Thank you bob.hood, That is exactly what I was thinking. ITman496, it would appear that the wing you have is a hybrid between the 1100 and the 1030 but mostly an 1100. Although Im sure your wing is just fine as is, I have no Idea how this effects your VNE.
On a side note, this is a perfect example of why a MiniMax has $0 resale value.
I wouldn't. Libal to do more damage than good but I'm no expert. bob.hood is way more qualified to answer that question than me.
The stringers are RS-5 (1/4 x 3/4 white pine) Former F-3 is RS-59103 (6mm Birch) The rest of the formers are RS-5891 (1/8" mahogany) Except for F-6 RS-=13 (3/4 x 2 1/2 white pine) The fairings are RS-548 (1.5 mm Birch)
I'm certainly not qualified to answer questions any more than anyone else. I just happen to have an 88, which is the UK equivalent of a 1030, and I downloaded the plans for the 1030 and for the 1100 to find out what the differences were. Just like you, I found that the 1030 has thinner stringers on the compression struts, and I noticed straight away that the 1030 wing only has three anti-drag struts and that the struts get smaller with each one, but what I didn't notice till much later is that the 1030 also has thinner strengthening longerons on the rear spar than the 1100. On the 1030 they're made of rs7 and on the 1100 they're made of rs8. I've attached bits of the relevant diagrams with the wood size underlined in RED
I'm not trying to sell anybody on Poly-Fiber. Just to clarify what I was saying: I was assuming that one would use the same system most people are using with Poly-Fiber where they start with the Poly-Brush which comes with the kit and possibly a layer of Poly-Spray to protect the fabric itself from UV. Then I was choosing top coats over that. That narrows the difference some.
However, while I may be misreading what you intended, it sounds like you were saying that the Poly-Tone has no UV blocking to protect itself and that it would be mixed 1 to 1 with Poly-Tone UV Blocking thus upping the price a lot. Actually you use only 1 ounce of Poly-Tone for each quart of Poly-Tone Finish, primarily on ultralights for extra UV protection. This comes in 1/2 pint cans, which is 8 fluid ounces. That means that one can ($26.15) will add additional UV protection to 8 quarts of paint. This is pretty cheap.
The only reason I bring this up is that you are saving only a bit of money on a job which takes a lot of time. It is pretty hard to imagine it really putting much of a dent in one's wallet over the time it takes to cover, prep, and paint. But it does mean that it may add value some day when you or your heirs wish to sell the aircraft. If you can make a point that everything is top aircraft quality right down to the paint system, it can add value. I have seen what a difference that sort of thing can make.
Again: If somebody is completely happy with the "latex" paint, that is fine, but I did feel that people might think it would make a much bigger difference than it actually does, and indeed you've kind of demonstrated that. Essentially I think the latex makes the most sense for the person scratch building to an absolute minimum budget. I think there are a lot of people for whom buying things as they go is no great strain on so small an aircraft. I can guarantee you that after your first flight you'll forget all about a few extra dollars won't spent during construction. I just want both the points of view to be out there.
However, while I may be misreading what you intended,
The only reason I bring this up is that you are saving only a bit of money on a job which takes a lot of time. It is pretty hard to imagine it really putting much of a dent in one's wallet over the time it takes to cover, prep, and paint. But it does mean that it may add value some day when you or your heirs wish to sell the aircraft. If you can make a point that everything is top aircraft quality right down to the paint system, it can add value. I have seen what a difference that sort of thing can make.
Again: If somebody is completely happy with the "latex" paint, that is fine, but I did feel that people might think it would make a much bigger difference than it actually does, and indeed you've kind of demonstrated that. Essentially I think the latex makes the most sense for the person scratch building to an absolute minimum budget. I think there are a lot of people for whom buying things as they go is no great strain on so small an aircraft. I can guarantee you that after your first flight you'll forget all about a few extra dollars won't spent during construction. I just want both the points of view to be out there.
Tom
Yes you misreading what I intended. I was simply combining the cost of materials, not the materials themselves.
As I said before, "My estament for my minimax was $550 minimum for poly tone, thats 1 gallon poly brush, 1 gallons poly spray, and 2 gallons for color (one white and one blue). Vs $100 for 2 gallons of latex (one white and one blue) for the same if not better results." If you are doing just a one color paint scheme, you can get away with one gallon at $32.98 a gallon at home depot. That's a savings of $517.02. A substantial savings that would take a dent out of anyone's wallet.
As far as it making a big difference, the pictures speak for themselves.
This is Malcolm Morrison's Micro Mong Painted with Sherwin williams Latex house paint. This paint job did not detract from the resale value of Malcolm's Micro Mong at all.
Unfortunately it is not the paint job that detracts from the resale value of our beloved Minimaxes. It's the fact that they are built in a garage by amatures (myself included) who think they know better than the designer how it should be built. Which is what ITman496 is experiencing now. And for all their charm and simplicity they look like something someone built in a garage. I mean, lets face it, if aviation had a soapbox derby, the minimax would be the soapbox derby airplane. When I am sitting on the airstrip, ready to throttle up and take to the skies for the first time, I will have almost $12000 invested in my minimax. If I decided to sell it, Id be lucky to get $4000 out of it and it would have nothing to do with the paint job.
I'm not trying to sell anyone on latex paint but I won't allow it to be so quickly dismisses as sub standard when clearly its not. But in the end, Its your airplane, do your research and do what ever you feel comfortable with.
I'm not regretful. I wanted to build an airplane, and I'm getting that experience. When its all over, I'll have a machine that I know inside and out and will have many, many years of fun with, as well as a whole bunch of new skills. I am never one to buy things mainly thinking about the resale value of them before I even use it, it seems like a somewhat depressing way to live.
Should I look into replacing the bottom compression rib with thicker wood? Or is it fine if both are RS-5? I'm willing to bet, probably not worth it.
According to the stress report, the upper (smaller) compression rib member has a buckling strength of 470 lbs. In the 1100R, the lower member is twice as thick as the upper member giving it twice the buckling strength which exceeds the glue joint shear strength of 863 lbs so the total compression strength of the 1100R rib is 1333 lbs and not 1410 lbs. The lower rib member could be 1/16" thinner without sacrificing strength.
So the 1030R compression rib would have a compressive strength of 2 x 470 = 940 lbs. Is that enough? Well, the 1100R maximum compression at rib #3 is about 588 lbs. Then the safety factor is 1.6, marginally better than the 1.5 needed. However, if we factor the load by 46/56, the ratio of MTOW's, the load becomes 476 lbs and the safety factor is 2.0.
The spar situation is the same. The upper spar cap doubler increases the bending resistance where bending stress is greatest, just inboard of the strut attachment. Factoring the 1100R rear spar cap + doubler depth of 1.5" by 0.82 we get 1.23". Then the doubler should be greater than 0.48" which it is.
How does this apply to Vne? From what I've read, Vne or really VD, the dive speed, is dependent on flutter resistance. For the wing this means its torque stiffness. For the TEAM planes wing torque is reacted by the struts. Therefore, I believe the Vne will be largely determined by the strength of the wing section outboard of the strut to resist torque. This will be dependent upon the bending strength of the spars and the torque resistance of the 'D' box of the main spar. I have looked for a simple method of analysis and found a couple purported to be so but simple seems a very relative term.
I'm not regretful. I wanted to build an airplane, and I'm getting that experience. When its all over, I'll have a machine that I know inside and out and will have many, many years of fun with, as well as a whole bunch of new skills. I am never one to buy things mainly thinking about the resale value of them before I even use it, it seems like a somewhat depressing way to live.
You have nothing to regret. In the end you will have a solid performer, May not have the Vne you would like, but still an airworthy airplane. I'm not downing your airplane or you for buying it. Just simply stating why minimaxs have no resale value, mine included. But like you said, I didn't build it for the resale value. And once I'm dead and gone, whether someone gets a decent price for my personal possessions or not will be the least of my concerns.
That is fascinating. I'll take good pictures of my wing once the skin is off and we can know for sure. Thank you for explaining in such good detail!
Toliver,
Agreed. A bunch of sensors came in for my engine, I'm excited to put them in now! I'm clearing space to work on the wings in the meantime, hopefully next week I can start to tear into them. How much U500 would you recommend for having enough on hand to eventually recover the entire minimax?
Also do you happen to know how much fabric it takes to do both wings, horizontal and vertical stabilizer, and fuselage + turtle deck?
Should I look into replacing the bottom compression rib with thicker wood? Or is it fine if both are RS-5? I'm willing to bet, probably not worth it.
Can you tell me what kind of wood you used in your turtle deck, the long thin pieces as well as the plywood?
I think the 1030 plans call for RS-5 for both top and bottom compression ribs. At least thats how I built mine.
Regarding Vne, I have seen some videos from Gyro Jeffro on YouTube where he is climbing in his Pt 103 HiMax at 40 mph indicated, and doing level flight at about 45 to 48 mph. I thought he was flying too close to stall speed.
I would be more than happy if I can do 60 to 65 mph on cruise without the airframe falling apart.
is it advisable to fly this 1030 airframe at 90 to 100 mph ? Firstly that is above Part 103 limits. But if I still want that kind of speed, I would prefer a stronger air-frame built for that speed, so I know it is safe.
My main concern is not necessarily flying that fast but just knowing 'she has it in her' so to speak, if I'm doing 65mph and suddenly hit an unexpected 30mph head wind.
Agreed. A bunch of sensors came in for my engine, I'm excited to put them in now! I'm clearing space to work on the wings in the meantime, hopefully next week I can start to tear into them. How much U500 would you recommend for having enough on hand to eventually recover the entire minimax?
Also do you happen to know how much fabric it takes to do both wings, horizontal and vertical stabilizer, and fuselage + turtle deck?
I just bought a second qt. of U500. I only had maybe a pint left after the fuselage and I still have the right wing to cover yet. I'll have a lot left over but at least I won't have to worry about running out.
As for how much fabric, well let's see here. The fabric kit from Team comes with 38 Yards, which is about 11 yards to much to my notion.
One wing panel is 11 1/2 feet long so you will need 4 yards for the top and 4 yards for the bottom for a total of 8 yards per wing. and you will use just about every scrap of it to.
The fuselage is 14 feet long, so you will need 6 yards. Five yards will cover the bottom, sides and front turtle deck. the last yard is for the rear turtle deck.
The stab is 8 foot long so you will need 3 yards for the stab and elevator. and another 2 yards for the fin and rudder.
For a grand total of 27 yards, but your mileage may vary. You will have to take your own measurements plan your layout and cuts to suit yourself , which will undoubtedly very from mine.
Thank you very much! Ordering 2qt of U500 and 30 yards of fabric and.. well, I guess a bunch of acetone and some varnish. You said you used thinned epoxy instead of varnish, how do you thin epoxy? I'm only used to 2 part epoxy where I mix equal proportions.
Regarding Vne, I have seen some videos from Gyro Jeffro on YouTube where he is climbing in his Pt 103 HiMax at 40 mph indicated, and doing level flight at about 45 to 48 mph. I thought he was flying too close to stall speed.
I would be more than happy if I can do 60 to 65 mph on cruise without the airframe falling apart.
is it advisable to fly this 1030 airframe at 90 to 100 mph ? Firstly that is above Part 103 limits. But if I still want that kind of speed, I would prefer a stronger air-frame built for that speed, so I know it is safe.
1030 specs from the team web site:
1030F Performance: Top speed 63 mph Cruise speed 55 mph Stall speed 26 mph Vne 90 mph Climb rate 650 fpm (@ about 40 to 45 mph from my understanding) Take-off Roll 150 ft. Landing Roll 180 ft.
So 60 to 65 mph cruise might be pushing it a bit but doable. Climbing out at 40 to 45 mph is fine as the stall speed is 26 mph (and its my understanding that 40 to 45 mph is optimal speed for climb out in a max). And just because you can cruise around at 63 mph doesn't mean you have to. Cruising around at 48 mph is perfectly ok, your a long ways from stalling out. 90 to 100 mph exceeds the Vne of the 1030. So if you want to cruise around @ 100 mph I don't think the Minimax 1030 is for you.
Thank you very much! Ordering 2qt of U500 and 30 yards of fabric and.. well, I guess a bunch of acetone and some varnish. You said you used thinned epoxy instead of varnish, how do you thin epoxy? I'm only used to 2 part epoxy where I mix equal proportions.
If you use varnish it has to be a two part varnish as the glue will dissolve anything but a two part varnish. You can thin epoxy with denatured alcohol or acetone. I used total boat epoxy with the pumps and thinded it with denatured alcohol. Two pumps of resin, two pumps of hardener, mix well, and about 2 ounces of thinner is just right. But you may not need any varnish as it should (hopefully) be varnished already.
Ah, okay, makes sense. I wanted to have varnish or epoxy on hand due to the worry that the acetone removal of the old fabric might remove the varnish too, if it's there.
I currently have a couple bottles of T-88 epoxy. But I'll look into yours if the wood looks unvarnished!
On Painting: Tolliver66 and I are just using the different systems differently. The way I would finish the fabric simply puts more emphasis on protecting the fabric before choosing "latex" top coats or Poly-Tone top coats. That reduces the difference between our estimates in that he is figuring on only using top coats.
On Epoxy: Very unfortunately I have to mention one thing. I would recommend before using epoxy that you read everything available from Gougeon Brothers, Inc. on WEST System(tm) which is the industry leader in epoxies designed for use with wood. One of the things which is made very clear is that you shouldn't "thin" epoxy. If you buy, as an example WEST System, you would choose a special hardener for clear coating and you will be able to coat with it without thinning. Why don't you thin epoxy? Obviously one reason is that it isn't intended to be thinned and you therefore are interfering with the physical properties. However to my mind one of the most important points for coating is that good epoxy is essentially 100% solids. There is no evaporation of a thinner during cure. This means that there are no micro-passages in the resin to pass water vapor. This means that a good coating of epoxy is much better at protecting the wood from variations in moisture that might cause warping and much better at protecting against any possibility of rot. Used as intended it is very long lived. I have no idea how much epoxy I've used in a lifetime, but it would have to be measured in tons, and I sell a lot of designs built in wood and epoxy (not aircraft).
I really hate to make statements which contradict people's advice or choices. In this case as a professional in the field of wood epoxy structures, I have a professional responsibility to speak out. I apologize if I'm offending people here.
You aren't offending anyone, I'm happy to have the advice! Thank you!
I'll keep that in mind. I honestly will probably be using varnish (if the wood isn't varnished already) but I am curious about using a special hardener instead. I honestly had no idea epoxy could be thinned in the first place so I suppose it makes sense that maybe it can't be without impacting its properties?
Also, one more question.. When one glues dacron to the plywood sides of an aircraft, do you glue the whole surface or just the perimeter?
On Painting: Tolliver66 and I are just using the different systems differently. The way I would finish the fabric simply puts more emphasis on protecting the fabric before choosing "latex" top coats or Poly-Tone top coats. That reduces the difference between our estimates in that he is figuring on only using top coats.
You still don't get it do you Tom. At least read the article so that you have a clue before you decide to argue a point. I'll post it again for your convenience. http://wienerdogaero.com/Latex.php
Latex is your Poly- brush to fill the weave. Latex is your Poly-spray for UV protection and lastly, latex is your top coat for a beautiful finnish.
Latex finish on aircraft is nothing new. People have been doing it for over a decade now.
As far as epoxy, thinned epoxy sets up hard as a rock same as unthined epoxy. I'm using the super slow cure "Tropical hardener" which takes a full 24 hours to set during which time the denatured alcohol has long since evaporated and the epoxy left behind has flowed out and filled any "micro-passages in the resin ". But to each his own. Its your airplane, your money, and your but sittin in it. So like I said before, do your own research, decide for yourself whats the best method or product and best of luck to ya.
Should I order the supplies to rib stitch the wings or should I just glue the fabric to the top and bottom of the ribs? The polyfiber manual seems to suggest that in a few years my wings will be ruined if I don't do it. It doesn't look that hard to do, honestly, but would I be completely wasting my time if I do it?
It's kinda fun to rib stitch. It looks good to airplane people. It gives one that i's dotted-t's crossed satisfaction. It doesn't add weight. It does add strength even if redundant for the tiniest weight penalty.
Even assuming you are going to rib stitch the bottom of ribs to the fabric, it won't hurt to glue the fabric to the bottom rib. Gluing the fabric to the rib spreads the load more evenly on the rib, and the load will transfer to the stitches only in the event of the glue separating. I am aware someone had mentioned that in certificated planes, bottom fabric is only rib stitched, and not glued.
I wonder if anyone else has also NOT glued the bottom fabric to the bottom ribs. To me, gluing fabric to the bottom rib seemed the logical thing to do while covering the wing. I did have a question about whether to glue the fabric to the rear spar too. That doubt arose because the fabric was touching the top and bottom of the rear spar at most places after it was shrunk. But I was told in this forum NOT to glue the fabric to the rear spar.
Okay, I know in the manual it says don't glue to the ribs at all, only stitch them. I guess glue and stitch would be extra strong?
So if I glue to the top and bottom of the ribs, lay the plastic tape, stitch from the top surface to the bottom, cement on some covering tape to hide it all, and call it done, I'll have a happy wing?
Plus gluing it to the other important areas on the wing, of course.
I'm just curious if anyone has had fabric start to pull away like the polyfiber manual says... Has anyone here got a 440ish sized engine in a Max with no stitching and it was fine for many years with no stitching at all, just glue on the ribs?
Me, my 447 powered 88 doesn't have any stitching, and it was made in 1994. There's no sign of the fabric ever having separated from the top of the ribs in the time I've owned the plane (since 2016) and I've had the plane up to over 85mph on the ASI, which is very close to the 90mph VNE of the plane.
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