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Nutech's blog
Posted by Nutech | Mar 22, 2011 @ 09:38 PM | 4,191 Views
Hi Guys I've started making aluminum servo arms for the popular servos in the market. Currently, we have Futaba, Hitec, Airtronics JR (Sanwa) and we're working on Hyperion's atlas line. If your not sure of the sizes needed for your servos, you can check here for compatibility list. If you're interested in other sizes, please send a PM to my attention.

Our arms are broached! No plastic adapters used here. We're packaging them in sets of two (2) for $11 US. plus shipping by POST to you're postal code.

Arms are remove and replace. They are taped M2 or M3 thread sizes for use with ball-links or standard clevis. We have arms in different sizes. Measured from the attach point to the out side clevis hole run 4/100 5/100 (1/2) and 7/100 (3/4). Customs sizes can be made too.

Our designs use a counter-sink feature for flat-head screws when clearances across the attach screw is needed for clearing you're ball-links. This configuration is popular with DS glider installations. Of course, you can always use the stock screws supplied with your servo too.

If you have fast flying gliders you should look into replacing stock plastic arms with aluminum. Of course our arms can be used with robots, cars, helios and aircraft.

If you need more information, you can send a PM or use e-mail. We're working on a website where customers can use PayPal for orders.

Steve

Servo Horn Compatibility

http://www.fyf3f.com
Dynamic Soaring
Posted by Nutech | Mar 01, 2011 @ 07:21 PM | 3,774 Views
Those of you who haven't acted yet, stop what your doing and get on it.

defend your right to fly model aircraft without government oversight
Posted by Nutech | Oct 26, 2010 @ 12:34 AM | 4,130 Views
Well, today we had a little wind so, over the edge she goes

We maiden our gliders at a location called Bluff-Park. It's located in Long Beach, California.

The Bluff is about 60 feet above the beach making for a good emergency landing area if something unexpected occurs However, we didn't have to declare any emergencies.

Trims were checked and were all set at zero through out from the bench. We didn't have any ballast in the ship for a light breeze blowing out of the S-SW between 14-16mph.

A flight check of the controls surfaces looked good and in this light breeze, we left the flaps in upper track, called the release and Steve tossed her to windward. She climbed out about 10 feet after clearing the rail and Steve said she was flying hand's off. I got to tell you using the "Arrow Perfect" digital inclinometer was spot on too. We didn't touch the trims at all. However, we did adjust for a little more down elevator as we felt it needed a bit more when flying in full flaps. We added the same amount in the CROW setting too when configured for landings.

The landing area is about 30 yards wide but you have to land in a cross wind. The cool thing is we have cut grass to land on.

Anyway, Steve indicated she was rock steady in the landing approach and he greased her in.

This is a great glider guys. Loads of fun to fly. We can't wait until we get our usual winds so we can check the performance with ballast on board.

Here is the video I finished cutting from the footage today. I posted a HD version on YouTube. Let us know what you think of the footage. Thanks for watching...

Steve

NAN Models 2m Speed (1 min 16 sec)

Posted by Nutech | Oct 26, 2010 @ 12:32 AM | 4,520 Views
Tonight I tackled tuning the glider in preparation for a maiden flight.

I start by making a lot of room on my bench for mounting a 2 meter wing span. I mount or secure my gliders to a board I build from a Paul Naton Video I saw once. I thought it was a great idea since working around this size of glider while programming it can be a task if you keep knocking it out of level or bump into it during the programming of your transmitter. Try it, you'll like it

I fly with Futaba's Z9 radios and mine are equipped with 2.4Ghz gear so I don't have to worry about shooting someone down or someone shooting me down...

Start by setting your glider level. I use some foam blocks cut to shape to fit the fuselage and then secure it. I use a seven second bubble level to adjust the model for level.

Next, I use three simple deflection gages setup where the flap and aileron meet and one more on the rudder. Since this glider is equipped with a full flying elevator I can't use these gages because there's no place to mount them stationary but, I have a electronic or digital inclinometer in my toolbox for setting the decalage between the wing's cord and the angle of attack of the elevator.

Mine is a AeroPerfect model and I use it with two Robart incidence meters after removing the pendulums. Place each, one on the wing and one on the elevator. I guess you could use one but, if you bump the model while moving it this process is going to take some time...

Anyway, start by setting...Continue Reading
Posted by Nutech | Oct 26, 2010 @ 12:25 AM | 4,206 Views
Well, I know it's been a while since my last post. So, lets get back to business.

I finished the flaps after doing the ailerons. This is the first time I done a top drive. I wasn't that big a deal.

I guess the scariest part was cutting that nicely painted wing skin. I decided to use a method I saw Finwizard used to build a NAN Shadow. He layout some paper templets. I downloaded the PDF file, fixed the scale, printed a few copies and using my trustee flash breaker tape to set the templets. I alined the reference skin lines and the center line to the upper wing's skin's EOP and went at it with a hand Dremel.

You'll need to clear a small area of the wiper just in front of the control horn's location. Take your time it pays off being carful here...

Next, I installed the control horn in the flaps and trial fit the linkages to see where the hight of the horns needed to be. After which, I used epoxy to set them.

After the epoxy sets up, place the clevis on the flap control horn and noted the locations in the rear spars where you need to open it to reach the servo bays. Again, take your time. Measure twice and cut once. By the way, this took the most time to perform.

Clean up the parts and prep the pockets for the servos. I used the same technique used on the ailerons. Let the RTV cure over night before messing with it.

I hooked up my Hitec HFP-20 to the servos and check for any problems like clearances. After which, I installed the upper fairing.

Checking the deflections, the flap has about 45mm just as the wiper start to uncover. Plenty.

Steve

References:
http://www.rcgroups.com/forums/showt...841007&page=13
Posted by Nutech | Oct 26, 2010 @ 12:06 AM | 5,470 Views
Today I tackled installing the wing servos and covers.

I like started with the ailerons by locating the control horns first. And I start by placing flash-breaker tape over the locations where paint and epoxy meet. This tape work great in protecting paint from chipping if drilling is involved or where epoxy can get on the paint during bonding.

Time to make up the link between your servo arm and the control horn. I like to use ball-links on the servo end with a 2-56 brass coupler to mount a clevis on the other. The thread on the clevis and the link will provide enough adjustment to trim the surface and the servo turing radio programming.

After the control horns have cured, I trial fit the servo and linkage so as to allow for laying out the trim lines necessary to locate the covers. Start by using standard masking tape to mark the edges of the servo pockets using a straight edge and a sharp pen. Use this lines to transfer the flange edges onto each cover from a best-fit over each pocket with the servo temporarily installed. Make sure there is enough clearance between the ball-link and the inside of the cover to avoid rubbing then transfer the lines onto the cover. Cut the rough excess off using a pair scissors and finish sand the cover's edges so each fit into the flanges of their pockets perfectly.

Time to bond the servos in. But first, one point here before moving on. I steer away from the use of epoxy in small wings where you can't install wooden or plastic...Continue Reading
Posted by Nutech | Oct 25, 2010 @ 11:57 PM | 5,190 Views
Today I started building the wing servo controls. I like using ball-links and this glider has very small wing pockets to work within. So, I ended up using a Heli-Max Pro helicopter accessory kit. MX400. The kit provides enough parts to complete a seven (7) servo aircraft.

The balls provided in the kit measure just over 4mm with each having a small shoulder where the ball rest on its mounting surface and a 2mm counter sinked hole thru from the top of the ball. When used with the supplied screws, they set flush with the top of the ball.

The balls are machined from aluminum and fit each of the plastic injected female links without the need for sizing.

I've built other NAN's slope gliders where I used .046" music wire sporting Z-bends to attach them to the servo's arms and then soldering them into a 2-56 sullivan coupler to attach a clevis for some easy adjustability. However, Z-bens are notorious for slop developing after a few hard landing or just simply flying a number for hours.

But, this time around I wanted to find another solution to a quick Z-bend that would not have any play or slop but, still provide easy adjustment and a method of disassembly should the need arise. And the good news is it didn't cost much either.

Steve

references:

http://www.rcgroups.com/forums/showthread.php?t=1103750

Heli-Max Pro linkage set MX400 $6.29

Sullivan Copper Coupler $4.09

Sullivan 2-56 Gold-N-Clevises $6.99 Or, Hayes Clevis $2.69...Continue Reading
Posted by Nutech | Oct 25, 2010 @ 11:53 PM | 4,463 Views
Today I tackled the wing wire harnesses. I cut enough wire to make a right and left hand harness. I use Hansen Hobbies 22-24AWG wire for this task.

My radio gear is Futaba so, I use EMS J connectors. It's worth while to have a supply on hand to make any combination needed, male or female. The male plug is the same one used in making a female only difference is a male pin is used and a outer cover is added to the male plug.

I also used Dean's plugs for making this project plug-n-play.

I start by cutting the length needed to just reach the aileron wing pocket and strip, crimp and install a EMS female end. Remember, there is still a good length of wire on the servo. don't cut the length to short, you many still have to remove a servo.

This wire harness only uses one power and neutral lead run out to the servo pocket. I spliced a short segment of wire into this main run for the flap servo. I again braided the elements together and solider their ends onto the Dean's plug.

I use servo safety clips to guarantee the two will not come unpluged After all, when was the last time you check inside your first projects wings?

Steve


References:

Servo Connector Safety Clips
Sonic-Tronics
Aero Works

Wire and supplies
Hansen Hobbies
Tower Hobbies
EMS Electronics

Polarizing plugs
Dean's...Continue Reading
Posted by Nutech | Oct 25, 2010 @ 11:43 PM | 4,198 Views
Tonight I tackled the wire harness for the fuselage. The mark-off on each wing root are the same as Dean's four poll connectors.

I start by taping off the mark-off with tape. I'll use this as a guide and to help protect the paint while cutting the opening. I like using a Dremel tool with a very small bit. Take your time and you will be rewarded.

Next, I cut enough servo wire to combine into a harness. Four white elements for servo signals, one red element for DC volts positive and one black element for DC volts negative. I used a braiding technique for this small space instead of a winding of a round shape because the braiding method finishes with a flat ribbon shape making it easy to route under the servos forward to the RX area.

Breakout the soldiering iron and strip each element of the root end of your harness and tin each end and the plugs too. I used the female plug for the fuselage side keeping with holes already there this way nothing is protruding to get caught on something and maybe damaging the plug elements. After soldiering, ring out the harness and mark each signal on the cockpit ends of the harness. Use a heat gun to shrink the tubing. Be sure the leads are not to long between the left and right hand plugs.

Thread the harness over the ballast tube and under the servo tray. Bond the female plugs into the fuselage's wing root. Use 30 minute for this job you'll need the time to manage it it's a tight space.

Next, I trial fit the battery, RX and the...Continue Reading
Posted by Nutech | Oct 25, 2010 @ 11:35 PM | 6,126 Views
The first step was deciding on the location to place the female receiver. It should be placed in the thickest section of a wing root near or forward the joiner in the fuse root. I decided to place this set mid way between the leading edge and the wing joiner.

Since the receiver is bonded into the fuse, it's important to note whether you have access inside the fuse where the receiver will be placed. When your happy of the location, drill a pilot hole first and then follow it up with a full size drill. Now, I have a old Great PLanes step prop reamer who's final size is just right for the female receiver and a light press-fit. So, I used it to finish the hole size. The female receiver is .422" (10.72mm) in diameter so, if you were to drill it, use a letter drill "Z" .413" (10.51mm) and hand finish the hole for a light press fit.

Next, I trial fit the receiver in the wing root. When satisfied use some thin CA adhesive and a bamboo cooking skewer to carefully carry a small drop inside and to the join between the receiver and the fuse to bond it for preparation of the final bonding with epoxy.

Now, looking at the instruction provided with the multilocks, Multiplex recommends that their locks be placed in plywood at a glider's wing root. Well, since NAN doesn't use plywood to reinforce their model's root I decided to make a small doubler from 1/8" plywood to reinforce the area.

I guess this is where I should expand on why I laid out the location...Continue Reading
Posted by Nutech | Oct 25, 2010 @ 11:28 PM | 4,426 Views
Finished the servo tray with intergraded ballast tube. Modern adhesives helped make the job go quickly.

Don't forget to drill a small hole in the rear of the ballast tube to allow air to escape. Makes for getting the slugs out much easier.

I used laminating epoxy to fiberglass reinforce the ballast tube to the bottom of the tray before installing the blind-nut doubler and the plywood doubler where I'll use RTV to glue the assembly into the fuselage.

Measure and mark the center of the ballast on some tape so as to make locating the center of the ballast at the CG.

Finally, I used some carbon fiber sheet I had to veneer the top of the plywood tray. Makes it look racer......Continue Reading
Posted by Nutech | Oct 19, 2010 @ 12:45 AM | 4,561 Views
After a few measurements of the cockpit area I decided to use CAD to design the servo tray with an integrated ballast tube. I'm going to use Hitec's HS-5085MGs for the rudder and elevator with in line placement of both.

I started by modeling the servos first and then developing the tray around the servos.

After servo is positions just in front of a 1 1/2" opening for loading and removal of 5/8" ID x 1 1/2" brass slugs.

PDF file of the tray design to follow tomorrow.
Posted by Nutech | Oct 19, 2010 @ 12:41 AM | 4,481 Views
After working out the problems with the elevator yesterday, this afternoon I tackled the rudder. Not much room for anything larger then a Z-bend.

I applied a little tape around the control horn's location and removed what was covering the depression molded in the model's rudder with a sharp hobby knife.

Slipped the brass horn onto the Z-bend and epoxied it into the hole drilled.

After the epoxy setup I measured the throws both right and left looking to see if clearing a little of the wipers would be necessary. No problem.
Posted by Nutech | Oct 19, 2010 @ 12:37 AM | 4,453 Views
Well, tonight I took a look at a problem that needed to be address.

Is it me or are the X-tails gliders I've encounter from our friends overseas using CAD/CAM applications to develop their models seem to over look the kinematics of their engineering?

They seem to forget you must rig 3D designs into assemblies and check for interferences before releasing them to create production tooling. Now, I can understand missing one but, all? Case in point, NAN models X-Tail gliders like their Alex, Shadow etc. They simply blew it when it came to their full flying horizontal stabilizers.

When you rig the horizontal on the empennage and move it thru it's travel called for in the setup sheet ("as much as possible") you'll note the elevator will not travel far enough in "up-elevator" direction to even cause the rear pin in the bell-crank to reach the upper end of the clearance slot. Why?

Because they failed to check the kinematics of their 3D CAD design. The problem is NAN failed to check the clearances needed for the leading edge of the vertical stabilizer as it transitions into the fuselage and the lower skin of the horizontal stabilizer when it's in a full up position.

The fix is simple but, compromises the stabilizer a little because you can see the spooge used to glue the two half's together.

I used my dremel tool with a 1/2" sanding drum to move the angle of the lower skin on the horizontal forward to match the angle of the vertical. If you set one side up and run it thru it's paces you'll see where the interference is and what it will take to remedy it. Take your time and be careful sanding a little then check it again. In no time you'll have it fixed.
Posted by Nutech | Oct 17, 2010 @ 11:41 PM | 5,278 Views
Over the next month I'm going to share the approach I uses to build one of NAN Models Alex 2 meter XL molded carbon gliders.

Earlier this year a friend and I build two of NAN's Alex 1.5 meter molded gliders and it's a joy to fly at the local slopes here in Southern California so, we both started eyeing their next step up and decided to do two of their 2 meters molded gliders too.

Anyway, for those of you who haven't seen NAN's glider before, I started by taking photos of the model fresh out of the bags.

With the experience of their 1.5 meter under my belt now and with a little more room to work within, I started by procuring the hardware I will outfit the project with. Starting with the intent of using more voltage. 6vDC volts to be exact. This higher voltage will supply a little more performance and safety too. With the use of a 5 cell battery pack, it will increase the speed and torque of the servo's output.

Looking at the space available in the nose of these gliders I'm going to use a custom battery pack so, I contact Hawk Ung at TNR Technical in the city of Santa Ana. Hawk has a huge supply of batteries in many "form factors" on hand and makes it easy to develop a custom pack to fit your needs. He also welds the cells to one another and only soldiered the hobby wire to the polls. After which, the packs are heat shrink wrapped. If you know the length of the hobby wire you'll be needing for your project, he'll put the correct male plug on the wire...Continue Reading