Page 11 of 11 FirstFirst ... 91011
Results 401 to 414 of 414

Thread: Therapy Project

  1. #401
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like
    Quote Originally Posted by CharlieN View Post



    Do NOT try to drill these, it might work but probably will not.

    Plastic bushings for high loads should be snug, low loads can be loose.
    Thanks Charlie. How about drilling out pillow blocks from blocks of delrin? Is it a heat issue?

    I see blocks available on ebay.

    I weighed things and it turns out the assembly above weighs 5 ounces more than if I simply use two parallel and offset torque tubes for the pedals. That works on Cessnas, my Skyranger, and I think on several RV designs. Simpler with less hazard of rust on moving parts. I think I'll use delrin pillow blocks to hold them in place. Just not sure if I want to machine them or find something premade.

  2. #402

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    1,604
    Post Thanks / Like
    Parallel tubes in Delrin is a superb way to do it. The Delrin can be drilled although an end mill or reamer will provide a nicer final cut.
    You might consider split blocks for the Delrin. This offers a way to adjust the bore a bit should that matter. You can however aim for a near zero bore clearance but consideration needs to be considered for long term corrosion control.

    Here is another option, turn an insert for the ends of the tubes that will fit inside a ball bearing. The center of the tubes can be supported in a HDPE or Delrin split block.

    The end bearing supports can be plastic or aluminum. Image for reference, these support my pedal mixer since I am utilizing full adjustable pedals on each side.

    Click image for larger version. 

Name:	IMG_7553.JPG 
Views:	36 
Size:	152.5 KB 
ID:	53967

    I am having a hard time finding some images, problem with not being in this file for awhile due to another project consuming my attention recently.
    Regards, Charlie
    Super Coupe E-AB build in process
    Thanks RVBottomly thanked for this post

  3. #403
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like
    Quote Originally Posted by CharlieN View Post
    Parallel tubes in Delrin is a superb way to do it. The Delrin can be drilled although an end mill or reamer will provide a nicer final cut.
    You might consider split blocks for the Delrin. This offers a way to adjust the bore a bit should that matter. You can however aim for a near zero bore clearance but consideration needs to be considered for long term corrosion control.
    Thanks. I was planning on split blocks and I have a nice set of end mills. I like the option of adjusting the bore with shims if necessary.
    Likes CharlieN liked this post

  4. #404
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like
    Been a while and I'm lazy when it comes to updates. But things have progressed.

    I went the parallel rudder tube approach with Delrin pillow blocks. I ordered a block of Delrin online to see what I could do.

    For the pedal assembly I cut little blocks from what I ordered, cut them in half and bolted them together. Then I put 3/4" holes right where they split. The first few I did with a 3/4" end mill. Then I ended up swapping out mill collet for the drill chuck to drill something. Then I wondered, "maybe a spade bit would work."

    Click image for larger version. 

Name:	IMG_4097.JPEG 
Views:	45 
Size:	233.2 KB 
ID:	54725

    Yup. At 120 rpm it worked fine. Delrin is pretty neat stuff.

    I had a bunch of shavings, of course.

    Click image for larger version. 

Name:	IMG_4108.JPEG 
Views:	41 
Size:	354.3 KB 
ID:	54726

    I wondered about flammability with it laying around. Grinding sparks and all.

    So, a diversion.... lightweight delrin firestarter:



    At least it works on wet tumbleweeds.

    FWIW, I swept up and vacuumed all the delrin shavings to keep me from starting fires in the shop.

    Then I went to the pillow blocks for the 1.5" torque tube, using my cheapo expanded mini-lathe. (16" bed instead of 10")

    Click image for larger version. 

Name:	IMG_4101.JPEG 
Views:	41 
Size:	164.8 KB 
ID:	54727
    Click image for larger version. 

Name:	IMG_4103.JPEG 
Views:	38 
Size:	251.9 KB 
ID:	54728
    Click image for larger version. 

Name:	IMG_4106.JPEG 
Views:	37 
Size:	239.4 KB 
ID:	54729

    Click image for larger version. 

Name:	IMG_4112.JPEG 
Views:	40 
Size:	244.2 KB 
ID:	54730

    I'm pretty sure I need steel reinforcing of some kind. Maybe a top plate with the edges bent down? The torque tube pillow blocks specified are aluminum.

    I didn't show the rudder bar assembly being welded up, or the torque tube fabrication. It was tedious but not bad. Here is a draft layout in the fuselage:

    Click image for larger version. 

Name:	IMG_4150.JPEG 
Views:	54 
Size:	306.9 KB 
ID:	54731

    Then it was back to welding on the torque tube. I was contemplating all sorts of alternatives, but ended up with going as drawn. I can spend three times as much time second-guessing myself as it would take to build something. For this I decided to go with what has been done before.

    Torque tube welding:

    Click image for larger version. 

Name:	IMG_4144.JPEG 
Views:	48 
Size:	218.7 KB 
ID:	54732

    Gussets were added but I don't see pictures

    Control arm bushing holes drilled (step drills seem to drill round)

    Click image for larger version. 

Name:	IMG_4152.JPEG 
Views:	41 
Size:	294.9 KB 
ID:	54733

    Click image for larger version. 

Name:	IMG_4153.JPEG 
Views:	40 
Size:	209.2 KB 
ID:	54734

    Then tabs put on control stick stubs

    Click image for larger version. 

Name:	IMG_4161.JPEG 
Views:	44 
Size:	199.3 KB 
ID:	54735

    Put it together held with welding rod to see how it fits:

    Click image for larger version. 

Name:	IMG_4163.JPEG 
Views:	48 
Size:	214.7 KB 
ID:	54736

    The sticks go back and forth with no interference on the connection rod. So far so good. Still have to weld the elevator arm.

  5. #405
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like

    Float fittings etc.

    So another month goes by. The new normal is not really normalized, but things plod along.

    I finished up the control stick torque tube assembly. Long ago I was thinking of simplifying it to one center stick. I got talked out of it and went with the drawing.

    Click image for larger version. 

Name:	torque tube.jpg 
Views:	37 
Size:	80.9 KB 
ID:	55394

    Suffice it to say it is a heavy assembly. Combined with the stick attachments, it is around 3 pounds.

    Click image for larger version. 

Name:	IMG_4299.JPEG 
Views:	47 
Size:	181.5 KB 
ID:	55395

    I also welded on tabs everywhere for the floor and other attachment points. No pictures, not really difficult work, but tedious bending and twisting of my stiff body.

    Then I decided to fabricate float fittings from the Northland plans. They are stout. .090 material for the flat square, .10 for the lugs, and .125 for the tabs.

    Click image for larger version. 

Name:	IMG_4211.JPEG 
Views:	34 
Size:	269.4 KB 
ID:	55396
    Click image for larger version. 

Name:	IMG_4213.JPEG 
Views:	27 
Size:	196.8 KB 
ID:	55397
    Click image for larger version. 

Name:	IMG_4214.JPEG 
Views:	27 
Size:	190.5 KB 
ID:	55398
    Click image for larger version. 

Name:	IMG_4226.JPEG 
Views:	28 
Size:	219.0 KB 
ID:	55399
    Click image for larger version. 

Name:	IMG_4288.JPEG 
Views:	27 
Size:	209.1 KB 
ID:	55400
    Click image for larger version. 

Name:	IMG_4289.JPEG 
Views:	29 
Size:	252.8 KB 
ID:	55401
    Click image for larger version. 

Name:	IMG_4290.JPEG 
Views:	29 
Size:	196.0 KB 
ID:	55402

    The fittings are heavy. 13.5-14 ounces each--not counting the milled insert that I don't have material for right now.

    But they look like the Atlee Dodge or Univair ones, and cost me some $20 in materials. I didn't count the gas I needed to get decent penetration, though. It was hot welding them. For some reason I don't have a picture of the final result, but they look like they will make very strong gussets if nothing else.

    Click image for larger version. 

Name:	IMG_4295.JPEG 
Views:	31 
Size:	305.0 KB 
ID:	55403

    The angle of the tab concerned me a little, because the fuselage is wider than a super cub fuselage at this point. I sort of adjusted for that based on what I could find on line. In the end I decided that, if necessary, I could adjust them with heat.

    This was an interesting diversion. I can see why the big-name suppliers charge $500-700 for weld on fittings.

  6. #406
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like

    Looking for ideas: door frames

    So I shifted gears and started bending sheet metal for the door frames. I finally figured out how to do the backward bends with the things I have, but then the gnawing started....

    The plans say to weld these channels every so many inches. Right.... Weld onto bare 4130 tubing things that will collect water and dust.

    I looked at various threads on rust developing from window and door channels. Predictable results, apparently.

    I'd like to be able to put a good coat of paint on these tubes before covering them up with door frames. So far I have played with various options, including laminated douglas fir, milled plastic strips, aluminum over foam tape. All of the ideas include the notion that they could be removable for inspection without having to grind weld points.

    Before I go off the deep end, has anyone seen something like this that I could adopt/adapt?

  7. #407

    Join Date
    Mar 2016
    Location
    Down low in the hills of Vermont USA
    Posts
    1,604
    Post Thanks / Like
    As if by now I am not known to do things differently. My doors close against the round tube. I am not a believer in needing the added structure for the door to close against.
    I will simply let the fuselage fabric wrap the tube with it's doubled tape as normal. I intend to then apply a strip of durable polymer tape as a wear protection to reduce damage from entry and egress.
    My doors are a rectangular frame with a flange that when closed will cover, call it half the tube. Within the rectangle tube and flange will be a ¼ Rd foam seal such that it's round face will seal to the round frame tube.
    This all will be durable and has no long cavities to try and protect over the decades from the elements.
    Regards, Charlie
    Super Coupe E-AB build in process
    Thanks RVBottomly thanked for this post
    Likes marcusofcotton, Dan Gervae liked this post

  8. #408
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like
    Quote Originally Posted by CharlieN View Post
    As if by now I am not known to do things differently. My doors close against the round tube. I am not a believer in needing the added structure for the door to close against.
    I will simply let the fuselage fabric wrap the tube with it's doubled tape as normal. I intend to then apply a strip of durable polymer tape as a wear protection to reduce damage from entry and egress.
    My doors are a rectangular frame with a flange that when closed will cover, call it half the tube. Within the rectangle tube and flange will be a ¼ Rd foam seal such that it's round face will seal to the round frame tube.
    This all will be durable and has no long cavities to try and protect over the decades from the elements.
    I like the idea. As you described this I thought about my Commonwealth doors. They overlap from the outside with a rubber seal. Simple. I don't know why I didn't consider that approach given I was just fiddling with the door latches yesterday.

    But the Commonwealth has a partial channel. I looked at the drawings I had and it specified "zinc chromate tape" between the channels and tubes. That's a new one on me.

  9. #409
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,724
    Post Thanks / Like
    I use weldable primer on the Super Cub u-channel in front of the D window and on the door channels on the Short Wings. Piper didn't do anything and it shows 50-75 years later. It splatters and spits as you weld over it but it has to help. I have thought about sealing between the stitch welds with that body sealant they use on car bodies now but haven't tried it.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers
    Likes Southern Aero, RVBottomly liked this post

  10. #410
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    11,104
    Post Thanks / Like
    How about filling the channel with linseed oil, paralketone or ??????????? Then draining the excess out the bottom through a drain hole.
    N1PA

  11. #411
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,724
    Post Thanks / Like
    Quote Originally Posted by skywagon8a View Post
    How about filling the channel with linseed oil, paralketone or ??????????? Then draining the excess out the bottom through a drain hole.
    I think that would be a nightmare. We had a fuselage someone filled with oil and it kept weeping out. Most people fill with oil, let it drain out and weld up the filler hole. I can't imagine trying to cover that, I would be afraid it would ooze out throughout the covering/painting process.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  12. #412

    Join Date
    Nov 2015
    Location
    Fairbanks, AK
    Posts
    63
    Post Thanks / Like
    Check out what Bob Barrows did on the Patrol I believe it was. He too was tired of the bare metal rust issue under door frames etc.
    He planned it out and welded tabs as required to the door frame areas, added nut plates or clip on nuts I suppose AFTER the fuselage was primed and painted. Nowhere left to not get a primer and paint protective coating. Then they bent up the door frames out of aluminum and attached them to the tabs possibly even after the fabric was in place. Lighter, plenty strong, no rust. Sounds like a win win to me. Enough so that’s what my plan is for my build, and that’s where I am in the sequence. Do some work on the tail post and then do the door frames. That will finish my fuselage and ready for final blast and paint.


    Sent from my iPhone using SuperCub.Org
    Thanks RVBottomly thanked for this post

  13. #413
    RVBottomly's Avatar
    Join Date
    Sep 2017
    Location
    Asotin County Washington (KLWS)
    Posts
    1,055
    Post Thanks / Like
    Quote Originally Posted by OzAK View Post
    Check out what Bob Barrows did on the Patrol I believe it was. He too was tired of the bare metal rust issue under door frames etc.
    He planned it out and welded tabs as required to the door frame areas, added nut plates or clip on nuts I suppose AFTER the fuselage was primed and painted. Nowhere left to not get a primer and paint protective coating. Then they bent up the door frames out of aluminum and attached them to the tabs possibly even after the fabric was in place. Lighter, plenty strong, no rust. Sounds like a win win to me. Enough so that’s what my plan is for my build, and that’s where I am in the sequence. Do some work on the tail post and then do the door frames. That will finish my fuselage and ready for final blast and paint.


    Sent from my iPhone using SuperCub.Org
    Thanks for that. I hadn't looked at Bearhawk.

    But this morning I looked closely at my Commonwealth SkyRanger. It does almost the same thing that you describe. Painted tabs on a painted frame; aluminum trim/frames over it that can easily be removed.

    But I'm still kicking around Charlie's minimalist idea, too.

  14. #414
    Southern Aero's Avatar
    Join Date
    Jan 2008
    Location
    kcco/1ga2
    Posts
    229
    Post Thanks / Like
    I have done like Steve in the past with the weldable primers. On the door frame sheet metal I use a Rotabroach to put in a series of access (lightening?) holes half way between the tubing and the outside edge of all the formed sheet metal .......... there are other brands that are the same difference ........... This allows access to the interior portion of the frames. The holes are about 1 1/4" down to 5/8 or 1/2. If you have sand blasted the fuselage, make sure to get all the sand out. Tape up the holes and skip welds with most any kind of tape but leave a place to tape in a tube to pour in your favorite primer. Roll it around to ensure total coverage then drain into a pan for reuse of what's left. It can be somewhat messy but it gives you the warm and fuzzy knowing SB819 will never be an issue for that airframe.
    ......... It doesn't cost any more to go first class! You just can't stay as long.
    Thanks RVBottomly thanked for this post

Similar Threads

  1. Stem Cell Joint Therapy...
    By fobjob in forum Medical Matters
    Replies: 62
    Last Post: 03-26-2016, 03:48 PM
  2. J5 project?
    By Wind River CNC in forum Member Projects in Progress
    Replies: 13
    Last Post: 10-23-2015, 04:28 PM
  3. Alternative Therapy
    By scout88305 in forum Sportsman's Den
    Replies: 3
    Last Post: 07-06-2015, 09:35 PM
  4. Project help??
    By WWeldon in forum Member Projects in Progress
    Replies: 7
    Last Post: 03-20-2015, 02:08 PM
  5. 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
  •