Tank build: GPM Challenger 2, RC conversion

Discussion in 'Armory & Military' started by Lex, Jan 22, 2008.

  1. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    Okay first thing, this is not a build by me, but rather by Leo on cardmodel.cn, I just thought it was so good that I decided to post it here... Thanks to Leo for sharing his build! :mrgreen:

    Original thread
    [ÖÆ×÷¹ý³Ì]GPMÌôÕ½Õß2£¨1£º25£©Ò£¿Ø¶¯Á¦£¨1.17¸üÐÂβµÆ¡¢×°¼×¡¢·¢ÉäÅÚµ¯¡¢ºÜÊÜÉË¡­£© - ½װģÐÍÖÆ×÷½øÐÐÇø(Contruction Reports) - cardmodel.cn Papermodel¡¢Cardmodel¡¢3Dcard¡¢3Dֽģ¡¢Ö½Ä£ÐÍ - Powered by Discuz!

    This is still a WIP, but let me just give a preview of the sort of features to expect from Leo: Fully movable tracks and suspension, and a mobile turret with RC rotation and elevation. Working BB bullet launcher, and a laser gunsight, lights, smoke...:rolleyes: Okay too early to get carried away......

    Project Start, formers cut out, nothing special at this stage... yet. This Challenger model does not have internal structures, and so it great for RC conversion. Some formers have been modified to accommondate for the internal machinery.

    [​IMG]
    [​IMG]

    Formers strengthened by superglue, to save the tank from falling apart during running
    [​IMG]

    Chassis:
    [​IMG]
    [​IMG]
    [​IMG]

    The motor, with some modifications to let it drive the wheels:
    [​IMG]

    Testfit...
    [​IMG]

    Space have also been left out for the suspension system:
    [​IMG]
  2. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    Leo then moved on with the suspension...... Some hard work there

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Driver shaft, steel rod bought on purpose
    [​IMG]

    Shafts for suspension, made from bicycle wheel struts
    [​IMG]

    Test-fit suspension and axle
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  3. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    [​IMG]

    More on suspension system...
    [​IMG]
    [​IMG]

    White glue won't be strong enough for this, considering what weight the final tank would take, so Leo had to drill holes and attach by metal wire
    [​IMG]

    ...And springs!! Leo got them from ball-pens
    [​IMG]
    [​IMG]

    More assembly...
    [​IMG]
    [​IMG]

    Springs when compressed
    [​IMG]
    [​IMG]
  4. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    Spring force is about 300g each... Combined, they can hold a 3kg weight on top
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Moving on... Guide wheels
    [​IMG]
    [​IMG]

    Assembles, contains springs inside
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  5. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    Putting on guide wheel
    [​IMG]
    [​IMG]
    [​IMG]

    Drive wheel, Leo strengthened it with epoxy -- it's going to drive the entire tank forward
    [​IMG]
    [​IMG]

    Now for the 12 wheels on the bottom...... (Not too furnished in the naming department, anyone tell me what they're called...?)
    [​IMG]
    [​IMG]

    Tin solder wire, used as additional weight to fit into the wheels' rim
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  6. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Finishing touches
    [​IMG]

    Woo! Done!!!!!! Great job so far Leo!
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  7. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    These are the "Real" suspensions, but here it's just an ornament >_<
    [​IMG]
    [​IMG]
    [​IMG]

    Finishing the chassis
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  8. rockpaperscissor

    rockpaperscissor Member

    Joined:
    Mar 4, 2006
    Messages:
    362
    Likes Received:
    0
    This is absolutely amazing! Thanks for sharing Lex. This modeler certainly puts me to shame. I doubt I could find the time, patience, and skill to build the Challenger "out of the box", and this guy ingeniously modifies his to actually move and respond to the terrain like the real thing! His work takes card modelling to a whole new level. I'm in awe.
    Regards,
    Don
  9. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    ...Here comes the sweet part ^O^ Scratchbuild BB launcher :eek: --Sad thing it's not in paper though...

    It took Leo sometime to figure out how to make such a launcher, the off-the-shelf one is too big to fit into the turret. He tried everything from springs to pneumatic to compressed air, and it finally worked on his sixth attempt ^^
    Specs: dimensions ~10 x 3 cm, operating at 6 Volts, fires 2 bullets (read: shells) per minute, at a distance of ~20 metres. It's not a complicated mechanism, and from the pics we should be able to figure out how it works.
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
  10. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    --Guess what is this piece of nylon used for?
    [​IMG]

    ...Yes, it's for making the tracks. This isn't your average display model where looks are everything. These tracks have to be strong, (oh well, for materials scientists, "tough") So Leo is reinforcing paper with this nylon sheet.
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    ...160 pieces in total :eek::eek::eek:
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Woohoo!!! Completed ^O^ Nice work there Leo!
    [​IMG]
  11. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    --But that was only the core... The tracks would have to be skinned...
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Epoxy glue... This is expensive stuff, but when combined with nylon this becomes a fibre reinforced composite with strength matching that of glass fibres, necessary for the tracks.
    [​IMG]
    [​IMG]
    [​IMG]

    Brass wire used as the axel, to save any corrosion...
    [​IMG]
    [​IMG]
    [​IMG]

    Nice fit! :rolleyes:
    [​IMG]
    [​IMG]

    --And now, for, morrrrrrrrre!! Go Leo! :twisted:
    [​IMG]
  12. lriera

    lriera Member

    Joined:
    Aug 29, 2007
    Messages:
    281
    Likes Received:
    0
    I am absolutely amazed. This build is a great learning tool. Thank you for sharing.
  13. cgutzmer

    cgutzmer Guest

    stupendous! thanks for sharing this beauty with us :)
    Chris
  14. rfktex

    rfktex Junior Member

    Joined:
    Jan 1, 2008
    Messages:
    7
    Likes Received:
    0
    Inspirational

    This is just awesome to see. We find here a grand level of patience and creativity.
    Thanks for sharing Leo's efforts. I'm sure he now has a new suite of war stories to share directly too.

    Russ K
  15. Nemesis7485

    Nemesis7485 Member

    Joined:
    Aug 13, 2007
    Messages:
    123
    Likes Received:
    0
    Good grief! This is amazing. It would take me about 30 years to build something that intricate.
  16. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    Thanks guys, I'll pass this on to Leo. --But behold, the most stunning is still to come...

    Leo has completed the track, finally, after 1 month's worth of work......... Here he's painting them. Black marker and pencils couldn't do, so Leo opted to using acrylic diluted with ethanol (personally I recommend enamel though...)
    [​IMG]
    [​IMG]
    [​IMG]

    Teeth, sticking to the original design is not good enough, --we all like modifications don't we? :mrgreen:
    [​IMG]
    [​IMG]
    [​IMG]

    ..You guessed it, Leo will be reinforcing them with copper wire
    [​IMG]
    [​IMG]
    [​IMG]

    But for now, anti-skid panels, this time made with rubber sheet!
    [​IMG]
    [​IMG]

    Rubber deforms during cutting, so Leo had to find matching pairs to glue on each section of track with epoxy......... Puzzle time!
    [​IMG]

    An army of... tracks?!:eek:
    [​IMG]

    Attaching the teeth, yes this is copper wire.
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Finally......
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    Test run, the first two cycles proved to be a bit rusty, but after that things begin to run smoothly. --Can run over cigarette boxes and TV remote!!!!!!
  17. Nemesis7485

    Nemesis7485 Member

    Joined:
    Aug 13, 2007
    Messages:
    123
    Likes Received:
    0
    Holy moly! Nice work. Spending a month on the tracks must have felt like pulling teeth.
  18. cgutzmer

    cgutzmer Guest

    Any idea what glue he used to attach that wire to the paper? Still a sore spot for me :)
    Chris
  19. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    I'm not really sure about that Chris, Leo didn't mention what he used... but I think that two-part epoxy is more than sufficient anyway...

    A shot of some RC equipment, those are for 1/16 tanks, so many of them won't fit... Some serious scratchbuilding ahead...
    [​IMG]
    [​IMG]

    --Another bolt out of the blue, with the barrel attached, the launcher's range drops sharply down to a mere 5 metres... Well still impressive, but Leo wasn't impressed. It's back to the drawing board >_<
    [​IMG]

    While coming up (or, trying to come up, at least) with a solution, Leo went on to work on the light system.

    Hi-intensity LED
    [​IMG]
    [​IMG]

    Aluminium foil
    [​IMG]

    Black acrylic paint on the inside, to prevent light leaking out
    [​IMG]
    [​IMG]
    [​IMG]

    Transparent cover
    [​IMG]
    [​IMG]
    [​IMG]

    ...Lights, camera, action! A mere 3 volts gives an extremely bright light...
    [​IMG]
    [​IMG]
  20. Lex

    Lex Dollmaker

    Joined:
    Dec 1, 2006
    Messages:
    1,930
    Likes Received:
    0
    A small machine gun... able to rotate in 2 ways! But sorry no BB for this one... sign1
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]


    Simpler lights at front:
    [​IMG]

    ...But the back lights really takes the cake... The LED's needed to be trimmed to fit.
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    ...It works!
    [​IMG]
    [​IMG]
    [​IMG]

    Now comes the smoke generator, pump is too big, so Leo had to replace it with a small fan... Let's leave that till later
    [​IMG]
    [​IMG]