1030 advertised weight is 250 which meets Part 103; 1100 advertised weight is 280 which does not.  The photos look alike to me.  

Has anybody compared plans to see why the 1030 is 30 pounds lighter?

Are those weights compared with the same engine on both designs?

While not being 30 pounds worth, off hand I believe there was a difference in the number (and I believe dimensions) of the drag brace diagonals in the wings, and the horizontal tail construction.

Aeronaut, good point.  My 1100R plans say it should weigh 280 but that's with the Rotax 277 engine which weighs 65 pounds.  The advertised weight of the 1030F is 250 pounds built with a Hirth F-33 engine which only weighs 45 pounds,  including electric start and reduction drive.   There's 20 pounds accounted for.

Assuming both aircraft were built with the same engine (Hirth F-33), then I'm looking for structural changes that would lighten the 1100.  Stilson pointed out wings and tail feathers and I'll take a look at that.  Anybody know of any other differences to save weight?

Lynn (Lake_Harley) may have more information on this.
He seems to have done some research on 1030/1100 before he built his 1100.

nathan.bissonette,

I've got an 88, which is the UK equivalent of the 1030, so I know what most of the differences are between it and the later models.

1. The fuselage is around 5" shorter, and originally was 2" narrower (20" instead of 22"), so the undercarriage is also narrower, and the steel axle is 2" shorter and therefore lighter.
2. Inside the fuselage station 4 was originally the sloping seat back, i.e. it was structural (mine is). However, in the updated plans for the 1030 and all subsequent models, station 4 is an extra piece of wood that is structural and sits vertically, while the sloping seat back is not structural and can be removed.
3. The tail feathers have hollow leading edges on the horizontal stabiliser and fin instead of the solid leading edges on the 1100.
4. The original design of the 1030 also had wire bracing above and below the horizontal stabiliser instead of just the two struts from the horizontal stabiliser to the tail fin as the later models have, and the tail was held to the fuselage with 3 bolts instead of the 4 bolts used on later models.
5. The wings have less anti drag struts, 3 instead of 4, and each one is made of thinner material than those in the 1100 wing. The rear spar is also slightly different, with the upper and lower cap strips made of thinner material.

There may be other differences as well, but those are the ones I know about.

Yes there is a difference in weight between a standard 277 with a gear box and Lake Harley's 277 with a belt drive. I am attempting to make my 1100R make the 254 weight cause it is a mountain to climb; nothing more than a challenge.I also noticed L.H. had the light nylon wheels. Every addition you make to these little airplanes be it for safety or convenience makes them heaver. They are also like snow flakes in that there are no two just alike. I am not saying that is a bad thing but it does tend to confuse the issue.

According to my uncertified bathroom scale (but compared to another scale) my 1100/1030 "hybrid" weighed 246# empty when completed. The fuselage is the normal 1100 plans length and design. The wings and tail are the 1030 design. I stick built from scratch and made sure that dimensions of raw stock were not oversized which would have just added weight. For example, to me 1/4" stock was .250" to .255", not .270" or .280". The fuel tank is made from .040" aluminum and weighed about 1.5#. Paint is thinned latex paint and primer and only enough to seal the fabric and give an even appearance. If I would ever build another (which I doubt will happen) I think I could take another 2 or 3# out of it and it would be fun to try just for the challenge! I did some weighing of the belt drive I used and a gearbox I had, and I don't recall there being much difference in weight. If there was a difference it was minimal.

Lynn

This doesn't necessarily address the 1030 vs 1100 question asked originally, but it does give an example of details that can make a weight difference.

I didn't do this on my MiniMAX, but I met and talked with a Hummel Ultracruiser builder who focused on building light throughout his plane's construction. Just one example of what he did was to substitute 2024-T4 aluminum round bar (I think I got the alloy right) that was threaded and used nuts on both ends to replace the steel bolts that held his wheel halves together. Now that might seem a minimal savings of weight, but that attention to the "little things", maybe 3 or 4 Oz. savings, adds up in the end.

Lynn

Thanks for the insights, Lake Harley.  Much appreciated.  I have some work to do over the winter!

The 1100R with Rotax 277 and minimal instrumentation and without brakes or a BRS should weigh 237lbs.  The 1030 used a slightly lighter built-up tail but also had a turtle deck and a fiberglass nose bowl.  My 1100R came in at 240lbs with a small turtle deck of my own design.

Wow, Bob! Compared to your 1100 at 240#, my 1100/1030 is "fat"! And I thought I did well.  

Lynn

Anyone do a full build yet with Oratex?  Would like to see how that compares weight wise (on an apples to apples basis).

[quote=537  My 1100R plans say it should weigh 280 but that's with the Rotax 277 engine which weighs 65 pounds.  

Made the Weight and Balance of my newly 1989 minimax plans build recently. Complete basic flight instruments, brakes, flaperons with Rotax 277. Empty wt. is 264#. Estimate gross wt. 500# or 505.5# with added ballast to improved cg to 14" from LE.. The above quote 280# wt of 1100R is heavier compared on early TEAM minimax design. My concern, does gross wt 505# can be handled by R277?

Phil,

The original 'max was powered by a Rotax 277 and had an MAUW of 525 lbs, so a gross weight of 505 lbs is 20 lbs lighter. It probably won't leap off the ground like a 1600R does, but it should fly without any problems.

Quoted from bob.hood

Phil,

The original 'max was powered by a Rotax 277 and had an MAUW of 525 lbs, so a gross weight of 505 lbs is 20 lbs lighter. It probably won't leap off the ground like a 1600R does, but it should fly without any problems.

What does MAUW mean? Thanks for your reply, Bob.

Phil,

MAUW means Maximum All Up Weight, or MTOW (Maximum Take Off Weight), or gross weight including fuel, pilot, passengers, baggage, etc.

The 1030 is what use to be called the original minimax. Light tail, lighter spar cap material, Two smaller anti drag diagonals in each wing, narrow fuselage, and probably a few other little things.
It makes it lighter than the 1100.
  Larry

Yup wood grows on trees and there will be a bit of difference in the density for each given piece in the airplane. I do not think it is a big deal but could have an affect if you got all heavy wood in a kit verses all light wood in a kit. I really do not think it would amount to more than five to ten pounds.