125% Slipso w/Built Up Wing - RC Groups
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Sep 15, 2011, 06:00 PM
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arcticflyer's Avatar
Build Log

125% Slipso w/Built Up Wing

Several guys on the Slipso thread wanted me to document my build of a 125% Slipso with a built up wing. I seperated this build from a regular Slipso so as not to clog up that thread. I am a wood worker soooooo...would like to keep this thread clear of hollow molding or bagging for the guys who just haven't gotten that far yet.

The reason for the built up wing is that a solid carved wing of that size tends to warp when glassing and finishing.
Soooooo...here we go.

First things first...get the plans in 125% here: http://www.rcgroups.com/forums/attac...mentid=2492756

Then cut the plans for templates. I do my built up wings by building on the bottom sheeting. The sheeting is made after putting several sheets together then the bottom sheet is cut out.

Then you must decide on a airfoil and the best place I've found is here: www.worldofkrauss.com/
This is great site the airfoil can be sized by the site and by the printer preview on your printer to get the size you want.

Once I got the airfoil (MH43) I printed it out...glued it to lite ply, cut it out and it became the template for cutting out all those ribs (one at a time)
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Sep 15, 2011, 06:31 PM
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Still working on the wing!

Next the leading edge is made...Pain in the neck! Used 1/4stock and tapered it with a small razor plane. this is glued to the front of the sheeting with slight overhang (1/8).

The ribs are then laid out on the sheeting as well as the spar locations. Decided to space the ribs 2" apart for this wing. It is probably over kill but I tend to build strong (but heavy). 4.5mm hollow carbon fiber rods for both the spars.

The center rib is tripled the next two ribs are doubled where the wing meets the fuz. (strong...but heavy) Almost forgot...the holes for the spars have to be put in the ribs. They are laid out on the sheet and the hole are put in where the spars run through the ribs. (Hope that makes sense)

The wing tips are a pain. Use 1/4" sheeting and mark out the outline of the wing and bring it up to meet the leading edge. This is later sanded and tapered from nearly zero up to 1/4 inch.

After this is done the ribs are glued down...BUT NOT FLAT YET! Glue the front edge to the leading edge with the back of the rib sticking up in the air. Later the rib will be glued down at the center and the back. This bends the bottom sheeting onto the airfoil shape as the gluing is completed. DO NOT PUT #1 RIB IN TILL LAST... or you won't be able to get your spars in.

Prior to gluing the ribs in make sure and cut off the ones that stop at the ailerons.
Last edited by arcticflyer; Sep 16, 2011 at 01:08 PM.
Sep 15, 2011, 07:20 PM
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Wing Again!

Next the trailing edge is cut and glued down. You will notice that the ribs have to later be trimmed down to the 1/4" stock trailing edge. I used the cut off ribs to box in the ends of the trailing edge.

Before going any further I cut the wing servo doors from lite ply and cut the sheeting to match.

The slots for the servo wires are cut into the ribs and a spar is test fit.
The servo is traced onto the door and will be glued in place later.
Both spars are in place and small carbon strips were added to the wing tips.
Alierons are cut but not shaped yet.
Starting to look like a wing.
Sep 15, 2011, 09:13 PM
munce31's Avatar
Ohh excellent. Looking forward to seeing the rest of this thread.
Sep 15, 2011, 09:49 PM
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arcticflyer's Avatar
Your wish was granted...I am recovering from heart attack #1 (at the rip old age of 50)that happened nearly four weeks ago so I got some extra time whether I wanted it or not!
Sep 16, 2011, 11:17 AM
munce31's Avatar
Oh dear.... Well its good to hear that your still alive and well? More time for this hobby is good for you, y'know
Sep 16, 2011, 11:42 AM
Annoying people since 1970 :)
Great work as usual. Wonder what the Cg will work out at? Mine is around 28mm which is odd as the 125% version should in theory be around 37mm. First flight scared the c**p out of me!

Best wishes for a speedy recovery
Sep 16, 2011, 01:01 PM
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Over Kill....probably!

Yes!....the CG was an issue with my first 125% as well and if memory serves me correctly it was around 24 or 25mm. You're right wastegate it would seem that it should be more.
When this thing is done I am going to start really nose heavy as I hate the "dying chicken" first flight as well.

I added some 1/4 stock to the rear of the leading edge between the ribs with this one. Just have a feeling that when all of the sanding on that edge is done it will be thin and weak in that area. I know...more weight...but it will be strong. Where I fly the field is rough and strong is better than light!

The wing is now in a holding pattern as the LHS is out of 1/16th sheeting. I drove nearly 100miles to another shop and they were out of all sheeting as well. RATS!!!
Sep 16, 2011, 06:14 PM
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Time for the Fuz!

Out of a lack of wing sheeting I must move to the Fuz construction.

First print out the plans and cut them out using the plans as a template. I lengthened the nose by 50mm. This was done because the last 125 that I did was crazy tail heavy. First flight was the "dying chicken" but since the build was strong, no damage.
It you build the tail extremely light you might be able to stick with the plans as is. Your own call on this one. 50 might be extreme maybe 30 or 40 would be better. I'll know more when the wind dies down and I get to maiden my 100% that is 40mm longer.

After cutting out the sides I put the triangle stock down first and unlike the original build I flush the stock with the top and bottom to give more room inside the battery area. Also I used smaller stock in the extreme tail area and larger from that area forward.

The triangle stock on the bottom goes from the tail all the way to the nose with no breaks. This adds strength to the long Fuz.

The formers are two pieces of 1/16 laminated to make 1/8th lite ply. Might glue the center former at the front of the wing with hot glue and remove it when all other formers and the motor mount is in. I left it out of the last one and it really helped with room in the battery area and moving things around. Will document if it is decided to go that way.
Sep 18, 2011, 11:03 AM
Annoying people since 1970 :)
My second 125% fuse under construction with 2 inches added to the nose and a T-tail. Not flown it yet but I think I added too much length to the nose and should have gone for just 1 or 1.5 inches.
Sep 18, 2011, 04:06 PM
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arcticflyer's Avatar
wastegate- Man....I love the T-tail. Would like to see some Macro Pics of the assembly.
Mine is about 2" longer as well (50mm) however, I am at the point where I can chop some off if necessary. Have you done any balance tests yet with all the gear?
Sep 19, 2011, 10:14 AM
Annoying people since 1970 :)
I'll have to take some for you but here's one I already have showing both fuselages. I built the t-tail version from 6mm thick balsa sheet so I could really lay into the wood with a plane and end up with a nice shape rather than worry about the wood becoming too thin. I milled the formers so that they were perfectly square and the fuselage is as straight as can be. The tail was made from 3 pieces of 3mm sheet with the centre piece having a strip cut out where the elevator snake runs. Finish is just Japlac paint and it looks pretty good. This fuselage is so much stronger than my original! Not fitted it out yet as my original fuselage is still serviceable.
Sep 20, 2011, 08:45 AM
Annoying people since 1970 :)
Here you go. New fuse weighs in at 180 grams.
Sep 20, 2011, 10:32 PM
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arcticflyer's Avatar
wastegate- thanks for the pics! I did the maiden on my built up 100% two days ago and it went bad.
TWO "dying chicken" launches....pitch up roll to the left and straight into the ground. but inspite of the hard landings the damage was minimal which confirmed that my "built up" is strong because both times the thing cartwheeled.
I'm gonna post pics over on the other thread....CG or wing incidence and I'm leaning towards wing incidence.
Sep 22, 2011, 09:55 PM
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fairplane's Avatar
Hey!!!-Check your PM's

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