Page 9 of 9 FirstFirst ... 789
Results 321 to 347 of 347

Thread: Introducing a J-4 project

  1. #321
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    475
    Post Thanks / Like
    Funny how I was looking at some old rotors just a couple days ago, wondering what I'd use them for. Now I know!
    Vic

    Sent from my SM-J320V using SuperCub.Org mobile app

  2. #322
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    9,739
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    Hey Charlie - know anything about the fuel gauge in the 16 gal fuselage tank? Will it come out without removing the windshield?
    Bob, mine does, it's just a big knurled nut that compresses the flange of the gauge to the bung on the tank. Once free you have to rotate the gauge a few ways to clear the windshield

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
    Thanks CharlieN thanked for this post

  3. #323

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Quote Originally Posted by RVBottomly View Post
    Funny how I was looking at some old rotors just a couple days ago, wondering what I'd use them for. Now I know!
    Vic

    Sent from
    I am in the process of rough forming the edges of the FW now, the curve of the upper radius is 6¾" which happens to be spot on for one of my tube bending dies. One frustration is I appear to no longer own fluting pliars, looks like someone else wanted them. Glad I am not making finished parts.

  4. #324

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    It ain't pretty but it's well a tool that represents my firewall.
    Click image for larger version. 

Name:	IMG_7667.JPG 
Views:	26 
Size:	202.0 KB 
ID:	43514 Click image for larger version. 

Name:	IMG_7668.JPG 
Views:	26 
Size:	194.5 KB 
ID:	43515

    The cross cut was done with a utility knife, what I am doing here is depressing the center of the FW to make room for accessories.
    Granted there will not be much on the back of the engine, maybe a mag, a gear driven alternator and a few oil lines. Next owner may need more room though.
    Click image for larger version. 

Name:	IMG_7672.JPG 
Views:	22 
Size:	215.5 KB 
ID:	43516 Click image for larger version. 

Name:	IMG_7673.JPG 
Views:	30 
Size:	247.9 KB 
ID:	43517

    What may look odd to many is the upper section of the FW does fold forwards. In order to carry the added weight of a Lycoming I chose to move the FW back a few inches and utilize a rather short mount. This coupled with the longer motor and prop spacer places the propeller in the original relationship to the wing while moving the increased mass back more than 6". If the numbers play out right this should not be a nose heavy pig.
    Click image for larger version. 

Name:	IMG_7674.JPG 
Views:	22 
Size:	223.8 KB 
ID:	43518 Click image for larger version. 

Name:	IMG_7675.JPG 
Views:	25 
Size:	228.5 KB 
ID:	43519

    So the reason for the forward lip, this allows the windscreen to not need to be stood up steeper than original. The plane will never be a speed demon but it will not be slow either.

  5. #325

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Sure all the hard to get at finicky spots to weld are what I have to do. Where is that 30 something Tig expert when I need one,I used to be him way back in time.

  6. #326
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,057
    Post Thanks / Like
    Charlie, This picture brings to mind the accessibility to the mags on my 7GCB as being very difficult to the point of having to learn a lot of new words just to take off the point cover plate. The later 7GCBCs moved the engine forward to improve the situation. I would hate to have to pull the engine just to inspect the mags during an annual.

    N1PA
    Likes RaisedByWolves liked this post

  7. #327

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Quote Originally Posted by skywagon8a View Post
    Charlie, This picture brings to mind the accessibility to the mags on my 7GCB as being very difficult to the point of having to learn a lot of new words just to take off the point cover plate. The later 7GCBCs moved the engine forward to improve the situation. I would hate to have to pull the engine just to inspect the mags during an annual.
    Yes but if you look at the image above that you will note the mount swings out to the starboard side. Another view.
    Click image for larger version. 

Name:	IMG_7666.JPG 
Views:	23 
Size:	196.4 KB 
ID:	43545
    The fuselage was built such that the mount hangs on two vertical fasteners on the starboard with three dowel and sockets that 3/8 bolts thread into to retain the assembly. Nuts can be then threaded onto these bolts from inside the plane such that they are "double nutted"
    Likes skywagon8a liked this post

  8. #328

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Here is an image of the firewall structure with the engine mounting provisions.
    Click image for larger version. 

Name:	Fusefront1.jpg 
Views:	26 
Size:	275.6 KB 
ID:	43546

  9. #329

    Join Date
    May 2015
    Location
    Northampton MA
    Posts
    4
    Post Thanks / Like
    The plan to build a true experimental replica is the way to go. BTW, I fly my C-85 powered J4A regularly and I'd be glad to come up to Rutland from 7B2 to show it off. I'm trying to sell it, looking for a reasonable offer or a swap for comparable condition and equipment C-120.

    The J4A with a C-85 will hit 100 mph but with that big wing (36' 3") it takes smooth air to do it while holding on to your dentures.

    Also wondering why no one mentioned going the DER-V route for modifications. I worked with Terry Bowden (barnstmr@aol.com) to get approval to install Grove master cylinders to match the Grove disk brakes on my J4A. It was a very straight-forward and reasonably priced process. And, it's great to have good brakes maneuvering that big wing on a crowded ramp.
    Likes CharlieN liked this post

  10. #330

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Would love to see it,
    Curious if you get a bit from the guy out West.

  11. #331

    Join Date
    May 2015
    Location
    Northampton MA
    Posts
    4
    Post Thanks / Like
    Would fly to Rutland Sunday morning for breakfast if you want to see the J4A Contact me at 413-218-1008

  12. #332

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Quote Originally Posted by George-Champ View Post
    Would fly to Rutland Sunday morning for breakfast if you want to see the J4A Contact me at 413-218-1008
    The weather should be nice that morning, will ring you closer to then.

  13. #333

    Join Date
    Sep 2003
    Posts
    6,627
    Post Thanks / Like
    I am a new J4 owner. Still six months away from the first annual, and all I know about maintenance is what a giant PITA the seat lacing is. I anticipate master cylinder maintenance - they are acting like reservoir masters.

    Not above swithing to Grove 95 masters - I love them on my J3. Does it require any welding?

    And - did we do ok? Semi-show quality, with 70 hr C-85 and starter - under 25 grand?

  14. #334
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    9,739
    Post Thanks / Like
    Bob, after the first year I redid my seat bottom and back with 5 ply 3/16 plywood
    I think masters cylinders are a 37 Plymouth wheel cylinder?

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  15. #335

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Bob, on your masters I would expect yes they would need welding. If not welding then some fabricated brackets made. The J3 are all above the floor with the pedals swinging sideways. The J4 has the masters below the floor with pushrods to pedals that pass upwards through the floor. I do not have good pictures of my masters although they are here in a building on my yard.
    I doubt wheel cylinders would be right for the job. If I were to go at changing them I would look into Girling, Tilton or other single masters as used in race cars although fluid compatibility may be an issue.

  16. #336

    Join Date
    May 2015
    Location
    Northampton MA
    Posts
    4
    Post Thanks / Like
    The tube that carries the brake pedals needs to be disassembled and the arms on that tube that transfer force to the master cylinders need to be lengthened by an inch to get enough throw for the Grove masters. It's a simple weld job that can be done outside the airplane. From there on it is just nuts, bolts, and plumbing. You can get all the details from Terry Bowden (barnstmr@aol.com) who is a DER-V. Mention the work he did on my J-4 and he can set you up to get get approval to install Grove master cylinders. Robbie Grove at Grove will put together the parts you need and the AI who is doing your annual can supervise and sign off on the 337 submitted with the DER-V paperwork. Of course, my J4 already had Grove disk brakes before I got it. They just didn't work much at all. Mismatch of high volume/low pressure masters with low volume/high pressure calipers. The replacement Grove masters did the trick.

    Sounds to me like you practically stole that J-4. I'd need more details to tell more but it sounds like a great deal.

    The ergonomics of the seat is pretty bad. I think it was designed originally for a goose - short legs, long neck. cubdriver2 has the right idea to replace the sling. That's my next project.


    Thanks CharlieN thanked for this post

  17. #337
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    9,739
    Post Thanks / Like
    A word of caution, great brakes on a J4 are a hazard. They are all nose heavy

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  18. #338
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    9,739
    Post Thanks / Like
    Bob, my friend Dan Fogal restored his J4 over the last 10 years. Hears his brake rebuild report


    This is my brake set up under the floorboards. I made an access panel to get to them from below. I believe they are 1938 Plymouth master cylinders. The reservoir is mounted on the firewall and fills both cylinders. There are check valves in both "fill" ends of the units. The rubber boots came from a farmall Cub touch control system! They work quite well.
    Kanter is the company in NJ that supplied the rebuild kits.800-526-1096
    Hope this helps.






    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
    Thanks RVBottomly thanked for this post

  19. #339
    SuperCub MD's Avatar
    Join Date
    Jan 2002
    Location
    Collins, Wisconsin
    Posts
    1,346
    Post Thanks / Like
    Those are Wagner Lockheed master cylinders used on prewar J3s and J4s. They were used on many vehicles in the 30's. Napa will have the seals. Cleaned up and resealed they will lock bushwheels. Be careful with to much brake on the J4. The 4 is the ugly sister of the Cub line but stock and light its a nice flyer.

  20. #340

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Current task, Machining the pivot tube for the tailwheel. This will support two angular contact ball bearings so when in flight the lack of friction will allow the most tactle feel of the rudder. Is this necessary, to most people, no.
    Click image for larger version. 

Name:	IMG_7680.JPG 
Views:	14 
Size:	242.5 KB 
ID:	43641 Click image for larger version. 

Name:	IMG_7681.JPG 
Views:	10 
Size:	216.7 KB 
ID:	43642

    Click image for larger version. 

Name:	IMG_7688.JPG 
Views:	10 
Size:	218.1 KB 
ID:	43643 Click image for larger version. 

Name:	IMG_7691.JPG 
Views:	11 
Size:	225.4 KB 
ID:	43644

    The stainless disk will be at the bottom, this will be milled into a cam that will release the TW lock as needed during ground operation.
    Likes RVBottomly liked this post

  21. #341

    Join Date
    Jan 2003
    Location
    nd
    Posts
    3,160
    Post Thanks / Like
    im looking forward to see how you mount that to the tube going forward.

  22. #342
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    9,739
    Post Thanks / Like
    Other then when spinning I have never had a need to feel what the rudder is doing. My butt feel whats going on and tells my feet what to do

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
    Likes DENNY, supercrow liked this post

  23. #343

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Next step on the tailwheel is to mount the bearing holder on a rotary table so I can cut the pathway for the TW release. In prep for this I had thinned the stainless disk from 3/8 down to 3/16.
    I first cut a flat to the depth the small radius will be.
    Click image for larger version. 

Name:	IMG_7695.JPG 
Views:	26 
Size:	265.5 KB 
ID:	43714 Click image for larger version. 

Name:	IMG_7697.JPG 
Views:	25 
Size:	238.1 KB 
ID:	43715

    Then I cut the small radius and ramps.
    Click image for larger version. 

Name:	IMG_7699.JPG 
Views:	19 
Size:	292.1 KB 
ID:	43716 Click image for larger version. 

Name:	IMG_7700.JPG 
Views:	22 
Size:	266.0 KB 
ID:	43717
    This will be followed with hollowing out the lower face of the disc.
    Not sure how much more I will get done before flying out to OSH on Saturday morning.
    Thanks RVBottomly thanked for this post
    Likes mike mcs repair liked this post

  24. #344
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    475
    Post Thanks / Like
    One of my sub-projects is to make a rotary table. I can think of a number of handy uses for it. Of course, the practical approach would be to buy one, but...why do that when you can spend lots of time making swarf?

    Really nice detailing, Charlie.

    Vic

  25. #345

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    I have been looking at buying one of the small imported rotary tables, either a 3 or 4". Just have something in my mind to not do so. The two I have are very good quality in a 12" and 18". They are stable such that the cutter will not pull them. I am afraid the small ones might have some play in the gears that will not allow running the cutter either direction without the cutter grabbing.
    Both of my tables need to be lifted with a chain fall onto the mill such that changeover is not a trivial thing to do.

    Making one would be cool once you find a decent worm gear set to build with. One thing to consider is the indexing, the arc I cut is 35° either side with a 15° ramp from perpendicular, the indexing scribed into the work table is kind of needed when the angles matter.
    Likes mike mcs repair liked this post

  26. #346

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    Can you tell stainless gets hot when you cut it? and this was with a synthetic lubricant.
    Click image for larger version. 

Name:	IMG_7703.JPG 
Views:	20 
Size:	329.6 KB 
ID:	43718 Click image for larger version. 

Name:	IMG_7706.JPG 
Views:	16 
Size:	283.4 KB 
ID:	43719

    I could thin this down more since there are essentially no loads on the outer diameter, just at the ramps where the lock pawl will be lifted to unlock the wheel.

    I want to do more but other tasks to do. The next 1500-1900 images taken by this camera will be out in Wisconsin.

  27. #347

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    792
    Post Thanks / Like
    After a week out in the midwest snapping 1376 photos I got to spend an hour in the shop with fitting then tack welding the tailwheel pivot tube to it's arm. I thought my camera would pass the 20,000 image mark but it is a few shy of that still.

    Click image for larger version. 

Name:	IMG_9050.JPG 
Views:	24 
Size:	213.8 KB 
ID:	43908 Click image for larger version. 

Name:	IMG_9051.JPG 
Views:	23 
Size:	194.8 KB 
ID:	43909
    Likes stknrddr liked this post

Similar Threads

  1. Our Cub Project
    By tcraft128 in forum Member Projects in Progress
    Replies: 206
    Last Post: 05-03-2016, 05:29 PM
  2. I need a new project
    By cgoldy in forum Experimental Cubs
    Replies: 6
    Last Post: 09-03-2013, 09:10 PM
  3. PA-12 project
    By munro in forum Cafe Supercub
    Replies: 1
    Last Post: 08-29-2005, 10:25 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •