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ASLAV (LAV-25) 8X8 Military Vehicle

Discussion in 'Road Giants 6x6/8x8/10x10' started by ScaleBuilder, Dec 19, 2014.

  1. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Today I was playing around with the shocks. I think these 70mm buggy shocks dont give me enough suspension travel. Also, I've seen some people do the "droop setup" which I really like the look of. What do you guys think of the droop setup? Should I do that instead?
    I know that too much droop can be bad, for example the wheels could fall into a cavity and get stuck (but in this case there are 6 other wheels and 4 motors of torque to get unstuck).
    Here is a picture of what I have mocked up with a couple 90mm shocks on the left.
    Is this too much droop? :eek:
    [​IMG]
    I love the new update to the site, making posts is easier. No need to preview. Not enough smilies though.
     
    #21 ScaleBuilder, Jan 6, 2015
    Last edited: Nov 30, 2017
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  2. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Yay! Parts arrived, still waiting on beadlocks. And the rc4wd 35t motors are out of stock :(
    I will source them out some place else. I will run on just 2 motors for now.

    Should have an update on the chassis tomorrow.
     
  3. darkside0914

    darkside0914 Studio Forums Elite
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    having you rig in droop probably wouldn't be a problem for you , not with your setup anyway, and no that doesn't look like too much droop to me. it looks like it should give you plenty of flex and still allow the tire to roll up any obstacle, but if your still unsure test it, when you get the chassis ready to run set up a situation where one set of wheels are off the ground and see how easily the other axles can pull it along.
     
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  4. ScaleBuilder

    ScaleBuilder Well-Known Member

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    CHASSIS

    Worked on the chassis today for 5 hours. Also running around to multiple hardware stores for materials.
    The chassis is 120mm in width so that two lipo batteries can be mounted side by side.
    Added some cross braces for more rigidity. The cross braces are also mounted to the lower link mounts to keep the lower link mounts at a nice 90° angle.

    The center lower link mounts have been replaced with better designed plates. These plates are more rigid and also keep things tidy in the center area. I couldn't put a cross brace in the middle as it would interfere with the upper links.
    [​IMG]
    And this is the mounting plate for the electronics such as the batteries, receiver box and ESC's. Will be screwing it in more securely.
    Also will be drilling holes into the plate for cable management and slots for the straps that hold the batteries in place.
    [​IMG]
    Chassis is made using basic tools like a hacksaw, power drill, hand file, ruler, T-square and a bunch of clamps.

    Next update, drivetrain assembled onto chassis! (just waiting on beadlocks to arrive, and need to source out 2 motors).

    Thanks for viewing, got any comments/suggestions let me know.
     
    #24 ScaleBuilder, Jan 10, 2015
    Last edited: Nov 30, 2017
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  5. darkside0914

    darkside0914 Studio Forums Elite
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    not sure if this will help but I found some on ebay
    http://www.ebay.com/itm/NEW-RC4WD-5...Control_Parts_Accessories&hash=item51c8cfb47d
     
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  6. darkside0914

    darkside0914 Studio Forums Elite
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    by the way your chassis is coming along very nicely, looks as good or better than some factory chassis I`ve seen.
     
  7. ScaleBuilder

    ScaleBuilder Well-Known Member

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  8. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Thanks. I couldn't say the same about it unless I had precision tools like I used back in high school!
     
  9. drzoo2

    drzoo2 Studio Forums Elite
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    Awesome build. Can't wait to see more.....

    I had good luck with the Novak Terra 35t. They are cheap and not rebuildable but I think that's what you said you were looking for. About $16

    [​IMG]
    [​IMG]
     
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  10. darkside0914

    darkside0914 Studio Forums Elite
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  11. ScaleBuilder

    ScaleBuilder Well-Known Member

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    ROLLING CHASSIS

    And now we see if everything fits together nicely...

    Nice low center of gravity.
    [​IMG]
    The steering is at maximum lock, and the clearance from the tires to the lower link mounts are about 3mm haha.
    [​IMG]
    Got some branches I found laying around to show suspension travel. Not really liking these 70mm shocks. I always had it planned for 80mm but they seem to be out of stock everywhere. Think I might get Gmade G-Transition shocks 80mm one day. I will have to test it's crawling ability once things are wired up.
    [​IMG]
    [​IMG]
    And a tip for those with Bully 2 comp axles. If you want to lock the front axle so that the wheels are always straight, you can mount the servo link to the servo mount. And lengthen the servo link to center the wheels.

    The other 2 motors, an ESC, and two batteries are on the way.

    Next update will be electronics. (2-3 weeks from now...)
     
    #31 ScaleBuilder, Jan 12, 2015
    Last edited: Nov 30, 2017
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  12. Antho11

    Antho11 Studio Forums Elite
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    Sick flex, should be better with 90mm or 100mm. I've never seen that much steering angle!
     
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  13. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Yeah thanks. Steering angle makes it a challenge with clearance. Can't decide what shock length until I tested it.
     
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  14. darkside0914

    darkside0914 Studio Forums Elite
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    but that's the nature of building custom right , test, test, retest, then test some more until its as good as you can possibly get it. it doesn't matter if you build rc cars, real cars, or the space shuttle,
     
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  15. ScaleBuilder

    ScaleBuilder Well-Known Member

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    ELECTRONICS

    Aaaaand I'm back.

    Battery, ESC's, motors, BEC, Receiver box and servos are now connected and soldered.
    And mounted to chassis.
    Decided to go with a single battery and run the ESC's in parallel from the battery.

    But first a quick update on the chassis. Four slots have been cut and filed into the electronics mounting plate. Then straps inserted through the slots to strap down the battery.
    Also holes drilled underneath for cable routing.
    70mm shocks are now mounted to chassis instead of the shock towers. Shock towers will be used again later for longer shocks.

    Update on the wiring diagram (now in colour yay) with fixed motor voltages (thanks drzoo2), addition of BEC for the power hungry servos, single battery, and reduced channels on receiver.
    A little easier to read a diagram than figuring it out with the pictures.
    [​IMG]
    Servo's are Savox SW-1210SG waterproof for the front two axles.
    I have since installed a BEC 20A 6V output between the battery and the power hungry servo's.
    Looks a bit like a squid:
    [​IMG]
    Cable management will be improved later haha. And getting to the battery is easier than it looks. Might make another plate for the ESC's behind the batery.
    Battery is a 5000mAH 7.4V Skylipo. I will need to test how much run time i get first before replacing with another higher mAH battery.
    [​IMG]
    [​IMG]
    [​IMG]
    Other thing I have done that you cant see is thread-lock all screws on all axles.

    Need to wait for 25 tooth servo arms because silly me bought 23 tooth servo arms and tried fitting them onto my Savox's for over half an hour because i was sure they were 25T! Finally took a minute to calm down and count the teeth lol.

    It has also occurred to me that I'vs spent over $3000AUD on the RC hobby and still using the same $25 transmitter from 3 years ago. So I bought a Futaba 4PLS for all my ground RC's.

    I also ordered materials for the plastic roll cage. 8mm diameter acrylic rods coloured black.

    Next update will be a running video!
     
    #35 ScaleBuilder, Feb 2, 2015
    Last edited: Nov 29, 2017
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  16. drzoo2

    drzoo2 Studio Forums Elite
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    It looks like you may be trying to eliminate a ground loop at the servo/receiver by not tying the ground back to the receiver. As it's wired in your diagram, the receiver/servo's signal ground has to make it's way back through the BEC, ESC and then finally to the receiver. That is a long path through a lot of components that create switch noise, which also use the same reference.

    I'm not saying you have to add this ground. The way you have it may actually work better. But if you find some glitching, this may be your cause. Just something to keep in mind when you start testing.
     
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  17. ScaleBuilder

    ScaleBuilder Well-Known Member

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    RUNNING VIDEO

    And here is an overview and running video :D

    I've since managed to get the front and rear wheels more in sync. Just the rear most 2 wheels are still slightly different speed than the rest. Will check gear mesh for that one.
     
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  18. Greenie

    Greenie VillAge iDioT
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    DUDE!!!!!!!!! not sure how I missed this build!!! AWESOME MATE!!!!
    there was a couple of things I was worried about, one was the droop and the other was the steering.

    Droop setups have an issue with climbing, as the tires load up(as they climb) they have a habit of starting to lift the front of the rig up, loosing grip and steering on inclines(as well as decreasing the angles they can climb). but with the shorter 70mm shockies I didn't notice that it was much of an issue. If you do go larger shockies, contemplate putting internal springs in the shockies to alleviate some of that.(food for thought)

    I obviously wasn't paying attention to the build, as I didn't realise there was dig(sorry!! was a quick read through to catch up!!), so ignore the steering questions I had!! LOL!!!

    but its an awesome build dude, and will be following intently!!!!!!!!!!!!!
     
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  19. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Hey man thanks!
    The shocks are now 80mm gmade g-transition shocks in a semi-droop setup.
    So it has internal springs. One long spring beneath the piston, and one short spring above the piston.
    So it is about 30% sprung and 70% droop.
    The springs can be reversed if running a sprung setup.
     
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  20. ScaleBuilder

    ScaleBuilder Well-Known Member

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    Hey guys great news!
    In a weeks time I will be attending the Melbourne International Airshow in Avalon. How is that related? Well there is a real ASLAV parked there so I can take detailed pictures of it.
    Great timing as it will help me in the next step which is to make the body shell :)
     
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