Basic clawbot with a six bar lift - from Starter kit

We decided to take the basic clawbot, that is built from the starter kit, to see if we had sufficient parts to make a working six bar lift. Here is a video of the end product, there are also a couple of videos on the channel of versions that didn’t quite work - we offer these as an encouragement to those new to VEXIQ who want to take things a little further. The advantage of a six bar lift is that the claw remains horizontal as the object is lifted rather than tilting with the robot arm as it raises - as with the basic clawbot. You can see from the early versions it’s important to move the weight to make the bot more stable, although this asks the question of where to mount the brain and battery. Have a go, it’s a good challenge.

Unfortunately the link(s) didn’t made it through the forum…
(edit) Ah - it’s here now …

I love this and your eight bar lift. Could you put this in an LCad file?

Tim, we had a ton of problems trying to make the 6 bar, pins just kept coming off, what did you used to connect the pieces of the 6 bar?

Kaverman, I haven’t had a chance to make a six bar lift. The closest that I have come is my scissors lift, which didn’t perform well with any weight on it. If I’m a betting man, (which I’m not BTW) I would say that a lot of the pins were either 1X2’s or 2X2’s with some 1X1’s thrown in. On my scissors lift I did not have any separation of beams as there wasn’t a lot of lateral movement. When building the part that comes from the 60 tooth gear, it looks as thought the bars are placed on each side of the gear and are held in place on the gear with 1X2’s.

Try using the metal shafts as pins. You will check that the rubber washers are not slipping off periodically, but overall they will hold a lot better.

Wow, jrp62!! I hadn’t even thought about using the metal shafts for pins. What a great idea.

Yeah, we tried the metal shafts… but we didn’t had enough of them :frowning:

We tend to use NEW small gears instead of rubber washers… we find that they don’t sleep as often as the rubber unless you take them out and in several times and they loose their grip, but the same also hapens to the rubber washers.

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That pretty well makes a case for lots of spare parts… LoL.

Hi, the 8 bar lift is held together with just plastic pins. what we found, and you will notice from the videos of the first two 6 bar lifts on the youtube channel and the last one (and of the 8 bar), is that we doubled up the beams on 3 of the ‘bars’. This gave the lift the extra strength it needed to hold itself together as it lifted the object ball. You can do the 8 bar with just the bits on the starter kit!

We have not had time to do a CAD of the lift yet, but will try to soon.

There is also some information about the 6 bar lift in the VEX forum.

Doubled up the beams… that could work.

I’m not sure if it is cause our kit was one of the first ones out… but pins don’t work out so well for us,

We have heard a lot of feedback from users that the red pins are “too weak” in that they are pulled out too easily, so four-bar and six-bar linkages were difficult to build without shafts because the pins would pop out.

As part of the new product announcement at VEX Worlds, we have strengthened the 1x1, 1x2, and 2x2 Connector Pins so that they now have about double the holding force. The rotational friction on the pins is unchanged, but the pins now resist being pulled out more.

The new pins work much better in four-bar and six-bar linkages. These new, stronger pins will now be blue in the VEX IQ Base Sets, and will also be available in the red, orange, yellow, green, purple, pink, and black Connector Pin add-on kits this summer.


  • Art

That will be a huge improvement for all types of connections. Will need to try them out before being convinced that they will hold up in a six-bar, but looking forward to trying.

BTW, when will the new kits be available? We will be adding a few more teams at our school, they will all be buying kits, and will want to get the latest and greatest.

Great job! We did a prototype ourselves. I’ll post ours when we are back on Monday.

I have had some applications of the red pins not holding as well as I would like, but for the most part they have been tough enough to hold most anything. I have had motors that have pulled out of their connections. I have also seen some applications where it looked like they had applied a rubber band to keep the motor connected. Looking forward to the new pins this summer!! (Save me a couple of sets… LoL.)