I was under the assumption that both 1100 and Max 103 ( also known as 1030 ) are identical designs except that 1030/103 has a turtle deck back and front , where as 1100 has a flat top fuselage. The additional weight of the turtle decks in the 103 design is offset by its lighter tail.
In the flight manual I see that the 103 model can accept only single cylinder engines with weight upto 65 lbs. Not sure if this weight includes weight of exhaust and redrive ?
It also further states that model 1100 can accept two cylinder engines.
So does that mean that the structure of the 103 model is slightly less strong than the structure of the 1100 model. ?
Because I have a 2 cyl engine weighing 45 lbs base weight, (but 93 lbs when you add redrive and exhaust and other small misc items), on a Max 103 airframe. My engine mount looks strong and I have had no issues with excess vibration etc while taxiing. But I am left wondering whether mine is an acceptable deviation in engine choice. Also do I need to add some stiffening members to forward fuselage box in 103 model ?
Specifically are there any builders who have used 2 cyl engine on a stock Max103 / 1030 airframe without strengthening the air-frame to accept a 2 cyl engine.
Thanks for any thoughts on this.
EDIT: I get a feeling the fuselage and engine mount structure may be the same in both models; but as model 103 air-frame may be a few lbs heavier than model 1100 air-frame, the engine size / single cylinder limitation on model 103 may have more to do with making weight as Part 103. But I am not too sure about this .
TEAM miniMAX originally designed to accommodate 20 to 50hp engines. Evolved to a series of different model designs. Here, a clip from Experimenter Magazine.
Thanks. My basic question is : structurally can a a Max 103 take a 447 engine without modifications, assuming you are not that interested to make Part 103 ?
These airplanes are just like snow flakes; there have never been two built just exactly a like. If you are looking for absolute guarantees I do not think you will find any. That being said you are prudent to look into the matter. Maybe an e-mail to Dave at TEAM will calm the anxiety . At 2,000 feet AGL you will probably be thinking about every glue joint that was made. The crafts men that built the tall buildings in New York city will tell you that after 6 feet up it really does not matter anymore.
Thanks, Aeronut. I may have seen some Pt 103 Maxes with 2 cylinder engines like Kawasaki 440 and Rotax 377 and 447, but right now I can't recall if their fuselages were stiffened to accept these heavier engines. As I said, my engine seems to be running fine. But just for the sake of knowing more about our model line up, this information may be useful.
Your good Keith, I know exactly how you feel, nobody thinks the floor in their home will give way and you will die, but somehow we think our spars will snap like twigs and we will die
Do crow hops for your first flights no higher than a foot above the ground using the throttle to manage your altitude
This really isn't a good idea. The hardest part of flying any aircraft is the landing. It's also when you're going slowest, so your controls are least effective. And because you're so close to the ground, you have very little time to react to gusts, bounces, engine hiccups etc - and when you're at your least experienced. The Max reacts very quickly in changes to throttle, so this too can catch you out until you know what to expect.
In my view, you are much better advised to get up to 3000' or so, and find out how it works up there. Much more room to recover from problems, and a chance to play with stalls, power settings, control inputs & to generally get used to flying for 30 or 40 minutes before you try landing it. That is what I did, once I'd mastered tail-up taxiing for a few hours. I also used this taxi time to break in the engine & prove engine & control systems, so I knew it would all work when I was airborne.
Too easy to get into trouble on hops at very low altitude with minimal Max time.
Incidentally, I put a 60hp engine in my Eros. Plans state 'up to 50 hp', but I reinforced the engine mount area a bit, & have had no problems in 2 years.
My impression is that the 1030 and 1100 airframes are also structurally different. The 1030 being lighter build. I am sure TEAM would know all the details.
Barring talking with Coop directly, you could always download the drawings for both birds and compare all the structural members to see what is changed.
Everything has a limit, and pushing (or exceeding) manufacturers design limits and (methodologies for the same) should be reviewed very very closely to ensure safety.
Everything has a limit, and pushing (or exceeding) manufacturers design limits and (methodologies for the same) should be reviewed very very closely to ensure safety.
Quite true.
Lynn, do you have any opinion on this ? I remember you had done some comparison between these two types and had observed that Max 103 and 1100 have slight differences in engine-bed placement. I was wondering whether you observed any other structural differences in the fuselages ?
The flight manual also states :
>>>>>>>>
MAX-103 can be built as either an ultralight vehicle, subject to limitations of Federal Aviation Regulations, part 103, or as an experimental category aircraft. FAR part 23 was used as a guide in designing the aircraft, to ensure more than adequate strength for normal operations. As such, the aircraft essentially meets the requirements for a utility category aircraft.<<<<<<<<<<<<<
I pulled out the plans for each to look at a few areas in particular, but as I recalled the basic structure of the fuselage of the 1100 and 1030 is almost identical. The exception, where differences exist, is pretty much limited to the most forward section of the fuselage, the engine mounting "bed", and the position of the engine. There might be other slight differences, but overall the 1100 and 1030 fuselages are literally twins. The 1030 of course looks a lot different because of the cowl and turtledeck.
Differences do exist in the wing construction and the use of the "light" tail on the 1030. I actually built my MiniMAX using the 1100 fuselage plans, since to me it's slightly simpler to build being a "flat-top". I did build my wings to the 1030 plans (after discussing that idea with David at TEAM) and also used the light tail since staying under 254# empty weight was a goal....and I made it by several pounds. The 1030 wing is very similar overall to the 1100 wing but the 1030 has anti-drag braces getting smaller in size in each pair of bays as you move out the length of the wing, there are only 3 anti-drag braces in the 1030 wing compared with 4 in the 1100, and the compression ribs are also smaller if memory serves.
One other difference is the 1030 plans, I believe, show a 22" wide fuselage, but that is also something that can be done on a 1100. I built my 1100 fuselage to 22", which is plenty wide for me at about 145-ish pounds. 22" is actually the fuselage width shown on some early (perhaps original design?) plans I have.
There is also a slight difference in the structure of the wood landing gear legs, with the 1030 plans using slightly smaller internal corner block and is also lacking a small, internal diagonal brace that the 1100 has. That's another weight saving measure I took the liberty of transferring to my "hybrid" 1100/1030 MiniMAX.
I hope this helps......and, as always, if I'm mistaken I hope someone will correct me.
Here's Hank Clark's 1030 airplane using a Kawasaki 340. That's his then 15 year-old son David flying. I saw the build in progress and witnessed some flying. David had a lot of experience flying Hank's J3. The 1030 performed well with the Kawasaki but both Hank and David were about 150 lbs. The 1030 has to have a light engine to meet Part 103. The airplane can't count cylinders, just pounds. The 1100 can easily meet Part 103 with a 70 lb engine.
Lynn , thanks for the detailed analysis. That was a great help. Bob, thanks for the info on that 1030 with a Kawasaki 340 engine. There might be some Max 1030's with R447 too.
When the manual indicates 65 lbs engine weight, one has to make an assumption that it is the installed weight including accessories. It is reasonable to include carb , exhaust header, exhaust pipes, starter as part of engine weight. The real question is whether Redrive is counted as engine weight. Prop and prop hub is usually not counted as engine weight, but in the 1030, does 65 include prop weight ?
The skypup has a clear definition of what constitutes engine weight, leaving no room for guesswork. I think they have a 62 lbs limit for engine and prop, accessories included. ( Or is it 65 ? )
As Lynn has stated, there is some difference in forward fuselage between 1030 and 1100. One major difference is location of station 1. Below is the comparison for foreward fuselage between 1100 and 1030.
In my Rotax book the total weight of a 447 is approx. 90 lbs which includes engine, gearbox, carb. starter, exhaust excluding prop. The 503 is approx 3 lbs heavier. The max 103 has a single 5 gal tank in the nose which will make your flight time short. Could go with 2 wing tanks but doubt if you would meet the 254 lb weight limit for part 103 if you really care.
Actually anything more than 5 gals and you blow the Part 103 rules anyway. I'd rather be 5# over the weight than have 5 extra gallons, as the Feds probably won't weigh the aircraft (or its remains) but will definately look for more than one tank.
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