RE: SIMLA BUILD THREAD
 

Try here. [link]http://www.rcgroups.com/forums/showthread.php?t=1516373[/link]

I gave up trying to understand him a long time ago.

Ray

RE: SIMLA BUILD THREAD
 

Ray..I'm surprised

I truly expected that he would design and build his Simla to be absolutely fathful to the original, with every detail being faithfully reproduced, possibly down to the hardwood block and bolts Ed used to hold the wings, the original aileron linkages...everything. BTW..I expect and hope that someone will do the same thing with Jeff's kit, and we have additional information to share with anyone who wants to do that.

With the premise in mind of an exact duplication, I was very surprised to see that Cees's Simla is obviously not an exact, identical copy of the original. Unless he plans on opening the area up at a later time, (which he may still do), he seems to have chosen to enclose the engine compartment as opposed to what Ed actually did in the original and only Simla. (We designed the kit so that the engine compartment can be built either way, [and indeed billberry is building his enclosed], but billberry is not making the claim of recreating a faithful reproduction of the original just as Ed built it).

Of course the Simla looks fine with the enclosed engine compartment, but that is not really the point...his was supposed to be much more authentic in every detail than our "amateurish" efforts. While he is certainly free to take license with the engine compartment, it seems at odds with his stated purpose, but maybe he wants to improve on what Ed did.

RE: SIMLA BUILD THREAD
 

Duane,

Check the curve at the top of the fin as well. It appears to be much rounder than Ed's. Besides, for anyone to claim exact representation of Ed's Simla is a mute point since only Ed could verify it's authenticity and of course he is no longer available to determine such authenticity.Apparently some people's egos overload their brains and good sense, causing them to make claims that they cannot possibly substantiate.At least in this thread we all seem to be trying to do the best we can to replicate a bit of R/C history without getting into a p______ contest. No one here is laying any claims to fame, only offering good ideas and advice. So I say let'skeep up the good work and have fun with this project until we are able to get together to share in the experience in person!

And that's my 2 cents worth

Bill

RE: SIMLA BUILD THREAD
 

Well, the fuse is beginning to look like one. As someone pointed out, the sides do start to taper ahead of the wing trailing edge. Since I'm now able to fit the wings, I'm wondering if the W1 rib assembly could be held in contact with the side, and the wing then fit. It *seems* that this would allow the wing root to completely contact the side.

Or is this already taken care of in some way?

What think the build masters?

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Richard,

It was my experience that holding the wing root rib tight to the fuselage side and then fitting the spars, LE and TE and then glueing them to the root rib would give a better fit of the wing to the fusalage sides.Of coarse you will have to have the wing CF tube installed as you do your fitting and glueing. Perhaps installing the hold down bolt would be of some help as well. Unfortunately, I had already glued my root ribs in before I tried fitting the wings to the fuselage, requiring me to cut the LE and TE of both wing sections loose and refitting them to eliminate the gap created by the curve of the fuselage.

1. Install the CF wing tube into the fuselage.

2. Fit the root rib to the fuselage side as tightly as you can get it, remembering to placea piece of waxed paper between the fuselage and the root rib. This will make it possible to remove the wing after you glue it to the root rib.Include thethe hold down bolt, and either masking tape or someother form of clamping.

3. Slide the wing section onto the tube all the way to the fuselage and wingroot rib.

4. Adjust(cut or sand) the spars, LE andTE to fit the root rib. When you are satisfied with the fit, proceed immediately to step 5!

5. Glue it!!!!!!http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif

All of this might also be easier toaccomplish if it is done before the fuselage top block is glued on. This is most likely the way I'll do it the next time.

Bill

PS- Make sure when you glue the spars to the root rib not to get any glue on the CF tube and sleeve. That would be a major oops!

Bye-Bye Now

RE: SIMLA BUILD THREAD
 

In his defense, I find lots of errors in current ad copy.

I'm sure errors were happening then, too. It happens. Editors aren't any more perfect than the rest of us. (OK, so maybe in spelling and grammar they beat us.)

Andy

RE: SIMLA BUILD THREAD
 

Andy,

And your point would be?

Bill

RE: SIMLA BUILD THREAD
 

Bill,

Thank you for the tips. I hadn't thought of the waxed paper.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Richard,

You may find that the wax paper will adhere to the part being glued somewhat, but it will keep that part from adhereing to the adjacent part or parts. ie-when you are done the wing will be free of the fuselage but you may have to peel the waxed paper off of the root rib. A little light sanding will remove any left over waxed paper.

I am sure there are other products that can be used as a barrier from unwanted glue. I just happen to use the waxed paper because it is inexpensive, effective, and been in my repetoire for over 50 years.

Bill

PS- Once again, take greatcare when you apply the glue to the spars, LE, and TE. It would be bestto "tack glue" them until after you remove the wing and then apply a more secure coat of glue wherever necessary.

Bye again

</p>

RE: SIMLA BUILD THREAD
 

Hi,
When I do not want glue like epoxy not to adhere to some surface I use thin plastic film You use for wrapping in food that protect foodagainst going bad for a day or two. You know the thin plastic on roll with small teethson one of the corners of the box You can rip it off in desired lenth with, you buy itin grocery store.

/Bo

RE: SIMLA BUILD THREAD
 

I can attest to that. Although I always included photo captions with my photos, often the editor would prefer his own. They were sometimes inaccurate. In the Simla article, most of the pictures were taken directly from my camera's CF card, not from what I sent, so nearly all the captions were the editor's. Some were amusing.:)

In this case however, common sense tells me that an editor probably wouldn't make up, or get the airfoil wrong...especially an airfoil from overseas. Jeff and I took this at face value as one of the "givens", (or clues), to base the model on, and if you study the wing closely, I believe it is a "dead ringer" for the original. If you look at the picture of Cee's wing ribs they look very much the same...basically a thick airfoil with a sharper L.E. that is symmetrical.

I think my "evil twin" took over in that one post, but I AM genuinely surprised the engine compartment is closed off. Obviously since the original is gone and there were no plans, nobody can claim 100% authenticity, and I don't think he is doing that. All we can do is TRY to get our model as close as possible based on everything that can be discovered about it.

His goal is beyond what our stated goal was, (to get the planform "look" correct, while using modern materials and building methods). He wants to build a REPLICA OF THE ORIGINAL, with all the details the original had such as adjustable dihedral, wing position, (shoulder, mid, and low wing), and adjustable stab, (which is a great project), but when you do that, you normally try to incorporate every little bit of knowledge you can find to get the model as authentic to the original as possible. The closed engine compartment of his Simla is a very noticable change from what Ed built. That was the crux of my original comment.

Anyway, back to our model...
Duane

RE: SIMLA BUILD THREAD
 

If the mag says "Bosch" and the photos clearly show otherwise (which I don't claim to be able to do), then in case of a conflict which to you accept - the printed word or a photograph showing otherwise?

"Clearly" is perhaps the keyword here. What's obvious to one may not be obvious to another.

Andy

RE: SIMLA BUILD THREAD
 

I know you have followed the Ed Kazmirski's Taurus thread carefully, and your name is on the Simla plans as a contributor, so you are familiar with the Bosch airfoil, (hope the spelling is correct), UStik talked about for the Taurus II, (which was flown during the 1964 season, and I co-own). Just for a brief refresher, Ed originally designed a semi-symmetrical REALLY THICK airfoil that he took to Belgium for the 1963 Worlds. There he was introduced to Fritz Bosch's airfoil. When he got home, he built a new wing for that plane and built up the wing saddle so it would fit, (BTW-Ed's "unfinished fuselage" has the same airfoil). If I remember correctly, the Bosch airfoil was just as thick as the original...not thick Taurus semi-symmetrical, only it had a sharper L.E., and the greatest thickness was a little further back. This allowed Ed to be able to do spins more easily while retaining the high drag wing he wanted.

When I looked at the B&W photos from Ed's estate that made this project possible, the airfoil looked similar to me...the Simla airfoil definitely does not have the same blunt L.E. airfoil of the Taurus...that coupled with the text in the caption convinced me, (us) that it really was the Bosch airfoil. Purely from a LOGICAL standpoint, we have every reason to believe that Ed was happy with the Bosch airfoil because he flew it that entire 1964 season, and that is the final airfoil on the last small pattern plane Ed built. It is also logical that he continued using it in the scaled-up Simla he was planning for the next year. If there is any evidence to the contrary, I'm not aware of it. To me it all makes sense.

One more thing just to think about...I am impressed with Cees's ability to recreate planes from photos, (it would have been a lot easier to re-create the Simla with his help back in 2009 when we were asking for it), but can anyone truly recreate the intracacies of any airfoil shape from a few photos of the Simla...none of them being a side view? I don't know, but I doubt it. The only actual side view we have is from the original Taurus II showing the thick wing, (attached).

Because of everything, I believe the caption in this case.

RE: SIMLA BUILD THREAD
 

What you're really saying is that you believe the photographs and text match, since both have a sharper LE, correct?

If that's the case, Cees is on the same track as you for the same reason - except that you are relying on the text and he's relying on the photograph, but they both are saying the same thing.

Andy

RE: SIMLA BUILD THREAD
 

What I'm repeating below is what I'm "really saying", plus a little more than that. I don't want to beat this issue to death, (but I'm responding to your comments). I think I have good, logical reasons for why I trust the caption.

I believe we are basically going to have similar airfoils, but likely not the same, (check the link...he made a very elaborate design out of his ribs, so you can get a pretty good look at them). Regardless of how meticulous his methods might be, I truly doubt his ability to faithfully create a perfectly true airfoil from photographs taken at an angle from a distance of at least 10 feet away, (he might have had a chance if we had a perfect side view, but we simply don't have a good view of the entire airfoil)...I don't think ANYONE can accurately do that no matter what software they have, and even if he can, shouldn't he check to see if his measurements match what is written in the caption(JMO)?

I assume what he did was to take his exhaustive calculations, and then come up with his own airfoil that he thinks matches them. The airfoils may look similar, but if they are different, then which is correct??...there can only be ONE correct airfoil if we are trying to duplicate what Ed did. Cees is assuming the caption is wrong, and trusting his own methods. In this case I'm trusting the caption because the evidence seems to confirm it.... the Bosch airfoil looks like the Simla's airfoil...why would someone assume the caption is wrong unless the calculations are way off...and then which should you trust?

We know EXACTLY what a Bosch airfoil is...exactly how thick it is, and its exact shape. His airfoil supposedly comes stricly from his own calculations based on oblique images from two dimensional photos. That is why it would be useful for him to compare the Bosch airfoil, (you can get that from the EKT thread, or from our plan which he has), and compare it with his.

We don't know everything going on in his secret laboratory, nor do we know his exact methods. In reality he might be relying on his own calculations and in the process, redesigning the Simla, then reporting it as the correct airfoil based on his own "scientific facts". Bottom line...if there is any difference, again I trust ours more for the reasons I give below.

[i][b]When I looked at the B&W photos from Ed's estate that made this project possible, the airfoil looked similar to me...the Simla airfoil definitely does not have the same blunt L.E. airfoil of the Taurus...that coupled with the text in the caption convinced me, (us) that it really was the Bosch airfoil. Purely from a LOGICAL standpoint, we have every reason to believe that Ed was happy with the Bosch airfoil because he flew it that entire 1964 season, and that is the final airfoil on the last small pattern plane Ed built. It is also logical that he continued using it in the scaled-up Simla he was planning for the next year. If there is any evidence to the contrary, I'm not aware of it. To me it all makes sense. ...I am impressed with Cees's ability to recreate planes from photos, but can anyone truly recreate the intracacies of any airfoil shape from a few photos of the Simla...none of them being a side view? I don't know, but I doubt it. The only actual side view we have is from the original Taurus II showing the thick wing, (attached).

RE: SIMLA BUILD THREAD
 

Actually Andy, it would be more fair to say we use both the photo and the text. There are occasions when we may only have text, eg the date of the PCM first flight, or we might only have a photo, eg the 'Japanese Taurus 2'. However where there is disagreement, eg the 'Big Stuff' article on the previous page, banging on about the aileron 'square drive' when the photo clearly shows a round aileron torque rod extension with a slot, obviously designed to fit a tube and pin in the fuselage, you gotta go with the photo. Where there is photographic and text agreement, eg the 'Bosch' airfoil on the Simla, then it really does not matter which you quote, it is not a 'one or 'tother' situation. And we would use both, just to be sure.
Evan.

RE: SIMLA BUILD THREAD
 

Exactly, Evan.

Andy

RE: SIMLA BUILD THREAD
 

I still don't think an exact airfoil can be determined from an oblique angle, two-dimentional photo, so I don't believe the photo alone will give as accurate a result in this case compared with the caption that tells exactly what the airfoil is. Many airfoils look similar...I believe he is making some educated guesses on his airfoil. It will work, but will it be exactly the same airfoil Ed used? I don't think the caption and an airfoil derived only from photos will be exactly the same. It would be interesting to compare them.

Duane

RE: SIMLA BUILD THREAD
 

No Duane, I don't think you can either, even if it were possible, you still only have the upper curve to work with. But at least the photo, in this case, does show that it is not a blunt 'Taurus' airfoil, and we boys know that Ed was experimenting with Bosch's section, and we have templates...the weight of the evidence points to Bosch's airfoil, or Ed's modification of it, if indeed he did modify it. So much conjecture...
Evan.

RE: SIMLA BUILD THREAD
 

Well, I've been away from the build for a few days. More creative deadlines at the office.

*And* I discovered, while fitting the wings to the fuse, that it *is* possible to have formers F2 and F3 perfectly perpendicular to the fuse sides and yet have the wing tube at an angle. No, I don't understand how it could happen, but it did. Thus, the wing panels were cocked.

After a couple days of deliberation and examining the situation, I finally broke the fuse completely apart. This required a saw, a hammer, a spreader clamp, and a hobby knife. Fortunately, I had not planked the bottom. (I no longer have any concerns that the plane will come apart in mid-air.)

I'm going to mention to Jeff that I consider emphasizing that the wing tube be perpendicular to the sides is more important than basing the directions on the two formers.

Anyway, the epoxy is curing and I'll be able to get on with the build. Considering that we got at least 4 inches of snow this morning, I probably don't have to worry about finishing the Simla before winter arrives. It's here.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Richard,

I feel for you brother. It seems that ever since you glued the plywood doublers to the fuselage sides it has been fighting you. I don't know if this will help, but here's what I did. First I punched outall of the alignment holes on the fuselage sides and made dowel pins that protruded from the fuselage sides about an inch on either side of the fuslage when I put them in my little fuselage jig (see post #355 on page 15). The fuselage sides in the photosarefor a Taurus but I'm sure you'll get the idea. Once the sides were in the jig with the top down and the bottom up I installed the cardboard sleeve supplied with the kit. That, with all the dowels pretty much sets the sides as they should be. Notice that I set the jig up over the fuselage plans,which I covered with waxed paper. Then I fit formers F2 and F3 and epoxied them in. Remember that they are both glued at 90 degrees to the fuse sides and that former F1(the firewall) is not at 90 degrees to the fuselage sides. In fact former F1 is narrower than F2 and F3 so the fuselage sides taper toward the front of the fuselage. You have to make sure that the vertical center line of F1 is lined up with the longitudinal center line of the fuselage.

Hope this helps,
Bill

PS- Check page #14 post #346 for the front taper. Notice that the wedges I used at the very front of the fuselage to hold the sides in place while I glued F1 in, are mirror images of each other. That helped me maintain the centerline alignment I spoke of above. If you have any questions, just give me a shout and I will try to explain in greater depth my "how to" http://www.rcuniverse.com/forum/js/f...eeth_smile.gif

RE: SIMLA BUILD THREAD
 

I'm sorry about that Richard.

Somewhat similar to what Bill did, when I was gluing the doublers to the fuse sides, I used the two supplied dowels and temporarily inserted them in the alignment holes while gluing. This also aligned the holes for the wing tube. This doesn't guarantee that the sides themselves will be aligned when spraed apart, but I believe I frequently checked each side's position and squareness while gluing. If F-2 and F-3 are properly aligned, the rest should be also. Drawing a centerline on each former and aligning it to a centerline drawn on the plan helps as well. After the tail off to one side on a fuselage once, I also am very careful on the rear fuselage joint being centered as well.

The King Altair wing is pretty much done, and almost ready for covering. I'll post a couple pictures later. Used Doxilla's (sp) Z-Poxy suggestion, and it worked great, (easy to work with), and glassed the center section yesterday. I have the wing equipped to slip into the same dowel holes and bolt pattern as the original, (although there is a slight difference in how the wings mate with the wing saddle, so the plane will probably fly a bit differently. I guess Jeff's airfoil, or my sanding made the difference...it's really hard I guess to get a built-up wing to match an earlier form wing built years earlier by someone else.

I took all the wing components, piled them on top of the basic wing and weighed them. Right now it weighs 15oz LESS than the original wing, (less covering and fiberglassed center section). It tentatively looks like I'll be able to save at least 8 oz compared to the original heavy foam wing...maybe more.

More to come.
Duane

RE: SIMLA BUILD THREAD
 

Duane,

When I glued the doublers, not only did I use multiple alignment holes, I also used the wing tube sleeve to make sure everything was aligned this time.

I also used Bill's jig idea.

When I realized the wing tube sleeve that passes through the fuse was off a bit, I rechecked the F2 and F3 formers. They were perfectly perpendicular to the sides.

All I'm saying is that the formers are not the critical element when aligning the fuse sides; the wing tube sleeve is.

There are two parts to this problem. The first is me checking the formers but not the sleeve, assuming that the sleeve would be perpendicular to the sides if the formers were. I won't assume anything like that again.

The second part concerns the alignment holes. They're just a bit larger than the 5/16 dowels, and permit a little slop in the alignment.

This time, the fuse is back together after making sure the *sleeve* was perpendicular to the sides. Still need to pinch the tail together. This is a bit troublesome without a better jig than I've been able to think of, and with only one person. I now can understand why some people use a laser level. It's unfortunate that the least expensive one I've found still exceeded $100.

Creative deadlines at work have, unfortunately, kept me away from the build again.

Cheers,
Richard

RE: SIMLA BUILD THREAD
 

Hmmmm...I don't know what to say.

You're saying that all the alignment holes lined up prior to gluing, but after gluing, they didn't line up? If that's the case, I can't understand how that could happen. Yes the wing tube is the single most important element, but if the firewall is off even a little bit because the doublers aren't right, then the right thrust if off. Everything has to be right at the beginning, and everything depends on everything else. The whole idea of a laser kit is its accuracy...I don't understand it.

Kevin reported some problem with his (larger wing rib) alignment holes not lining up properly on his prototype, but had no problem with the fuselage, and I had no problem at all. Whatever the reason, if the wing alignment holes in each fuselage half and doubler half, (those were the only ones I used), and wing tube holes in each fuselage side don't align before beginning, contact Jeff immediately and let him know. Jeff, being the kit's designer and engineer, should be able to help pinpoint the problem.

All I can say is that mine lined up perfectly.

Duane

RE: SIMLA BUILD THREAD
 

Duane,

Probably a little too late to notify Jeff. Also, he checked the alignment before sending the replacement fuse parts. The balsa and ply doublers aligned perfectly with the fuse sides. The misalignment seems to have occured after the sides were separated. Hindsight being 20/20, I now can think of a couple other things I could have done. I'll remember for the next model.

And I am *not* ruling out operator headspace error. In other words, I may have introduced the error. I'm just not sure how.

Fortunately, I have not yet glued the firewall. Shall make sure, one way or another, that the 2.25 degree angle is present.

Yet another learning experience. [sm=rolleyes.gif]

Cheers,
Richard