Knex Ball Machine Big Arm Lift




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Intro: Knex Ball Machine Big Arm Lift

This is a instructable on how to build a big arm lift. I based this idea on Shadowman39's Wipe Out lift element. This element is big, about 5 feet tall. It takes a lot of peices. But when its done, it's worth it. Good luck :)

Step 1: The Bottom Half of the Frame Part 1

This is the bottom half of the frame, were the ball will enter.

Step 2: The Bottome Half of the Frame Part 2

This is the other side. It should be the same height as the first side.

Step 3: The Half of the Frame Part 3

this is the last part of the bottom half. dont worry, the top half only has 2 parts.

Step 4: The Top Half of the Frame Part 1

This is the easier side of the top par to fthe frame.

Step 5: The Top Half of the Frame Part 2

This is were the ball will get  of. and you also have to make the other doo-hickey thingy in this part, the other photos show it. Then you connect them. sry for the confusion of the one connection, i forgot to take a photo of that connection.

Step 6: First Part of Motor and Gears

Due to the size, length, and weight, your going to want to slow your motor down a couple of times, as shown. This step does that. The red gears will conect later. connect it to the top of the base part 2

Step 7: Second Part of Motor and Gears

add the chain. it is excatly 75 links.

Step 8: The Big Arm, the Frame

The frame of the "piece de resistance," as well as the gears to get this behemoth movin'.

Step 9: The Big Arm, the Buckets

This part is finicky and tight, the hardest part to build.

Build 2!

Step 10: The Arc

this is were the ball will rest while it waits for the bucket to scoop it up.

Step 11: Putting It All Together

Now that you have built everything, let's put it all together!

Step 12: Congrats!

You have now completed the big arm lift. Due to complexity and prximity of peices, it may not work right away, and may involve some adjusting. I apalogise for this, but their is nothing that can be done. Anyway, this is my first instructable, please comment! ;)

Trouble shooting:
   1.  try adjusting the track that the ball is swept of form so that it in line with the buckets that grab it.
   2.  Try adjusting the yellow rods on the bucket. They should be at the point were the ball will not fall of intill it is almost completly veritcal.
    3.  if the arm looks crooked, check to see that all the connections are completly in and that all the 3-d connectors are completly snaped together
   4.  maybe the top is on backwards.

   5.  maybe the arm is going the wrong way. make sure that the arm is pushing the ball toward the high part of the arc.



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    32 Discussions


    7 years ago on Introduction

    ive finished making it
    i had to mod the bottom part a bit but then it was fine.
    the only problem was the ball receiver et the top which i'm still trying to modify so it catches the ball
    anyway 5*

    1 reply

    Reply 7 years ago on Introduction

    thanks :p ya, the ball receiver is definetly the most finicky part


    7 years ago on Step 2

    thank you for help. And i have to say your creation is amazing :-]

    1 reply

    Reply 7 years ago on Step 2

    thx, but the origianl idea is shadowmans39' s, i just improved it a bit. He featured in his wipe out ball machine


    8 years ago on Step 2

    How tall does the tower go on picture one.Can't really see how high it goes..
    please can you tell me :-]

    1 reply

    Reply 8 years ago on Step 2

    woah your right!, thats not very clear, my fault. sry :/
    Its the same height as the bottom of the frame part 1, its 4 grey rods, and then its got 4 green rodsat the top pointing inwars, just like on the top of the the base part 1.
    sry for the confusion :/
    if you have anymore questions, feel free to ask


    8 years ago on Introduction

    Yeah, my rennovated design did not work. I took apart the lift then used the structures to start building a ball machine but hten my relatives came to visit, and my mom made me move the ball machine to my basement, where i had to take it apart and rebuild it 'cause my basement ceiling is at least 2 and a half feet shoroter then where i was originally building it. I will post before and after pictures when i finally finish it, which won't be for a while, because I'm not allowed to play with k'nex until the end of the summer. I LOVE NACHOS!


    8 years ago on Introduction

    i changed your design a little bit

    1. i removed the turning thing that works by the gears being pulled by the chain and replaced it with a different one.
    2. My arm kept hitting the path where the ball came off at the top and kept swerving around the arc, not going straight, so i replaced the blue rods connecting the two sides of the arms with the shorter white rods and ajusted the part connecting it to the rod powered by the motor#.

    3.i also changed the device you used for carrying the ball ("the bucket") with a carrier from a different lift om instructables, found on the attached link.
    4. I changed the path the ball exits the lift from, lowering it a little and making it stick out, Using the same path to unload as the afore posted link on this comment.

    4. i am also building a chain lift inside the supports on one side and making a switch to alternate the balls going to each lift

    i might post instructables if I can find the time

    Otherwise, 5 STARS!! AWESOME!!

    4 replies

    8 years ago on Introduction

    I have build it and I love it! It is over 2 meters high. I made 4 arms instead of 2. Thanx for the idea


    8 years ago on Introduction

    on a contest i choosed that this is best lift for ball machine (chain could'nt be picked) and guess what... I WON MY ANSWER WAS BEST