rg1911

My Feedback: (1)

Duane,

Thank you for the information. Let me see if I understand correctly.

1. For the fit of the aft top block and the vertical stabilizer, it is correct that the gap beneath the front of the stab and the fuse is 1/4-inch less than the thickness of the aft top block that is provided. Just slot it as necessary to maintain the correct curve.

2. The very tail of the fuse is *supposed* to be wider than the rudder post. Balsa can be added to each side of the rudder post. That is, the tail does not need to be made more narrow. (I can still do this since I have not added any bottom or top planking.)

Note that I have found no images that clearly show the very tail end of the Simla.)

3. I'm still not sure about the ledges at the tail (see the circled area in the image). Is the transition from the vertical stab to the fuselage at that point supposed to be invisible? If so, I would have to cut apart the tail to make it more narrow.

It's just that the plans very clearly show a tail that is 7/8-inch wide, but that measurement seems to conflict with how people are actually building the fuse at the tail. I would like mine to be correct.

Confusedly yours,
Richard

kingaltair

My Feedback: (4)

I think you should sand the area where the fuse sides join at the rear to be as narrow as possible SO THAT IT IS AS CLOSE AS POSSIBLE TO THE WIDTH OF THE RUDDER. In other words, the rudder post area that comes down should make a nice, smooth transition to the rudder itself. There is a limit to what can be removed before you sand right through the fuselage side, (which of course you don't want to do). It's a little late now, but make sure the plane itself conforms to the top view of the fuselage on the plan. To do that, you have to shape the top triangle stock where the two halves join.

I'm including the Simla article itself. Look at the picture of the tail section...it might help some. You can also see the aft top block where it meets the stab, (notice this is the original fin before we recognized it wasn't as accurate as we wanted...you can see the photo where the fin is rebuilt.

Duane

rg1911

My Feedback: (1)

Duane,

Thank you. The article image shows the tail being much more narrow than I measured on the plans. As I said, I'll just cut the tail apart again and reshape the triangle stock so I can pull the halves closer together. At the speed I work, I should have this done by May or June.

Finally, just to be certain, it seems that no-one has changed the long (middle) top block so that any hatches are on the top. That is, both hatches are on the bottom, as shown on the plans.

Richard

kingaltair

My Feedback: (4)

rg1911

My Feedback: (1)

Aacckk! Pressure!

Shall see what I can do.

;-)

Richard

doxilia

My Feedback: (3)

Nice article Duane!

Thanks for posting it - have something to read over lunch now...

David.

kingaltair

My Feedback: (4)

Thanks...really appreciate that. That was quite an interesting project...to create a lost model out of almost nothing. We had just enough information to make it possible. The article appeared in the March 2011 Model Aviation, and is the basis for this thread. We just need everybody to order their Simla(s), and get them built. We are planning on a Simla Fly-In in the fall, (which will also probably be written up one way or another).

Be there of be square!!

We are still looking for additional original Simla pictures...somebody somewhere must have taken additional photos of it. They are probably in some "shoebox" somewhere.

Duane

billberry189

My Feedback: (1)

Duane,

Have you any idea where the fly-in will be held? Getting my Simla ready will not be a problem, however, planning and financing a trip could be a bit more difficult. Actually I am still hoping to have two Simlas and one Taurus ready for the event. As I stated earlier, my first Simla is being prepped for paint as I write this post, the Taurus is waiting for a right wing half(the rest is already in the finishing stages), and the second Simla is still sitting in the corner awaiting a build date.

Bill

PS- It's really nice to see a renewed interest in this build thread. I was getting kinda lonely.

kingaltair

My Feedback: (4)

I was planning on trying to get it scheduled for Triple Tree Aerodrome, site of the annual Joe Nall fly-in. It is located near Greenville/Spartanburg South Carolina.

This was the site of the Simla's first flights October 2 of 2010.

Duane

rg1911

My Feedback: (1)

Fuse has been cut apart, tri-stock amputated, and everything glued back. Tail is now the width of the rudder post and the base of the vertical stab. May have to do some cosmetic surgery on the elevator so there isn't so much of a gap between its inner edges and the fuse.

Onward!

Cheers,
Richard

billberry189

My Feedback: (1)

ANDUPWARD!!!

jjpetro

Richard,
You have correctly pointed out where I could have done a better job of drawing the tail post. There is actually another layer I could have drawn in there to make it clearer for you. Sorry you had to go thru the trouble of cutting your fuse and re-gluing. Though I'm sure it is of little consolation to you now, I have made an addition to the drawings. I'll try to upload it shortly.

rg1911

My Feedback: (1)

Someone probably wants to add "To infinity and beyond!" but I'm not going to be the one.

;-)

I decided to splurge a few more dollars and ordered a carbon fiber pushrod for the elevator from Central Hobbies. It's 3/16-inch in diameter, so I don't have to worry about having to support it. Still haven't decided exactly where to mount the elevator servo. If I mount it near the elevator, I'll need to make a fairly large hatch near the tail. If I mount it so it's accessible from one of the other hatches further forward, I'll have a long length. The thick CF rod takes care of that problem.

Richard

rg1911

My Feedback: (1)

Jeff,

Oh, well ... Think of me as a beta tester. And it's a heck of a good learning experience.

Cheers,
Richard

rg1911

My Feedback: (1)

I was able to come up with enough usable pieces from two orders of sheeting from National Balsa to make the wing top skins. (Warped, cracked, split, you name it. I'm not a happy camper.) Yup, I weighed the sheets and the heavier ones are going on the left wing. BTW, I glued the strips together using Super 'Phatic, a penetrating aliphatic glue I bought from Hobby Lobby. It worked well and sands nicely.

Does anyone have a favorite adhesive to apply wing skins? I'm debating among regular Titebond wood glue, Ambroid (that I've used for much of the model), and 30-minute epoxy.

A "problem" with the wood glue and the Ambroid is that there's a strong chance that the glue on the first rib will have dried by the time I get to the end of the ribs unless I can come up with a much faster application method. The "problem" with the epoxy is applying it without getting more on the table than the ribs. Again, a method better than scooping it on with the stir stick is needed.

Suggestions always appreciated.

And if you have a better source for balsa sheeting, I'd really like to learn it.

Thank you,
Richard

billberry189

My Feedback: (1)

Richard,

When I was ready to cover the wings, I made four complete sections and rough trimmed them to fit the area of the wing that they would be covering. That is, two top sections right and left and two bottom sections right and left. I did this because I found it easier to splice the planks together while they were on the flat building surface rather than on the wing airframe. That left me with the problem of how to glue such large panels to the airframe of the wing. I solved that problem by pre-shaping the airfoil curve. To do this I taped each panel to it's respective wing section(one at a time) and wet it down with windex. When dry, this made a near perfect fitting wing panel. Then I used Elmer's white glue to glue each panel to the wings, once again using masking tape to hold the panels in place while the glue set up. It' true that you must move quickly to do all this, however, I found that there was sufficient time to accomplish the task without any problems. I also left the steel rib jigs in place and weighed the wing down to my build board while all this gluing and set up took place to insurea true wing and it worked well.

As a side note, I use a small bottle of Elmer's to dispense glue to the ribs, and a large bottle to dispense glue to the spars and leading and trailing edges. When the small bottle runs out, just refill it from the large bottle.

I hope you find this helpful

Bill

kingaltair

My Feedback: (4)

Agree with Bill, I've included the article PDF again because page 35 shows the wing skin ready to apply. Another advantage to joining the sheets in advance is being able to pre-sand them, then all you have to do is finish sanding. The only potential problem is near the leading edge, and if you pre-moisten the front portion of the sheeting and tape it until it dries, it should pretty much hold its shape.

Epoxy would be too heavy and take too long IMO, wood glue, (with perhaps some CA to quickly anchor the edge in areas where the curvature is greatest), works fine.

Duane

kingaltair

My Feedback: (4)

Agree with Bill.

I'm including the Simla article PDF again because page 35 shows the pre-made wing skin ready to apply. Use wood glue, (with maybe a bit of CA help in the most curved areas), moistened with water or Windex, and tape until it dries. It will pretty much hold its shape well enough to make attachment easier.

Another advantage of making the wing skins as a single unit has to do with being able to pre-sand the balsa prior to application, then only finish sanding remains.

Duane

rg1911

My Feedback: (1)

Bill / Duane,

Fortunately, I did create and sand the skins on a flat surface. So now I've adopted Bill's suggestion about the Windex; just waiting for it to dry. And I think I've got some cheap hobby syringes (somewhere) that I could use to apply the wood glue along the tops of the ribs. Would certainly provide more control than the large spout on the bottle.

Still looking for a better source of balsa. National Balsa has not replied to my question about trimming edges and providing sheets that aren't cracked. I even sent pictures (attached here). Let me know if I have unreasonable expectations.

Cheers,
Richard

billberry189

My Feedback: (1)

Richard,

You might try The Balsa Store on a website of the same name. I haven't used them yet, but I am planning to on my next Simla build. They seem to have plenty of 4" sheeting which I would prefer over the 3" the National Balsa offers.

Bill

PS- Be sure to let us know how the wing sheeting is going

Bye-Bye

rg1911

My Feedback: (1)

Bill,

I just checked the Balsa Store and they do have 3/32 x 4 x 48 balsa for (memory already fading) around $5.50 a sheet. Note that the description said they had only 46 sheets available.

I've been scrounging through my supplies and came up with 10 3-inch sheets to use for the bottom skins. I think that will *just* meet the requirements. If not, I'll be checking with the Balsa Store.

Cheers,
Richard

rg1911

My Feedback: (1)

Bill,

Got the top skin on the left wing panel. The process did not go smoothly. I think I should have used more Windex, because the sheeting didn't conform as well as hoped, especially at the LE. I also think I should have rough-trimmed the sheet a little more closely to the wing.

I did find a hobby syringe buried in my stuff, but even working as fast as possible, the wood glue on the first ribs was drying as I finished the rest. And bunches of glue on the plans/table. I also can tell that the sheeting isn't adhering to all ribs equally. In this case, it isn't a huge problem since I can apply CA or some other glue from the back side. This won't be possible when sheeting the bottom. Obviously, I need to refine my technique.

I used tape and 1/2-pound lead weights to hold down the sheeting. I think that a system that conforms better to the surface would be a big improvement. Possibly bags of sand or lead shot. I think I have some that I bought just for this purpose.

Ah, well ... Another fine learning experience.

;-)

Cheers,
Richard

billberry189

My Feedback: (1)

Richard,

Perhaps I was not completely clear in my description of the procedure that I used. First, when I had a panel glued and sanded, I fit it to the wing and trimmed it to shape so that there was very little "Wiggle Room", and then I used the windex and tape to fit the airfoil before I glued it to the wing. I used 1 3/4 inch tape applied every couple of inches on the leading edge running roughly parallel with the ribs before I sprayed the windex on the sheet. The trailing edge can either be taped or clamped to hold it secure. After I was satisfied with the fit, I sprayed the windex mostly on the leading edge half of the panel and then let it dry. When done it was nearly aperfect fit for each panel. I realize that this process is somewhat time consuming, however, I felt that the end result was well worth it.

As far as the actual gluing process, I suspect that practice will improve your technique to the point that the last two panels will meet withgreater success.

Good luck

Bill

rg1911

My Feedback: (1)

Drat! Yet another Adventure in Skinning.

I got everything perfectly set up, quickly applied the wood glue, and then applied weights. This time I had a bunch of baggies each filled with 2 pounds of shot.

Everything was going smoothly until the entire structure collapsed, breaking all the rib tabs. By the time I got enough tabs glued back on to put the wing back on the table, the glue had set and I ended up with a small twist.

Several attempts to straighten that out have now resulted in an opposite twist *and* an upward curve.

If there's a way to get the wing back into shape, I'd love to hear it. I hope I don't have to start over because I'm out of the lightweight balsa (and I'd have to cut out all the ribs).

Richard

kingaltair

My Feedback: (4)

OH BOY....that's too bad!! That has to be frustrating. It might have been best to ask BEFORE hand before adding that weight. Those little tabs can't hold that much...as you found out.[]

In my own case, (as seen in the article), I had most of the weight supported by the metal alignment rods and the end blocks with the holes drilled in them the diameter of the rods. I pre-bent the balsa by rough-trimming to shape, then taping down the LE sheeting, then wetting the sheeting with a fine spray of Windex or water. After it dried, it basically held its shape so that after adding the glue, I retaped the L.E. down every three inches or so, and added some modest weight to the T.E. to hold it firm to the table.

I don't know what to tell you to do...the wings have to be ward-free for it to fly its best...it depends how bad the warp is. You could try steaming the wing while twisting the wing in the opposite direction.

Is the sheeting only on one side? It will be easier to twist if that's the case. You might still be able to save it by making sure the other sheeting is correct if you make the support blocks as described earlier, drill the holes at the right height, and get the metal rods to put through the alignment holes. Take you time and be sure the blocks and rods are right...you can then add SOME weight to help keep everything aligned.

If that doesn't work, as a final solution, maybe Jeff can send you a wing kit.