RE: Hostetler Pitts S1-11  
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All Forums >> RC Airplanes >> Scratch Building, Aircraft Design, 3D/CAD >> RE: Hostetler Pitts S1-11
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RE: Hostetler Pitts S1-11 - 3/8/2005 6:30:42 AM   
RENORACER



Posts: 53
Joined: 10/12/2002
From: Reno, NV, USA
Status: offline 		Well Mark, it looks like you've got a handle on it. Talk about time consuming, I figure I have about 8 hours in just cutting the balsa ribs, ( one at a time ) using an exacto knife.

I made templates using tracing paper, cut and glued them to the balsa, let dry over night. then use the same initial piece to cut the remaining ones. Plywood ribs are next.

It will probably take me about another week to get all the formers and fuse. sides cut, then its time to start building.

I'll try to get some pics posted this weekend. Going to be a fun one for sure.

(in reply to MarkNovack)
       Post #: 51

RE: Hostetler Pitts S1-11 - 3/8/2005 10:08:41 AM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		And I'm ready to sheet the top of the wing. Shears are in, LE is shaped, TE is on. I'll cut two aileron sheets to exact size and glue along with that. I have to remind myself not to sheet the bottom of the aileron until I have the reinforcing blocks in place. I'm sure that most of us have had to reopen a structure to inlay forgotten pieces? Some photos...boring photos. I want to see wing/fuse/cabane alignment photos NOW!!! Voices are tellig me to stop writing, start building!!!

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< Message edited by MarkNovack -- 3/8/2005 10:11:59 AM >

(in reply to RENORACER)
       Post #: 52

RE: Hostetler Pitts S1-11 - 3/8/2005 10:53:44 PM   
mrbigg



Posts: 2972
Joined: 10/30/2004
From: Streator, IL, USA
Status: offline 		oh man, i forgot those blocks for the hinges! i just let it ride. keep up the good work. reno, how come you don't use a jig saw? i assume you don't have a band saw.

_____________________________

PROVERBS 15:22 - Plans go wrong for lack of advice; many counselors bring success.

(in reply to MarkNovack)
       Post #: 53

RE: Hostetler Pitts S1-11 - 3/9/2005 5:58:05 AM   
RENORACER



Posts: 53
Joined: 10/12/2002
From: Reno, NV, USA
Status: offline 		Yes , it is true, I do not have a band saw. I do have a scroll saw to cut the formers with, and a jig saw to cut the large side pieces for the fuselage. All ribs and other pieces for the wings are now cut, and will start on the formers tomorrow night after work. May just get all of the cutting done by this weekend, and be able to start building.

I think making my own cabanes is going to be the hardest part. I am going to have to buy a new building board tho. the one I have now is only 2' x 4' and is just a tad to small for this bird. Thinking about buying a door from lowes. Saw some last Sunday for $25 and have no hole for door knob. Looks good and straight. Lots cheeper than a sheet of nice plywood. ( $45 ,,,,, OUCH )

(in reply to mrbigg)
       Post #: 54

RE: Hostetler Pitts S1-11 - 3/10/2005 11:58:45 PM   
mrbigg



Posts: 2972
Joined: 10/30/2004
From: Streator, IL, USA
Status: offline 		i know about the 45 buck deal. that's what i spent on a sheet of 1 1/4" OSB. but it will never warp. i still have a door for smaller planes. my daughter bought me a small band saw for Christmas and Dad got me a belt and disc sander combo. just in time for my building project. i don't know if you've seen my "huge ultimate build" over in the profile plane forum. i was just whining about cutting and fabricating parts myself. if i scratch build another one, i'm going to have at least the ribs laser cut. that way they are all consistent.

_____________________________

PROVERBS 15:22 - Plans go wrong for lack of advice; many counselors bring success.

(in reply to RENORACER)
       Post #: 55

RE: Hostetler Pitts S1-11 - 3/11/2005 5:11:04 AM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		Well, the wing is sheeted on both sides. Its not light, but not tooooooooooo heavy. It is stiff with 1/8" sheeting. I love it. For once I have enough sheeting to sand out any lumpies or uneveness without developing paper thin spots, buts its darned straight and incidence is exact. To sheet the bottom side, using the 3/8" rise of two extra spars (one each side) to shim the rear spar worked perfectly inducing zero twist into the wing. If, IF, you do get twist, NO PROBLEM! Covering will take it right out. The wing remains a bit flexible and will adjust to your satisfaction. Once again, this is really much easier than I imagined. Simple airplane...this is not a topgun detailed Stuka.

So, next comes a little sanding to knock down high spots. Then I'll cut four exact chord, over length aileron sheets. My plan is:

1. Cut sheets
2. Glue sheet to aileron riblets and tack glue to the non-moving inboad aileron bay rib to give a jigging hold while I install the blocks.
3. Flip wing and install blocks.
4. Glue remaining sheets.
5. Cut away aileron using the sheet edges as the cut line and bordering inboard bay rib.
6. Back cut aileron bay ribs 6/8" for the two 3/8" face caps.
7. Install caps, bevel, hinge.
8. Make paper tubes, install for servo cables (I will use independant aileron servos)
9. Cap strips on ribs.
10. Sand, sand, sand some more.
11. CLEAN BENCH AND SHOP FOR NEXT WING or pay job???

It figures, just as I get steaming on my OWN airplane that someone needs an F3A airplane built YESTERDAY!!! Of course, that could be enough to fill the Pitts with servos. I'm going with Futaba coreless, non-digital. I cannot see stuffing this with the latest in high-tech bits. Its short, fat, a bit weighty and should fly wonderfully on normal, high quality goods.



Finally, long live Great Planes CA. Love the stuff. All my ZAP is crap after a few months. The no-name stuff lasts a week. The GP stuff is still going strong after more than a year stored away, acting like the industrial CAs at 1/3 the price.

I'll post some photos later today after the sun rises. Too cold in the basement right this moment. Lens fogs up.

(in reply to mrbigg)
       Post #: 56

RE: Hostetler Pitts S1-11 - 3/11/2005 5:30:30 AM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		Oh, I should list a mistake/poor-forethought.

I did normalize the spar slots in the ribs, however, I did not cut enough depth for the rear spars on one side. Hence, I have 1mm of spar above flush with the ribs for the rear spar. I will use a flat file and file a 1mm flat in each cap strip where it passes over the rib. This will save trying to even out the cap strips from the finish side, another great advantage of 1/8" sheeting.

Second thoughts. 3/8" square, medium firm weight balsa with a ribbon of carbon fiber CA'd down the length would make awesome, weight saving spars. 3/32" sheeting would also work, but I expect to sand down a bit (1/32"?) so 1/8" is fine. I used the medium grade sheeting as it allows me to handle the wing without fear. All of my other bipes (kits built, the ARFs are heavier) have such thin sheeting that I must use extreme care when lifting the model.

(in reply to MarkNovack)
       Post #: 57

RE: Hostetler Pitts S1-11 - 3/11/2005 2:52:28 PM   
RENORACER



Posts: 53
Joined: 10/12/2002
From: Reno, NV, USA
Status: offline 		I will be using spruce main spars, and balsa rear spars with carbon fiber strips on the rear 's. The engine I have is quite heavy, and is why I am using spruce for mains. I will also be using Hitec 1/4 scale servos for the tail surfaces, and 4 standard size ones for the ailerons. looking forward to this weekend,as it is the first time in 3 months that I will have 2 days off in a row. Should be able to get a lot done.

(in reply to MarkNovack)
       Post #: 58

RE: Hostetler Pitts S1-11 - 3/12/2005 10:21:48 AM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		A couple of photos. I need a couple extra 1/8" sheets for ailerons so I finished the rest of the wing minus ailerons and caps strips. I'm waiting for the LE's to dry to rough them into shape. I cleaned the bench and shall glue up the bottom wing spars today.

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(in reply to RENORACER)
       Post #: 59

RE: Hostetler Pitts S1-11 - 3/12/2005 1:04:02 PM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		On my German digital scale that I use for measuring my composites ,the top wing, without ailerons or cap stips yet, weighs 712 grams. After ailerons and cap strips the TE will get beveled down, I'll remove some uneeded material from the wing tips, and final shaping of the LE and overall sanding should result in a similar weight. I guess about 2.3-2.5 pounds finished with servos. I'll make a servo box and sandwich it between a balsa half rib and the ply strut rib for a very strong and light servo installation.

I'm using the wood from PCK, awesome in form and grain, but some of it could be lighter. I could see this wing weighing at 2 pounds RTF with woods selected for lightness and still be plenty strong. In particular, the sub LE should be ultra light woods, the LE is heavier than necessary, the ribs could be lighter and thinner than they are, balsa spars on the rear, 3/32" in place instead of 1/8" for sheeting and shear webbing, but then I would enlarge the ribs ever so slightly to maintain the airfoil mass (cut to the outside of the line instead of the inside). OK, I'm knitpicking now and changing the design. I'm happy to see it come together.

I have started the bottm wing spar assembly. I'll shoot a few pics before I go to far. The dihedral bracing is well cut and STRONG as can be. Large cow could sit on this one.

Mark

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       Post #: 60

RE: Hostetler Pitts S1-11 - 3/12/2005 1:54:34 PM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		And the center joint/rear spar assembly. Dihedral is right on the money. I'll do the front spar tomorrow as I used 3 hour epoxy and ALL my clamps, besides, is Saturday, in-laws for dinner.

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(in reply to MarkNovack)
       Post #: 61

RE: Hostetler Pitts S1-11 - 3/16/2005 10:40:33 AM   
MarkNovack



Posts: 1547
Joined: 2/9/2002
From: Nameche, BELGIUM
Status: offline 		I'm now underway on the bottom wing. Just as Wendell suggests, I built the spars and slid the ribs in between. Just make sure the spars match dihedral angles. The spar braces will be the most important angle you cut. Cut them over each other and then trim the other side to get equal angles on at least one side and use that as the register. Also, you can use the center long-grain shear web dimensions to final file the spar slots in the ribs so that the spar lays nicely all the way across top and bottom (or use the space beween spar slots to detirmine exact height of the shear web, whichever gets you closer to the planform). The way one chooses to build all depends on how accurately the details are cut. Through various building methods, with these plans one need not have perfect parts to achieve a great and straight airplane. Get them as close as you can and its easy to adjust along the way. PCK cut fairly perfect parts so its really easy.

Nothing exciting to report. Its a simple airplane. It can be built really really fast or slow. A good CA could be used to join the center spars with all that surface area to save time...I chose epoxy out of not having lots of quality CA on hand. The only things on the wing that scream for epoxy are the pieces that carry the wing bolts on top and bottom wings. I choose wood glue for joining the sheeting and gluing the cap LE just for the ease of sanding the joints. The sheeting gets layed down with CA. I'm doing a bunch of projects at once so I'm slow, but the thing could be build in a few days after cutting. A real speed builder could knock out both basic wings minus major sanding and ready the fuse plans in a 12 hour building day with coffee breaks and a French style lunch. I tend to stare at my work too much!!!LOL.

I'll shoot a few pics after I clean up my building scraps.

Mark

(in reply to MarkNovack)
       Post #: 62

RE: Hostetler Pitts S1-11 - 3/17/2005 12:21:52 AM