Go Back  RCU Forums > RC Airplanes > Beginners
Reload this Page >

I would like my Four Star 40 (4*) to be a bit more snappy

Notices
Beginners Beginners in RC start here for help.

I would like my Four Star 40 (4*) to be a bit more snappy

Old 06-19-2008, 04:14 PM
  #1  
n19htmare
Senior Member
Thread Starter
My Feedback: (1)
 
Join Date: Mar 2008
Location: San Diego, CA
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
Default I would like my Four Star 40 (4*) to be a bit more snappy

I've a 4* 40 as my second plane and I dunno if thats how the plane is but I'd like it to be a big more snappy if possible. Mostly on the ailerons side of things. I'm using the Futaba 3004 servos with 4Cell pack. Do I need to get servos with faster response/torque and a 5Cell pack?

The throws are the same recommended by the manufacturer.


2nd question. I'm not too fond of the plastic control rods that came with the ARF kit. Seems like they flex too much....(not applicable to ailerons) ? what is your opinion on plastic control rods?
Old 06-19-2008, 04:49 PM
  #2  
Steve Steinbring
Senior Member
 
Join Date: Jul 2007
Location: Homestead, FL
Posts: 584
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

I know that Ken has some graphic drawings of how to make your controls faster. Without the drawings move the control rod clevis on the servo control horn outward and the clevis on the control surface horn inward. That will give you much quicker responses to control imputs.

It would be my suggestion to make one change at a time getting used to the responsiveness of the airplane after the change.

Moving your CG aft will also make the airplane more responsive in doing aerobatic maneuvers. Make small changes there also so you don't bite off more than you can chew.

Plastic control rods IMO have their place. If installed correctly they do pretty well in most sport flying airplanes. However, I would not install them in any kind of airplane like a pattern flier where more exacting flying is required. I mostly use them in throttle linkage applications where I am able to take advantage of being able to bend the plastic control rods.
Old 06-19-2008, 05:08 PM
  #3  
DavidAgar
My Feedback: (107)
 
DavidAgar's Avatar
 
Join Date: Dec 2001
Location: Battle Ground, WA
Posts: 5,050
Likes: 0
Received 5 Likes on 5 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

The 4Star is not really a punchy type of plane. You can make the ailerons faster and increase the throws, however do not expect much from the plane. You will also want to be careful so as not to over stress the wing. Good Luck, Dave
Old 06-19-2008, 05:12 PM
  #4  
2HI2C
Senior Member
 
Join Date: Mar 2006
Location: Burlington, OK
Posts: 575
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Take the outer ribs off the wing which will make it 4" less wing span. Did it to mine during a rebuild & it is a totally different plane.
Old 06-19-2008, 05:51 PM
  #5  
ChuckW
Senior Member
 
ChuckW's Avatar
 
Join Date: Jun 2006
Location: Clovis, CA
Posts: 5,165
Likes: 0
Received 1 Like on 1 Post
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy


ORIGINAL: 2HI2C

Take the outer ribs off the wing which will make it 4" less wing span. Did it to mine during a rebuild & it is a totally different plane.
This works very well and the plane doesn't seem to mind one bit. It still floats in for nice landings.
Old 06-19-2008, 09:20 PM
  #6  
nobodytwo
Senior Member
 
nobodytwo's Avatar
 
Join Date: Jun 2007
Location: North Little Rock, AR
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

If you want to increase the response of the surfaces just go to a 5 cell (6 volt) receiver pack. Then if you're still not happy change out the push rods to something less flexible. Those plastic rods have a tendency to expand when they are warm and contract when there are cold. Trim never stays the same!

Happy Landings!
Old 06-19-2008, 09:30 PM
  #7  
Jetdesign
Senior Member
My Feedback: (8)
 
Jetdesign's Avatar
 
Join Date: May 2008
Location: Mason, OH
Posts: 7,054
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy


ORIGINAL: nobodytwo

If you want to increase the response of the surfaces just go to a 5 cell (6 volt) receiver pack. Then if you're still not happy change out the push rods to something less flexible. Those plastic rods have a tendency to expand when they are warm and contract when there are cold. Trim never stays the same!

Happy Landings!
Does this really make a big difference? Also I've heard that the 6v battery packs actually give less flying time - is that true? I noticed my ailerons really take a long time to go from max right to max left and was wondering if the 6V battery would make that faster, and what, if anything, would have to be changed to accept the change.
Old 06-19-2008, 09:40 PM
  #8  
plugin
Senior Member
 
plugin's Avatar
 
Join Date: May 2007
Location: Bogota, COLOMBIA
Posts: 538
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

If you're using a modern receiver and servos, you can just make the change without any further caution. Going from 4.8 to 6 volts will in fact increase the servo's travel speed.
Old 06-19-2008, 10:00 PM
  #9  
Gray Beard
My Feedback: (-1)
 
Join Date: Apr 2003
Location: Hemderson, NV
Posts: 14,385
Likes: 0
Received 3 Likes on 3 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Just because A servo is modern doesn't make it able to handle A 6volt load. You can look up your servos and see if it gives the torque for both 4.8v and 6v. and what the speed and torque differences are. If nothing is stated for the 6 volt then 6 should not be used.
6 volts helps but it isn't all that much more. If you have the plastic rods as mentioned that can be part of the problem too. They flex and tend to change the trim if they get hot.
Like David said, the 4* isn't really A super fast plane, it's really A smooth flying plane with A big fat long wing. By removing the outer wing bays you will get A faster roll rate and it's still A nice smooth plane.
If you want more kick then build/buy something to be twisted and torqued. Any of the fun fly or 3-D type of planes will give you what you are looking for.
Old 06-19-2008, 11:16 PM
  #10  
plugin
Senior Member
 
plugin's Avatar
 
Join Date: May 2007
Location: Bogota, COLOMBIA
Posts: 538
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

I guess Gray Beard is right, you might as well check, I don't want a surprise bill for a receiver and 5 servos
Old 06-19-2008, 11:42 PM
  #11  
ChuckW
Senior Member
 
ChuckW's Avatar
 
Join Date: Jun 2006
Location: Clovis, CA
Posts: 5,165
Likes: 0
Received 1 Like on 1 Post
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy


ORIGINAL: n19htmare
2nd question. I'm not too fond of the plastic control rods that came with the ARF kit. Seems like they flex too much....(not applicable to ailerons) ? what is your opinion on plastic control rods?
I don't see flex as too much of an issue if they are done correctly but one thing I do hate is that they change length when the ambient temperature changes. This makes it necessary to re-trim the airplane throughout the day. If there is one thing I'd recommend changing on a Sig airplane, that would be it. Some of the Nylon rods from Sullivan and Dubro don't seem to grow and shrink nearly as bad.
Old 06-20-2008, 05:37 AM
  #12  
jetmech05
 
Join Date: Jul 2005
Location: Jacksonville, FL
Posts: 4,855
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

A four star is well a ...Four star...Kinda like trying to do 3D with a LT-40.....
I know what you're feeling my second was a 4 Star 60..I put in dual rates..as much as I could get had to back off of aierons though, the travel was so much that they were slower than the elevator and rudder to return to nuetral....
Use the 4 Star to perfect your landings, inverted flight, and as many aerobatic manuvers as you can...plus you learn to taxi with full up elevators as you should with all tail draggers...
Old 06-20-2008, 07:41 AM
  #13  
CGRetired
My Feedback: (1)
 
CGRetired's Avatar
 
Join Date: Sep 2004
Location: Galloway, NJ
Posts: 8,999
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

ORIGINAL: n19htmare

I've a 4* 40 as my second plane and I dunno if thats how the plane is but I'd like it to be a big more snappy if possible. Mostly on the ailerons side of things. I'm using the Futaba 3004 servos with 4Cell pack. Do I need to get servos with faster response/torque and a 5Cell pack?

The throws are the same recommended by the manufacturer.


2nd question. I'm not too fond of the plastic control rods that came with the ARF kit. Seems like they flex too much....(not applicable to ailerons) ? what is your opinion on plastic control rods?
I converted mine to two aileron servos which, I think, really helped it. The aileron response, was great. I also used a 6 volt pack, which may have had more effect on it's response, but it would do just fine for me.

If you decide to do something like this, it requires that you carefully grind out the torque rods from the wing center, then locate the position in the center of the wing at the center point of each aileron, installing a 'servo box', I used a piece of 1/4 x 1/4 hardwood, and glued it using CA. The hardwood frame was CA'ed into position on the complete length of the chosen rib (from spar to trailing edge stock) with another in parallel to it for the other side (set to fit using the servo itself as a guide) and then another piece at the front and rear of the servo to screw the servo screws in place. See the crude pictuire below.

Before putting the servo in, I sanded it to shape then covered the hole with matching or contrasting covering. Then I cut out the servo hole to match, and then placed the servo in the manufactured box using servo screws. I used 2-25 hardware. You also have to use a servo lead extension which has been secured together using you favorite method.. I use a piece of cotton string tied around the lenght of the connectors, tied to a knot and a drop of CA added to the knot. Light and holds like nothing else could. Then route the extension to the center and through the original servo hole and then to the receiver. I used a Y connector to the Aileron port on the RX. Works fine.

I use Airtronics servos, which are compatible with a 6 volt pack. Not to say that the Futabas are not, just to say that the Airtronics are.

I also replaced the stock elevator and rudder rods with Sullivan Goldenrods. This required access to the inside of the fuselage along the formers to secure the rods in place with small plywood frames that were drilled, slid on the Goldenrod tubes, then epoxied in place. The Goldenrod tubes were scuffed up with sand paper and also epoxied in place. I did this on each former. The rods do NOT flex after that. I've done that on most of my models that have rods from the servo trays back to the control surfaces. I just like the Sullivan Rod installations.

CGr
Attached Thumbnails Click image for larger version

Name:	Pm34713.jpg
Views:	13
Size:	13.5 KB
ID:	974653  
Old 06-20-2008, 09:44 AM
  #14  
Jburry
Senior Member
 
Jburry's Avatar
 
Join Date: Jul 2006
Location: Cape Spencer, NB, CANADA
Posts: 566
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

3004 servos are 6V rated. I doubt the transit speed has much to do with your plane's perceived sluggishness. My money has that down to inadequate throw. The 3004's have adequate torque for the plane too.

Do what you can to maximize aileron throw. Run pushrods from the outtermost servo horn hole to an inner hole on the surface. Move them 1 notch at a time until you find a setting that's fast enough. Run your CG back to 29-31%. Shorten the wing if you like, it'll definately roll faster.

J
Old 06-20-2008, 10:11 AM
  #15  
Gray Beard
My Feedback: (-1)
 
Join Date: Apr 2003
Location: Hemderson, NV
Posts: 14,385
Likes: 0
Received 3 Likes on 3 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

These are some shots of my students first build. I like to teach students how to build so they can make repairs and changes to there ARFs in the future. It's the 4*60 with just A couple of minor mods. We just removed the outside bays of the wing to help the roll rate A little. Not A big thing but it helps. The rudder was enlarged by A bit over one inch, again, nothing that's going to turn this plane into A 3-D aircraft but the kid likes to do knife edges and stall turns so this is just that little kick. The 60 size is already designed for A servo on each aileron but I like doing the same thing to the 40.
In this case it's getting powered with A Saito 1.00 and has DS 821 servos. There is nothing in the way of plastic or fiber control rods.
This plane should be snappy and by snappy I mean about as snappy as the 4* is going to get. I could do more to it but it's A 4* and designed for basic stunt training, very stable and nothing real herkey jerkey.
You want some snap then get something like an Up-Roar or the Sig Something Extra.
Old 06-20-2008, 10:13 AM
  #16  
Gray Beard
My Feedback: (-1)
 
Join Date: Apr 2003
Location: Hemderson, NV
Posts: 14,385
Likes: 0
Received 3 Likes on 3 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Forgot the shots!!
Attached Thumbnails Click image for larger version

Name:	Zx70317.jpg
Views:	15
Size:	73.8 KB
ID:	974696   Click image for larger version

Name:	Cx74256.jpg
Views:	16
Size:	69.2 KB
ID:	974697   Click image for larger version

Name:	Mr42311.jpg
Views:	13
Size:	62.5 KB
ID:	974698  
Old 06-20-2008, 11:44 AM
  #17  
n19htmare
Senior Member
Thread Starter
My Feedback: (1)
 
Join Date: Mar 2008
Location: San Diego, CA
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Thanks for the replies guys.

I guess the easiest and most cost effective methods I've read are to shorten the wing by one rib and try a 6V pack.

These things I can do? Any guides on shortening the wing. By looking at the photos posted by Gray B (Thank you Gray), it seems All I need to do is remove the covering from the side, cut the wood up to the next rib. Reinforce with some wood glue or CA and recover?

BTW I run the DX6i with AR6200 which should handle 6V and the 3004 servos are also supposed to handle 6V.

My CG exactly where the manufacturer recomended it. t he plane is perfectly horizontal to the floor. I may try moving it back a little.
Old 06-20-2008, 01:09 PM
  #18  
Jetdesign
Senior Member
My Feedback: (8)
 
Jetdesign's Avatar
 
Join Date: May 2008
Location: Mason, OH
Posts: 7,054
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Another option for dual aileron servos is to widen the section in the center of the wing where the one is already installed. Put two in there, side by side, with the servo horns coming out the right side on one and the left side on the other, so each servo controls one of the torque rods. Your plane is similar to mine, and there seems to be plenty of room in the fuse (width) to do so. Might be easier than installing servos in the wings. This was suggested to me to do with my Dolphin one day, but no need for that yet. YET.
Old 06-20-2008, 01:31 PM
  #19  
Jburry
Senior Member
 
Jburry's Avatar
 
Join Date: Jul 2006
Location: Cape Spencer, NB, CANADA
Posts: 566
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

To remove a wing bay, cut the covering about 1/4" towards the tip from the rib that will now be the tip. Remove covering from the last bay out to the tip. Cut the LE, Spar(s), TE and ailerons flush with the new last rib. Cut the stubs of the LE, spar, and TE from the old tip. Glue the old tip to the last rib. Use the last 1/4" of covering you left on the wing to cover the seam with the tip.

Not much load out here, so keep glue to a minimum. Just enough to do the job.

All said, should be an hour's work, not more than 2 for a first timer. Take your time, look closely at what you're trying to achieve, measure 2x, cut 1x.

Fun and easy first bash!

J
Old 06-20-2008, 01:46 PM
  #20  
flyX
Senior Member
 
Join Date: Jul 2007
Location: el centro, CA
Posts: 645
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

I don't even know what a regular 4* flies like.lol

Even after cliping the wing and lowering the deihedral , it's still not as snapy as I would like it to be.
But it's still a floater to me.
You can install two servos side by side at the center of the wing to go dual servo.
I havn't tried extending the airlerons...yet.

After I got an SE..i found it easier to just build an SE then trying to force the 4*.
Of course i still like to bash things...I extended the rudder and sheeted the rear deck.
The extended rudder helps the SE retains a knife edge a little better.
You can do multi rolls to the next county with an SE without any modifications to the design.
I opt the SE instead of an Uproar,UcanDo, magic or profile types model due to storage and transport.
I also have a Magic..but don't like the way the fuelage is put to together and it require some sturding up.
All of these models still have non tapper leading edge air foil.
Old 06-20-2008, 03:45 PM
  #21  
spiral_72
Senior Member
 
spiral_72's Avatar
 
Join Date: Mar 2007
Location: Chesnee, SC
Posts: 511
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Hey, you've got some good advice here. You might think twice before buying a "more capable" plane. Modifying this one will help you understand why and how things work.

The CG in the manual is very conservative to make the plane as stable as possible. Add tail weight or move equipment rearward in small increments. You'll be rewarded for it. As you unload the nose, the plane will become more and more responsive up to a point. You'll reach a point where you'll know to stop and back off. Go slow with the CG!
Old 06-20-2008, 04:57 PM
  #22  
ChuckW
Senior Member
 
ChuckW's Avatar
 
Join Date: Jun 2006
Location: Clovis, CA
Posts: 5,165
Likes: 0
Received 1 Like on 1 Post
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

ORIGINAL: gaRCfield

Another option for dual aileron servos is to widen the section in the center of the wing where the one is already installed. Put two in there, side by side, with the servo horns coming out the right side on one and the left side on the other, so each servo controls one of the torque rods. Your plane is similar to mine, and there seems to be plenty of room in the fuse (width) to do so. Might be easier than installing servos in the wings. This was suggested to me to do with my Dolphin one day, but no need for that yet. YET.
Dual aileron servos really aren't necessary on this type of plane, especially this size. A single servo with torque rods is plenty effective. In fact, I've built a 4* both ways and there wasn't much of a noteable difference. It just added unnecessary weight I think.

Many planes with the single servo set up are extremely responsive and have fast roll rates. It has more to do with airplane design than the number of servos.

Larger planes or planes with much larger control surfaces are another story of course. They may need the extra power of dual or even multiple servos or they may benefit form the tighter, shorter linkage.

Here's a picture of a 4* .40 that I clipped the wing on, added wing tips and a bunch of other changes. I used the dual servos here but it would have been fine with one.
Attached Thumbnails Click image for larger version

Name:	Ec88872.jpg
Views:	21
Size:	98.1 KB
ID:	974883   Click image for larger version

Name:	Bw71909.jpg
Views:	15
Size:	43.2 KB
ID:	974884  
Old 06-20-2008, 05:00 PM
  #23  
Jetdesign
Senior Member
My Feedback: (8)
 
Jetdesign's Avatar
 
Join Date: May 2008
Location: Mason, OH
Posts: 7,054
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

Looks nice, Chuck! Did you carve balsa square stock for the wingtips?
Old 06-20-2008, 05:05 PM
  #24  
ChuckW
Senior Member
 
ChuckW's Avatar
 
Join Date: Jun 2006
Location: Clovis, CA
Posts: 5,165
Likes: 0
Received 1 Like on 1 Post
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

They were 3/16 or 1/4 balsa sheet I think. If I were to do it again, I might try 1/8" light ply with some lightening holes. I'd also like to see how angled tips (forget the proper name) like those on the Tiger-2 look and work on this plane.

I've owned three 4*'s altogether.

Attached Thumbnails Click image for larger version

Name:	Mk27707.jpg
Views:	14
Size:	111.6 KB
ID:	974889   Click image for larger version

Name:	Xt59953.jpg
Views:	15
Size:	92.6 KB
ID:	974890  
Old 06-20-2008, 05:07 PM
  #25  
CGRetired
My Feedback: (1)
 
CGRetired's Avatar
 
Join Date: Sep 2004
Location: Galloway, NJ
Posts: 8,999
Likes: 0
Received 0 Likes on 0 Posts
Default RE: I would like my Four Star 40 (4*) to be a bit more snappy

ORIGINAL: gaRCfield

Another option for dual aileron servos is to widen the section in the center of the wing where the one is already installed. Put two in there, side by side, with the servo horns coming out the right side on one and the left side on the other, so each servo controls one of the torque rods. Your plane is similar to mine, and there seems to be plenty of room in the fuse (width) to do so. Might be easier than installing servos in the wings. This was suggested to me to do with my Dolphin one day, but no need for that yet. YET.

One of the main reasons for putting the servo's in the center of each wing is to place the torque arm in the center of each aileron evenly distributes the torque on each aileron and centers the control. This prevents any twisting of the aileron during load. It most likely won't happen in a plane of this size because there just isn't the loading on the aileron as there would be with a heavier plane. But, taking the servos away from the center joint is one of the main purposes of doing the two servos.

I did it on mine as an experiment and it worked just fine. I never flew it without them (meaning with only one servo) so I can't compare it. But, it flew just fine and I had plenty of control and plenty of roll rate.

CGr.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.