http://www.patternflyer.com/troy/

Hello Troy.
My Focus Sport has arrived and I am in the process of Looking and checking before building. I would like, for several reasons, to install the DEPS elevator system. Looking at the restricted space available through the former where the rudder servo rails are located, would I have to remove these rails to make a little more space to get ones hand in there? replacing them at a later time. Since, when ones hand is inside the fuselage through the former, one can not see inside to place a support for the DEPS rods, could you give some idea of what "You would do".
Some thoughts on your part regarding my post #266 would also be very much appreciated.
I am looking forward to being able to read all that you have put into this post on your Blog and thank you again for all you have done over the past year. I look forward to hearing from you.

Robert in Vancouver Canada.

DEPS in the Focus Sport.

Well we are going to be putting a DEPS in a Focus 2 in the next couple of weeks. I'll post some photos and do it on the Blog regarding this. This was the plan of attack in using the new Blog website for this.

The Focus 2 has a little more room in the fuse, but you can build a ship inside a bottle...or let me say some people can. Its the same process. If you give up and have to be a sledge hammer mechanic you can cut a hole.

I have been putting the Deps in completed fuses on $3500 Oxai models that have one piece wings and no access to the tail at all... You don't need to put your hand down the back...The existing rudder servo rails would stay in place and you could put the rudder servo and elevator servo side by side in the Focus Sport.

I'll post some more step by step how to do this. The Deps deal is not difficult to install with no access...I'll show a couple tricks on the Focus Sport to being able to see down the back end of the model, but reality is you don't need to see very far back in there to do it.


Troy Newman

Hello again Troy,

I am looking forward to reading about the DEPS on your blog, particularly anything to do with the Focus Sport.

I have just been reading your construction "How to" series at Central Hobbies. Another great source of information. In the linkage section you have a drawing of the Rudder Pull Pull set up in which the wires do not "cross" right to left, left to right but go direct from the left side of the servo to the left control horn on the rudder. The same for the right side. As I mentioned before, I have never installed a pull pull system before and have only seen illustrations. Also, for your recommended 1.25"/1.5" long rudder control horns, how far from the screw hole of the servo would the wires connect to the servo arm to get the advantage you speak of?

Thanks again for all of your help.
Robert, Vancouver Canada.

Sorry Troy, forgot to ask, do you use the twisted wire cables or the newer Tetra type filament cables on your rudder set up?

Robert.

RMFISH,
Like you I planned to do a DEPS setup on the Focus Sport I recently assembled for a friend. I discovered there is a laser cut plywood bulkhead inside the fuselage just ahead of the stabilizer leading edge. The DEPS is rather bulky in the same area and there is very little access to modify that bulkhead without damaging the covering or weakening the tail structure. While I am sure anything is possible given sufficient motivation it really is opening a can of worms. I discovered that without completely removing a significant amount of that bulkhead the rods would bind unacceptably. FWIW, Mike.

I ran into the same issue Mike. I just went with Futaba 9650's in the tail to make life easier.

Thank you both for your input. I wonder what Troy will have to say about this problem?? I have found this post to be the most informative information package that I have ever read. Cheers.
Robert.

Not sure what he will say other than I can tell you he used the JR equivelant of the 9650's. No DEPS in his.

This may be a lame novice question, but how do you cut a new slot 1/32" above an existing slot? Do you move the new slot to the right or left, or do you fill in the existing slot, or just cut a new slot on top of the old one? It seems with just 1/32" of wood between the new slot and the old slot in the stacked method you would introduce a weak link in the hinge attachment. Sorry if this is obvious to everyone else, but I'd appreciate a little guidance before I make the wrong cut.

thanks!
Scott

Scott,

You can move the slot to the left or right a little, or you can cut a CA hinge in half and use it to fill the old slot on the mis-cut side. Just don't glue it in until you glue the other hinge in place. Use it was a filler, on the one side. This piece of hinge will not go across the hinge line it just stays in the one side. Leave it in there and trial fit the new hinge location right on top or below the old one. Then when you use CA to secure the new hinge in its location the Thin CA will wick into your filler piece.

This is what I did. But moving the slot to the side also works very easily.

Troy

I am new to this thread and have a few questions. I just crashed my Aero-works Yak 90-120 which had a Saito 150.
I want a good Pattern plane and want to know your opinion of the Focus Sport with the Saito 150??
Any suggestions will be greatly appreciated.
Thanks.

WAY too much power and weigh too heavy (spelling error intended)

The YZ110-S is about all it (or you) could handle. Many will tell you that the 110-S is the equal in power to the Saito 150____simply not so, I own them both. It is closer than you might expect but still a bad comparison.

It balances very well with the 110S or with the Saito125 (move the pack about four inches)

The Saito 150 is seven ounces heavier than the 110-S and that is out of reason.
It is also too wide and too long.

The Focus Sport is a very, very good A/C.
With a Saito 125 on 30% the vertical is unlimited (not high speed but unlimited). BUT, the 110-S puts out 800 to 1000 rpm more on the same fuel and prop. Max the prop for the 110-S and it is even more pronounced in performance difference.

With the Saito 125 you can fly it WOT throughout a sequence. With the 110-S roughly half throttle with whatever you wish to add____particularly vertical.

Note: Thankfully (personal opinion) this is NOT a 3D A/C but a Pattern practice plane.

Just finished my Focus Sport, Great flying plane.
Here are a few photos.

What is you all up dry weight?

9.5 lbs, It's completely glassed and painted. I think I got a little carried away on the clearcoat so it's a little heavy but it looks really slick and it still flies great with the YS 110. This was may first painted airplane so I'm sure I can make the next one lighter.

Yes, you are .75 lbs heavier than a film covered model.

Automotive paint???
If so, DuPont or PPG???

What clear did you use as this adds up in a hurry?

Yes I did use automotive paint. It was dupont Chroma premier with 72500s clear.

I use the same except that I go lazy and shoot just the cowl and wheel pants now.

Ultracote won me over!
And NO it is NOT as nice as a painted model______however, when you get rid of the house and buy a Condo it requires a few changes in building style.

I do not feel that .75 lbs is any sort of extreme penalty for the ability to shoot and design your own scheme.
If however you are bouncing around close to the weight limit on a two meter, then yes.
But as we each are simply enjoying the excellent flight characteristics of the Focus Sport it makes little difference.
I'd be willing to bet that the flight characteristics are virtually identical.

Hi Troy!

First, thank you for this most excellent thread.

Second, I just received my ARC version of the focus sport (largely inspired by this thread!). I figured that the ARC version would be an uncovered incarnation of the ARF, but I've discovered an important difference. It seems that the ARF version comes complete with the fiberglass tube receiver for the aluminum wing tube already installed in the fuse. The ARC version does not.

In examining the pictures of your ship, I see that the tube is installed with plywood ring doublers on either inside of the fuse. I'll have to create these myself, since the kit doesn't seem to include them.

So then, do you have any advice how I might get this install step done with precision? I know this tube must be level to some reference in roll axis (canopy rails?), and square to the centerline of the fuse in yaw axis. I'm not entirely sure how to get this right.

Any help is much appreciated!

-George Mohr

Edit: it is worth mentioning that the fiberglass tube is not a perfect slip fit into the holes in the balsa fuse sides. There's about 1/16th inch play, just to make it interesting lol.

Installing the wing tube in a pattern plane is not what was intended for this thread. The idea was an ARF, however I thought the ARC's came with the wing tubes already installed.

Regardless this allows you to get the fit perfect and dead on. I prefer this usually. The Focus Sport I built was really close, but I think I could have done a little better by my own install.
So a quick and dirty review.

The sloppy fit is on purpose so you can shim and adjust to the wing in the model straight.

On a normal pattern model I like to work from the fin to the stab to the Wing. This keeps things in line easier as the fuse is molded. In the case of the Focus models the Fin is not always guaranteed to be straight as you have to glue it on. So working backwards from wing to stab to fin is probably the best course of action.

The plywood rings are easy to make. Just get a set of hole saws from Harbor Freight. The plywood centers that you cut out with the hole saw are the blanks. Use say a 1.5" hole saw maybe 1.75" then a 7/8" hole in the middle of the donut.

You triangle measure the tips of the wings on the tube and tube in the fuse. You also check the roll axis for straight. Shim and block up things to get it all aligned properly. Then tack glue the ply rings in place and on the fiberglass tube with a couple small dots of medium CA. Then carefully remove the wing and tube and use 30min epoxy to paint the donuts and build a small fillet between the fuse side and the wing tube center section.

Sometimes you have to elongate the holes in the fuse a little more to get everything straight. Most important is the alignment not the perfect fit of the socket into the fuse...The ply donuts are for that....make them fit the fiberglass perfect slip fit. Then the ring gets glued to the fuse sides.

I'll get in touch with the guys and see if the ARC models have the tubes installed already or if its standard to let the builder do it.

Either way its not much work, a couple hours tops. This above was a fast and dirty explanation to do it. There are other resources with step by step instructions. I just don't have them handy right now.

Troy

Thanks Troy,

For clarity, after tack gluing the completed and measured setup, I should remove the wing and tube, but leave the ply rings tack glued (since they are the item holding the alignment correct). If I understand you correctly, the epoxy only creates a fillet around the ply ring, and the epoxy is not used to glue between the ring and the balsa fuse side. Do I have that right? If so, I suppose wicking some thin CA in between these parts first is probably a good idea?

Regards,
G

If you use a thin 30min epoxy or even better some finishing resin. This stuff is really thin and it will soak into the joint between the ply ring and the fuse side.

Yes remove the wing and tube lest you glue them onto the model.

The ply rings and everything are tack glued in place and stay put to keep alignment.

I would make the ply rings fairly large for surface area contact with the balsa sides. This means the plywood ring might be 1/2" of plywood all around the socket.

But let me contact Piedmont and double check to make sure you didn't get a one of....I also need to look at the inside of my Focus Sport to confirm the ply rings and how they did it. Its been a couple months since I had the canopy off the plane. A buddy has been flying in a couple contests since mid May and I have been working on my Euphoria Bipes for the NATS. Right now my mind is blank on Focus Sport stuff.

Troy

You sir, are the man.

I don't mind doing this step myself, its a good experience and I'll be able to make it "just so".

-G

Ok looked inside last night....The fuse sides are balsa but they have a 1/32" ply doubler on the inside where the wing attached.

So you just glue the plywood rings directly to the sides of the fuse. A couple spots of medium CA the Purple Bob Smith stuff. The tack glue the fiberglass socket the plywood rings same way. Don't get carried away with the CA. We want the epoxy to penetrate and absorb into the ply for the best possible bond.

Then remove the wings and tube after all alignment is perfect and everything is tacked in place....and epoxy the socket and plywood rings in place.

Here is a drawing of the plywood rings and the socket. In this case the socket was phenolic or Carbon. The fiberglass socket is usually lighter weight....but same idea. Sometimes the 1" ID is too large for the socket...so you need to under size this middle hole and open it up with a dremel tool drum sander and the like to get a perfect fit on the fiberglass socket.

Also try to have the socket over sized just enough to pass through the fuse sides too. This will make everything stronger...The socket should come out flush or near flush with the outside of the fuse side. Carefully trimming and trial fitting will get it correct.

This way the socket has a mechanical link to the fuse side not just relying on the glue joint of the plywood rings to the fuse side.

If you have to open up the holes in the fuse side to get perfect alignment only open one side up...this will make life easier. The other side will stay semi tight and the "loose" fuse side will allow for the adjustment. This is a trick to helping in the process.

When triangulation measurements are taken choose a point on the wing panels that is the same...You may have to double check to make sure things are the same. Never trust sanded wing tip edges. However joints where the wing tip meets the foam core are usually pretty accurate. I suggest checking multiple points like aileron cut out corners and such...But measure and make sure they are the same on both wings...Sometimes an error in cutting out the ailerons or facing ti will translate into a problem with the alignment.

Finding a reference you can trust is sometimes difficult. for this triangulation.

Also the reference of the fuse being straight in the roll axis can be a little tough at times too.

You have to find out what you can trust...Don't blindly assume that the canopy rails are the reference, although they should be. On the Focus the bottom of the fuse is suppose to be flat too...but again don't blindly trust it. Setup the fuse on a flat table and check the fuse side with a square. To help hold everything from moving a little trick is sand bags. I have also used bags of pinto beans or little weights. These help keep the fuse from moving around. If you find a reference or can shim the fuse a little here or there and then the canopy rails become the reference and are good use them... Bubble levels, digital levels are great ways to keep checking your reference during the process. Before you glue it all up double check it. Go have a soda or a beer and come back and triple check it. Then glue it in place.

Notice I said 1 beer not a 6 pack...the 6 pack can change the perspective a little.

Its not too hard but is a intimidating task the first time through. I have done it enough...Its a no brainer. You just need some patience.


Troy Newman