RE: SIMLA BUILD THREAD
 

Glad you're paying attention. ;) The post is #120, and the 189 comes from billberry 189, which was right by the post number, (so it's your fault...I'm from the Obama school of not taking any blame.)

No more political comments...I promise. :eek:

Duane

RE: SIMLA BUILD THREAD
 

Duane you are a funny guy!!!!!http://www.rcuniverse.com/forum/js/f...eeth_smile.gifI accept full responsibility for said error.

RE: SIMLA BUILD THREAD
 

One unusual thing you might experience about the "radio hatch", (from F2-F3), is the shape it assumes when you sand and round to shape. The hatch line assumed an unusual shape for me, (may not be straight) when the curvature went from curved to flat. This bothered me some at first, but then I noticed that from the side, the side view is preserved...the curved hatch line is just a byproduct of sanding between two formers with different shapes...no big deal. If I remember right, Jeff said he might take a look at that with the idea of changing it...don't know if he did.

It looks like you have a lot of room to round the fuselage bottom into the triangular stock if you choose. This gives a more curved appearance like Ed's, and takes off unnecessary wood, (translated weight). I'll take some pictures of the finished hatch area from my Simla to try to illustrate what I'm talking about. I don't think the "inverted picture" above shows it, (I had only sanded on one side), but you might want to take a second look at it.

Duane

RE: SIMLA BUILD THREAD
 

In relation to the elevator, rudder and aileron gaps, I have been playing with something that gives plenty of travel and almost no gap. It takes a bit of effort to get it just right, but IMHO it is well worth it. It looks like the bottom drawing on the attached photo.

RE: SIMLA BUILD THREAD
 

Bill,

Looks like an interesting variation on the shrouded hinge lines of, say, warbirds, where the top and bottom sheeting extends past the TE to cover the hinges. I think you also could achieve max deflection with a rounded LE on the rudder by using Robart hinge points with the actual pivot point set back into the rudder's LE. I confess that my personal experience using the hinge points has been a study in aggravation and gaps that I consider to be excessive.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Richard, that is correct about the warbird hinge line. I too have worked with the Robart hinge points, but I felt the Dubro flat hinges would serve the purpose better on the Simla. When assembled, the travel on the rudder is about 45 degrees(or about 2.5 inches to each side)to either side,and when I hold the fin/rudder assembly up to a light source no light appears along the hinge line. I'll try to post a photo soon.

RE: SIMLA BUILD THREAD
 

FUSELAGE CONTINUED

Here are some additional pictures...this time a bit further along, but probably not as far along as billberry 120;)

Before I get people disagreeing with me on technique, remember that each builder is "king", and you build to your own taste. I had a very definite idea of what I wanted and what looked right to me. We were not only interested in building to the plans, (the plans could be changed), but were primarily guided by the photos of Ed's Simla, and we constantly tried to capture his look in the final product. On the prototype I found myself constantly trying to make it look more slender and less like a 150% Taurus. I "sanded the heck" out of the blocks to make it as slender as possible. When we met to discuss our prototypes and suggestions for changes, Jeff and I agreed that the actual Simla was more "slinky" in spots than the prototype as originally drawn. Each of us built small details of our prototypes differently so we could test out what worked best. One example was the fin, and along that line, Jeff realized the need for the fuselage nose change sooner, and actually rebuilt his fuselage narrower than Kevin and I did. Your kits already reflect the plan changes, and should be more narrow in the spots where the prototypes were too thick and "Taurus-like".

I'd like to draw your attention to the picture of the long, rectangular box...believe it or not, THAT is the Simla before the sanding starts. For those of you used to modern ARFS and kits with fuselage formers that are sheeted, THIS was the traditional way to build a fuselage in the 1960s. You used blocks and hollowed out a solid balsa top block shaped to the rough side view outline. It isn't much to look at is it? That will change quickly!!

As I said in the Simla article, my favorite part of the fuselage build is the afternoon when the box is transformed into a shapely Simla fuselage with the help of my trusty electric orbital sander and some coarse sandpaper, (I feel the orbital sander isn't absolutely essential, but boy is it nice to have). It keeps you from becoming discouraged with the time it takes to do the job by hand. With the sander it actually isn't nearly as bad as it seems, and the balsa dust flies off. Of course, you must always keep your ultimate goal in mind and pay close attention. Have some definite lines drawn that you sand up to...but not beyond. I draw a centerline on the top block, (which is already approximately the correct height according to the plan side view).

This I'm sure is obvious to many readers, but notice in the inverted picture that your fuselage bulkheads become your lines to sand up to. I sanded the fuselage bottom with my two hatches in place to get a uniform final shape, (see post #120 picture of the inverted fuselages together..that was 1/2 rough-sanded at the time). When you get close to those fuselage formers, it's time to start taking it easy and take your time. For those of you who haven't built much, you will develop a sense for what to do and when to do it. It is just so "cool" to finally sand down to those curved formers and leave the "box" behind.

On the top, don't be afraid to sand into the area where the nose top block and the main top block come together. This joint forms a very noticable angle and bulge...your job is to get a smooth curve from one block to the next so that nobody should be able to tell just WHERE the blocks join. It doesn't hurt at all to take off a lot of wood on top to get that nice top line. It is important to me to try to match the slope of the spinner when viewed from the side. It makes a big difference in the overall sleekness of the final model, and you don't need lots of structural strength there anyway. Just be sure your curves are smooth and uniform, and don't get too aggressive, (especially on the side where the blocks join the fuselage and the engine area). Look at the picture of the side view below. Slightly darker areas where the nose top block joins the fuselage side are thin spots. Watch these areas on your plane just in case...again, your kit has been modified from the prototype so none of this may happen when you try to get that smooth, sleek look. If you do sand too far, you can add wood, (or I sometimes use 1/32" ply), to repair any holes, or thin spots. Use some scrap wood/balsa filler or whatever you need to fix the area.

After the rough sanding, you graduate to finer sandpaper, and it takes on a much more refined look. Keep sanding being careful not to let the orbital sander take off too much. Final sanding is achieved when the balsa has a slippery, (even a bit shiny) look to it.

You can see from these pictures that even after the fuselage is rough-sanded, there are little areas or bulges that you will want to make sleek and of uniform curvature. These pictures were taken early, so the fuse looks thicker than the final Simla. When you are done with this phase it will look like you're really getting somewhere.:)

Happy sanding!! :)

Duane

RE: SIMLA BUILD THREAD
 

BTW.....Notice in picture three above the method Kevin devised to retain the wings to the fuselage. Two 1/4" nylon bolts in either plywood or hardwood keep the wings from backing out on their own. After seeing what he did, Jeff and I decided to use Kevin's method instead of rubber bands, or screws into the wing tubes or whatever. After my Simla's eight flights, and (Kevin's 8-10 flights), there have been no problems with this method.

Questions on this??

Duane

RE: SIMLA BUILD THREAD
 

BTW #2

With all the mentions of Kevin and Jeff in the text, I decided to go back and edit post #189 ;), (no that's post #1), to include photos of the three of us so you can associate the names with the people.

These pictures were taken at Triple Tree, (site of Joe Nall) October 2nd 2010 of the date of "prototype #1"'s first flights. The first photo shows Kevin and Jeff trying to look calm and confident before the first flight, and the second is of the three of us taken AFTER we knew that it would fly. ;)

Duane

RE: SIMLA BUILD THREAD
 

Lots and lots and lots of sanding.............

RE: SIMLA BUILD THREAD
 

Do you have an electric sander?

Are you about ready for the wing?

RE: SIMLA BUILD THREAD
 

Duane, I do not havean electric sander but my air driven DA sander works quite well. Thanks for asking though. Yes I am about ready to start the wing but I must wait until I can order the CF wing tube and sleeve since the holes for the larger sleeve and tube must be drilled individually in each rib. Finances dictate next Thursday as my next day for ordering any goodies.http://www.rcuniverse.com/forum/js/f...sappointed.gifOh well, there's plenty to do with detailing the fuselage and tail feathers. I suspect that by the time I actually receive my tube and sleeve I will either have the fuselage painted or at least ready for paint.

RE: SIMLA BUILD THREAD
 

What are you going to use as covering material, or are you going to paint the balsa itself?

I can recommend the Polyspan Lite material I used on my prototype and briefly discussed in the article. It adds no particilar strength, but it is a good base for the paint. It's a heat-shrinkable tissue-like product that is very easy to work with. This is the only material I've EVER used, (I am only so-so in the covering department), where I was able to remove all wrinkles prior to doping with nitrate dope...even in highly curved areas. It produces a wrinkle-free surface. If anyone wants a more detailed description, or application techniques, just ask and I'll post in greater detail when we get closer to the finishing end.

Duane

RE: SIMLA BUILD THREAD
 

Possibly in the original Taurus thread, someone mentioned covering everything with carbon veil and nitrate dope. The veil is very thin (you can pretty much see through it), but would add a bit of strength and ding resistance. Since I have the veil, I have planned on using it unless someone knows of a problem. Then, solely in the interests of saving weight, I was going to use Ultracote.

I had planned on painting, but with the field at 7,000 feet and density altitude hitting 12,000, I'm loathe to take a chance on adding excess weight, even with the 1.20 AX engine. Does anyone have a better idea of the difference in weight between paint and Ultracote? If it's only a few ounces, I'd prefer to paint. If it's a pound or so, I'll stick with the Ultracote.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

I'm sure I could have finished the Simla with the Radio South polyurethane paint so it weighed less than it did, (I had a couple minor "runs"). All I know is that my wing was a full pound less than Kevins, but my finished plane wound up weighing a pound more...that's a two pound difference. The Ultracote would have to weigh less.

I did the best with the skills and the sprayer I had, and I take some comfort that the paint LOOKS beautiful, but at 10.5 lbs. final weight.

Duane

RE: SIMLA BUILD THREAD
 

I am going to be using 0.5 oz. glass applied with two coats of brushed on urethane clear, sanded smooth with 180 grit and then one coat ofsprayed on urethane clear sanded smooth with 320 grit. After that two sprayed on coats of each color in base coat (very light weight) followed by threesprayed on coats of urethane clear. If needed I will wet sand with 1500 grit and buff the wholething. That just about covers my finishing techniques.

RE: SIMLA BUILD THREAD
 

Just weighed everything - fuse and tail feathers 37.5 ozs.-engine, prop, spinner, motor mount 35 ozs. - tank 2.9 ozs.- landing gear with Dubro ultra light wheels 7.4 ozs.- canopy 1.9 ozs. for a total of 84.5 ozs. or 5.28 lbs. All of these weights are dry weight before any covering.

RE: SIMLA BUILD THREAD
 

Certainly sounds like you know what you're doing...where were you when I needed you? I would have paid your expenses to Asheville, and begged you to paint my prototype.:)

Duane

RE: SIMLA BUILD THREAD
 

I confess I'm hoping the rest of the build is more straight-forward than the fin. I think I have enough balsa dust to make two or three little Guillows gliders and I'm still not sure if the transitions are right. I suspect that I'll call it finished when I get tired of messing with it. Okay, enough whinging.

Naturally, after I sheeted the rudder, I reread Duane's post that mentioned adding a hard point for the control horn. That's now done and the surgery doesn't look bad at all.

I'm hoping to get started on the fuse today after work. Still need to sheet the fin and make a few magnet-attached triangles to hold the fuse sides in position.

I'm still trying to come up with a scathingly-brilliant way to open up the holes in the fuse and the ribs for the new carbon wing tube sleeve. This may actually have to wait until I have the new parts from Radio South RC, since I have no idea of the actual diameter of the new sleeve. Right now, my idea is to create a tool with a pilot the size of the current holes, and a tapered sandpaper-covered section that will open up the holes to the correct diameter. I like the idea of the pilot, but I'm not completely thrilled with the sandpaper part. Right about now I wish I had a lathe.

Bill, perhaps you have an idea?

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

I confess I'm hoping the rest of the build is more straight-forward than the fin. I think I have enough balsa dust to make two or three little Guillows gliders and I'm still not sure if the transitions are right. I suspect that I'll call it finished when I get tired of messing with it.

I'M WONDERING ABOUT ALL THE BALSA DUST YOU SPEAK OF. I DON'T KNOW EXACTLY WHAT YOU DID, BUT IT SHOULD HAVE INVOLVED SOME RELATIVELY MINOR SANDING OF THE AREA AROUND THE L.E., THEN RE-SHEETING THAT AREA. HOPE YOU'RE HAPPY WITH IT.

I'm still trying to come up with a scathingly-brilliant way to open up the holes in the fuse and the ribs for the new carbon wing tube sleeve. This may actually have to wait until I have the new parts from Radio South RC, since I have no idea of the actual diameter of the new sleeve. Right now, my idea is to create a tool with a pilot the size of the current holes, and a tapered sandpaper-covered section that will open up the holes to the correct diameter. I like the idea of the pilot, but I'm not completely thrilled with the sandpaper part. Right about now I wish I had a lathe.

WHAT SIZE TUBE DID JEFF MAKE HIS HOLES? THE HOLES IN MY KIT WERE THE CORRECT 1 INCH SIZE, BECAUSE I DON'T REMEMBER A PROBLEM GETTING THE SLEEVE TO FIT. I JUST TALKED TO KEVIN, AND HE BELIEVES THE HOLES WERE 1" TO FIT A .99" SLEEVE WIDTH. HE WILL DOUBLE-CHECK. IF THAT'S THE CASE, (1"HOLES), THEN I WAS WRONG WHEN I SAID IN POST #3 THAT THE TUBE ITSELF WAS 1"...THE O.D. WAS 1", THE TUBE WOULD BE SMALLER THAN 1". IF JEFF WENT TO A 7/8" TUBE FOR THE FINAL KIT, I WAS NOT AWARE OF IT. I HOPE NOBODY HAS BEEN "MESSED UP" BECAUSE OF CONFUSION OVER THE TUBE SIZE.

IF THE HOLE IS ONLY FOR A 7/8" TUBE, YOU COULD 1) GET ONE OF THOSE ARCHITECTURAL HOLE DRAWING "THINGS", AND DRAW NEW HOLES, AND CUT THEM OUT WITH A X-ACTO KNIFE, OR 2) GET A 1" HOLE BIT, OR 3) SIMPLY USE THE SLEEVE ITSELF TO IMPRINT A CIRCLE ON THE BALSA, THEN CUT THEM OUT SOWEHOW. 4) A DRILL PRESS WITH A 1" BIT WOULD BE NICE.

[b]GETTING AN ORBITAL SANDER...(MINE IS AS OLD AS I AM, AND I INHERITED IT FROM MY FATHER....I HAVE BUILT EVERY PLANE I'VE EVER MADE USING THAT SANDER...I'LL INCLUDE A PICTURE) WOULD REALLY BE WORTH IT. I'M SURE YOU CAN FIND ANOTHER USE FOR IT AROUND THE HOUSE LATER, AND THERE WILL BE OTHER PLANES.[/i];)

RE: SIMLA BUILD THREAD
 

Richard, I have several ideas but I am waiting until I get my tube and sleeve before I settle on just one. I'll let you know asap. In the mean time maybe someone else has some ideas born of experience with wing tubes and sleeves. Right now I am pretty much occupied with shaping, smoothing and covering the fusalage and tail feathers with 0.5 oz. glass cloth and urethane clear.

RE: SIMLA BUILD THREAD
 

Duane,

Here are a couple quick images.

I'll have to check if my recently-bought-but-not-yet-used sanders are orbital or random.

Richard

http://www.ragtopphotography.com/Sim..._edge_4015.jpg http://www.ragtopphotography.com/Sim..._side_4016.jpg

RE: SIMLA BUILD THREAD
 

LOOKS GOOD;)

RE: SIMLA BUILD THREAD
 

Thanks! Shall cease fretting and get on with this.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Ditto