RE: .60 size Pattern Tiporare Build
 

David,
I am not too sure about your comment on building style. Do you think that I am going about somethings backward or that I just go about things differently. I try to think things out ahead of time so that I only do things once and as correctly as I can. Being a graduate mechanical engineer has taught me that, but if you see something that makes it easier please let me know.
Jim

RE: .60 size Pattern Tiporare Build
 

Managed to get the horizontal stab to fit into the fuselage. I cannot set it in place without having the wings built up and in place so that I can verify the angle of incidence. One related to the other.
I still need to reinforce the firewall with triangle stock, get the throttle line in and decide on a fuel tank size. I am thinking 8 to 10 ounces if I can get those sizes to fit and be near the center of the carburator. Once I decide on the tank I can proceed to put a floor in for the fuel tank.
I am dropping down in size for my robart hinges. I normally use 3/16 inch and am going to use 1/8 inch this time because of the thin elevators.
I am not sure just how much fiberglass cloth I am going to need for the fuselage but I have one square yard of 3/4 ounce on hand. At least I remember the old toilet paper method of removing the excess polyester resin when laying down fiberglass.
I have also ordered some aerogloss clear to mix with baby powder for making fillets and to fill dents and what and wherever as required. This is the lightest method I know. If someone knows a better way, speak up please.
David, since the plans do not show too much, are the wing farings (where the fuselage fairs into the wing) butt joined at the fuselage matching the wing angle or what? The supplied fairing strips are very thin ply and obviously will need some filler to create the radius.
I took Davids advice and found a sanding tool that has a flat with a radius on the side and used that to better define the tucks in the side of the fuselage.
Jim

RE: .60 size Pattern Tiporare Build
 

Jim,

my comment was just to point out how some builders go about things in a different way than others. Not being in your shop its also hard to know whether this is indeed the case so I'm mostly commenting based on what you're writing. But just as an example, lets take a wing or stab construction:

Some builders like to get their cores sheeted and then add LE, TE and join the panels. My preference is to delay the junction of the panels until everything that is needed in each panel is complete and done. There are two primary reasons I prefer this: 1) Because the panels are easier to handle and build on when they are half span. This helps to avoid hangar rash and also makes the work shop larger by keeping components smaller - if you will. 2) The other reason and the main one is because it allow me to build and confirm perfect symmetry in each panel. If the wings are joined and then say I add, carve and sand wing tips, I can't compare them other than by eye and I suppose if I had it, with a contour gauge. With the panels separate I can line up the panels side by each and more easily scope the differences/asymmetries. I also like to do this incrementally in the sense that I track the symmetry as I go. I for example don't add any wood stock (TE, LE, tips) until both panels are identical once sheeted. I sand the two of them in a single stacked shuck block using a straight edge as a reference so I don't change the planform of the wing.

You had commented that you had joined the stab panels but your elevators needed to be carved and sanded to shape. I would never be able to do that easily or to satisfaction (I'd be cursing at myself for what I'd consider a procedural mistake) because you can't lay the panel flat on a bench or in the shucks. Doing so makes the shaping and contouring of the elevators to airfoil much easier in my experience. But as I say, that is just the way I choose to do things. I actually had no mentor when it came to building and learned what I know by trial and error. I looked at airplanes, figured out how they were built and then "reverse engineered" it so to speak. I tend to envision builds a little bit as if they were a chess game; I see myself building things up in a series of steps but if I find myself in a "check" situation, it means I "moved" badly somewhere along the line, so I go back and map it out in my mind again until I see it flowing smoothly.

I have learned a great deal from the 4 short years I have been reading/posting on RCU as seeing others build has tought me cool tricks that my "chess" approach would probably never have envisioned. But that is what I guess can be chalked down to experience. On the one hand I consider that I have little since I'm "young" among my other classic pattern peers, on the other i feel that I have grown a fair bit in experience since I have been at it for over 35 years (started at 8). Some of that "experience" actually simply comes from having gotten older - somehow it seems to have helped. I made many mistakes in my 20's. Now, I seem to make fewer. More models under the belt I suppose.

Well, after that overly academic analysis :eek:, I'll sign off and let you continue with your excellent build.

I'll reply to your next post later as I have to step out.

Cheers, David.

P.S. BTW, an 8 oz tank on an SF 61 will be gone in a flash. 16 oz tanks used to be the norm on 60's since that was the fuel burn for a masters schedule. To keep things light and for sport, a 12 or 14 oz tank should be fine. No less than 10 though unless you plan to do a lot of thermal gliding! [8D]

RE: .60 size Pattern Tiporare Build
 

Jim,

the 1/64" ply strips for the wing fairings are to be used as follows:

You fit the wing to the fuse making sure everything is lined up and square (evidently). Since you're wing is not complete, you ought to wait to do the wing fillets until you have a finished wing in hand that has been mounted. You want a small gap of a tad over 1/64" between the wing and the fuse wing saddle once its mounted. If you don't have it, sand it into the saddle. The ply strips are then taped down on to the wing from the outside edge at the correct position so that the "insert" the width of the fuse walls under the saddle. In other words, the strips taped to the wing will be in between the wing and the saddle when the wing is mounted. It is important to have a flush fitting between the fairing and the wing while its not so important for the saddle to contour the wing perfectly - that's what the fairings will be for - you are making the fit.

You then tack glue the strips to the fuse sides with CA wherever they make contact. At the LE, they will barely be wide enough so that the fillet really will start at the LE or slightly behind it. The TE on the other hand will have strips that extend beyond the back of the wing - these sections of the strips will be bonded to the side of the fuse on the outside which requires a notch in the strips in the rear where the saddle ends. Once the strips are adequately in place, tacked and will not move, you untape them from the wing, unmount the wing and the strips will be left behind tacked to the fuse.

You now begin by building up the fillet by using balsa tristock which may be of two different sizes - smaller (1/4") in the front and larger in the rear (3/8" or 1/2" - depending on the strips made). The tristock bonds on the bottom to the strips and on the side to the fuse exterior. Once that glue has dried (I prefer wood glue here), you can then fill the inside gap between the original saddle and the strips up to the tristock. You can use filler provided it is strong or my preference is to use a very light epoxy/microballoons filler mix. You fill the gaps by inserting the mix with your finger and once full, then "wash it down" with a finger dipped in alcohol. A final wipe with a paper towel and alcohol keeps epoxy from your fuse sides. Let the hole thing cure over night making sure that the strips are not peeling up due to the epoxy mix you just used.

Once that prep work is done, you can then proceed to make the fillets by more epoxy/mb on the outside between the fuse side and the strip base over the tristock. It is important to create the contour while the epoxy is about half way to begin curing (I like 30 min epoxy here). Keep your "paste" as light as possible as the epoxy is really only needed to adhere the filler (MB) together. If for some reason you over built the fillets once cured, you can sand it down with a dowel provided the mix is low in epoxy. It is preferable to build it up in stages than it is to sand it down so I might take 2-3 evenings on fillets while doing other things after the application.

At the end you can sand it smooth with 2 or 3 different finer grits.

Regarding the glassing of the fuse (and wing/stab?), 1 sq yard won't be enough. Pick up an additional 4 or 5 if you will be doing the wings/stabs too and you'll have some spare. If you have never tried water based Minwax Polycrylic for glassing rather than polyester, you might want to consider it. It hardly smells, is easy to clean up, is very light and dries fast. You can apply is straight up on to the glass as it comes out of the can. It requires a few more coats than resin or epoxy, is not as tough but is a better all around way and is of low health impact. If you choose to polyester the fuse, you might want to try the Minwax on the wing/stab for lightness. Once dry and "glassed", the cloth weave will still have to be filled. Oh, one other benefit, if you are glassing foam core surfaces, there is no risk of the polyester melting your core away if it penetrates too deep. I have not tried this method myself but have seen the results and know of several people who have used it.

I hope this helps,

David.

RE: .60 size Pattern Tiporare Build
 

Great information David,
Thanks for the input. I do still have a lot of work to do.
I wil continue to post activity and results.
Jim

RE: .60 size Pattern Tiporare Build
 

duplicate post

RE: .60 size Pattern Tiporare Build
 

David,
When I said that the elevators needed more shaping I was refering to the leading edge chamfers and nothing else. I am sorry I did not clarify exactly what needed shaping.
Jim

RE: .60 size Pattern Tiporare Build
 

Not a lot of accomplishments today. Added triangle stock to the back of the firewall, did some more shaping on the fuselage. I still have a flat spot along the back of the fuse about six inches long just over the wing saddle. I will eventually get that removed.
I should receive my wing cores next week and maybe proceed further.

I did try out something new to me. I but joined some sheet stock (1/64 inch) using medium C/A and immediately used a teflon heat iron behind the C/A application. The results were much better than I expected. There was little or no C/A on the back side and the joint was smooth.

I cleaned up my work area and put all of the tools where I keep them, that alone seems to be a major accomplishment to me. Tomorrow there will be a lot of vacuuming going on as I have a guest that might be comming next weekend. My building area is a mother in law suite on the back of the house and most guests stay in that area. Television, radio, A/C and Heat thank goodness.
I am vacallating between 4-40 and 2-56 pushrods for the elevator. I know the rudder is going to be pull-pull so there are no mental issues there.
Oh yeah, I went and flew one of my Goldberg Bucker Jungmans today. You talk about rusty, I was pathetic. It did get down in one piece, a broken prop was all of the damage. I missed the runway because of a strong cross wind and set down in some tall grass where it flipped onto its back, and yes I knew better.
Jim

RE: .60 size Pattern Tiporare Build
 

Today I managed to remove the flat spot on top of my fuselage. I used the old shoe shine method with a sheet of sandpaper. Worked out pretty good.
I created a servo tray floor but came to a halt when I picked up my JR 4131 servo. Its height is much more than I thought. I want the servo wheel to be vertical so that the pushrod for the elevator is not affected with rotation of the servo arm. I will have to come up with some locations to get them all to fit.
I plan on using JR 4131 on all of the flight surfaces. I realize that they are not digital and not too very quick but then neither am I.
I am trying to work out a scheme so that the front lower cowling for the retract is removable without makin it look ugly. Might have it locked in place by putting a tab in the front and some screws through the former A.
I have settled on a 12 ounce tank but the location has not been selected, I would rather it be near the CG if at all possible. Time will tell there. Not much else to report.
Jim

RE: .60 size Pattern Tiporare Build
 

Thought I would post this finding. Today I started thinking about the incidence angles on the Tipo because the plans call for .125 inches of negative incidence in the wing and zero in the horizontal stab. Just for giggles and grins I checked out my incidence meter (old laser type) and decided that I did not know if the markings on the meter were in degrees or in inches. For a period of time I was quite confused and started checking out why. After doing some trig calculations it did not make any sense to me. I took the incidence meter and placed it on a flat surface and set a span of 13 inches and took a reading. I then raised the incidence meter .125 inches and the difference was .250 on the meters scale. I thought this was a little eerie. If I am wrong please tell me where I went wrong. Any thoughts?
Jim

RE: .60 size Pattern Tiporare Build
 

Jim,

would have to have a look at your incidence meter. Do you have any pictures?

Sounds a little strange but perhaps I don't follow.

David.

RE: .60 size Pattern Tiporare Build
 

Jim,

I was a little surprised when you said 1/8" negative so I took a look at the plans. It would be pretty rare for a symmetric wing classic pattern plane to have negative incidence. The plan actually calls for 1/8" positive. This equates to ~+0.73 degrees if your meter provides angles of incidence.

When the Tipo rests on its gear, the nose can be slightly lower than the mains so that the fuse datum line is slightly negative. This will actually put the wing close to zero when on the ground. If I recall Dick's article, this is supposed to aid in the tracking of the model during take off and landing.

David.

RE: .60 size Pattern Tiporare Build
 

David,
You are correct it is a positive incidence. My error. I have taken a picture of the meter and attached it.

BTW,
I just picked up a .60 Rossi with inflight adustable carb.

Jim

RE: .60 size Pattern Tiporare Build
 

I have to apologize. This posting is in error. I looked up the manual on this incidence meter and had it set up wrong, my error. After setting it up like the manual showed, it in fact does read in degrees.
I put it on a flat surface ant took a reading. The span was 13 inches and the rise was .125 inches and it showed an angle of approx .5 degrees of angle.
Sorry for the bad posting.
Jim

RE: .60 size Pattern Tiporare Build
 

Jim,

that looks line a nice incidence gauge. I take it the laser pivots freely and lights up the meter on the side?

Regardless of chord width, if you rise one end of the aluminum bar, it should indicate the angle.

Actually, I believe I made a mistake in my post above too with respect to the angle of incidence. Probably just off a touch though. I used a scaled down plan for the chord width and calculated the angle not having scaled down the plan shown 1/8" positive.

On the 60 size plan, I measured the fuse side chord to 13.2" with a 0.125" rise from level (half the thickness of the 1/4" dowel shown actually). That angle would then be:

alpha = arctan (0.125/13.2) = +0.54 degrees. Not the +0.73 degrees I mentioned above.

So it sounds like your gauge is spot on.

David.

RE: .60 size Pattern Tiporare Build
 

Jim,

That Rossi should make that Tipo Haul A___.!!! Just make sure your wing is bolted on well before you fly it....:D

David

RE: .60 size Pattern Tiporare Build
 

Nicely put David!

Jim, by the way, I believe that Rossi's and OS 61SF's have engine lug bolt spacing that are close enough for your to use either engine on the same mount. What might be slightly different is the length of the engine which might require you to shim the mount forward slightly. This, I am assuming that the Rossi is shorter than the OS but maybe not so. If it's longer, well, you would just end up with a wider gap between the nose ring and the spinner.

I'll have to check that out.

BTW, were you planning on an OS SF or FX?

Of course, another option would be to just use an identical mount for the Rossi and drill it to suit.

The two Tipo's I'm building will have one Rossi and one OS SF. The Rossi will be finished first (hopefully some day soon!)

David.

RE: .60 size Pattern Tiporare Build
 

David,
As it stands right now I plan on using an OS .61 SF long stroke. That is what is in there now.
Still waiting on a longer pipe header to route the pipe to the underside of the wing.
No wing cores as of yet.
I did find some .5 ounce glass and was able to procure 2 yards of it. It is still enroute also.
So, I am kinda in queue for now but there is no hurry, it gets done when it gets done. Kinda sounds like something Yogi would say.
Jim

RE: .60 size Pattern Tiporare Build
 

Jim,

.5 oz cloth is great and so will the 61 SF. You'll need the extra long header for the underslung pipe - hope that's the one you ordered.

How's your stab lookin'?

When you're done with your Tipo, you can scratch a Deception for the Rossi! Another beautiful classic.

David.

RE: .60 size Pattern Tiporare Build
 

David,
The extra long header is in fact what is in shipment from macs. Dave at macs is just shipping it at no charge and I will send the short header back. I did take some measurements on the pipe and header so that I will know where to put the pipe on the new header.
I received the Rossi in the mail today and it is in great shape. Smooth bearings and lots of compression. I have not ran it yet but the worst that could be wrong is o rings.
I am waiting on the smaller hinges before I glass the horizontal. Once I get the hinge locations where they belong I will chamfer the leadiing edge of the elevators and then glass it. I plan to use the Mini Wax product then prime and paint. Sure this does not turn out to be a lead sled.
I might want a Curare instead of a Deception but we will see.
Jim

RE: .60 size Pattern Tiporare Build
 

In that case you would need a Webra Speed 61... :D

Actually, I learned yesterday that Prettner used a Rossi on his Super Sicroly in Italy '73.

David.

RE: .60 size Pattern Tiporare Build
 

David,
I have a Webra 145AAR in my focus.
Jim

RE: .60 size Pattern Tiporare Build
 

I don't know if you guys remember it or not but there was also a Hippo Tipo with a recess in the fuselage for the tuned pipe. I have a Hippo Tipo with a piped Rossi. It's a great flying plane and I'm going to restore it. It has some cracks in the paint and it needs a good cleaning anyway.
Jay.

RE: .60 size Pattern Tiporare Build
 

Another pattern flyer chimes in.

Jay, glad you are getting pumped up about pattern as it was in the old days.
Jim

RE: .60 size Pattern Tiporare Build
 

Not too much activity on the Tipo this week. Wings should arrive tomorrow according to the tracking info. Well see.
I spent yesterday and today repairing a friends Midwest Giles 202 which had a crack in the horizontal stabalizer at the aft end near the fuselage. I opened it up and backed the trailing edge with an ash piece of hardwood shiplapping the crack and soaking the cracked area with thin CA. Replanked the area, sanded it flush, re monokoted it and installed .022 inch thick flying wires. This thing is powered with a Moki 180 and it goes pretty fast at full throttle. He should pick it up tonight.
The elevator assembly on t5he Tipo has been hinged and is ready for glassing if I choose to go that route. I want to get the wings assembled and the incidence verified before I go any further and check out the weight before deciding on the glassing.
Jim