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Narfi's Life after EU: Chapter Five - CH750-SD 3 Place Aircraft

Discussion in 'Life, the Universe and Everything' started by narfi, Sep 5, 2020.

  1. Wistrel

    Wistrel Kick Ass Elf

    I think it's good work for the time spent. Total aside, it will be interesting to see what the total time is on this. Just from the perspective of "what is the actual worth in man hours/pay to make one from scratch?". Think that might say something about the world... not sure what, but sure it will be something.
  2. narfi

    narfi Lost

    For my boats and airplanes.... I expect that I could sell them for roughly the cost of raw materials I put into them with $0 per hour worth of my labor in addition to that.
    That is a rough estimate for these sorts of projects, however exceptionally good craftmanship can be worth a little more, and poor workmanship would be worth less than the materials into the project.
  3. narfi

    narfi Lost

    It has been pretty cold this last week, cold enough to keep me from working out in the tent but it significantly warmed up to around 25-28ish F which is warm enough to get our first snow to stick for the winter.

    I was able to take off my jacket and just wore a thick sweatshirt with a labcoat over to keep most of the dust off.

    2 more hours got the cutting templates and form blocks done for the rear wing ribs.

    My wife came out and helped me unroll the aluminum and get it into the rack. Left out a sheet of .016 to start cutting up as well as the .020 I have already cut into. I had made the two stabilizer end ribs, but for the superduty there are actually 2 end ribs on both sides as the forward spar doesn't extend to the tip.





    Total time spent building: 24 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  4. Wistrel

    Wistrel Kick Ass Elf

    Sad reality there... how did the world come to this...
  5. Wistrel

    Wistrel Kick Ass Elf

    That snow pic... haha so hard core!
  6. narfi

    narfi Lost

    About 10 more hours this weekend got some visable progress.
    Cut out and bent two more stabilizer end ribs since each side uses 2 instead of one with the partial length spar. Then cut and bent all the rest of the horizontal and elevator ribs as well as the rear wing ribs.
    Still need to cut and flange the lightning holes in the wing ribs, tool kit that has the hole cutter from aircraft spruce is still backordered so may end up with another ghetto set-up since it worked so well making the dies.
    1/4" end bearing router bit is supposed to get here from amazon this week, tracking says it was in state Friday. Then I can cut out the slat and flaperon ribs, they are smaller peices with tighter radius flanges so the 3/8" I have been using is too big for them.

    The cutting and bending of all the ribs went very quick and easy imo, I probably spent more time making the templates and forms, but well worth the time and effort, I am quite pleased with how they look. (Esp. Knowing how much(textron?) Piper, Cessna and Beech charge for each little peice :p



    Total time spent building: 34 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  7. Jamira

    Jamira Samurai Girl

    Last edited: Nov 10, 2020
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  8. narfi

    narfi Lost

    About 3.5hrs in the tent.
    Cut the lightning holes in all the rear wing ribs and flanged them. Used my router with a peice of plywood screwed to it as my hole cutter with 1/4" holes and a bolt as my pivot point in the tooling holes.

    First hole I cut the center hole to the larger hole dimensions so that rib was scrap..
    After finishing I cut out a replacement rib blank and bent it over the forming blocks. I had my ghetto hole cutter set to the smallest hole size so cut it first...... however it was only supposed to have the 2 larger holes cut in it so reinforcement could be riveted to it on the fuel bay..

    so in the end I have 1 extra rib(I still flanged it so it is a good completed rib) and one scrap rib.

    Flanging with the dies was easy just using a rubber mallet. I was just careful to keep them square and hold pressure down on the male die once started to prevent it bouncing, I didnt just wail away at it with the mallet but more controlled hits mostly centered to start, then finished off around the parameter once down mostly formed.

    On the zenith forum someone posted yesterday having issues with his ribs being warped after hand flanging(not using a die) so I payed close attention to mine to see the difference.

    You can see it is stretched some but snaps back straight when the edge flanges are held at 90° so I think it is ok.

    All in all, not bad for an evening after work :)




    Total time spent building: 37.5 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  9. narfi

    narfi Lost

    2.5hrs last night.
    Smaller end bearing router bits came in so cut out all the slat and flaperon blanks..
    Cut out all the flaperon blanks individually which took most of the time then got impatient and stacked up all the slat blanks to cut at the same time. Not a good idea with cheap bearing bits... I promptly burned it up and blew up the bearing. Ill probably need to redo one or two of them as they weren't quite aligned in the stack and missing some of the edges..

    Lesson learned,, all things in moderation. Maybe 3 or 4 stacked to save time but dont try to cut 10 blanks at once with cheap tools.

    Still happy with the results though :)

    Total time is up to 40hrs or a standard work week. As a hobby it feels like I have got a lot done, but if I was on the clock I might be ashamed to have so little to show......
    It is a hobby though so all good :)


    Total time spent building: 40 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  10. narfi

    narfi Lost

    2.5hrs got all the slat and flaperon ribs bent.
    1hr yesterday got the wing nose rib forms and cutting templates ready, but while it was in the teens F° the wind was cutting through the tent pretty well and mechanics gloves just weren't enough :/ 5° this morning so progress may slow down a bit if my body goes into hibernation mode. Will see :)


    Total time spent building: 43.5 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  11. Wistrel

    Wistrel Kick Ass Elf

    This guy is building a plane

    Everyone: WHAAT?

    In the cold...


    Seriously great work there. I know what you mean about the "on the clock" thing but as the saying goes "fuck that shit". It's different when it's a hobby, you can relax, take the extra time to do it right or experiment some more or do whatever is needed to make it enjoyable. There is no clock here.

    Must be really nice to see the payback from all that work on the formers. Quick question, I see a sort of bend round the edges of the holes. Is that for strength? Are these parts going to form the ribs for the wings? or is it bits of flaps? (sorry might not be using the right technical names for these things - I'm following a chap designing a model plane in Fusion on youtube... but other than that don't have much knowledge of them).

    I've been back designing stuff this last week in Fusion. Been away from a while but I've been trying to learn how to do mechanical design which is a really fun puzzle. Trying to work out how one thing can push/turn another etc using linkages. It's even involved some high school maths! I think I'm getting there now... but even at the end I have another fun puzzle which is how to break things up so it is actually possible to print/assemble. I've taken the approach of "everything is as big as it is simplest to be" at first with a mind that I can always chop parts up or make them smaller, if need be, later. I'm not sure if this is a good way to go about designing something, but I'm running with it for now.

    Probably a good alternative approach might be "measure anything you can't change" then design around that.

    Still, having fun and learning stuff is the main thing

  12. narfi

    narfi Lost

    The bigger ribs you see with the 3 large holes in them are the main wing ribs. Rear ribs specifically, they are between the front and rear spars which makes up most of the wing. I am working on the forward nose ribs now, and then the flaperons will be the hinged sections behind the rear spars. if that makes sense :P


    The 3 large holes in the ribs are called lightning holes (there to make them lighter) and they are flanged to increase strength. I don't know the math behind it, but am guessing that the flanged holes are stiffer than the rib is without cutting the holes, so it is both lighter and stronger (but again I am not 100% on the math, I am just following the instructions of someone smarter than myself :P )

    The control surfaces on a typical wing are in two sections, the outer section is called the Aileron, and it moves up and down, opposite of the one on the other wing, and it controls and stabilizes the roll rate of the aircraft. The inner section are called Flaps, and they only go from neutral to down usually at a labeled degrees setting. The flaps change the airfoil of the wing and can in affect increase wing area a little bit and are used for stability in slow flight such as landing, but are not allowed to be down over a specified speed as they are large and have huge wind resistance and leverage against them, can cause damage at higher speeds as well as being counter productive in slowing you down.

    This plane though uses 'flaperons' which has the inboard and outboard sections doing the same things together in more of a hybrid approach, which is a great compromise on a slower style of aircraft which this is.
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  13. narfi

    narfi Lost

    1hr was all my fingers could take of the cold last night, hot coffee and rum don't seem to help the toes and fingers much. Got the wing butt nose rib formers done. Picture includes the main nose rib I did Sunday, still need to grind the fluting in them but that's pretty quick.

    Someone posted yesterday(not on this forum) stating I would spend 10s of thousands of dollars and never have a flying airplane. I wanted to quickly address that in saying that while someone should be aware of their limitations before starting a project like this, I took all precautions before beginning to ensure I was prepared to see the project through. I set myself a reasonable timeline 3yrs(which I currently have a hard time seeing how I can drag it out that long) and a commitment to plug away at it one bite at a time. It is fun for me, and even when it is painfully cold, I still want to be working on it and will push to put in that hour or two each day because I enjoy it and it is therapeutic for the mind and body to end a day with no stress, just focusing on a fun productive project.


    Total time spent building: 44.5 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
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  14. narfi

    narfi Lost

    Made the form and cutting blocks for the wing root ribs and ground out the fluting grooves in it and the nose rib blocks I had forgot to grind them into.

    The root ribs top flange goes from 60° at the nose to 90° at the rear spar. I puzzled over best way to do that and decided to just make the forms like all the others and free handedly not beat it down all the way at the front. As easy as cutting out and bending is once the forms are made, I can try a couple if I mess up one or two, and I only need a good left and a good right, so not worth trying to overthink the formers..... We will see :)


    Total time spent building: 47 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  15. narfi

    narfi Lost

    0 hours
    Went to start building the rear bulkheads last night and found a contradiction in the dimensions, so called it early and binge watched some shows my son was wanting to watch.

    Called Roger this morning and he is looking into it as well as more parts for me to build.
    Anyone know what scratch builders are doing for the tips of the flaperons, slats and wings? they all seem to be plastic or fiberglass parts. Just thinking ahead....
  16. narfi

    narfi Lost

    Made the cutting and forming blocks for the two rear bulkheads. Could have probably freehanded them in less time, but if I mess one up during assembly and need to remake one, or inevitably damage one during the life of the plane, it will save me time in making a replacement and be a "quick" simple fix.


    Total time spent building: 49 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  17. Wistrel

    Wistrel Kick Ass Elf

    I have to admit, I'm feeling Jamira's silent scream on the "former" parts here. They look like (some of them - others, sure 10 mins and done) would take a a lot of work to cut from wood (I guess depending on tools available/how good/fast you are) where as, once you've got a handle on CAD, you can do these things quite fast then throw them at the printer.

    Admittedly though the "quite fast", like with any skill, only comes with practice/getting good. I'd say I'm now at the point where I can do stuff fairly quickly, but it's taken me a while (with ad-hoc hobby level of effort - among others).

    That said... I definitely need more practice at following plans still.

    I get that wood is more durable and pleasing of course :D
  18. narfi

    narfi Lost

    Friday the last of my aluminum came in and my wife helped me unroll and put it in the rack.
    I went threw my drawings to see which pieces to leave out on the table for the next parts and discovered a huge mistake I had made.
    The rear wing ribs are supposed to be .025 and I had made them from the same .016 as the tail ribs.........
    In all it's not a huge setback, a couple hours of work and 2/3s of a sheet of .016 aluminum wasted. If that's the worst mistake of the project ill be happy ;)

    4hrs friday night cutting all new rear wing rib blanks, nose ribs, and root ribs (all .025 this time) and the two rear fuselage bulkheads(one is .040 and one is .032)

    (Not counting the bulkhead parts, that is a full 4x12 sheet of .025 shown in the picture, all wing ribs from one piece)

    2.5hrs and 3.5 hrs Sunday bending them all. 2 bulkheads, 14 rear wing ribs, 20 nose ribs, and two sets of two root ribs. The wing ribs are a larger front radius but it felt like the .025 forms better than the .016 on the tail pieces, the thinner stock wanted to fold more while the thicker could be (pushed around) easier with a brass hammer.

    My boy even came out to help bend some of the parts which made me proud.

    I had one flute crack out so needed to make one extra rib, but not bad for the mass production over the weekend.

    Just need to cut and flange all the lightning holes.

    That's all the parts I have from Roger to build so far, he is working on getting me the rudder drawings next.





    Total time spent building: 59 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
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  19. narfi

    narfi Lost

    1.5hrs cut the lightning holes in all the ribs, nose ribs and root ribs. Need to clean them up and flange them now.


    Total time spent building: 60.5 hours
    Total Cost: $8276
    Airplane + consumables + project specific costs: $5340
    Tools, etc.. I will keep for future projects: $2936
  20. Wistrel

    Wistrel Kick Ass Elf

    ah easy mistake to make on the thickness. I was doing something the other night and was taking me ages because I'd never done it before and I was super worried I'd make a mistake.... mainly cause I kept noticing I was making mistakes so kept thinking there's be more of them (thankfully they are easily fixed if you spot them).

    How are you cutting the metal out of interest? Hack saw or some sort of CNC?

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