Lego to servos...

Zog · Post by **Zog** » Sat Sep 04, 2010 9:02 am

Hello all,

So i was wondering what would be the best way to secure a lego wheel to a servo and a lego 1x8 brick with the technic holes in to a servo? I have widened the holes so then they fit, the only problem is, they don't stay on! How can I secure them on so then they don't come off in battle?

George

joey_picus · Post by **joey_picus** » Sat Sep 04, 2010 9:19 am

The simple answer is glue or bolts

if you drill through the wheel and a servo horn and bolt the two together in at least two places, you should have a pretty secure connection - failing that, just do whatever you were doing before but use epoxy to hold the wheel in place.

Attaching a lego brick is trickier but you may be able to use some big washers to bolt it through the holes to a servo horn - Dave Lawrie might be able to advise as he's worked with lego more than I have.

Paddonjon · Post by **Paddonjon** » Sat Sep 04, 2010 9:30 am

i have tried this, and what i did was to get the X bar thing and drill a hole in the center to push the bar of your motor into then glue it, that way you can put any lego wheel on

Zog · Post by **Zog** » Sat Sep 04, 2010 10:45 am

Ok, I've used Loctite now to glue it on.

Next question: How do I get the wheel motors to work on one channel? (at the moment they only turn left/right, and not forward/reverse...)

My transmitter has reversing for all channels, and mixing for channels 1/2 and 2/4.

George

joey_picus · Post by **joey_picus** » Sat Sep 04, 2010 11:01 am

Try enabling mixing on whichever channels you use for drive, and then if it's still a bit strange play with servo reversing or switching the channels you have the servos plugged into until you get something that works?

Zog · Post by **Zog** » Sat Sep 04, 2010 11:40 am

If it's any help, the transmitter is the Hitec Laser 4.

Underneath the mixing switch, it has: "V-Tail" on the left, "Off" in the middle, and "Elevon" on the right.

It actually has reverse on 4 of the 5 channels.

I have servos in channels 1, 2 and 4.

Channels 1 and 2 are the main drive motors, and channel 4 is the weapon motor (which works a treat, dw)

George

Zog · Post by **Zog** » Sat Sep 04, 2010 12:50 pm

I've got it working now

It's a bit slow, but it works. And it has a great flipper.

Weight: 301g.

I know it's overweight, but isn't everyone's first ant?

George

joey_picus · Post by **joey_picus** » Sat Sep 04, 2010 1:21 pm

...301g?!

What on earth did you build it out of?

Zog · Post by **Zog** » Sat Sep 04, 2010 1:43 pm

1mm poly. THe flipping arm is made of lego.

The battery is quite heavy... Problem is, I don't know how to replace it... Any tips?

joey_picus · Post by **joey_picus** » Sat Sep 04, 2010 3:49 pm

It depends what battery you have at the moment

the obvious solution would be to move to a smaller NiMh pack or even LiPos with a regulator, but I suspect if your robot weighs 300g the battery can't be at fault for all that weight unless you've got a small lead acid battery inside there.