My-RC Guide

RC Planes, Trucks, Cars and Boats => RC Airplanes => Topic started by: KeithLuneau on October 23, 2010, 05:35:55 AM

Title: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on October 23, 2010, 05:35:55 AM
I'll soon start converting this one to big brushless and lipo power, to replace the current Homelite engine. The engine is a converted chainsaw engine, 26.2cc from an old XL saw. It's a load of fun but it's beating the plane to pieces, so electric power it will be. I've got a list of parts together to order, I should be able to get it done for about $200 give or take.

I'll post here as I make progress with it, just wanted to start with a few pictures now, and a video I made when I first got it in the air. ;)

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/4star120-1.jpg)

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/4star120-2.jpg)

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/4star120-3.jpg)

Sig Four-Star 120 with a converted Homelite chainsaw engine. (http://www.youtube.com/watch?v=T__b-nqOvZE#)

I'll order the stuff for the conversion next week from HobbyKing, so I'm looking at a couple weeks or more before I can start to actually work on it. :(
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLDick on October 23, 2010, 08:12:03 AM
Very Cool Mod...  I got a Four Star 40 that had a crappy 4-stroke Magnum XL .52 in it and it would barely get off of the ground so I put a O.S. .46 AX in it now it kicks butt... hehehe
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on October 23, 2010, 08:23:20 AM
I flew a Four Star 60 a while back at a flying field and loved it! I learned to fly with a Sig Astro Hog that had a O.S. .91 four stroke, and man was that one nice! :) I sold it, and regretted it ever since. This big Four Star flies so nice though. I kinda wish I'd gone with the 60 though. I got the big one just so I could use the Homelite since I already had it. If it were a kit it would have been simple to build it strong for the engine, but this one was the ARF. It's already got stress cracks in the canopy from the vibrations, and the firewall is starting to separate from the fuselage sides! I've only got about 5 flights on it too.
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLDick on October 23, 2010, 09:05:02 AM
Man that sux....

I sold my Rascal 40 the other day and I had never flown it...  The guy fly's it for the 1st time and has a bit of a hard landing and the Landing Gear brace in the fuse broke, he says they used "Monkey Wood" instead of plywood on the brace... hahaha

It was an older ARF, but he says it would be a quick fix and it didn't even tear the Monocote so that's cool... It sure did fly nice tho....  :220:
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on October 23, 2010, 09:13:16 AM
Yeah, Sig does have some awesome designs! I think their ARFs are a little lower quality than their kits though. This one actually had papers in the box where it came from World Models. My guess is they're building the ARFs for Sig, and Sig markets them here in the US as their own products, when truthfully it's only their design... ;) I could be wrong though!
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: pinguin6218 on October 23, 2010, 09:59:22 AM
Sig Four-Star 120 with a converted Homelite chainsaw engine. (http://www.youtube.com/watch?v=T__b-nqOvZE#)

I'll order the stuff for the conversion next week from HobbyKing, so I'm looking at a couple weeks or more before I can start to actually work on it. :(

Nice flying  :130:


That sun is really killing my eyes
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on October 27, 2010, 11:52:29 PM
Just a small update... I've got most of the parts on the way now. (Motor, firewall mount, prop, ESC, battery, BEC, battery for the BEC, etc.) I'll still need a cowling to cover up the motor later, but there's no rush for that. I'm also not sure what I want to do for a battery tray. Depending on CoG and where the battery ends up, I'll either have to remove the wing to get to it each time, or cut a hatch on top in front of the canopy if I need to slide the battery up there where the fuel tank currently is. I guess I'll just have to wait and figure all that out! ;)

Parts should be here in a week or two, however long it takes for EMS shipping from Hobby King. ;)
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 01, 2010, 04:23:45 PM
Small update...

I ordered everything last week from Hobby King, all except the ESC which is out of stock. I waited too long... lol I ordered an 80 amp Hobbywing ESC though, from Hobbypartz. Shipping from Hobby King is EMS, from Singapore so it'll probably be a little slow, but it'll get here eventually!

I've already pulled the Homelite engine off the plane and repaired the damage around the firewall from the vibration, and ordered a new canopy which was also breaking up from the vibration! While I was at it I ordered a fiberglass cowling from Fiberglass Specialties.

Here's the plane as of this morning:
(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/fs1.jpg)

Here's the cowling that I just got in the mail:
(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/fs2.jpg)
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 04, 2010, 02:00:11 PM
Just a small update... I got the canopy in the mail yesterday, and trimmed it and cowling up last night, painted them, and glued the new canopy on. I finished the cowling up this morning, so here's some pictures...

The other parts should be here soon, they've already made it to the US and cleared customs, won't be long now! I'm hoping either tomorrow or Saturday!

Not perfect, but not half bad either! :D I used some servo mounting grommets through the cowling, with washers on the inside. Gives it a nice cusioned mount!

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/1.jpg)

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/2.jpg)

You can see here the 3 holes where the old canopy screwed on... Apparently the ARF and kit canopies are not the same. This new one fits the fuselage way better! It's glued on with canopy glue, and I also added a few tiny screws in it for extra measure. I'd hate to loose it in flight! The darn thing cost me nearly $30 after shipping and paint... lol

I need to get some trim tape or something and cover those holes up.

(http://i447.photobucket.com/albums/qq197/keithluneau/FourStar120/3.jpg)

Will update more when I get more parts!
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: jdr00ejr on November 04, 2010, 02:14:27 PM
Keith,

Sweet Bird!  I was struggling to get a size idea until I saw it beside your PC (that's speaking my langauge).  That thing is huge!  That's got to be loads of fun but I'm assuming you need a big ride to transport to and from the flying field.

I've avoided Gas/Nitro RC at all cost (both land and air) and think it's very cool that you are converting such a large plane to Electic.  Because of my ignorance in the area I have a question:  How will you know how long you can fly before needing to land (and still have safe battery left)?
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 04, 2010, 03:36:00 PM
On all my planes, I just use the LVC (low voltage cutoff). When the battery is low, the ESC will cut power to the motor, or reduce throttle, depending on how it's set up. When power is cut, you can set the throttle stick back to idle and re-arm the throttle so you have power to make a nice controlled landing. I wouldn't recommend this on a heli though... ;)

I usually end up landing before the battery is that low anyway though, I tend to fly about 10 minutes at a time and have my fill. :)

No problem transporting either, I've got a 400' long "runway" right out in the back yard, that's surrounded by fields on 3 sides. I love living out in the country! lol It's not that bad to carry it in a vehicle though, the fuselage is the worst part, the wing splits in half. I used to have a Sig Astro-Hog that had a one-piece wing with 71" wingspan. That one was hard to haul around in my mom's Ford Escort! lol I ended up selling that one, but wish I had it now that I've got room to fly it!

By the way, maybe this will give you an idea of the scale... That's the wing on the wall above the monitors. The large monitor in the middle is a 28", the one on the left is a 22".

(http://www.rcflighttest.com/home/wp-content/uploads/comprc.jpg)
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: dfarmercse on November 05, 2010, 05:25:02 AM
Big Plane Keith,
Nice living out of town. I have a 300 ft runway and 250 acres of field around my house. No other house for 1/2 mile. Just walk out the back door and fly.
 :130:

Dave F
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: jdr00ejr on November 05, 2010, 06:06:59 AM
Keith,

Can I come be your best friend / neighbor?  :132:
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 05, 2010, 08:06:57 PM
Keith,

Can I come be your best friend / neighbor?  :132:

Only if you keep the grass cut on the runway/field! lol

I got a shipment from Singapore this morning, now the real fun can begin. :)

(http://www.rcflighttest.com/home/wp-content/uploads/5.jpg)

(http://www.rcflighttest.com/home/wp-content/uploads/4.jpg)

More details here - http://www.rcflighttest.com/home/2010/11/preview-of-things-to-come/ (http://www.rcflighttest.com/home/2010/11/preview-of-things-to-come/)
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: pinguin6218 on November 06, 2010, 02:26:36 AM
Looking good  :130:

I'm following the build or transformation
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 06, 2010, 12:10:39 PM
Just a small update... ;)

I ended up squeezing the UBEC and the small battery in the front as well as the main battery, and got the CG pretty close to where it should be, with no extra weight. Here's what it looks like in there...

(http://www.rcflighttest.com/home/wp-content/uploads/7.jpg)

(http://www.rcflighttest.com/home/wp-content/uploads/8.jpg)

(http://www.rcflighttest.com/home/wp-content/uploads/9.jpg)

You can see the two "runners" that the battery rides on, those are some 1/4" x 3/8" lite ply, and are tied into the firewall, and the plywood former on the back end. They shouldn't go anywhere. :) The ESC and UBEC are mounted on the fuselage sides where there's plenty of airflow around the battery, so everything should stay nice and cool! That's the plan anyway... ;)

At this point, all I have to do is charge it all up and go fly it! I did hit a snag this morning though... :( My trusty Thunder Power AC6 charger is just not up to the task when it comes to the main battery! It got so hot that the pretty blue screen turned purple, and I nearly burnt my finger on it! lol It never did finish the balance charge either. I checked the cells with a meter, and they're all sitting right at 4.19-4.20V, so it's good to go, but the charger just can't handle it I guess. To be fair though, it's only good for 50W. ;) Looks like I'll be needing a new charger now!
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 06, 2010, 07:31:32 PM
Got some good news and bad...

(more good than bad, so it's ok!)

Weather was near perfect this evening, so I brought out the Four Star for a test flight. Went over the pre-flight, taxied to the end of the runway, turned around, and powered up. I was stunned with it hopped off the ground after about a 3' rollout! I pulled it vertical, and it just kept going and going...

So I leveled off to set trims since I'd never flown it with this transmitter I'm using now. All the trims were pretty much spot on, but the ailerons were much to sensitive for my liking. I set up for a perfect 3-point landing, and set up dual rates and expo. (Actually triple rates, I use "Switch C" on my Futaba 9CAP) Took off again, everything felt great, about halfway through the first turn, the motor let out a loud squeal and locked up! I immediately cut it back to idle, and tried to power up again, but it only spun a bit, squealed, and stopped again.

Luckily I had just enough room to make a big S-turn and set up to land on the runway, so there was no crash or resulting damage. Back on the ground, I could barely turn the motor by hand, it was stuck good! So I got it back in the house, took the motor off the plane, and opened it up expecting to find a thrown magnet or a winding jammed under a magnet, etc. It looks perfect inside though, absolutely nothing out of place!

I was going to put it back together, thinking maybe something was caught in the motor and fell out when I opened it up, but when I went to put the clip back in place that holds the shaft it, I noticed that with the clip out, the motor spun free, and to put the clip in, I had to jam the outer "bell" into the back plate, and still barely had enough room to get the clip in. Of course the motor was bound up again now.

Come to find out, the silver bell that the magnets are glued into is threaded onto the front plate, and had loosened up, and backed out onto the rear plate, pretty much spreading out between them and locking the whole thing in the process...

Luckily it should be a simple fix. The plan is to take it apart again, and unscrew that silver bell from the gold front plate, then put it back on with some good thread locker. In theory that should solve the problem, as long as the thread locker holds!

So while it was a disappointing first run, I'm just happy that things didn't go as bad as they could have! No crash, no broken airplane, no burnt up ESC, etc. Just a taste of what to expect once I do get the motor sorted out. The few laps I did fly around the field was all smiles! It's a rather pleasant thing to see the big plane flying around so smooth and quiet, and knowing that it's got power to pull vertical at any moment. I'm also happy to say that with the weight loss, it lands in half the distance I needed with the Homelite motor. That's a blessing!

I'll have to get a good video of it once it's sorted out. I was planning to this evening, I wanted to get the transmitter adjusted and dialed in, then I was going to shoot the video. Looking back, I kinda wish I'd gotten the emergency landing!
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: chm60 on November 11, 2010, 07:40:35 AM
very cool plane!! it is def on my list to build one day..

I have heard quite a few stories like this with those turnigy motors locking up like this. Lots of people say its the bearings over heat and seize up quite a bit on those motors so i have tried to stay away from them
Title: Re: My Four Star 120, soon to go brushless. (Currenly powered by Homelite)
Post by: KeithLuneau on November 11, 2010, 11:37:25 AM
Yeah, the Turnigy motors can be hit or miss it seems, but at a 3rd of the price of a Rimfire, I took a chance. ;) It seems to be fine now after getting the kinks out, and makes good power too. I've got a couple of videos posted in the video section here - http://myrcguide.com/index.php?topic=7338.0 (http://myrcguide.com/index.php?topic=7338.0)