PA-18-95 Plans
- Thread starter JRD
- Start date
mike mcs repair
Registered User
chugiak AK
I scratch my head when people want to build ("blue print") 4 generations and upgrades back.....
ok some updates were not upgrades....
but really???
ignore 60 - 70 years ago of learned lessons ???
ok some updates were not upgrades....
but really???
ignore 60 - 70 years ago of learned lessons ???
Still new to most of this. Can you list a few of the "learned lessons"? What plans would you suggest? Thanks.
Drop a message to these guys.http://www.supercub.org/forum/showt...Scratch-Built-Cub&highlight=scratch+built+cub
Bill Rusk
BENEFACTOR
Sandpoint, Idaho
Here is a list of mods. Not all would be applicable but these are all fairly common "Mods"
1. Reverse dog leg - makes it easier to get stuff in the extended baggage area - weight penalty zero
2. Metal Belly Tabs - tabs on last 4 feet of fuselage to attach a metal belly pan - access improved and easier to wash out fuselage - weight penalty will be tabs, hardware, and .020 AL pan itself
3. Removable rear crossbar - makes loading larger items in baggage easier - weight penalty will be a small section of tubing (2" or so) and hardware
4. Tie Downs in Cargo area - to keep loads from shifting - weight would be the tabs
5. Bushing the tailwheel attach tube - keeps the tubing from collapsing - weight penalty will depend on tubing size increase and bushing.
6. Extended cargo area - room to carry more stuff - weight penalty will depend on several factors. I plan to use the lower longerons rather than build the shelf. This will necessitate running the elevator cables under the fuselage.
7. Float fittings (FWD)
8. Float fittings (AFT) - rather than weld on the external fittings I used a flush set up on my last build that I think worked well and added little if any weight. Here is a link to some photos and a description. http://www.supercub.org/forum/showth...ing+smith+bill (you will have to scroll past the electric trim section).
9. Lift rings for floats - these can be welded in or they could be left out and the brackets bolted to the spars as necessary. There are advantages to each. The spar brackets would only be added if someone went to floats so perhaps a few ounces lighter for someone who is not planning on floats but that then requires cutting into the wing fairing and they are not easy to take on and off so they tend to be left on year round. With the weld in ones the holes in the skylight can be plugged easily and the eyebolts are easy to remove or install when going to or from floats.
10. Extra tail lift handle - Easy to weigh a piece of tubing to get the weight. The handle needs to be a little larger than factory so you can get a gloved hand in there and the extra handle is useful for ski flying where it is necessary to manually move the tail around. If there is only one handle there is a tendency to push on the side of the fuselage, often using the shoulder, which then bends the upper turtle deck stringers. Thus with the extra handle you can pull on the fuselage rather than push.
11. Tabs for Amphib float set up. - I don't know much about this in terms of where they should best be located.
12. Firewall Brace tubes - the extra tubing effectively makes an X brace on both sides of the fuselage at the firewall. Cubs are known to collapse the engine in a hard landing/crash often crushing the pilots ankles and possibly trapping them in the wreckage. The extra tube is easily weighed so we could determine the weight penalty here. I have seen this mod without tying the tubes together. That would significantly reduce the effectiveness of this mod. Much better to weld the tubes together at the X even though it would require a small (1/2") interconnecting brace of some type. This mod does interfere with the map pocket.
13. Overhead X brace - Pretty standard now. Keeps the wing attach area from caving in during a crash causing head injuries. The original tubing was a 3' beam. By welding in the X the beam is now only about 18" now so we might be able to reduce the tubing size, or thickness, or both to save weight. Also makes it easy to put in the cross tube for the shoulder harness.
14. Extended gear - most common is 3" which is what I will get. Some are also going to 3X3 gear which is 3 inch extended and the axle is moved forward 3 inches as well. This makes the tail heavier (bad for ski flying) but it allows more aggressive braking without standing the plane on its nose.
15. Seat belt attach welded in to the floor tubes rather than being attached to the seat.
16. Shoulder harness attach fittings welded in.
17 Flap handle moved outboard - I like to take credit for this one but the reality is someone else probably thought of this before I did. I think all the experimental airframes are pretty much doing this now. No weight penalty and helps with the knee interference issue in a crosswind.
18. Bushing the landing gear for the long step
19. tabs for the BLR fins. (Some folks are using the BLR set of Vortex Generators. These require tabs for the metal fin attached just forward of the horizontal stabilizers. The BLR system and the Micro VG's seem to be about equal in effectiveness with the edge going to the Micros. The downside to the BLR system is that big metal fins on the side of the fuselage. It REALLY gets in the way when moving the airplane around by the tail lifting handles when on skis, thus I am not a big BLR fan. I think the only ones using this system are Cub Crafters).
20. Longer seat attach fittings for rear legs of front seat. This will get the bolt up high enough so it does not conflict with the floorboard making it hard to get the front seat out.
21. ELT antennae mount
22. Tail "X" brace or "H" brace. Strengthens tail area for ski and off road work.
23. Third seat/baggage area reinforcement. I think some of the reinforcement tubes may be overkill in terms of size and thickness so I will work with Jay to see if we can go smaller and still retain the strength.
24. Reinforce/brace outside rib of Horiz stabs to keep the fabric from warping it. Also move it 1/2" closer to fuselage to gap seal this area.
25. Extend the arm on the bottom of the stick by 1" where the aileron cables attach. Gives more aileron throw to the stick.
26. Make the front seat back folding and set the angle at 80 degrees Vs the factory 90 degree seat. No one sits bolt upright. Makes the seat much more comfortable but you have to be more careful with rear stick interference.
27. Control lock brackets welded to front seat, and on front stick base. (This is the "V" shaped lock that hooks into a bushing on the front stick)
28. Tail stinger light mount on rudder.
30. Upper and/or lower baggage doors.
Just a few of the possible mods and changes. Obviously if you did all this you would probably need a larger engine than a C-90. If you are going to build a C-90 Cub it will be critical to keep it light.
Bill
1. Reverse dog leg - makes it easier to get stuff in the extended baggage area - weight penalty zero
2. Metal Belly Tabs - tabs on last 4 feet of fuselage to attach a metal belly pan - access improved and easier to wash out fuselage - weight penalty will be tabs, hardware, and .020 AL pan itself
3. Removable rear crossbar - makes loading larger items in baggage easier - weight penalty will be a small section of tubing (2" or so) and hardware
4. Tie Downs in Cargo area - to keep loads from shifting - weight would be the tabs
5. Bushing the tailwheel attach tube - keeps the tubing from collapsing - weight penalty will depend on tubing size increase and bushing.
6. Extended cargo area - room to carry more stuff - weight penalty will depend on several factors. I plan to use the lower longerons rather than build the shelf. This will necessitate running the elevator cables under the fuselage.
7. Float fittings (FWD)
8. Float fittings (AFT) - rather than weld on the external fittings I used a flush set up on my last build that I think worked well and added little if any weight. Here is a link to some photos and a description. http://www.supercub.org/forum/showth...ing+smith+bill (you will have to scroll past the electric trim section).
9. Lift rings for floats - these can be welded in or they could be left out and the brackets bolted to the spars as necessary. There are advantages to each. The spar brackets would only be added if someone went to floats so perhaps a few ounces lighter for someone who is not planning on floats but that then requires cutting into the wing fairing and they are not easy to take on and off so they tend to be left on year round. With the weld in ones the holes in the skylight can be plugged easily and the eyebolts are easy to remove or install when going to or from floats.
10. Extra tail lift handle - Easy to weigh a piece of tubing to get the weight. The handle needs to be a little larger than factory so you can get a gloved hand in there and the extra handle is useful for ski flying where it is necessary to manually move the tail around. If there is only one handle there is a tendency to push on the side of the fuselage, often using the shoulder, which then bends the upper turtle deck stringers. Thus with the extra handle you can pull on the fuselage rather than push.
11. Tabs for Amphib float set up. - I don't know much about this in terms of where they should best be located.
12. Firewall Brace tubes - the extra tubing effectively makes an X brace on both sides of the fuselage at the firewall. Cubs are known to collapse the engine in a hard landing/crash often crushing the pilots ankles and possibly trapping them in the wreckage. The extra tube is easily weighed so we could determine the weight penalty here. I have seen this mod without tying the tubes together. That would significantly reduce the effectiveness of this mod. Much better to weld the tubes together at the X even though it would require a small (1/2") interconnecting brace of some type. This mod does interfere with the map pocket.
13. Overhead X brace - Pretty standard now. Keeps the wing attach area from caving in during a crash causing head injuries. The original tubing was a 3' beam. By welding in the X the beam is now only about 18" now so we might be able to reduce the tubing size, or thickness, or both to save weight. Also makes it easy to put in the cross tube for the shoulder harness.
14. Extended gear - most common is 3" which is what I will get. Some are also going to 3X3 gear which is 3 inch extended and the axle is moved forward 3 inches as well. This makes the tail heavier (bad for ski flying) but it allows more aggressive braking without standing the plane on its nose.
15. Seat belt attach welded in to the floor tubes rather than being attached to the seat.
16. Shoulder harness attach fittings welded in.
17 Flap handle moved outboard - I like to take credit for this one but the reality is someone else probably thought of this before I did. I think all the experimental airframes are pretty much doing this now. No weight penalty and helps with the knee interference issue in a crosswind.
18. Bushing the landing gear for the long step
19. tabs for the BLR fins. (Some folks are using the BLR set of Vortex Generators. These require tabs for the metal fin attached just forward of the horizontal stabilizers. The BLR system and the Micro VG's seem to be about equal in effectiveness with the edge going to the Micros. The downside to the BLR system is that big metal fins on the side of the fuselage. It REALLY gets in the way when moving the airplane around by the tail lifting handles when on skis, thus I am not a big BLR fan. I think the only ones using this system are Cub Crafters).
20. Longer seat attach fittings for rear legs of front seat. This will get the bolt up high enough so it does not conflict with the floorboard making it hard to get the front seat out.
21. ELT antennae mount
22. Tail "X" brace or "H" brace. Strengthens tail area for ski and off road work.
23. Third seat/baggage area reinforcement. I think some of the reinforcement tubes may be overkill in terms of size and thickness so I will work with Jay to see if we can go smaller and still retain the strength.
24. Reinforce/brace outside rib of Horiz stabs to keep the fabric from warping it. Also move it 1/2" closer to fuselage to gap seal this area.
25. Extend the arm on the bottom of the stick by 1" where the aileron cables attach. Gives more aileron throw to the stick.
26. Make the front seat back folding and set the angle at 80 degrees Vs the factory 90 degree seat. No one sits bolt upright. Makes the seat much more comfortable but you have to be more careful with rear stick interference.
27. Control lock brackets welded to front seat, and on front stick base. (This is the "V" shaped lock that hooks into a bushing on the front stick)
28. Tail stinger light mount on rudder.
30. Upper and/or lower baggage doors.
Just a few of the possible mods and changes. Obviously if you did all this you would probably need a larger engine than a C-90. If you are going to build a C-90 Cub it will be critical to keep it light.
Bill
Thanks for the info. I have a welded fuselage. It has the inverted dog leg baggage. It lacks the upper and lower x bracing though. From the searching I've done it sounds like maybe my best bet is the Northland Plans. Maybe get a set blown up and printed off for easier viewing in the workshop. Not sure what my first move should be. That would be the biggest help to me from the plans. Providing some type of order to attack the project. I was thinking of getting the fuselage on gear and than start the wings? I'll probably build a all wood wing.
mike mcs repair
Registered User
chugiak AK
do NOT bother doing that one...
the ONLY way that is an issue is if you FLY your plane into the ground... like whiteout... not hard landing...
I like your idea Denny, but if i ever do it again theres going to be an aluminum cover screwed to tabs on the bottom of the fuselage, or a 3/8ths channel framework thats at least 2 feet front to back and the width of the frame. To drain junk and crud out of the belly. And make any work a breeze. And then with the fittings underneath they would also be easy to work on.
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Or overrun and hit something during an "event" - - Having done that and having had the deformed firewall tubing injure my foot, I'm thinking maybe not a bad idea. On the other hand, with no collapse there something else will collapse or the impact on other body parts be harder.
Mike those 2 tubes dont weigh more than a big turd.
MainlandCub
Registered User
New Zealand
Reading between the lines……… I hope you understand that the Northland set are not really plans but Piper's production drawings. They just aren't arranged like typical homebuilt drawings. They won't tell you what your first move should be. It follows that a lot of things were designed to be built in a factory and don't lend themselves to the basic techniques that is all many homebuilders have available. The front seat for example will provide a lot of challenges to build exactly per the drawings.
It sounds like you are already willing to deviate from the drawings by building an all wood wing. If that is the case you probably need to get the Wagaero plans (and they really are plans).
The 90 hp Cub needs to be really light to fly well or even to be useful. That means you probably need to leave out as many of the "improvements" as you can live without. There are some 90 Cub aficionado's on this site, including some who have built from scratch. Hopefully they'll tune in and tell you what works best.
Andrew.
Cub junkie
Registered User
My Moms basement
It would be cheaper to build all aluminum wings over wood. Wood spars will cost at least twice as much as metal. Metal spars are easy to source from several different suppliers. I waited 7 months for my spar blanks for my champ rebuild. Douglas fir is more available, about 15% heavier if you don't mind the extra weight. The wag aero drawings utilize a lot of J3 wood spar parts such as aileron hinges, strut fittings etc.
How much do you estimate the cost would be to build a set of aluminum wings? The local cub builder here told me around $1500 to build a set of wood wings.
Cub junkie
Registered User
My Moms basement
That $1500 seems pretty optimistic. 17 ft long aircraft grade wood spar blanks are the biggest expense. The rest of the cost depends on how much you are willing to fabricate on your own. There is quite a difference in the construction of wood vs metal in cub wings as far as aileron cove, hinges and tank mounting. Of course it can be done, the end result is you would have your own brand of cub wings. Suggest you look at many cub build pictures on this site and wherever else you can find them on the web to see the difference.
Thanks for the advice. I'll continue to check out different builds for more insight. If I remember correctly he said the spars would be around a $1000. Than I can either build my ribs from cap strips, or router out a solid rib. The learning and experience of building the wing myself, ribs and all is very appealing. I have seen some videos of people who formed their own aluminum ribs as well. This would also be a option for me. I just haven't seen anyone make cub ribs themselves out of aluminum? Has anyone here done it?
Larry G
Registered User
Minocqua WI
Look at this building blog lots of good stuff on how he built his.
http://www.supercub.org/forum/showthread.php?44825-New-member-building-a-PA18-95
I bought both Wag plans and Northland plans. I am by no means an expert, but I would suggest using the Wag plans if you choose wood no flaps, or use the Northland plans if you choose aluminum and want flaps. A wise member suggested to me early in my decision making process to use the material I like working with the most. I am a wood butcher, so I chose aluminum. If you really want to see some nice wood wings, look at Roger Peterson's thread or Marty 57's thread.
Neither set of plans are a step by step set of instructions, but there is enough there and plenty of good help here to help you either way.
Hardly anything in the wings is the same between the two plans. Choose between wood or aluminum, buy one set of plans and go for it would be my advice.
Thanks,
Jim
Neither set of plans are a step by step set of instructions, but there is enough there and plenty of good help here to help you either way.
Hardly anything in the wings is the same between the two plans. Choose between wood or aluminum, buy one set of plans and go for it would be my advice.
Thanks,
Jim
Marty57
PATRON
Nipomo, Ca
If you are interested, I built the wood wing following Wag's 2+2 drawings with some modifications. The wing now matches a Super Cub wing but in wood. I added wood flaps and built my ailerons out of wood also. I have drawings of all the necessary wing parts and wood wing layout on my web site if you are interested. The link is http://www.marty2plus2.com/ Go to the Drawings Download to see the drawings I put together, all done in CAD.
Marty
Marty
MainlandCub
Registered User
New Zealand
But whatever you do, DON'T incorporate the headknocker spars as shown in the Wag plans!
