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Justin

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Posts posted by Justin

  1. Thanks Anthony,

    Interesting comment on the helicopter skids. I think the jig is a developing design. The skids and struts are there to add dimensional stability to the formers, but if the spine part is made with aluminium extrusions I could foresee that the skids and struts could be replaced by extruded angle brackets bolted directly to the spine. As the foam planks are added these brackets are removed, to ensure ease of jig extraction from the finished core with the external skin.

    Hmmm....

    • Like 1
  2. Hi Folks,

    This is progressing, and it is becoming quite a complex assembly, so it is worth making the whole system reusable. I uploaded a CAD update at  https://grabcad.com/library/quickie-q2-fuselage-jig-april-26th-2023-1   .  It is only the jig. All the previously uploaded planks are unchanged.

    I foresee that all the formers will be water or laser cut.

    The new plank layout gives an assembly order of planks that adds dimensional stability to the assembly, and parts of the jig structure can be progressively removed to allow the second and final planking operations.

    First the upper planks, down to the waist line are added. Then the jig is turned over; possibly on axles from the ends of the spine parts. BTW, the spine is a 4" square aluminium extrusion, with a smaller 2" x 2" tail extrusion.

    When the assembly is  upside down the former support struts at FS146 and FS158 are removed. Then the bottom planks are added.

    Next; the 'helicopter skids' all the former support struts are removed, and the remaining side planks are added.

    Then the planks are faired and the skin laminates added.

    I will work next on how the foam core with the outer skin is separated from the jig formers and spine. The process will be to make the fore - aft fuselage split, and the top and bottom tailcone split. The spine can be extracted, and most formers can be extracted. It looks like the cockpit area formers at FS 53.5, FS63, and FS74, will need to be made in two parts, to enable extraction.

    After this the internal foam surfaces can be cleaned up and skinned. I still see no need for the main fuselage part to be split at the waist. It will be open at the ends, and where the canopy frame core is cut out.  Until the inner skins are added there will be a need for some simple external cradling to ensure accuracy.

    So... there is some more work to do !

    Here are a few pictures.

     

    Jig1.jpg

    Jig2.jpg

    Jig3.jpg

    Jig4.jpg

    Jig5.jpg

    Jig6.jpg

    Jig7.jpg

    • Like 1
    • Thanks 1
  3.  

    re:-

    "

    They're "in an absurd format" because the decision, before my time, was to convert them to text only so they would be Internet searchable. It would be nice to have them as PDFs (now that PDFs are searchable) and that is on the list of things to improve. I just went through 3 sets of printed copies to select the most scan-worthy issues.

    "

    Just a little something I discovered, when saving the newsletters. Using Chrome, I just open the newsletter and hit CTRL-P  . Windoze then gives an option to save as PDF.

  4. 2 minutes ago, zolotiyeruki said:

    Do you plan to eventually build an Q200 with this method?  It looks very promising, and very accessible, assuming someone has access to the jig.

    Well, I don't know. The aircraft fascinates me. Q1 as well. It is such clever design, with a small robust structure.... quite short lifting surfaces.... very easy load paths.... and it is super sleek.

    If I built one I would use this technique. Kit cores are probably not available secondhand here in the E.U.  Mine would be a Q260 ! I would use the UL260i engine. It is a tiny bit lighter than the Revmaster. It is a lot more expensive, but has 97hp, fuel injection and FADEC.

    I will make the jig design easy for anyone to build. The formers could be mill, water or laser cut MDF 10mm thick. The CAD modeled formers have edges bevelled to the inside of the foam, but they could be cut square, as long as the builder pins the planks on very close to the plank-former contact edge. I have done this in foam boatbuilding. The foam planks strain easily, and need very light fastening pins to constrain them to the jig until the adhesive between the planks sets.

    The other part that is also probably not available it the LS-1 round canard spar. I don't like it anyway, and would follow the Wieshaar Doyle idea...      https://aerobase.weebly.com/ls-1-canard.html

  5. Just a small screenshot update.

    I am re-planking in a layout that uses mostly parallel sided 2.5" wide planks, with tapering in some places. These would bend in the plane of each plank, as well as around the jig templates, so only the width of the plank is relevant. The planks could be cut pretty much straight, with this new layout.

    I am inclined to go with 0.5" thickness foam sheet to start with, because something like 0.08" to 0.1" will be faired off. It is likely this core will end up a little heavier than the thermoformed kit core, but I expect the difference in weight would be very small.

    q2-113.jpg

    • Like 1
  6. Hi Anthony,

    Thank you for that information. The holes on the 1" grid are probably bleed holes to let resin through to a breather layer when the foam is being vacuum bagged onto a skin in a mould.

    I forgot to answer your question about flat development of planks. Rhino has a command for this. It will unroll any surface that has 1 degree curvature in one direction; just like a plank has across its width. The surface should have reasonable parameterisation in the other direction, and then this command produces very accurate developments.

     

  7. Hello Anthony,

    I do a lot of the CAD work in Rhinoceros, but for detail and assembly work I use my day job Catia. I am considering getting my own Autodesk Inventor license for other projects too.

    I would be interested in finding out the thickness of the kit shells. It is likely that was an easier way to go, but foam planking is really easy too. I have made a few boats that way.

    • Like 1
  8. Hi Folks...

    Well, here is the new Quickie Q2 helicopter !

    It is really the bare bones of a fuselage foam core jig concept. This will get another 9 formers in something like 3/8" MDF, arranged on a spine, and braced to the 'helicopter skids'. The entire fuselage would then be planked in H35 Divinycell. I hope this can be found in 1/2" thick sheet, but it is almost impossible to find out if that is available. I would need to 'expand' the complete plank layout. In shibbuilding this is called a 'shell expansion' or 'plank expansion', and in foam it would be nice to avoid planks tapering to zero near the tail. A layout with 'nibbed' ends needs to be devised. I can do this in Rhinoceros.

    A suitable adhesive to go between the planks is required. It could be dry micro, but there are adhesive available specifically for foam bonding that are as strong as the foam, and as light, and as easy to sand fair. I don't yet know of a suitable one for H series Divinycell.

    The technique would be to start planking round the sides and bottom, and gradually remove the bracings to the 'skids'. The foam core will reach a stage where it maintains the dimensional stability of the whole core on the spine part alone. This spine part might need to be made of steel tube, but the skids could be wood. All the formers must have polyethylene stapled on their edges to prevent foam core adhesion to them. I foresee that the spine part has bearings at both ends, so the fuselage core could be rotated, once it is dimensionally stable. All pins constraining the planks to the formers can be removed once the core planking is complete. Then it can be faired and externally skinned. I think the front-rear fuselage can then be carefully sawn, along with the canopy frame. The rear fuselage/tailcone part can have the waistline split cut. The front fuselage can remain unsplit at the waistline. There is plenty of access to make all the internal fairing, inner skinning and structural additions.

    It could be that a further external longitudinal support is required, along the top centreline of the fuselage, but it would be nice if it can be done without it.

    There is a long way to go with this concept; especially the tail end of it. All ideas are welcome.

    Cheers,

    Justin

    q2-109.jpg

    Fuselage-Jig.zip

    • Like 2
  9. Thanks Guys,

    From the plans I reckon it looks like 0.5" thick, but H35 or H45 sounds about right for the material.

    Eugen, I have followed your super Q1 project, and your materials link is superb. Thanks !

    I will post my fuselage core idea at some time. It is basically a foam plank system, as I have used in many boats. I see no reason for the horizontal split in the forward fuselage part.... only in the tailcone part. I will figure out the tooling for this.

    I have no idea if I will build a Q2/200, but I am fascinated by the really logical design, that I used to think was just freaky. Well, it isn't. It has really short load paths all concentrated in a very compact design. It is utterly brilliant.

    Cheers,

    Justin

  10. Hi Folks

    Here is basic model of an engine mount for a UL260. I have made a spaceframe type that takes loads nearer the edge of the firewall. Some small webs inside the firewall will be added. The lower ones can transfer engine loads directly to the canard. Perhaps a few gussets are required in the engine mount.

    The UL installed weight is  slightly lower than the dry weight of the Revmaster 2300. It also produces more peak power, and equals the Revmaster 2300 peak power at just 2800 rpm. It is about double the price of the R2300. It does offer fuel injection and FADEC. There is still a huge saving in using the Revmaster.

     

     

    q2-106.jpg

    EngineMount-Q2-UL260i.zip

    • Thanks 1
  11. Hello,

    Well, there was little response to my ground attitude question. However, I had modeled the Q2 with standard gear and the canard jigging templates produced an anhedral of 6 degrees. This put the ground attitude at 11 degrees pitch. Somewhere I read it should be between 7.5 and 8 degrees, but almost all photos show that the pilot has a better view on the ground than the standard design really makes. Also, many photos show that people have considerably lowered the tailwheel.

    In the attached CAD STP file I have reduced the canard anhedral to 5 degrees. I have not lowered the tailwheel yet, but it should lower by 3.5 inches. Using a UL260i engine with a 48 inch diameter propeller, and allowing for 2" of strain in the canard and a loaded tyre radius, these changes still give propeller to ground clearance of 16.6" and a ground pitch angle of 8 degrees.

    Cheers,

    Justin

    q2-90.jpg

    q2-91.jpg

    q2-92.jpg

    q2-93.jpg

    q2-94.jpg

    STEP-Q2-Assy2023-03-11.zip

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    • Thanks 1
  12. Hi Folks,

    I have been CAD modeling the Q2, but have found difficulty in meeting up with the ground attitude measurements given in the plans addendum.

    Of course, if the canard bends the tailwheel height when WL15 is level, will be reduced, but surely not enough to compensate for this apparent error. I know some canards are stiffened to reduce bending, and I have seen photos where some Quickies have a lower tailwheel.

    'Anyone got experience or comment on this ?

    That's all Folks !

    Justin

    GroundAttitude.png

    PlansChangeAoAonGround.png

    q2-56.jpg

    q2-57.jpg

    q2-61.jpg

    q2-65.jpg

    q2-71.png

    Q2-Assy.3dm Q2-Assy.zip

  13. On 11/19/2022 at 1:19 PM, Chris007 said:

    I have bumped into this website from time to time over many years. But circumstances always have conspired to keep my own EZ dream from becoming reality. This thread has inspired me. Combined, we have more than enough knowledge and skills to create an EZ for the 21st century. If someone with good CAD skills will work with me, I will build it. The original design was revolutionary, a generation ago. Yes, it is that old. We can design something, sleeker, sexier, lighter, and more efficient, and most importantly, reduce the build time by an entire magnitude. Making a kit as simple to assemble as an Airfix. Gone will be the days, years, of being the third, fourth owner of a partially built kit, with still no end in sight. I am aiming for a 200, not 2,000 hour build time. A 50% weight reduction, and a 2,000 mile range, with a 80hp class engine. Thats all very achievable. I will build the prototype. Once that is flight proven, I would crowdfund to create moulds and mass produce. I just need the design put into CAD. Who wants to do that? 

    Rutan is brilliant enough to have done this if it was at all possible. Why would anyone want 2000 mile range? 80hp is not going to propel it all that fast, so that is optimistically 12 hours flying. I would need a comfort/rest/coffee stop about 6 hours into the flight, and I am really good at long trips. The e-Go project got tooled up with a light single seat canard. It cost about the same as two very well built, well equipped Long EZs.

  14. It is just my guesswork, but I think there is no rocket science in the landing gear bow. I think it is made mainly of unidirectional glass. This is probably laid into a mould between two bobbins, one at each wheel end, The mould has to be open on the top side to do this, and excess material would need to be taken off after curing. Then the builder covers the whole thing in a number of layers of biaxial glass at +45/-45 degrees. This ties the UD together, so that it cannot 'burst' when strained. If I was building an Open EZ, instead of a Midget Mustang, I think I would try this method and test it.

  15. I have had ECU controlled engines in fuel injected cars since the late 80s. None ever failed in any way.

    If I get back to Open EZ and build, I would enjoy having no mixture controls in the cockpit. I would prefer the UL390 to any Rotax. It is direct drive, and has only air cooling, and you can see the engine when the cowl is off. The more powerful Rotax engines have a lot of complexity in their installations, and you can barely see the core of the engine with all the clobber on it. It is just my preference to keep it simple, and I do know that Rotax engines are exceptionally good, but I think their best engine is the 912. It has small frontal area and suits sleek ultralights, but not the EZ.

  16. I have not uploaded the Dynon Skyview 10". You can get that from the Dynon website. The large display needs a rectangular aperture in the IP frame at FS40. This aperture could be handy for working access to harness.

    My engine cowl lofting is suited to the UL390i with the 110mm propeller drive extension. The engine STP file can be downloaded from the UL Power website.

    ez275.jpg

    ez276.jpg

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