We finished building the normal ribs for miniMax EROS1650. About to work on the root and tip ribs; and I think it's #5 that gets something for bracket's. I'm wondering exactly what it is we're supposed to do. Looks like we cut that forward, vertical, rib stick in half (vertically) at the top area. Is that correct? Any photos will help a lot. Any advice is also appreciated.

Two other questions. I've called and emailed Team Minimax, but never a response. How do I reach them? Also, I see it's know called a 1650R EROS. Does the "R' mean something in particular?

Thank you,

John C
Eastern PA

project photos are here:
https://imageevent.com/eaa839/photosection

Pretty sure the "R" just signifies that the air frame (or more specifically Firewall ) is designed to mount Rotax engines. There use to be HiMax 1400Z model. That one was expected to hang a Zenoah 50 Engine on it.
I'm waiting to see if Team builds any "C" or "L" Model aircraft!   (I bet no one can figure that out   )
                                                                                                                TTT  

"R" stands for Rotax.  Don't cut anything in rib #5, just drill the 1/4" hole for the bearing bolt.

Thank you! Funny one TTT!

John

I took these pics today. Maybe they will help. Rib 5 is in there. I'm getting ready to epoxy the spacer to rib 5 and aileron horn on the others.

Thanks! Photos always help.

John C

Some more questions.

Pages 16 and 21 both indicate 1/4" RS672 for ribs 4, 7 and 5. But page 20 indicates 1/8" RS654 for ribs 4 and 7. That has me confused.

On page 20, if the nose pieces are 1/8", are they glued inside the rib or to a outside edge?

When gluing the nose pieces, do I take a piece of RS653 Aileron Web Spar to set the spacing?

Does the full sheet go over (on top) the 1/4" pieces that are inside the rib at the rear?

The center of page 21 regarding RS17... One drawing makes it appear I make one straight cut, but the other makes it looked curved when creating a space for the nose piece.

I attached three images of the plans I'm looking at. From top down.....Page 21, 20 and 16

John C

Hi John.  It's been almost 30 years but as I recall the reasoning is this (subject to correction by those with current projects or better memories):

The root and tip rib and rib 5 get the 1/4" ply inserted "inside" the rib RS-1 members because these are the aileron hinge locations and the thicker material (as opposed to 1/8" ply) is used for the aileron hinge assemblies.  You do NOT also add the 1/8" ply at these locations because at the root and tip it is sheathed fully with ply on the "exterior side".  IIRC you could add the 1/8" ply to one side on Rib 5 (the side that does not have the "hinge strap" on it, but this is not called for by the plans.

At ribs 4 and 7 the 1/4" ply is "inset" between the ribs RS-1 components to make this nose rib thicker and give more glue area because per plans the aileron leading edge skin has a butt joint seam at this location and the wider rib gives more glue area.  Additionally it calls for adding the 1/8" plywood also at ribs 4 and 7, again to increase glue area.  You could actually add it to both sides at ribs 4 and 7 and get even more glue area.  I guess you could go crazy and add 1/4" plywood on both sides and have even more glue area, but the plans do not call for that, but it could be a "fix" if you really cut your leading edge plywood with a really bad "seam joint".

Yes when gluing on the 1/8" ply it is indicated to be glued on the sides of the ribs (you pick which side) as opposed to the 1/4" ply pieces which are "inset".  At all the ribs except the root and tip and 4,5 and 7 ca there will be ONLY the 1/8" ply nose ribs.

As far as spacing for the spar web I cannot recall (again its been a long time) a reason not to assemble the wing and then insert the spar web and glue it to the RS-1 and THEN glue on the nose ribs right up against the spar web.  Then you cut the aileron free of the wing (you can even wait until the aileron is cut away to glue on the aileron nose ribs) and then wrap the leading edge ply around the aileron, making sure the aileron is flat on the table and not getting any twist put in it as the leading edge ply will "lock" any twist.

Yes the drawing looks like a curved "concave" cut in one location but that would be a difficult cut to make (maybe not with a bench router) along the entire length of the trailing edge RS-17 stock.  Straight is most common and ordinarily the "gap" here is such that the trouble of making it curved would not be time well spent.  Easy to cut on a table saw at a simple straight angle.

I'm not sure what you mean by:  Does the full sheet go over (on top) the 1/4" pieces that are inside the rib at the rear?

I note also that where it appears as a curved cut on page 21 that this is not referring to the RS-17 but rather referring to the portion of rib RS-1 that is removed.  In practice you will cut this well clear of the "aileron contour" and then later sand the RS-1 on the aileron to this curved shape to follow the contour of the aileron nose and 1/8" nose ribs.  The piece removed and discarded will be in the form of a crudely cut scrap and some sawdust.  It is cut when cutting the aileron free of the wing.

Thank you for that detailed response. As far as my question about the full ply sheet.....the plans show full ply on one side (I see in the top photos of this thread on four ribs). The plans show three locations at the rear that have the 1/4" inserted between the RS1's (the bottom image I posted). I was wondering if I'll cover those with the full ply covering also, or if I end the full ply prior to that area. That bottom image I posted seems to show the full ply on the left...and then broken to reveal the three 'inset' 1/4" pieces.

Thank you Fenix!

John C

John I think I understand what you are asking.  If my response does not make sense then perhaps I don't.

The "inset" pieces of 1/4" ply in all 3 locations of each of the root and tip ribs and ribs # 5 are there to facilitate the assembly of the aileron hinges.

At ribs 5 there will simply be the typical gussets on each side.  Of course the 1/4" ply needs installed prior to gluing the gussets on the "second side" or the gussets will need removed or notched to install the 1/4" ply.  No big deal.  One way to remove them is with a dremel moto tool and sanding drum but there are other methods that work if necessary.

In the case of the root and tip ribs they are usually built with gussets only on one side (be sure to make left and right wing versions).  Then the 1/4" ply is inserted and then the "exterior" surface of each of the root and tip ribs (4 ribs total) are sheeted entirely with plywood.   Normally the root ribs have lightening holes cut in this ply that also allows for inspection into the wing.  These holes can also be cut in the tip rib and closed over with fabric.  Yes this exterior ply sheeting covers also the areas where the 1/4" ply pieces have been inset.  I think what you are seeing that looks like the ply is "broken" to reveal the inset plywood is that on one side it has the typical rib gussets which do reveal most of the inset 1/4" ply.  However on the exterior side the 1/4" ply will not be "revealed".  

Note however that this ply sheeting should not be continuous from the main rib onto the aileron portion or it will have to be cut in an arc when you cut the aileron free from the wing. (It may also be true that the aileron and main wing call for different thickness of plywood exterior sheeting - I don't remember anymore)  In any case sheet only main wing portion of the rib and cut the aft end of this ply in the arc required to match up to the aileron leading edge "nose".  Later you can put the sheeting on the aileron portion but it also will "go over" or "cover" the 1/4" plywood inset in the aileron.  Note that if you glue the exterior plywood sheeting on both the root and tip aileron ribs prior to inserting the aileron spar you will be challenged to insert the aileron spar without slotting one of the end ribs to allow for the spar insertion.  I can't think of a reason (again, its been a long time) not to wait to put the ply on the ends of the aileron until after the aileron is cut free from the wing.

Thank you for taking time to explain so much and in such detail. It helps a lot.

John C
https://vimeo.com/463113334
http://inspire.eaa.org/2020/10/01/youth-aircraft-building-project-teaches-skills-enthusiasm/
http://inspire.eaa.org/2021/03/11/after-the-build/

Concerning the RS-17 strips....  Many of us have had those strips break free from the ribs when the covering is fully tightened.  Mine held initially but broke loose within a year or so.  The fix is to add reinforcing blocks on each side of the ribs where the ribs and strips join.  Short pieces of 1/4" sq. rib stock work well here.  Easy to do while building the wing....hard after.

More info here: http://www.lonesomebuzzards.com/cgi-bin/forum/Blah.pl?m-1155496739/s-8/highlight-RS-17+loose/#num8

Quoted from radfordc

Concerning the RS-17 strips....  Many of us have had those strips break free from the ribs when the covering is fully tightened.  Mine held initially but broke loose within a year or so.  The fix is to add reinforcing blocks on each side of the ribs where the ribs and strips join.  Short pieces of 1/4" sq. rib stock work well here.  Easy to do while building the wing....hard after.

More info here: http://www.lonesomebuzzards.com/cgi-bin/forum/Blah.pl?m-1155496739/s-8/highlight-RS-17+loose/#num8

That's great to know! Thanks!

John C