control again unless i fully back it down to zero... I tried moving the BEC connection straight to the battery but this had no effect on anything... Any ideas? Are my esc timing's programmed differently?

Sent from my EVO

[CHELLIE]

Originally Posted by jap71173

Well, I've got everything setup right and tested... But one of my motors seem to be running faster than the other... By the time I back down the throttle from full to 1/4... One motor stops and the other is still spinning slowly... on top of that, once that motor stops, it wont respond to throttle control again unless i fully back it down to zero... I tried moving the BEC connection straight to the battery but this had no effect on anything... Any ideas? Are my esc timing's programmed differently?

Sent from my EVO

Swap your ESC around and see if the problem happens to the other motor, if not, the motor KV is not matched, if you got the motors from heads up rc, give Jeff a e mail, you might need to send the motors back and have Jeff send you a matched set of motors, the KV on motors will fluctuate a Little bit from motor to motor. if the problem happens to the other motor when the esc is switched around, then your ESC is to blame, reset the ESC throttle end points, one at a time, hope that helps, Chellie

http://www.wattflyer.com/forums/show...tle+end+points

[jap71173]

Originally Posted by CHELLIE

Swap your ESC around and see if the problem happens to the other motor, if not, the motor KV is not matched, if you got the motors from heads up rc, give Jeff a e mail, you might need to send the motors back and have Jeff send you a matched set of motors, the KV on motors will fluctuate a Little bit from motor to motor. if the problem happens to the other motor when the esc is switched around, then your ESC is to blame, reset the ESC throttle end points, one at a time, hope that helps, Chellie

http://www.wattflyer.com/forums/show...tle+end+points

You were right (as usual)... it's the motor kv. Switched them and the opposite side was the one to slow down first. Just as a backup, i did the second test of reseting the throttle end points and no change so it's definantly different motor kv... i guess this is not uncommon in low quality motors. Thanks for your help Chellie... i'm sure Jeff will help me fix the problem.

[jap71173]

Originally Posted by CHELLIE

Swap your ESC around and see if the problem happens to the other motor, if not, the motor KV is not matched, if you got the motors from heads up rc, give Jeff a e mail, you might need to send the motors back and have Jeff send you a matched set of motors, the KV on motors will fluctuate a Little bit from motor to motor. if the problem happens to the other motor when the esc is switched around, then your ESC is to blame, reset the ESC throttle end points, one at a time, hope that helps, Chellie

http://www.wattflyer.com/forums/show...tle+end+points

Originally Posted by jap71173

You were right (as usual)... it's the motor kv. Switched them and the opposite side was the one to slow down first. Just as a backup, i did the second test of reseting the throttle end points and no change so it's definantly different motor kv... i guess this is not uncommon in low quality motors. Thanks for your help Chellie... i'm sure Jeff will help me fix the problem.

Well Chellie, it turns out it's not the motor kv, but rather just a bad motor. Jeff explained that if I can "see" the difference in speed, then it's something wrong with either the solder connection points or the motor itself. He said you can take two completely different motor kv's (ex: 1000kv & 2000kv) and they will both stop and start at the same exact time because that’s what the esc tells them to do... I of course tested his theory for myself as i have tons of motors just lying around so i tried a wide variety of mixed match motors on the two esc setup and he was right... never once could I tell any difference in speed "visually" and they both started, slowed and stop all at the same rate. The ONLY way to tell the difference was with my tachometer.

So long story short, it was a defective or damaged motor i got and he's swapping them out for me. So in truth you were correct that 2 motors can in fact be spinning at different kv, just that you can’t see it visually the way I was and in my case it was a defective motor. Thanks again for your help.

[CHELLIE]

Great Glad you and Jeff got it figured out, I belive that Wrench66 here on Wattflyers had a similar problem with twin motors, he sent them back to Jeff and Jeff was able to get him a Matched set, i belive that problem was one motor was spinning faster than the other motor at higher speeds and would cause the plane to want to turn with out rudder, jeff got him a matched set of motors and the problem went away, so i belive in that case the kv of the 2 motors was off enough to cause a problem, Take care and have fun, Chellie

[road king 97]

Originally Posted by CHELLIE

Great Glad you and Jeff got it figured out, I belive that Wrench66 here on Wattflyers had a similar problem with twin motors, he sent them back to Jeff and Jeff was able to get him a Matched set, i belive that problem was one motor was spinning faster than the other motor at higher speeds and would cause the plane to want to turn with out rudder, jeff got him a matched set of motors and the problem went away, so i belive in that case the kv of the 2 motors was off enough to cause a problem, Take care and have fun, Chellie

So i get this straight if i want to build another multi brushless motor plane i need to have them all matched and the esc,s by the seller ? I have twins coming up on 3 different builds and will have to get the right ones. joe

[CHELLIE]

Originally Posted by road king 97

So i get this straight if i want to build another multi brushless motor plane i need to have them all matched and the esc,s by the seller ? I have twins coming up on 3 different builds and will have to get the right ones. joe

Hi Joe if your going to build a twin and if you get the motors from Jeff at Heads Up Rc or any other seller, have them Match the motors for you to get the KV as close as possible, the kv will be off a little between motors of the same rated KV and brand, its just good cheap insurance to do that before the build, hope that helps, Chellie

[road king 97]

Originally Posted by CHELLIE

Hi Joe if your going to building a twin and if you get the motors from Jeff at Heads Up Rc or any other seller, have them Match the motors for you to get the KV as close as possible, the kv will be off a little between motors of the same rated KV and brand, its just good cheap insurance to do that before the build, hope that helps, Chellie

I own a K+A grumman mallard sea plane that was going to be brushed motors and i will pull a extra wire for brushless . http://www.kamodels.com/ thanks chellie. joe

[jap71173]

Originally Posted by Fly Time

I finally have just about everything I'll need to put this one together. My order for motors, ESC's, servos, etc. from HobbyKing took a really long time to get here. About 2 1/2 weeks! It may have taken longer because I added a couple of lipo batteries to the order. I actually forgot to order an Rx so placed a second order for that a day later, and it arrived in less than half the time

I plan to glass the bottom of the hull and of course add the water drop tank, but first I am going to get her flying. I will probably go ahead and do the flap mod before the first flight. From everything I've read on this plane, the flaps are hardly needed, but I have never regretted adding them to any of my other planes. Flaps definately add a lot to the coolness factor

Hey Flytime, You still there... i need your help on this build???

[jap71173]

Well, decided to start it without help...

first problem i ran into was the ESC/Motor wires were not long enough to be routed through a shaft leading under the wing... so i used 22 gauge servo extension wire... I’m thinking it may cause some resistance in power flow since both the esc and motor wires are heaver gauge.

[CHELLIE]

Originally Posted by jap71173

Well, decided to start it without help...

first problem i ran into was the ESC/Motor wires were not long enough to be routed through a shaft leading under the wing... so i used 22 gauge servo extension wire... I’m thinking it may cause some resistance in power flow since both the esc and motor wires are heaver gauge.

Hi, Use the Same size/gauge wire as the ESC to motor or your might burn up your motor or ESC.

[jap71173]

Originally Posted by CHELLIE

Hi, Use the Same size/gauge wire as the ESC to motor or your might burn up your motor or ESC.

too late... all glued up

[jap71173]

Took me all day but it's done. This is a nice sized plane. I must say this plane is good quality and fits together nicley. Instuctions were absolutley useless and can be tossed before starting!

I used all HeadsupRC parts and the watt meter reads 19amps @ 240 watts with a 3200mAh 3S, GWS 8040x3 blade props, 45oz flying weight.

[Fly Time]

Originally Posted by jap71173

Hey Flytime, You still there... i need your help on this build???

Oh man!! Sorry about dropping out. Not sure I would have been much help anyway since I haven't built mine yet

Last night I finally got around to waterproofing all of my electronics with CorrosionX. Hopefully this evening I will start the build.

BTW, I share Chellie's concern about using servo leads to run brushless motors. Servo wires are rated for relatively low power loads, whereas motor leads are rated much higher. Fortunately the motors in this plane will not draw too many amps, but all the same I would keep an eye out for gremlins...

Do you have a maiden flight report for us yet?

[Fly Time]

I'm finally putting this project on the work bench! Last night I got all the electronics figured out and soldered together. The ESC's will be in the fuselage, so I had to extend the motor leads to about 20". I also added a 5A UBEC.

Before installing the motors, I figured it would be a good idea to bench test the motors to make sure everything is running within limits. So tonight, I balanced the props and mounted the motors on a block of wood. Hooked it all up to a 25c 2200mAh lipo and a power meter, and the results were perfect: with both motors spinning GWS 8040 3-bladed props, I'm getting 31 amps and 325 watts. The HK 2824's are rated for 20 amps, so divided by 2 they are running WOT at 15.5 amps. That is perfectly in the sweet spot for efficiency, and well within the limits of my 20 amp ESC's as well And this plane will have plenty of power for water takeoffs.....and hauling it's firefighting cargo

[jap71173]

Originally Posted by Fly Time

I'm finally putting this project on the work bench! Last night I got all the electronics figured out and soldered together. The ESC's will be in the fuselage, so I had to extend the motor leads to about 20". I also added a 5A UBEC.

Before installing the motors, I figured it would be a good idea to bench test the motors to make sure everything is running within limits. So tonight, I balanced the props and mounted the motors on a block of wood. Hooked it all up to a 25c 2200mAh lipo and a power meter, and the results were perfect: with both motors spinning GWS 8040 3-bladed props, I'm getting 31 amps and 325 watts. The HK 2824's are rated for 20 amps, so divided by 2 they are running WOT at 15.5 amps. That is perfectly in the sweet spot for efficiency, and well within the limits of my 20 amp ESC's as well And this plane will have plenty of power for water takeoffs.....and hauling it's firefighting cargo

Hey fly...

Whats with the seperate BEC? the HK 20amp your using has a 3amp BEC should be more than enough for 4 small servos... well i guess more is always better so nothing wrong there ,,,

Your electronic package is better than mine and mine flies good so yours will do great!!!

If you decide to do grass landings, make sure to spray Polycrylic on the bottom or all the red paint will come off... Also, i found the wood braces for the floats need to be supported more as the tend to rip off even for water landings... i made 1/4 rounds x4 out of wood and glued them to the brace on the wing side.

P.S. Is that the Seawind stand???

[Fly Time]

Originally Posted by jap71173

Hey fly...

I will eventually be running quite a few servos: 2 for ailerons, 1 each for rudder and elevator, 1 for flaps, and probably another 2 for my water scoop and drop system, so the UBEC is installed in anticipation of running 7 servos eventually

Thanks for the advice about protecting the hull. I was already thinking of glassing the bottom, so I will almost certainly go ahead and do that now. I have used polycrylic without fiberglass on a couple of other belly floppers and found that it helps a little, but only a little. This one will get the full treatment!

Bracing the tip floats was also on the list.....which is getting long!

[Fly Time]

Originally Posted by jap71173

P.S. Is that the Seawind stand???

Yep, that is all that is left of my little Seawind

[Fly Time]

So this is why I build so slowly....

Instead of just slapping these ARF's together and flying them, I see these little things all along the way that could have been engineered better, and I can't help but make the changes

The cowlings on this plane do not allow for easy access to the motors. Even though brusless motors hardly ever require maintenance, it drives me nuts to not be able to get to them if I need to. And I was having some difficulty getting a firewall installed to replace the stick mount, so I took a razor saw to the foam. After installing firewalls, I took some hatch magnets from my crashed Seawind and used them to secure the front section of the cowlings. Now I have easy access to my motors

....and I added another day to my build

[xmech2k]

Good job with the cowls, and nice looking models. I like the unique scale stuff.

It takes some cajones to cut into your brand new model!

[Fly Time]

Originally Posted by xmech2k

It takes some cajones to cut into your brand new model!

You aint seen nothin yet!

[Fly Time]

A little more cutting of foam tonight

I need to pick up a few things at the LHS tomorrow to make these fully functional.

[CHELLIE]

Looking Great Just a suggestion, you might want to add 2 pins/dowles next to the magnets, one on top and one on the bottom to keep the cowel from ever wanting to twist off, Just my 2 cents worth, Take care and have fun, Chellie

[Fly Time]

Originally Posted by CHELLIE

Looking Great Just a suggestion, you might want to add 2 pins/dowles next to the magnets, one on top and one on the bottom to keep the cowel from ever wanting to twist off, Just my 2 cents worth, Take care and have fun, Chellie

You know, I was actually going to do that, but those magnets hold so strong that I can't really imagine them coming loose from the forces of airflow and motor vibration alone. A crash would knock them loose, but I'm not going to do that