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-   -   Four Star 40 Kit - Oops!! (http://www.rcuniverse.com/forum/kit-building-121/11258815-four-star-40-kit-oops.html)

HampdenTech 10-11-2012 06:18 AM

Four Star 40 Kit - Oops!!
 
Okay, I'm making my way through the build of the Four Star 40. I'm almost done with the wing but I made what I'm sure is a newbie mistake. Despite the warnings not to get glue between the aileron torque rod and the brass collar, I somehow did. This morning when I went to test the travel in the torque rod on the left side, there wasn't any. Locked tight. Just to add to this, I used epoxy to glue the aileron assembly to the trailing edge because I thought it was important that it not fall off during flight! The rod is basically welded to the brass collar.

Anyway, I was able to cut the assembly away from the trailing edge but it's not useable. I need to replace this with something similar or possibly even better. I saw some assemblies listed in the DuBro catalog but I'm not sure which one will work. Obviously, not the micro or 1/2 A versions that they list, but are there others that will work? What about other manufacturers?

Any help would be appreciated as I'm close to finishing the wing. I'm moving on to the fuselage now to see what else I can mess up:(. Anyway, it's been enjoyable building it thus far. It looks like a great kit, however, I did have to order some additional 1/4" stock because one aileron was cut slightly smaller than the other for some reason.

Thanks!
Bob

ronwc 10-11-2012 06:57 AM

RE: Four Star 40 Kit - Oops!!
 
Any of them the proper size will work. Better yet, just use two servos about 1/2 out on each wing half and forget the torque rod. These are great flying planes, any 40 - 46 engine will work fine.

eddieC 10-11-2012 07:06 AM

RE: Four Star 40 Kit - Oops!!
 
I second the dual servo idea. Torque tubes are so... 70's ! <div>;&gt;},</div>

JPMacG 10-11-2012 07:22 AM

RE: Four Star 40 Kit - Oops!!
 
Dual servos are excellent. If you search this forum you may find photos of how someone else has implemented dual servos.

Too late now, but sometimes heat will soften epoxy. Applying a soldering iron to the brass tube might have allowed you to wiggle the torque rod free.

HampdenTech 10-11-2012 07:28 AM

RE: Four Star 40 Kit - Oops!!
 
Hmmm, 3 votes up for dual servos and no votes for torque rods. I had originally considered duals, but being this my first build I thought it might be easier to go with the plans and instructions. Now I'm thinking it might be worth investing in a second servo and the necessary wires.

I'm guessing since the single servo opening is already there I can just use this as the channel where the servo wires meet up with the RX, right?

eddieC 10-11-2012 08:19 AM

RE: Four Star 40 Kit - Oops!!
 
Correct.

blw 10-11-2012 08:24 AM

RE: Four Star 40 Kit - Oops!!
 
I've fixed the same mistake by cutting off the old brass tubing. I had some slightly larger diameter on hand, and carefully cut a slot down the length of a piece. I cut out the length I needed and spread the slotted brass tubing with a slot screwdriver just enough to slip over the torque rod. I then used duck billed pliers to compress the brass tubing enough to work smoothly with the torque rod. Glued carefully in place and it worked fine.

Are you sure there is too much CA to not use uncure and soften it up? I would try that first.

HampdenTech 10-11-2012 08:28 AM

RE: Four Star 40 Kit - Oops!!
 

Quote:

ORIGINAL: blw

I've fixed the same mistake by cutting off the old brass tubing. I had some slightly larger diameter on hand, and carefully cut a slot down the length of a piece. I cut out the length I needed and spread the slotted brass tubing with a slot screwdriver just enough to slip over the torque rod. I then used duck billed pliers to compress the brass tubing enough to work smoothly with the torque rod. Glued carefully in place and it worked fine.

Are you sure there is too much CA to not use uncure and soften it up? I would try that first.
I used epoxy not CA, but in removing the brass/aluminum torque rod from the balsa assembly peice I pretty much destroyed that part. I would need to cut a new one from 1/4" stock. I'm starting to lean toward dual servos as I was considering that option at the beginning anyway.

blw 10-11-2012 09:16 AM

RE: Four Star 40 Kit - Oops!!
 
Dual servos is best. No question at all. Go for it and good luck!!!

HampdenTech 10-11-2012 09:37 AM

RE: Four Star 40 Kit - Oops!!
 
Thanks for all of the replies. I'll post a few pic's once I get the wing done.

Gray Beard 10-11-2012 10:18 AM

RE: Four Star 40 Kit - Oops!!
 
Just an FYI but for anyone using epoxy and making a mistake, epoxy softens with heat. It can be removed with a covering heat gun very easily and the wood and in this case metal parts are not damaged and can be used again.
To torque rod or not to torque rod??? It works and has been a good system for a lot of decades. The 4* 60 uses two aileron servos, it's often done on the 40 but it's just another either or thing. Today a lot of builders aren't good enough to install the rods correctly and opt for two servos. I use two servos just because it makes my set up easier with my radio.
One of the wonderful things about kit building is the choices you have. My next build I have decided to not install ailerons at all, my choice.
Have fun with your build.

acdii 10-11-2012 10:20 AM

RE: Four Star 40 Kit - Oops!!
 
Duals man, DUALS!  And if you really want to go nuts, separate channels on the TX if you got them.  I had given thought to a triple setup with the ailerons on a 3 pos switch setup, one position normal, second position, flaperons, third position, Spolierons!   <div>
</div><div>Imagine the plane on a straight level flight suddenly dropping and then blooming when you flip to spoilers then flaps.  :D   Crazy, but the 4* can do some crazy things too. </div>

swify 10-11-2012 10:53 AM

RE: Four Star 40 Kit - Oops!!
 
I built a 4*40 nearly 20 years ago, it was a nice flying plane. I went with the single aileron servoon it, worked OK for me. Brought it in for a landing one time a touch too slow,stalled itand fell off on one wing causing considerable damage, didn't bother to rebuild it and bought a 4*120 kit that I will finish up this winter after many years of it sitting in my basement.

KitBuilder 10-11-2012 12:45 PM

RE: Four Star 40 Kit - Oops!!
 
The 4* 40 is an aerobatic trainer... floats on landing with no bad issues... I miss mine. I had duals a well with High Tech 81's.

If you want ot make it easy you can just mount them so the top of servo is hanging out the bottom of the wing.. but I always lay them on the side and just have the arm coming out a slot in the tray. more difficult to build somewhat but purdier too :).

flynte 10-11-2012 03:10 PM

RE: Four Star 40 Kit - Oops!!
 
Ahh yes, duals rule. Just so much better, as it frees up a good chunk of space in the fuse.

flynte

hsukaria 10-11-2012 06:42 PM

RE: Four Star 40 Kit - Oops!!
 

Quote:

ORIGINAL: flynte

Ahh yes, duals rule. Just so much better, as it frees up a good chunk of space in the fuse.

flynte

+1


MetallicaJunkie 10-11-2012 07:26 PM

RE: Four Star 40 Kit - Oops!!
 

Quote:

ORIGINAL: eddieC

I second the dual servo idea. Torque tubes are so... 70's ! <div>;>},</div>
+1

rgburrill 10-12-2012 04:33 AM

RE: Four Star 40 Kit - Oops!!
 
A huge advantage to duals in an aerobatic trainer is that with good mixing functions in the transmitter you can play around with rates and travels in each of the 4 endpoints independently.  That allows you to get perfect axial rolls in a low wing with dihedral.  I did that with my Tiger 60 which has pretty much the same wing as the 4 Star 60.

ArcticCatRider 10-12-2012 07:04 AM

RE: Four Star 40 Kit - Oops!!
 
The biggest advantage to dual servos is the redundancy if one of the servos is to quit. Apart from the mixing options, there isn't much you can do with duals on a 40 sized airplane that you can't do with a single. You'll have more weight from the extra servo, hardware, and framing that you'll need for the servo bays. The good news is the 4 Star has a nice big wing and you will not notice some extra weight.

Not sure what is more work...repairing the damaged trailing edge and using the work you've already done, or building bays and rails for the outboard servos.

If you do with a dual set up, tape the servo wire to the extension...or somehow make sure it won't work its way loose. It's too late now for a wire tube through the ribs. Also, as someone suggested...use separate channels in place of the Y-harness if you have it available.

If you repair what you've done, cut out a sizeable chunk of the wood near the damaged area....and epoxy in a replica. Sure, it will tough to get uniform...but it will be a solid and reliable repair.

Not trying to be negative here...but just saw many were quick to shoot down the torque rods. There's nothing wrong with them and they've worked well for a long time. I have used them on planes up to .60 size (GP Ugly stick) without issue..with plenty of abusive flying.

HampdenTech 10-12-2012 07:09 AM

RE: Four Star 40 Kit - Oops!!
 

Quote:

ORIGINAL: ArcticCatRider

The biggest advantage to dual servos is the redundancy if one of the servos is to quit. Apart from the mixing options, there isn't much you can do with duals on a 40 sized airplane that you can't do with a single. You'll have more weight from the extra servo, hardware, and framing that you'll need for the servo bays. The good news is the 4 Star has a nice big wing and you will not notice some extra weight.

Not sure what is more work...repairing the damaged trailing edge and using the work you've already done, or building bays and rails for the outboard servos.

If you do with a dual set up, tape the servo wire to the extension...or somehow make sure it won't work its way loose. It's too late now for a wire tube through the ribs. Also, as someone suggested...use separate channels in place of the Y-harness if you have it available.

If you repair what you've done, cut out a sizeable chunk of the wood near the damaged area....and epoxy in a replica. Sure, it will tough to get uniform...but it will be a solid and reliable repair.

Not trying to be negative here...but just saw many were quick to shoot down the torque rods. There's nothing wrong with them and they've worked well for a long time. I have used them on planes up to .60 size (GP Ugly stick) without issue..with plenty of abusive flying.
Actually, the trailing edge is in pretty good shape. I was able to cut out the torque rod assembly fairly cleanly so I only need to do a little sanding.

ken78cvx20 10-13-2012 03:31 PM

RE: Four Star 40 Kit - Oops!!
 
1 Attachment(s)


My four star build has stalled hope to get back to itsoon maybe seeing your's progressing will inspire me. AnywayI plan ongoing with duel servos on the ailerons here are some ideas that helped me.</p>


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