44 replies to this topic

[Firky]

The mans a genius. I like this I'm glad I asked now :)

Thanks

Firky

[freggel]

.

Edited by freggel, 22 October 2012 - 08:30 PM.

[Carsten Svendsen]

Firky, on 22 September 2012 - 03:03 PM, said:

Sadly I don't have enough parts today to try the offsetting.

Lol what?

Zblj, on 22 September 2012 - 03:28 PM, said:

Guys, do it like this:

*snip*

Also its a higher gear ratio this way.

Now that's genius, I've never worked with gears that aren't aligned along a 90° axis. Nice

[Firky]

Carsten Svendsen, on 22 September 2012 - 03:58 PM, said:

Lol what?

Yh erm. My lego collection went from thousands of pieces to about 100 pieces.

Its on the up again now tho.

[Paul P]

Zblj, on 22 September 2012 - 03:28 PM, said:

Guys, do it like this:



Also its a higher gear ratio this way.

Hi zblj
This is looking good for a robot arm wrist joint, the 8 tooth pinion even fitted first time in LDD. I hope you do not mind I have added a possible up, down to the wrist. No linkage yet to opperate.

Attached Files

•  Wrist.lxf   11.57K   24 downloads

[allanp]

The 8t to 28t gear combination I found to be very useful when driving the old 28t differencials.

[Firky]

All designes are welcome. I find that often my ideas need a bit of a push or I make things far to complicated and miss the obvious. I've never worked with 28 tooth before I didn't even see that lego turntable in LDD before I'm going to work on a smaller wrist design than I've used before trying to keep the weight down.

If you look on youtube for "firky2010" you will see my designs for a robotic arm.

[Firky]

Here is a quick mock up of my current goal for the wrist. I used a similar set up with the larger turntables. But this time I'm trying to keep weight down and would like to put the motors in the forearm. So I need to route all drives from the wrist to the forearm

The next challenge will be getting the drive for the grab out of one side and the drive for the rotation out of the other.

 mini Wrist idea.lxf   10.26K   21 downloads

[Firky]

Here is a video of the same design but fitted with a motor to reduce the amount of drives that need to be routed to the forearm. its by no means the final design but its a rough idea of what I'm trying to get to.

You tube vid.

Thanks

Firky

[Alasdair Ryan]

Looks good.

Edited by Alasdair Ryan, 23 September 2012 - 03:11 PM.

[DLuders]

@ firky:  Do you have all of the necessary parts to build it in real life?

[Firky]

@ DLuders thanks for embedding the vid. I couldnt get it to work.   Sadly not at the moment I will have order most of the parts in the video. I was also thinking about getting a L motor instead of the M motor. as it has far more fixing holes. also the 24 tooth black gear will be changed for a clutch gear.


I've also attached the design to this post.

Attached Files

•  mini Wrist idea 2.lxf   18.36K   16 downloads

[Alasdair Ryan]

I would recommend brickshopglobal for parts.Thats were I like to order from.

[Carsten Svendsen]

Alasdair Ryan, on 23 September 2012 - 03:39 PM, said:

I would recommend brickshopglobal for parts.Thats were I like to order from.

I'd rather order parts where they're the cheapest

[Firky]

I use yellow farm bricks. It may not be the cheapest. But every thing is well packed and the delivery is fast.

[mescalinum]

I've done a similar design of spherical wrist, but using the big turntable as I don't own those small turntables (but I should definitely get some they look very useful!)



all the motor are attached outside the structure.
soon I will post some preliminary video of the whole 6 axis arm NXT controlled

[Firky]

Here is my previous design using the large turntables

[Firky]

So guys my Lego pieces arrived today.

So I build up what I designed in LDD









There isn't enough room to use the clutch gear as I had planned so I think I'm going to use direct drive from the motor ( I can only hope this does not destroy the grab ). Only draw back to this is that the actual motor blocked the centre holes of both mini turn tables making it much harder to route the rotational drive to the forearm.

Thanks

Firky

[Phoxtane]

Do you think you could whip up a .lxf file for these claw designs? They look extremely promising!

EDIT: I was able to reverse-engineer the third claw from the photos posted. Here's my mockup in LDD:



I colored the parts that wouldn't connect easily in bright colors. When assembling it in real life, all you have to do is connect those colors! I've included the original model and a design that I modified to attach an M-motor easily.

Download the .lxf here: https://dl.dropbox.c...irkygrabber.lxf [All credit goes to Firky for the original re-make!]

Edited by Phoxtane, 03 October 2012 - 06:18 AM.

[Firky]

@Phoxtane  Great job with LDD. I really need to learn how to use it. the mount for the M motor is good. But wouldn't suit the current needs when using a mini turn table.

Thanks

Firky