w8ye

My Feedback: (16)

I've been using the carbon fiber Sullivan rods. They still expand and contract a little with temperature but not as much as the standard flex rods do.

Darklotus

My Feedback: (4)

wrong sign in...

Pit-Viper 1

My Feedback: (12)

Yeah, the ones from centralhobbies are a little more expensive for the whole package, but they aren't supposed to flex. We'll se though...


Shane

cjmarch

I just built a 4*60 kit. I added 1.2oz of angle stock around the stab to beef up the tail. everything else was stock. I mounted a saito .91 4-stroke. When i went to balance the plane it needed 13 oz of weight in the nose. I could not believe it! I have never had to add that much weight to any of my kits or arfs. I got a longer great planes engine mount (it allowed the engine to be 1 inch farther forward), moved the battery up against the firewall and added 2oz of weight under the engine mount and 3 oz inside the front edge of the engine compartment. It balances nicely in the middle of the CG range on the plans. I weghed the plane and it comes in at 8 lbs. on the nose. It seems heavy to me , but it must balance to fly. I would have thought that this plane would be nose heavy with such a large engine. Did i do something wrong when I built this kit? I am very anal when i build. Thanks fror listening. I also chenged out the control rods to metal so the heat would not bother my trim settings

delman

The 4 star 60 can build a bit tail heavy to start with but the saito 91 is about the lightest 91 displacment engine around. Plus the metal rods and extra wood at the back make it more tail heavy. A friend of mine had one with a robust 2 stroke on it at a 8 pounds - it flew fine. Mine came in at 7 lbs with a heavier os 91 fs, light weight wheels, lighter pull-pull sys on rudder and battery under the fuel tank to balance.

buzzard bait

CJ, it will fly fine at 8 lbs--a very typical weight by the time people add their mods. I do think angle stock is extreme overkill for the stab. The 1.2 oz translates into about 4 ozs up front to balance it, and if you used any epoxy you have to add that weight. You multiply by about 3 to account for the leverage that tail weight has on the nose. It's easy to create a need for a half pound of nose weight just by not building light in the tail, using a solid rubber tailwheel and aftermarket bracket, and sheeting the turtledeck, etc. I am always very careful to keep the tail light.

I used a bit of balsa triangle stock under the stab, absolutely no epoxy, the stock tailwheel bracket and a super light foam tail wheel. I also tapered the control surfaces. One reason Four Stars come out tail heavy is those thick slab elevators and rudder. Use a razor plane and save a lot of weight. Mine is almost finished, and a quick assembly test makes me think it will balance with no nose weight. The engine is an OS 70.

Delman--nice job coming in at 7 lbs--the lightest I've heard of. I'm hoping mine will equal that. I'll know the weight and balance next week when I finish painting.

Jim

jship

My Feedback: (4)

This is My new kit built 4*60. As has been stated many times it was a pleasure to build. I'm going to try flying it on thursday. Wish Me luck. I had a 4*40 loved it except for landings.
john[img][/img]

Fuel Dinosaur

Balancing the Four Star 60, some comments- One way to avoid this problem is to sheet the top and bottom of the wing at the leading edge back to the wing spars on the top and bottom of the Four Star 60. I beefed up the tail to fuselage link too, but only with a few chunks of balsa and used 30 min epoxy. When you sheet the top and bottom of the leading edge of the wing, you prevent little dings in the wing, top and bottom, on tall grass and weeds. Also, you do not end up adding much if any weight to balance the plane to the CG. I strongly believe that you only add dead weight as a really LAST resort to any model. I have seen a few biplanes with so short a nose that you almost had to add dead weight to the nose for balance. I also have Saito .91 engines in all my four stars. They are light, run great and reasonably powerful and easy on fuel. They are also a bit more that other engines of similar displacement. Nice plane, you may assume I LIKE this one. [[img][/img]

ggroyal1

That is a great job, I wish I could do that good. I am about half way done with mine.
George G. Royal

Student Pilot

My Feedback: (2)

Shoot, I have a K&B Sportster .65 to go in mine. I didn't add triangle stock to the tail, but I did extend the elevator and rudder out a 3/8" or so with solid balsa. I wasn't thinking about balancing it when I did it and forgot about drilling some holes to lighten it up when I finally covered it (it's been a very, very spread-out build).

If all else fails I have a TT .61 Pro that I can throw in it. It's a very heavy engine @ 26 ounces or so. I don't know what the Sportster weighs, but I can feel quite a bit of difference between them.

FlyingGreg

My Feedback: (4)

I've been flying mine 4 Star 60 for at leat 5 years. Fuel Dinosaur sheets his wing, others go to great lengths to customize or beef up. Others have had balance issues. Mine is completely stock with battery under fuel tank. OS 91 FS on front. I have no idea what the weight is, or where the balance point is but if flies just fine--they have a fairly wide balance range. I have had a Super Tigre .61 with tuned pipe on it from time to time and flies good on that--just the wrong type of engine for that plane, IMO. I think four stars are made for four stroke engines. I wonder why guys spend so much time altering a great design for a plane that is just great at putting around. Mine does great knife edge and with crossed airelons flat spins like crazy. After five years it's got some dings on the wing tips where they have skidded on the runway. Other than that it is jsut a little dirty but flies great. Oh I did take the canopy off when my pilot came loose. Now I have just a windshield.

It's still my favorite plane.

Greg

jship

My Feedback: (4)

I test flew Mine thursday. I am in love with this plane. This plane did everything I wanted and is capable of much more. What a grear desine. I built Mine with the canopy as far forward as I could and added 1/2 " to rudder with St 90. I am in love with this plane, did I already say that?
john in missouri

FlyingGreg

My Feedback: (4)

I have been reading and posting in another thread that compares the 4* to the BTE Venture. When my current 4* goes to airplane heaven, I might build one of those. Designed by the same guy that did the 4*, Bruce Tharp--and everything I hear about the plane is great, as is the customer service delivered by Bruce personally. Over the weekend I'll take some photos of my 4* and post them here, just for grins. Bet you can't waite11

jship

My Feedback: (4)

I'm moveing My cg back just a little. I'm also adding a little right thrust (one washer top and bottom). Mine pulls a little to the left more than I want. No real compliants after ten flights.
I'm still in love with this plane.
john in Missouri

jship

My Feedback: (4)

Last week I move the cg back this week I'm moveing forward. Did not like the cg back at all. In Knife edge it pulled to the gear with the back cg. Looping with the forward cg it will stop pulling so much.
john
Oh I still love this plane!

Kmot

My Feedback: (24)

I still have yet to install my radio and wheel pants. I will be surprised if I have to add dead weight to the nose.

FlyingGreg

My Feedback: (4)

Looks great Kmot--I like how you cut down the canopy. It gives the plane a more sleek look.

Pit-Viper 1

My Feedback: (12)

It is a common problem with the 4*60 to pull towards the belly while knife edging, this was one of the things that Bruce changed when he designed the Venture60. Which is the upgraded version of the 4*60, he changed the design of the rudder to help with this problem. Here's the link to his site, [link]http://www.btemodels.com/venture.html[/link]

I love my 4*alot as well, was gonna build another but think I will try the Venture60 this time and see how it compares.

I agree about the canopy, was the first thing I did was to eliminate that "bubble" look. This was also another change on the Venture60.. I also cut the last bay out off of each wingtip, this helped the roll rate and made acrobatics a little more responsive.

Shane

Kmot

My Feedback: (24)

Thanks. I just followed what other people had suggested.

jship

My Feedback: (4)

I just went to http://www.btemodels.com/venture.html and read about the Venture 60 . I’m sure that He builds a great kit. I loved the laser cutting on My sig four Star 60. I laid the wing up without any glue, for trial fit. I do like the idea of the Venture being about a pound liter. I keep thinking that if I can find the sweet spot on My cg, and I am very close right now, the knife edge will be one handed.

john

Tee Bee

I love your plane, Kmot.

w8ye

My Feedback: (16)

This is friend's Venture. After it having a ST 61 he changed and put a Homelite 25 on a shortened nose.

The plane flew OK but was much heavier. Sorta ruined Bruce's intentions

capt17

That Venture 60 posted above looks nothing like a venture 60. The stock model is a lot sleeker and fine tuned. Here's a link to a bunch of other Venture 60s. My Venture 60 is 90% complete. Just finished covering last night. www.venture60.com

Pit-Viper 1

My Feedback: (12)

John, in relation to the knife edge ability. I believe that the rudder mod was used to get it to work properly. I did the same thing with mine as far as CG went and didn't really get alot better. Don't get me wrong, you're probably a heck of alot better at K/E than I am. I think I've done 3, kinda... let us know how it works for you.

Anyway, heres the link to the differences on each. Kinda cool to have if anyone decides to build a 4*, you can do most of the mods yourself.

[link]http://btemodels.com/vt_vs_fs.html[/link]


Shane

seniorspud

My Feedback: (69)

Hi, Need some help bought a 4* 60 air frame need to know where the cg point is located on the wing thank you all hope someone can help Chick.