Troy Newman

Once the rear adjusters are bolted in place clean the bench off. We want to check our work one last time before we set the front adjuster plates and also we are getting ready to do the stab install. If the Trailing edge center lines are off just a little it’s OK to use the adjuster to adjust it to get the mark dead on. If you have to move a bunch then I suggest you remove the adjuster make a new ply plate and try it again. Once the TE marks line up properly you can install the front adjusters.

I’m a messy builder and I have to stop and clean. I want a clean and clear bench so that the stab just goes in one time and I can glue it without tipping over a bottle of glue or knocking something over and hitting the model while it s all blocked up.

Mark the Elevators so that you know which side they of the stab they are mated up with. Use a Sharpie as it cleans off the Ultracote with rubbing alcohol. This is crude but don’t make mistakes as to which one is the right and which is the left. They are already hinged up and the elevator was cut from the core. So its a perfect fit back in the same spot. Even the best of builders can get a slight difference between sides. The idea is to get the sides matched perfectly but this doesn’t always happen. So keep the left and right marked. The stab doesn’t have a top or bottom mark so I just marked one.

With the fuse slot opened up, remove the elevator surfaces and slide the stab in place. Mine went it tight but with no binding. In fact it’s a really good fit. Without looking to see if its straight with the wing or the incidence it fits snug. Next is setting up the incidence and doing the triangulation to make sure the stab straight in the fuse.

If you notice the rear top of the fuse where the fin attaches is a nice sanded flat surface to mate the fin. I decided to make a couple holes in this surface to get a good look inside of the glue joint when its time to glue the stab. I used a couple sections of tubing with notches cut in the end as a drill to cut a clean hole in the balsa. We don’t want to remove and weaken the material too much. The idea is just get a window to the inside for my peace of mind in the glue department. Through these holes you can make a nice fillet of epoxy on the inside of the fuse.

The photos below show the holes I made. This is not needed but worked well. Oh and I saved some weight too!

Troy Newman

Align the Ultracote stripes so they look like the stab is straight. We can’t trust these stripes but it’s a starting point. We then start the process of measuring 200 ways to Sunday. We are going to install this stab in a dry run 100% align it and make sure everything in all angles and dimensions are correct. Measure the dimension “X” as shown in the manual Fig. 7 This means the stab is centered left to right in the fuse. I do this at the rear of the stab only. This is an easy location to measure and the triangulation will get the front in the proper location. Next we are going to the angle lines. This step can be done many ways. Feel free to do it your way, just make sure it straight. Most that have built a model understand about the triangulation and setting the stab straight. The figure #7 in the manual explains the way to triangulate the stab location.

I do it a little differently. I make a center of the fuse location. I attach a section of pull-pull cable to this center point in the fuse. Then I use the elevator cut out corner in the tip as the point to reference. In my habits of assembling models this is easier for me. We all have our own methods and this one works quickly for me. To get the cable attached to the fuse I tack glue a hard balsa cross member to the fuse just in front of a former in the fuse. See the photos below. Once you fit this temporary cross member in place measure the center of the member and mark this center line. Drill a small hole on this centerline. The screw in the photo will thread into this hole. The cable is attached at the center point in the forward of the fuse and this is a fixed point. Now it’s a one man operation to set the tip dimensions correct on the stab. The stab side of the cable gets a section of small fuel tubing, and small section of music wire as the pointer. I would love to take credit for this little device but Sam Turner is the person that showed it to me. We now have the stab set in 2 axes but there is still work to do to make it straight.

Troy Newman

So the stab is now triangulated properly. It is in straight left to right and forward and aft in the yaw axis. Now you want to make sure the stab is parallel with the wing. There are a few ways to do this using the flat table and our height gauge. However I have found that I can measure all day long and still not get it correct. The best way is the eye ball test. Sight down the top surface of the main wing and look out toward the stab tips and align them with the top surface of the wing with your eye from a few feet away from the front of the model. You can see if its off very quickly and this is probably a better test than any measurement. This is shown in the first photo below.

My stab was nearly perfect. It needed a small balsa shim that is installed on the bottom left side to raise this side slightly. I mean very slight like 1/32” or less. Once everything is installed straight use a fine point sharpie to mark the edges of the fuse on the covering of the stab.

Now I have the stab straight in all 3 axes but I have no idea about its incidence.
The manual tells us in Fig. 6 that the stab needs to be set to zero. So you will notice that model is still blocked up like when we did the wing incidence setting. I do the exact same steps on the stab as I did on the main wing. This time there is no need for the Math lesson. The leading edge and trailing edge center lines of the stab should be the same distance from the reference table. We did this on the wing to get where zero reference line was. This is exactly the same steps we follow on the stab.

Guess what the photos below show my stabs install there were NO changes needed. It was dead on. In fact if you look it so dead on that the stab tips also aligned properly on their centerline. Once I set the height gauge for the first dimension…the LE and trailing edge on both sides, as well as the tips on both sides matched up perfectly. The factory did an excellent job on the fit of this stab cutout in the fuse. I had zero sanding to do and only a small shim as the left tip was a fraction low in the roll axis.

Below are bunch of photos with the height gauge and the pointer. These photos were taken to show all the places to measure. There are actually 6 different center lines that all need to be the same. The stab root LE and TE on each side and then the Tip Trailing edge each side. Sometimes the tips don’t hit perfect do small errors in sanding. If the roots are correct and the tips are off just a little bit it could be a number of things. Investigate why but don’t stress too much over it. Mine came out just spot on all the center lines were right on. This makes me very happy no messing around trying to fit this stab it basically fell into place. This speaks to the quality job in building and aligning this model at the factory.

If yours doesn’t fit and align properly carefully sand the saddle slowly and try refitting everything again. Small shims can be added and you want to take your time to get it as close to dead on as possible. I find it very hard to believe that every single one of these is as good as mine. I just don’t think I could have built it this well. Small tweaks and adjustments here will pay off big time in your fitting of the stab. We will eliminate lots of problems in the trimming of the model if this stab gets installed properly and straight.

With all the measurements correct removed the stab. You will see the photo below of the marks on the stabs covering. Using a x-acto knife cut the covering about 1/16” inside the sharpie marker line. This will give a small Ultracote overlap to inside the fuse sides. I found the covering in this area is white but is two layers thick. There is Red underneath the white. Just take your time and use a new #11 blade. Be careful not to cut into the balsa sheeting of the stab. I you cut too deep into the sheeting the stab could fail while in flight. This is the weak point of the stab to make it break so be careful with your knife activity. You need to get down to bare wood in the middle but want to keep the sheeting intact.


With the covering removed its time to glue the stab in place. We have to repeat all these steps above but it goes pretty quickly the second time. Hopefully you didn’t get carried away and start sanding way too much on the stab saddle. If you do then you will have a whole batch of shims and wedges to get things straight. My guess is its really close…you might just need a very slight tweak here or there.

MarkGrabowski

Sam Turner was a very clever fellow ideed! What ever happened to him?

Troy Newman

Hey Mark whats up man?

The weather here in Phoenix is starting to turn cooler. Lows in the mid 70's over night. I think the entire monthof August had a low of about 88 degs. You need to come back out here and bring some planes this time.

Yes Sam Turner gave me lots of advice over the phone. He even built a couple sets of wings for me. Finally he taught me how to do it via emaila nd telephone calls. Sam was great and getting things easy to align and coming up with little tools to aid in the job. I know the Pattern community really misses his contributions.

Troy

Troy Newman

Glue the stab in is the next step. We want slow set epoxy. 30min maybe even some 2hr. The idea is to glue this up and not touch it until morning. Remember all those measurements you made. We have to do all of them again. The epoxy needs to not setup until we know everything is correct and right. Plenty of working is a key to getting the job correct.

I used some Z-poxy Finishing Resin with very little micro balloons to give it some body. It would still flow well similar to a Fondue or Nacho cheese. Yes Nacho Cheese sounds MANLIER. I slide the stab back in place with the sharpie marks this gets us pretty close and only fine movements to get it correct. I then add some masking tape on the Ultracote surface. This will allow me to not make a mess of the epoxy as I’m moving things around. Any little film of epoxy that gets on the tape will pull off with the tape. A photo below shows the idea. Slide the stab partially out of the fuse to allow for glue application. With tape installed I mix up the epoxy to the consistency of the Nacho Cheese. I put a small bead of epoxy on all 4 areas, top and bottom of both the left and right sides. Don’t get carried away just get some glue on it.

Now is the time to work QUICKLY and ACCURATELY. All those steps we did above to measure need to be done. Set the X dimension per the Fig 7 drawing in the manual. Then use your pull-pull cable tool triangulate it in the yaw axis. Take a few steps back front eh nose of the model and sight down it and make sure the stab is parallel to the wing in the roll axis. Then grab the height gauge or a metal ruler…and get the stab centerlines to be equal distance from your flat table.

With everything set correctly….you might go back and check it again. If you are satisfied with it close the door to the shop and keep my Niece Catlin and Toby the Wonder dog from the room until morning. There have been more than one time when I started working on something else in the shop like a clean up or the likes and I bumped the model. This really made for a bad day. So now head to the living room for a cold one and leave the room. If my clumsy butt is not there in the room it won't screw up all that good work.

The epoxy will cure and the stab will be set permanently and dead straight if you did your measurements correctly.

Troy Newman

Any questions guys?

I have obviously either over-loaded you with info or I have done a good job of explaining things. In the next couple days I'll be building a list of goodies to order from Central Hobbies. We will also talk about optional stuff like engine mounts, control horns, linkages, servo choices and other stuff to keep you interested.

As I said above our flying weather is getting good with the temps coming down to normal summer temps. Our average temp last month from my Electricity bill was 97degs. This is Avg for the entire month...we were basically 97degs all month long...not just the average High but the highs and low together.

If you guys have some questions now is a good time. If you are trying to keep caught up again its a good time...

So far I am really pleased. No problems to speak of in putting the beastie together and its coming out very accurate this is important for pattern flying....Also an Accurate type pattern plane will make the sport guys look good flying it too.

I haven't run into any problems that didn't take more than a couple mins to solve. The accuracy and fit has been excellent.

Troy Newman

Zippi

My Feedback: (10)

Troy,

Thats a lot of nice information and very helpful. I do have one question and with all the info posted maybe I just missed it. The wing adjusters, if and when these need to be tweaked how can you adjust them and hold onto the nut on the bottom once all the servos, cables, etc. have been installed or does it matter? I noticed that when you turn the adjuster the nut rotates as well. I assume that the adjuster pin that the bolt runs through is tapped so maybe it does not matter. Just curious.

Troy Newman

The nut on the bottom is suppose to turn. The screw "stays in one Place" while the pin is threaded and moves up and down on the bolt. You install the adjusters with the socket head pointed toward the canopy opening. This allows for the adjustment.

Tighten the bolt and the pin rises, loosen the bolt and the pin lowers. This is how it works.


Troy

dreadnaut

My Feedback: (5)

Troy, thats a lot of writing, but keep it comming. I am not building a Focus sport. Was on the cusp of getting one, but other stuff happend. Still, I am folowing the thread. You may remember seeing me loose an Exeleron at Perris earlier this year. I mention this because of what you said about gluing the stab. Like you, I use Z-poxy finish resin, thickened with Resin Thick (like cabosil, I get it from south bay plastics in LA).

I lost this plane because the stabilizer came off in flight. What happened was that I thickened the resin too much (Mayonase), and it did not get in there as well as I thought it did. Then there were a cascade of falures. I believe that one of the elevator pull pull cables failed, leading to massive elevator flutter (I saw it for a split second) that ripped of the poorly glued stab. My technique was to get everything lined up, then inject the resin into the joint. I use a plastic bag with a small corner cut off, like a cake decorating bag for this. It was a bad idea.

I have another that I hope to have ready in time for Lancaster. It is finished, but I have not flown it due to the Honeydo factor, and the fact that I decided to replace the elevator pull pull that it comes with with a solid pushrod. There is so much slop and play in it that I will not fly it until I rip it out and replace it. I am waiting till you get to the elevator pushrod, since there is a good chance you will be using DEPS on it, and I want to go that route on this project.

Zippi

My Feedback: (10)

Troy,

Thanks for the info on the adjuster. I have an incidence meter and thought about what you said about making a height gage so since I work in a Quality department and have plenty of precision tools I came up with this idea. I tack glued a thread gage 90 degrees to the blade of my square and it worked great. I was checking my work surface which is a new hollow door with my incidence meter to get it nice an level but everywhere I check its a little off. I checked on top of the canopy area and it looks good there. What do you think?

After going back and re-reading your post it seems I don't have to have the table level if I'm using the height gage method. If I'm reading it correctly, there is a lot of info there.

Troy Newman

If your table is flat you don't need to be absolutely level.

But the table needs to be level.

A hollow core door is not the best solution for a flat table.

I use a Door also as my flat surface. However it is a FIRE Door from a high rise building. Its a big thick heavy MDF door with laminate on both sides. I have had this door for years and It has stayed extremely flat. There is one end that has a slight bow in it so I stay away fro that corner. I have used it for over 10years and its still flat I checked it last week before the Focus Sport build started.

To think I got this door during a construction project my company was working in Denver. It came off the 28th floor of a building as was the fire door from the office space into stairwell area. The contractor was getting ready to cut it up in little pieces and I asked if I could have it. The word was if you can haul it out you can have it. A buddy and Hauled it all 28 floors in the stair well. The freight elevator was being worked over and we couldn't take it down the freight elevator.

I guess I was luck. It has been cut down to size for my needs but is still very stable and flat for building models.


Troy

BERUSTY

My Feedback: (3)

Focus Sport 110 YS Powered

Troy...Fantastic detail!

Rusty Dose
Team YS Parts and Service
Team Futaba

Zippi

My Feedback: (10)

Ok, as long as the table surface is flat and the thrust line is parallel to the table surface we don't have to have the table perfectly level with the world using the height gage method. If this is correct then I think I'm ready to start setting the incidence.

Troy Newman

That is correct. You just want the table as flat as possible just doesn't have to be level to the world. Just flat.

And the refernce is not the thrust line....it a that flying line reference. Thrust line is a bit different.

The Focuse Sport has 1.5 degs down thrust and then it has some right also. Like 2-3 degs. Not sure on the number but I know its 1.5 deg down.

The canopy frame and your table should be paralell when the tail has a 1" block underneath.

Troy

Zippi

My Feedback: (10)

Troy,

Thanks for the info. flying line it is, not thrust line.

flywilly

My Feedback: (121)

Hey Troy,
You must be a beast. I grabbed a similar door out of the dumpster when they were 'remodeling' my building 20 years ago. Those damn doors are HEAVY. 2 months later my brother in-law asked if I could use some solid core doors. He had a dozen that were factory rejects for imperfections that I didn't care about. I took 4 (gave 2 to my dad who is also an R/Cer). Those doors were lighter, but only 30" wide versus the 36" wide door I pulled out of the dumpster.
I've also gotten 'free' pool table slate with minor imperfections. Usually one corner is broken. These are also very 'light' , but they are dead flat!
Great thread!
-Will B.

onewasp

Zippi-------you've been here before-----see post #26 by Troy ------

---and I quote: "This is a no Bit-chin' area. If you feel you need to do that take it to another thread please. "

Troy laid down the ground rules----simple eh what?

Zippi

My Feedback: (10)

onewasp,

Thanks for reminding me. I have altered my post.

Troy Newman

I have not gotten there yet but we can discuss the stripe issue you have and the rudder issue.

I don't know if its just yours or if mine is this way. I have not gotten to it. Patience...I will.

As for the stripe issue the covering is genuine UltraCote.

Flame Red is HANU883
Bright Yellow is HANU872
White HANU870
Black HANU874

You have to be careful with Ultracote it will shrink a bunch if you are not careful with your heat gun. I recommend using the iron with a cotton sock on it. If you aren't careful you can really shrink the ultracote a bunch. This shrinkage can pull the stripe edges away from the each other.

I have to finish up the stab and put the fin on on and then I'll look over the rudder situation.

The device you made looks like it will work. Its not very flexible in terms of the height you can adjust to but it will work on this model for sure.

Troy

Zippi

My Feedback: (10)

I made a little headway today and got the wing adjusters installed, and the stab and vertical fin glued in but I'm a little concerned about the stab. As you can see by the pic the stab is lined up with the wing but if you look closely and it's hard to tell from the pic but the stab is not 90 degrees to the fuse. I've never seen this before. I've always got the wings in place and then set the stab by viewing it from the front and rear to get it parallel to the wing. I didn't notice this until it was all finished. It's almost like the wing tube is not installed properly. Not sure how this will effect the flight characteristics of the plane.

Can't seem to upload a pic at this time.

BERUSTY

My Feedback: (3)

Focus Sport 110 YS Powered

Zippi's proclamation that "...the stab is not 90 degrees from the fuselage..."

Zippi,

How are you measuring the 90 degree angle? You do realize that the stabilizer is NOT a constant thickness, rather a taper, from the root to the tip.

If you follow the directions, align the wing, then the stab to the wing and then the fin to the stab/wing...your model will be able to be trimmed very satisfactorily. There are many variables which will ultimately require no, very little, or minor "adjustment" based on the absolute weight of the wings (they will be different), equipment location, engine/muffler combination...

Your model, assembled per the instructions, using sport equipment and a modest .90 - 1.10 4-cycle (these are lighter than any 1.20 or 1.40 and not needed) will have an enjoyable model able to "fly" any precision manuever.

Troy's detailed and thoughtful processes and concepts will certainly inspire applications beyond the modest Focus Sport.


Rusty Dose
Team Futaba
Team YS Parts and Service

Zippi

My Feedback: (10)

BERUSTY,


I realize that the stab is "NOT a constant thickness, rather a taper, from the root to the tip" and I guess my phase "stab is not 90 degrees to the fuse" was kind of a loose term. Looking from the front or back of the fuse I can eye ball the wing and stab and they are really close but from the back if you look at the fuse in relation to the stab you can see that the fuse is a little cocked to one side. I have some pics to post but RC Universe is on the fritz again.

Troy Newman

Last time we messed with the Focus Sport was Thursday last week. Today is Sunday 9-23-07. I got some time to work on things again today. The stab was glued in and the model was left to sit over night. When all the epoxy was cured I re-checked all my measurements. The good news is Toby the Wonder Dog didn’t bump the table and the epoxy cured with the stab in the correct location.

Notice in the photos above that I made some small holes in the fuse top decking where the fin will glue in place. This was to allow a window to the fuse and stab joint. I mixed some epoxy up with micro balloons again the consistency of Nacho Cheese. I laid a small fillet with a small brush down on the joint from the inside. Is this part overkill…yes likely but I want to make sure I get a good joint. The way the fuse was built allowed for me to get a window inside and not just trust the first glue job. I always try to hedge my bets. The idea is to use the minimum amount of glue as possible yet get as strong of joint as possible. So the little circle holes cut allowed me to direct the glue directly where I need it and make sure good coverage was achieved. It’s important to wipe any excess glue off the flat balsa surface. This can screw up you fin install. Plus it is extra glue that is not doing anything. Every bit of epoxy is weight….


I let the model sit for about 20mins until the glue kicked off. This allowed me to clean up the shop table and get ready for a fin installation.

Troy Newman

Fin installation. The table is cleared off mostly and the fuse is still blocked up. I use my height gauge to make sure the stab is parallel to the table again. My height gauge is still set properly from the stab install. I blocked up the fuse and double checked the stab parallel to my flat table. The instructions say to make sure the fin is installed at 90degs to the stab. Again what is important here is not he fin to the world but the fin to the stab and wing. Since we made sure on the stab install the wing and stab are correct in the “roll” axis from sighting down the front. The fuse is blocked up so the stab is parallel to the table. I found that when I flipped the fuse around on my table one stab was slightly low on the flat table compared to the other side. You can see it in the photo. The other stab tip was slightly high. I used small balsa scrap about 1/16” thickness to shim the fuse. It needed a very slight rotation to make the stab parallel. This is not a problem and we didn’t install the stab wrong remember we sighted down the front of the wing and stab and made sure they were aligned properly. So the wing and stab are correct we just need to re-block the fuse so that this relationship is correct to the other end of my table. If you notice in the photos I swapped ends of the fuse on my table to make it easier to work on the fin install.


Next step is to mark a centerline on the Trailing edge of the fin. It may fit perfectly but we need to check it. We are trying to make a very accurate model here. Accuracy is only as good as your measurements. With a centerline on the fin use a builders square to fit the stab 90degs to the table. Since the stab was shimmed parallel to the table the fin will be 90deg to the stab as well. The photo below shows the square in place.

My fin was off about 3/64”. NOTE: don’t trust the hinge slots as they may not be in the middle of the fin. They could be but there is no promise. You and I didn’t cut the slot so I don’t trust it yet!
My fin was leaning toward the left of the model at the top of the fin about 3/64”. I then looked over the mate surfaces on the fin and fuse. Both were very flat but the minor sanding differences in building the two parts could account for a difference. A really minor angle change on either part would be magnified greatly at the top of the fin which is 8 inches away. To be precise an error in sanding either part of about 0.5degs could result in this amount of misalignment. That is not much when we are sanding balsa wood. Maybe two swipes of 100grit could cause the error. I also noticed that the Leading edge of the fin block didn’t cleanly contact the front of the fuse. Yes it was close…but not as good as I would like.

I first sanded the front of the fin block. Actually what the difference was some wrinkles in the Ultracote as the covering was ironed around the corner. I use a large block of MDF with 150grit paper to sand the front of the fin block as shown in the photo below.

Once I had the fin butt joint at the front correct I re-checked to the 90deg of the fin to the stab. It didn’t change but I wanted to make sure. Check the fin block to make sure it doesn’t have any uneven surface or a wrinkle in the covering that is causing the misalignment. If it does have some unevenness on the surface a couple swipes of the big sanding block will do the trick. Re-check it the fin for 90degs. Look over the fuse mounting area and make sure its level and no uneven surfaces. A few swipes of the block can clean these uneven surfaces up also. Re-check the fin.

I had to do a little more sanding on the fuse side of things. I grabbed a slightly heavier block of fresh 100grit to work a little faster on the fuse area. This task took about 10-15mins of sand and fit, sand and fit. Once the fin sat as perfect as I could measure I was ready to glue it in place. I had to play a little with the covering on the fin block as it was sanded away in some spots on the mounting surface area. This was not a big deal and we will take care of this later. For now use your covering iron to iron the edge back down as well as possible. Perhaps a knife blade is used to trim up the edge of Ultracote on the bottom surface a little.

I mixed some 30min epoxy with some micro balloons. I mixed about ½ the balloons that I used on the stab install. My fin fit was fairly tight and there was not much need for any filler. I used the balloons just to give a little body to the epoxy. This time it was consistency of about honey.

Place the fin on the fuse and re-align it. Once happy with the install take some masking tape and tape the fin in place with the fuse. I used tape on the sides to keep it aligned with the sides of the fuse and tape in the front to keep the Leading edge of the block down on the fuse. After taping the fin in place re-check the darn thing again. Make sure it did not move on you.

Let the epoxy cure for a couple hours. Then remove the tape. The fin is now installed at 90degs to the stab, and as a result to the wing as well.

We now have the hard alignment parts of the model mostly done. The last alignment part is the engine and thrust plate.

I think our next discussion is going to be of those optional parts like servos linkages, engine mount options and so on.

Troy Newman