Aluminum frame with landing shocks

Discussion in 'Frame Design' started by GJH105775, Dec 26, 2014.

  1. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    Weight: 453.5 grams/ 16 oz (no electronics) or 1190.6grams/42oz (w/electronics)
    New weight: 255 grams without electronics

    Prop size (designed for): 9''
    Prospected weight when finished: 276.691 grams /9.7oz (no electronics) or 736.5 grams/ 25.97oz (w/electronics)

    [​IMG]

    The frame is not completed the spring is supposed to be in the aluminium tube. I chose to use a bolt so I could extend the landing gear and adjust the stop and spring tension.

    I plan to cast the ends in a mold and use square fibreglass tube as spreaders.
    [​IMG]

    Therefore 20 solid cubic inches of fibreglass weighs 1.1 pound, and 20 solid cubic inches of aluminium (alloy 6061 T-6) weighs 2.0 pounds. The frame would weigh approximately 0.61 pound. Of course the fasteners take up more of the weight.

    If anyone knows where I could get some sort of strong but lightweight composite/epoxy that can be molded/cast, I would REALLY appreciate it.
    [​IMG]

    UPDATE: Cut the weight down by almost half. I dropped the landing gear off and replaced them with simpler design. I can still bolt them back on if needed. i also had to add lights :).

    Click for pictures
    [​IMG]
    [​IMG]


    Here are my latest additions.

    Latest (Revision 4)
    I added a aluminium battery holder, the battery makes a nice click and is held pretty well, I'll probably add some Velcro to keep it in even better.

    I also added lighter legs that are bouncy (not finished in picture) and bolted the motors down, as the screws vibrate loose.


    [​IMG]
    [​IMG]
     
    Last edited: Apr 15, 2015
  2. Abdur-rehmaan Seba

    Abdur-rehmaan Seba electrolux

    Looks good, but rather heavy for the size don't you think?
     
  3. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    A little perhaps, I did this more as a concept with cheaper material, I plan to build a lighter frame from fibreglass tube, it will weigh around 208.45 grams. My motors generate ~6ibs of static thrust and 2 of which will be taken up by the parts and accessories. That still gives me a 2:1 thrust:weight ratio.

    1/8 T x1 In OD Sq, 5 Ft Fibreglass tube

    Thanks for the input. I was wondering the same, if nothing else it will drain my already limited battery life. I have yet to decide whether to use fibreglass tube or cast it, I think I may cast the ends and use the tube for the spreaders. Do you know where to get any carbon-fibre/plastic channel or square tube?
     
  4. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    One last thing, if anyone knows where I could get some sort of lightweight composite that can be molded/cast I would REALLY appreciate it.
     
  5. Abdur-rehmaan Seba

    Abdur-rehmaan Seba electrolux

    Oh, I see 208 grams seems very light weight now!
     
  6. Abdur-rehmaan Seba

    Abdur-rehmaan Seba electrolux

  7. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    Thanks for the link, I don't believe that it is exactly what I want.
     
  8. sayed

    sayed Member

    mine is 26 grams but the problem is i cannot purchase brushless motor and i don't think brushed motor can work any solution will be appreciable
     
    Last edited: Feb 21, 2015
  9. sayed

    sayed Member

    did u tried hobbykings.com
     
  10. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    Yeah, they did not have exactly what I wanted., I managed to cut the weight almost in half though. I updated the main post with pictures.
     
    Last edited: Feb 21, 2015
  11. sayed

    sayed Member

    i think u should visit a hardware shop near by you or you should deal with manufacturer if you have enough budget
     
  12. sayed

    sayed Member

    by the way nice design what is specification and price of your motors
     
  13. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    Turnigy 150W 1240 KV motors I use 9x4.7 props. I should have went with 950kv - 1000kv motors to carry a little more weight. So I could swing a 10''-12'' props.
     
  14. GJH105775

    GJH105775 Avid Linux User, and U.S. Air Force 1C631 Moderator

    Added DIY battery holder, and landing skids. Because I was really hard on the others with my forward momentum.
     

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