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Jun 20, 2019, 03:59 PM
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Gameengineer's Avatar
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Build Log

SIG 4 Star 60 Build


I am getting geared up to start a new build. I haven't built from kit in a long time. I chose the 4 Star 60 for a few reasons. First, its a SIG kit which doesn't really need explaining. It is also a plane I intend to fly and it was suggested by a few guys at the club. It also looks fairly straight forward and something that will take a plastic covering well.

I bought this kit from Graves Hobby who had one new in the box. I paid the same price as I would have if I bought it directly from SIG. It wasn't available from SIG at the moment though.

After settling on this kit and placing my order I looked around for some building tips. Well I found some and from a very good builder, VincentJ, who recently just finished this kit and logged the build on a different site. I want to add a few of those changes there were done to improve the kit.

This will be my first build log here ... or anywhere for that matter! I know there are a lot of master builders out there including Vincent so I welcome suggestions and comments if you happen to find this thread and want to follow along. My main reason for the log is to help keep me going to be very frank here. I have the engine and some of the hardware but others like servos and electronics I will be picking later. I am a fairly new pilot so this plane will be a simple flier, no 3D for me at this point. Less expensive analog servos should be fine since I may not need the speed and accuracy/precision of the digital servos. It may be less critical if the control surfaces do not find their exact centers. That being said I'd love to have a discussion to that end. this will be a learning process for me.

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Last edited by Gameengineer; Jun 20, 2019 at 04:08 PM.
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Jun 20, 2019, 04:27 PM
A man with too many toys
What engine do you have?

I found that Tactic servos (from Tower Hobbies) are reliable, good performance and a fantastic price.

.
Jun 20, 2019, 06:19 PM
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Quote:
Originally Posted by RC Man
What engine do you have?

I found that Tactic servos (from Tower Hobbies) are reliable, good performance and a fantastic price.

.
I have an OS FS .91 4 stroke I will be using. I think its a Surpass version 1. Older but we'll see how it fairs. I think at some point I'll just switch to gas but right everyone is getting rid of their nitros on ebay at reasonable prices! I defaulted to hitec servos only because that's all I've ever bought, and my local hobby shop carries them but I'll take a look at tactic. More than the brand what about analog vs digital? A 30 year veteran at the field said analog, cheap servos are fine for my level of flying at this point. But I don't want cheap to dictate the level of risk since I will be building this kit vs an ARF. Maybe its worth investing in decent servos. Yes you're right, tactic servos are significantly cheaper for BB and digital. Nice!

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Doing some inventory of the parts.
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Not sure if I'm embedding the pictures correctly. I am uploading them but there is not picture code so im using [attach]<picture id>[/attach]
Jun 20, 2019, 08:36 PM
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I 've built two now. The first one was powered by an MDS .65. This latest one by a Cobra outrunner and 6S pack. Hasn't been maidened yet as the weather up here in Northern Michigan has been uncooperative the last couple months.
I also have a 4*40 and the kit for the 4*20. The 4*40 is powered by a Hyperion outrunner and 4S pack....crazy power.
Jun 20, 2019, 08:49 PM
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Quote:
Originally Posted by jollyroger
I 've built two now. The first one was powered by an MDS .65. This latest one by a Cobra outrunner and 6S pack. Hasn't been maidened yet as the weather up here in Northern Michigan has been uncooperative the last couple months.
I also have a 4*40 and the kit for the 4*20. The 4*40 is powered by a Hyperion outrunner and 4S pack....crazy power.
Seems I picked a good kit! Very popular. My club flight instructor has the 4* 60 and 120. He flew the 60 last week and it could fly slow or quicker with some interesting maneuvers. He did some fancy servo tricks making what I think is called flaperons and he also mixed the elevator with flaperons to make some interesting small radius pitching. He landed without the flaperon and even without the flaps he came in so slow you could almost catch it by hand! Since Im a new flyer slow is appealing to me. At least right now while learning.
Jun 21, 2019, 03:17 AM
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VincentJ's Avatar

4*-60


This is a great kit that you chose to re acclimate yourself to building. I noticed the Titebond II glue on your build table (good choice) however, the way this wing is assembled, it is conducive to CA. You'll find out what I mean as soon as you piece together the wing. I built mine without using any CA, just giving you a heads-up...

The 91 4-stroke is a great engine and will pull this plane with authority, good choice. Have fun with this build, you're off to a great start...
Jun 21, 2019, 05:03 AM
Aerotow and sloping Holland
MaartenX's Avatar
Good luck with the build Gameengineer and have fun.

The Fourstar is a super plane to build and fly. My fourstar 120 is my favourite plane. I have a new .90 Fourstroke engine waiting for action. Maybe I should build the Fourstar 60 as well...

Regards, Maarten
Jun 21, 2019, 10:17 AM
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Vincent, I was going to give wood glue a shot. Thanks for the tip on CA for the wing assy. I've seen this before where some use CA for the initial bond and then come back over all joints with wood glue. Structurally not sure if that makes a difference. I know CA is brittle. Plus my CA usage could use some improvement. I usually get more on the wax paper than on the joint therefore causing me to have to pull all that wax paper off the balsa. With thin CA at least. Thanks for visiting my thread.
Last edited by Gameengineer; Jun 21, 2019 at 10:30 AM.
Jun 21, 2019, 10:29 AM
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Quote:
Originally Posted by MaartenX
Good luck with the build Gameengineer and have fun.

The Fourstar is a super plane to build and fly. My fourstar 120 is my favourite plane. I have a new .90 Fourstroke engine waiting for action. Maybe I should build the Fourstar 60 as well...

Regards, Maarten
Thank you Maarten! thanks for looking at my thread too. After handling every piece yesterday during my inventory check I was very impressed with the quality of the wood and cuts. This will be my first laser cut kit. The parts almost just fell off the sprue. I will have to consider the 120 as well. I have an OS 120 4 stroke waiting for a host.
Jun 21, 2019, 10:51 AM
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I'm starting with the left wing since it was closer to me on the plans if for no other reason even though the manual says to start with the right. Don't think it makes a difference.

Used a 3/4" square aluminum tube to keep the main spars straight while the epoxy cures.
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While that was setting up I removed, labeled and sanded the ribs.
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I was very happy to see nicely lined up grooves. I don't have to do much if any clean up.
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One of the modifications to the wing I wanted to do was to add sheeting on top and bottom along the whole leading edge, back to the main spars. However I will have to consider how to do it given the different sizes of ribs. The inner ribs (W-1 - W-3 near the fuselage) are smaller than the outer ribs, W-4, W-5. There are (4) W-5 ribs that make up half the left side of the wing. The inner ribs will take 3/32 sheeting while the rest of the wing only has sheeting for the trailing edge.
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I can try to shrink the W-4, W-5 ribs (leading edge to spar groove, top and bottom) to match the others but I don't have a way to accurately sand them down. I think I'll leave the ribs alone and consider other alternatives.
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Jun 21, 2019, 06:58 PM
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Well I ran into my first problem. After the ribs and lower main and trailing spars were all glued I tried sliding the wire tube through the pre-cut holes only to find ribs W-3 and W-2 had the holes cut too high. My heart sank because I thought I might have glued the ribs improperly. However I inspected everything and all ribs were squarely slotted onto the lower main spar with no issues.

So I grabbed the right wing ribs, lined them up and saw that the the wire tube holes were definitely cut wrong.

The top two ribs are W-2 and W-3. The offset rib shown through the hole is W-4. Ribs W-4 though W-5 ribs all line up fine. In fact W-1 (2) ribs line up with W-4 and W-5 ribs. Only W-2 and W-3 are off.
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If you were to line up the ribs along the bottom and not by the slot the holes would line up. Notice the lower slot all lines up but the wire tube holes do not. The rib on the bottom has the correct hole position, the top two are too high.
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The ribs themselves for W-3, W-2, W-1s are sized differently because the center of the wing gets sheeted with 3/32 balsa sheeting. The outer ribs W-4, W-5 do not get sheeted. However I am going to sheet the leading edges anyway.

If I missed something and I misaligned those ribs (don't know how I could have done it though since they all sit on the lower main spar okay) then it is what it is and I'll have to figure something out to get the surface flat and lined up.

I ended up carving out the holes in W-2, W-3 so I got the rocket tube through there. I am more concerned about wing straightness.
Last edited by Gameengineer; Jun 25, 2019 at 10:39 AM.
Jun 22, 2019, 11:41 AM
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DGrant's Avatar
On this type of plane, I'll use CA for the framing(wing, fusalage, tail), and 30min epoxy for gluing major structures(firewall, wing center, tail to fuse, etc...). If CA is used correctly you won't need anything else. I have planes that are 25yrs+ old that were built with CA and epoxy that are still very intact. Glue can get heavy, so you don't want to use any more then necessary. Clamps are your friend too.

Another tip, if you can clean that laser charring off a little, that can help strengthen the joint. I find I like to give everything a clean face for glue/CA to penetrate and bond the wood.

It's a great kit... good luck with it.
Jun 22, 2019, 03:46 PM
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I ended up using CA almost exclusively for the wing because wood glue took too long to set. I needed instant bond in some cases. I did go over all joints with wood glue however.
I'll remember to sand the charring off more.

Gluing the LE to the ribs. As careful as I was to try to maintain straightness there were two stubborn ribs that were not completely straight. I use weights to hold everything down while gluing the spars to the ribs.

The LE with clamps did pull them in a bit.
It make me wonder if drilling holes in the ribs and using a wing jig would guarantee straight wing. I used wood glue on the LE just to give me enough time to position and clamp things. Even Med. CA sets fast.
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save the comments on the assorted clamps! I get them when and where I can. Trying to build my toolset up as I go.

I am enjoying the build so far and I certainly am learning things. I know the right wing will be better.
Jun 22, 2019, 04:01 PM
The runway used to be longer
Mad_Mike's Avatar
The 4stars are great planes.
I had a 4*20 for quite a while - still fly the wing on another fuselage.

I prefer analog servos over digital. Digital servos draw more current and tend to shake at center. I believe you can program some of the shake out but I've never looked into it.
Jun 22, 2019, 04:17 PM
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Thanks for posting Mike! I appreciate the digital vs analog feedback. Didn't know about the current draw increase.


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