drobbs

My Feedback: (1)

You've got me on that one. All I know is that I set mine the way I stated and there's no problem. Also, especially if you haven't flown a bipe before, now you've got 2 ailerons / side and this isn't a 3-D machine. When you statically test for maximum deflection, you've probably gone way too far compared to actual flying conditions. Let's see what the other guys say.

somegeek

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drobbs - After looking at the angles again and your comment regarding 3d throws, I did a sanity check and I will just connect the upper and lower ailerons on the back edge.

Got to working on the cowl. Using a straight edge razor and cork backed ruler worked great to get clean edges on the two halves...





Can also press the back edge flat to clean it up...



I used CA to put it together and a few of the molding scraps as reinforcements on the upper and lower seams. The CA worked great on this plastic as it partially melted the surface as it set up. Tested the bond on some scraps and the plastic will tear before the bond breaks. Good stuff.





Need to figure out what I will use to smooth this seam which will still remain flexible and not add too much weight.



Got the upper wing mostly sanded. Next is to get some putty on it to fill stuff in. Sure cleans up nice with some sanding.



To bolt the wings on I will use 4-40 hardware. Added hard spots on the upper wing. Will install small 1/4" ply blocks with 4-40 blind nuts on the outsides of the cabanes to attach to. Going to add two 1/8" carbon fiber rod cross members to add some rigidity and will remove the rubber band hook ends on the cabanes.



Lower wing hard points. Added blocks inside the fuselage to bolt into using the same hardware size. Still need to sand and putty the lower wing.



Think I figured out a color scheme as well. Getting close to covering now at any rate. Gonna somewhat copy the scheme on my Sig Somethin' Extra...





...cept use Ultracote Corsair Blue and Ultracote Pearl White and maybe some Monocote Pearl blue for some accents.

somegeek

somegeek

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Put the upper wing mounting blocks together tonight. 1/16" ply w/ 1/4" ply to get the proper height to match the cabane for mounting. Drilled holes for the carbon fiber rods and put the blind nuts in place before mounting...



In place with epoxy to dry overnight...



somegeek

somegeek

My Feedback: (2)

Cut off the rubber band mounting tabs from the ends of the cabanes...



Got the upper wing drilled and the washers counter sunk. Wing mounted with bolts cut to length. Still need to add a few drops to the back bolt holes to harden the tapered hole(screwed the screws down tight to crush the taper vs trying to do this with a drill.



Bottom view...



Pretty happy with the results. Kinda pondering adding washers to the back bolts.

somegeek

Scar

My Feedback: (3)

Great build documentation, great thread. I have a Herr Pitts, don't know when I'll start on it, but I'll definitely refer to this thread.

Also liked your graphics that read 'Somegeek's Extra', is it printed, painted, or cut from vinyl covering & ironed on? Or other?

Looking forward to seeing the completed item and some flignt documentation.

Best wishes,
Dave Olson

somegeek

My Feedback: (2)

Thanks for the kind words.

I spent some time in MS Word getting the fonts matched up to the kit sticker and then printed the size I wanted. Taped over a monokote trim sheet and cut out with a razor. Applied with windex and then a little heat. Good tips in this thread if you have questions regarding this method. Monokote graphics and another Monokote graphics thread.

somegeek

drobbs

My Feedback: (1)

Back now after a long trip. Your method of bolting the wing on looks different than mine, but still a great job. On your cowl, you might consider placing a patch of CA hinge material in the cowl in those areas you drill through for mounting. It will strengthen the holes considerably. Have you started to mount the lower wing yet? Also, regarding the aileron throws - unless you plan to do 3-D, as builders we tend to want our control surfaces to move a minimum of 45
degrees. But when you actually set the plane up, you'll rarely exceed 25 degrees (on high rates). Anything beyond 25 degrees and the plane becomes overly responsive and unless you're VERY QUICK, the plane will be more than a handful.

somegeek

My Feedback: (2)

drobbs - I have the lower wing mounted. Did this last night. Need to add some pics. Been a busy week.

I did manage to create a covering template for sketching up designs over the last few nights. Have my color scheme figured out(I think). Fired up Visio, grabbed a yard stick and the plans. They're not perfect but pretty dang close.

herr_pitts_special_bipe.vsd - Visio 2003 Diagram



somegeek

drobbs

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This is my color scheme - just like on the box except for using yellow trim instead of white. Yellow is easier to spot in the air.

somegeek

My Feedback: (2)

Herr's plans are great for the engine mounting box since they have lines drawn for the different size of engines.



Came up with a covering scheme...



Got the sides and bottom of the engine mount installed. Got an itch to do some covering so I covered the upper wing since it was ready. Did Ultracote over Ultracote for the pearl white stripes with windex and an iron which can be touchy but it turned out okay. Had a few bubbles that got a pin hole to flatten. Goldberg Smoke colored trim tape. While trimming a piece of tape, I dropped my scissors and put a hole in the left side of the wing. Got it patched... crappy lesson to be a little more cautious.



somegeek

balsabuster2003

Subscribing.

somegeek

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Hey balsabuster! We get any more rain and we'll be using floats at the field.

somegeek

Phlip

All you have to do is click the subscription link at the top right of the page.

Andrew

SomeGeek --

Was that a HERR option for the mounting blocks on the upper cabanes or your design. If yours, then my compliments -- they were very well done and nicely designed. Even if a HERR option, you did an excellent installation.

somegeek

My Feedback: (2)

My design. Thanks man.

somegeek

balsabuster2003

Thanks, Philip, I thought there was another way.

Chuck.

somegeek

My Feedback: (2)

Got the tank and firewall installed. Triangular stock installed with epoxy on all edges possible inside motor mount box since the top won't be closed up too much with the Hayes 3oz tank being a little tall. Used 5-ply birch plywood for the firewall. Before mounting the firewall, I mounted the triangle stock to the front edge of the bottom and sides of the box and sanded that front surface flat so the plywood would have an even smooth surface to mount on. Shifted the engine mount ~3mm to the right of the stock mounting position since the firewall is further back than the stock position to assure it lines up in the center of the cowl.



Painted the cabanes with white Aerogloss dope. Will do the same with the outer struts.



Got the throttle servo mounted. Didn't have small rubber mounts so I inserted a 1/16" piece of fuel tubing betwen the servo and the surface it's mounted on for some vibration absorbtion.



Bottom wing finished. I mounted the bottom wing and then used a pencil going in through the back of the fuselage to figure out where the servos would mount without interfering with each other nor the fuselage.





Mounted the horizontal stab tonight with epoxy. Used pins to keep in place while setting up. Usually check it every few minutes while the 30-min epoxy sets up since it can lean a bit while the epoxy sets up. A plastic clothes pin was just enough weight to keep the stab parallel with the upper wing until it set.



somegeek

Tee Bee

It's looking great, somegeek. I'm enjoying this build.

somegeek

My Feedback: (2)

Got the fin and blocks mounted. Epoxy works great(not only for it's adhesion properties) for this when your truing up your angles if they don't match the surfaces of the fuselage. The epoxy doesn't shrink like Titebond II so it should stay where you brace it to set. For those not familiar, you want your tail surfaces squared up with your main wings. I did my best to mount the top wing square and level and trued up the tail feathers off this as a reference. Just the elevator mounting needed a slight tilt to match the main wing.

Also covered up any darker spots with White Aerogloss dope so they won't show through the Pearl White Ultracote. Funny how CA shows up as a dark spot when taking pictures with the flash.



The fuselage tail end ended up slightly shorter than the fin so I put some microbaloons on the end to build up the tip so I can sand it to match the fin for the rudder mounting.



First time using the microballon/epoxy mix for a filler. Cool stuff.

somegeek

somegeek

My Feedback: (2)

Polished up the 2-56 control rods for the tail feathers... can tell the one that is not polished. Used aluminum polish. Quick hit with it makes them look really nice.



Side view of the control rod path.



Top view... sliced a piece of fuel tube down the side and slid it between the servos as they were very close when secured.



Bottom view of the tail feather servos...



Going to cut out this hole in the covering to access the servos and then install a piece of covering over the hole with a 1/4" overlap so removal of the covering to access the servos won't be too difficult. The HS-81 3-hole dual arm horns fit with about 1/4" of clearance from the side covering after cutting off the opposite arm.

somegeek

somegeek

My Feedback: (2)

Nice reference da Rock posted on the differences with the movement of the aileron surfaces due to the staggered positions of the aileron pivot points. Sanity check for me.

I did ditch this design and installed the servos in the center of the bottom wing in the fuselage and will just go with aileron horns on the inner surfaces of the ailerons. Figure with the smaller deflections I will be using, I won't need to install the upper aileron horns on the top surface.

somegeek

somegeek

My Feedback: (2)

Got the fuselage covered...



Was a bit tricky covering the tailfeather blocks. Had to cover them with two pieces with a seam down the middle. After that things went pretty quickly. I thought covering the tailfeather surfaces would be tough with them being so thin but they went pretty quickly and turned out nice. Taking advantage of a hot iron and Ultracote's shrinking ability at high temp helped get smooth overlapped edges.

Elevator linkage...



Rudder linkage(added 1/2" of material to the rudder surface before covering)...



Bottom view... was going to go with a pearl white bottom but I wanted more color on the bottom surface to better see this in the air.



I cut out the material to acces the servos to install the control rods. I taped this scrap to the front of my plane build manual for later use as a template.

Need to visit Home Depot with a chunk of covering to spray my cowling with. Gonna paint with latex and then clear dope.

somegeek

somegeek

My Feedback: (2)

I think I might have brainfarted with this antenna installation... I didn't want to use the bobbin to decrease range and I had good luck on a foamie stryker by installing the Rx wire in a V shape where the ends of the V were about 12" apart. Am I going to run into issues with this antenna routing? Folks say not to double back an antenna on itself, how close does the antenna routing have to be for it to be a bad thing? I could put half of it on the bobbin and then route the antenna down and back just once using the outer-most holes if folks think the current configuration will be an issue... appreciate any input!

Edit - called Hitec and they stated that every time you double back the antenna you cut the range in half so this configuration would yield 1/4 the range it would normally have. Thinking I'm near the same boat I'd be in if I just spooled up 18" on the bobbin and then routed the antenna down and back?



Read about using dental floss for lacing in cables to keep them from getting tangled in the wrong places. Drilled some 1/16" holes and laced stuff in.. looks nice and much cleaner and lighter than a zip-tie...



Laced the ailerons servo leads together as well to keep these from interfering with any moving parts...



Finished up the upper ailerons...



somegeek

somegeek

My Feedback: (2)

Baslabuster2003 forwarded a great reference... R/C Antenna Experiments - Does Rx Antenna Length Really Matter?.

somegeek

somegeek

My Feedback: (2)

On the home stretch of this build...

Got the wing cabanes sanded and fit and the port side cabane is 1/8" short to span the gap between the wings so I added a piece to take up the slack... and then started wondering if this 1/8" difference will make a big impact on flying? The empanage is squared up with the upper wing. The lower wing is the surface which is off slightly.





Truing up the lower wing would involve altering the lower wing saddle. Would this be worth the trouble?

somegeek