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SIG Four-Star 60 Build

Old 04-07-2020, 12:37 PM
  #251  
VincentJ
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Where I put mine where it is easily accessible and serviceable on the plane's CG. Anytime you can put your gas tank on the CG, the balance of the plane won't change regardless of the level of fuel in the tank. Pretty much nothing on my plane is stock as I deviated from the plans and I absolutely love how it fly's. I wouldn't change a thing! My plane required zero additional weight to balance.
Old 04-08-2020, 09:00 PM
  #252  
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Ah yes the tank is at the CG. That makes sense. I didn't catch that with the build pics but your latest one is clear. I've done a few changes in mine the biggest one is creating the D box for the wing. I reinforced the turtle deck stringers as well but I didn't add the extra ones.
Old 04-09-2020, 01:22 PM
  #253  
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Being able to mount a fuel tank on the CG is great feature of a gas powered engine. It's really pretty standard to mount the tank on the CG where a gas engine is used. With the glow engines though, you still want that tank as close to the firewall as you can get. Glow engines rely on a slight vacuum to pull fuel, which works fine, but gas engines have a pump that pulls gas in, and you can mount a tank a considerable distance from a gas engine... which in most cases is within the CG of a plane, and stands to reason. Good stuff, and that's a great looking Four-Star!!

A big reason for balancing a plane with an empty tank is, it will end up slightly nose heavy when its fueled... and a nose heavy plane stands a much better chance of flying then a tail heavy plane... and the CG changes on a conventional glow plane throughout a flight.... so as you fly and run the tank down, your plane will still be in the recommended CG range.

With a gasser, and tank mounted on CG, there's no change to CG as the tank runs down, which for those that might notice, makes for consistent flight characteristics throughout your flight. On some of these sport planes every little advantage can make a difference I think it's great seeing these sport planes running small gas engines!
Old 04-10-2020, 08:13 AM
  #254  
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@DGrant,
I was planning on leaving it near the firewall per the plans not on the CG. That is good advice about the different operation of both engine types.
About the tank. The plans are vague. I was thinking about how to be able to access the tank after the fact. The plans say to block the tank in but nothing is shown that hold the tank from the top. I have used tie wraps to secure the tank but once they are on for this kit there's no good way to get to them again unless you add a hatch. If you don't use a hatch and/or tie wraps or velcro to secure the tank what do people typically do? My thought is to secure the tank from all sides including the top which isn't covered in the plans and secure a removable block from the rear of the tank so it can be pulled out if needed by removing the screw(s) that will hold the rear block. I'm trying to avoid a hatch mainly because i've already glued the bottom fuse ply in place and don't want to cut a hatch.

Last edited by GameEngineer; 04-10-2020 at 08:49 AM.
Old 04-10-2020, 09:59 AM
  #255  
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If it's possible, use thick foam around the tank, to keep it in position, and a simple stick glued at the rear somewhere(bulkheads are handy for that sometimes)... and if the tank ever needs to come out, just snap the stick out, and pull the tank. Thick foam-rubber, or sponge foam(not styrofoam) is light, and that plane isn't that big up there.

If gripping the tank for removal is any problem, do yourself a favor and place some straps(velcro or otherwise), around the tank lengthwise when you install it, and use those as a grip to pull it. It's up to you though, there's always a way to do things... regardless of what it is. You'll do fine I'm sure.
Old 04-15-2020, 05:01 PM
  #256  
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Turned out this Dubro 12 oz tank did not slide out to the rear because it hit the F2 former top part. I ended up cutting the tank floor tabs and lowered it about 1/4". I like the foam around the tank idea with the stick to hold the tank from the rear. The tank should now be able to slide out from the rear.
Old 05-04-2020, 09:58 AM
  #257  
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Default 4 Star 60 DLE 20 Question

Originally Posted by VincentJ View Post
Having flown my Four Star now for a few weeks, I thought I could better describe what a jewel this plane is. I couldn't be happier with how well all of the modifications I made turned out. From clipping a bay from each wing panel, reducing the dihedral, custom landing gear, custom tail wheel assembly to the DLE-20RA engine that pulls this beast with authority.

It tracks straight and true on take off and with the minimal dihedral, along with the shortened wingspan it does not float as many have described. It slows down and almost lands itself! Rolls are crisp and quick. The DLE-20RA equipped with a 16x8 carbon fiber prop is a perfect match for this plane and the 8 oz. tank is more than enough for 10-12 minutes of flying. I think I nailed the position of the CG on the first try!

If you're thinking about building a Four Star, then consider the mods I have incorporated in this thread. I promise you won't be disappointed!!!
Hello from one Vincent to another! (My name is Vince)

I'm a huge fan of this build thread and the ideas I've gotten from you. This thread inspired me to build myself a 4 Star 60 from kit after crashing my old Tower Kaos 40 ARF. The kit build so far is a very rewarding experience! (Almost done with wing)

I'm incorporating many of the modifications you and many others suggest, including wanting to try the DLE 20RA as my first gas fueled plane! However, I'm thinking I do not want to do the cowl like you did, rather just keep it simple and open air.

My question is, do you believe the relocation of the firewall with the DLE 20 was MANDATORY in order to use it, or was it more of a personal preference in order to keep the engine's thrust washer in original intended location? Also, since I will not be using a cowl, do you believe that it would be ok to mount this engine with cylinder-up on this plane? With the twin exhaust tubes shooting up over the deck in front of the canopy? This would be my preferred approach I believe.

Finally, what engine mount did you use? I did not see it listed in your parts list.

My son with the new almost complete 4 Star 60 wing


Many thanks in advance, Vince
Old 05-04-2020, 10:36 AM
  #258  
VincentJ
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Hi Vince. I cut back my firewall to get the engine in the correct location for the cowl. Since you don't plan on using a cowl, you don't have to do that, just mount your engine in the stock location, but increase the thickness of the stock firewall and be sure to use tri-stock on the inside to further brace it as gas engines vibrate more than glow engines. The DLE-20RA is well suited to that plane and is a great engine for you to have as your first gasser. The engine can be mounted in any position that you want to, however keep in mind you have to bolt an exhaust on it. I would still mount the engine upside down and then you can use the stock supplied exhaust with them pointing towards the ground. That engine will have a ton of power for that plane and it is very easy to tune as well. Good luck Vince, and your son is adorable!
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Old 05-04-2020, 02:16 PM
  #259  
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Originally Posted by VincentJ View Post
Hi Vince. I cut back my firewall to get the engine in the correct location for the cowl. Since you don't plan on using a cowl, you don't have to do that, just mount your engine in the stock location, but increase the thickness of the stock firewall and be sure to use tri-stock on the inside to further brace it as gas engines vibrate more than glow engines. The DLE-20RA is well suited to that plane and is a great engine for you to have as your first gasser. The engine can be mounted in any position that you want to, however keep in mind you have to bolt an exhaust on it. I would still mount the engine upside down and then you can use the stock supplied exhaust with them pointing towards the ground. That engine will have a ton of power for that plane and it is very easy to tune as well. Good luck Vince, and your son is adorable!
Thanks a bunch for the quick response! My son is an excellent supervisor and he loves to hang out in the workshop.

Regarding your motor mount, where did you get it? It looks like a Hangar 9 mount, but from what I see they are discontinued at Horizon. Would the stock SIG motor mounts be sufficient? Also, your muffler is black. All the pictures I see of the DLE mufflers are simply raw metal. Did you paint yours?

Thanks in advance!
Old 05-04-2020, 03:48 PM
  #260  
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The motor mount that I used was from Hangar 9, and you're right they are discontinued. I'm lucky that I bought a few before they were discontinued and put them away. They may be available on e-bay, just a thought. The muffler was not painted, it came that way right from the factory. My other DLE-20RA engine that I've installed in my current build (Beechcraft Bonanza) is the same...
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Old 05-10-2020, 05:55 PM
  #261  
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Default Control Surface LE centerlines

Hey Vincent, what’s your preferred method for marking or scribing the LE centerlines of control surfaces like ailerons prior to beveling?

I have a a potential center scribe solution but am curious what you do.

Thanks in advance!
Old 05-11-2020, 02:05 AM
  #262  
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Originally Posted by rcFLYBOY14 View Post
Hey Vincent, what’s your preferred method for marking or scribing the LE centerlines of control surfaces like ailerons prior to beveling?

I have a a potential center scribe solution but am curious what you do.

Thanks in advance!
Have you seen that inexpensive tool to scribe the center of the control surface prior to installing flat hinges? That is what I use. I scribe the center on both ends of the control surface and use a ruler to connect the two marks. If you don't know what I'm referring to I can take a picture of the tool.
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Old 05-11-2020, 05:09 AM
  #263  
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Ok yes that makes sense! I have the Great Planes center scribe version of the tool - which does work really well. My concern was that it does leave an indentation, which I didn't really want. But, your method of just doing the ends then connecting with a pencil would alleviate that concern. I'll give it a try!

Vincent, I have some things that I would like to share with others regarding my 4 Star build. Would you be ok if I simply added on and extended this build thread of yours, rather than make my own? My intention would be to cover areas that you did not spend as much time on and some "unique" aspects such as Navigation Lights that I'm adding. That and maybe adding some context on building from someone who's never built a kit before.

What do you think? I would be happy to post elsewhere if that's what you prefer.
Old 05-11-2020, 04:35 PM
  #264  
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Start your own, please.
Keep this one pure VincentJ.
Old 05-12-2020, 01:34 AM
  #265  
VincentJ
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I agree with you Lupe.

RCFLYBOY14, please start your own thread...
Old 05-12-2020, 03:55 AM
  #266  
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Default Question about bevels

I appreciate your feedback on starting a separate thread - I have no problem with that. I hope I have the motivation and content to make a separate thread worthwhile.

I have a question on control surface bevel angles for this kit. You mention that the kit calls out a 45 degree bevel angle. I actually interpret things differently. The manual states "Sand two 30 degree bevels on the leading edge of the ailerons with a sanding block", and, if you actually measure the angle on the kit plans, I believe it's closer to 30 degrees.

I may be making a big deal of something very inconsequential, but I am curious do you believe that going to a 45 degree bevel vs a 30 degree bevel is inherently better and necessary for this kit?

Originally Posted by VincentJ View Post
Part Two - How To Install Robart Hinge Points




The pencil pointing to the LE of the aileron shows that it's beveled at 45 degrees.
Old 05-12-2020, 06:40 AM
  #267  
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Originally Posted by rcFLYBOY14 View Post
I appreciate your feedback on starting a separate thread - I have no problem with that. I hope I have the motivation and content to make a separate thread worthwhile.

I have a question on control surface bevel angles for this kit. You mention that the kit calls out a 45 degree bevel angle. I actually interpret things differently. The manual states "Sand two 30 degree bevels on the leading edge of the ailerons with a sanding block", and, if you actually measure the angle on the kit plans, I believe it's closer to 30 degrees.

I may be making a big deal of something very inconsequential, but I am curious do you believe that going to a 45 degree bevel vs a 30 degree bevel is inherently better and necessary for this kit?
On a sport model I would say that consistency is more important than fretting over 30 vs 45 degrees. On something such as a 3D style airplane where you are trying to get every bit of throw possible it can make a difference but not so much on 4-Star.
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