Let's Make Robots!

My first robot

Hi all,

First post.. first robot. :-)

 

I'm designing my own bot because I cant afford a Nao. I have a 3d printer which I'm slowly getting to grips, this is what I aim to print my bits out on. The bot is designed in sketchup. My idea so far is to print my bot and see what comes next. Installing a Arduino is looking likely with the basics like walk / turn / lie down etc.. coded into it, but with also a connection to the pc where a server type program will run to do most of the calculations. I'm a little stuck on the arms at the moment. Not too fussed if it can pick things up but if it could it would be a big bonus. I've also no idea on what sensors I have access too. All comments / recommendations / advice would be most welcome. Once designed I will release all the bits for others to print.. well thats if I get that far. Thanks Steve
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Now that you have a peice made, consider making a build page and filling it with pics!

ok done a little more :-)

 

Redesigned the lower part and I'm still waiting on my servos to come so I can design in the arms of the servo.. also did a little print on my printer.. there was an error in my design as I missed a corner out so the next one I print will have the indent in the foot. It's nearly all configured now mind :-)

more to come :-)

I've got some MG90S Tower pro servos coming.. cheapest with the highest torque I could find on ebay.. Paid £25 for 8 of them. Unsure if they will be suitable or not. Great info on the UBEC.. Just been on ebay and very cheap and I can just pipe the lipo straight into the servo board now :-) I tried to figure out the power usage on them but I'm lost with all that stuff. I've put the size of the battery i found on the back of my bot on sketchup and it looks just right, so I'm just going to go for that.

Redesigned my feet to slot the servo in.. and two screws.. Will see what this one prints out like :-)

I'll order a battery and UBEC now as they take weeks to come from China. :-(

 

Steve

 

 

First try to get an idea of the power consumption of your bot. A couple of mcus/nanos don't need much power, but your servos will. The regulator in the nano is not made to power things like servos, you need something much more powerful. Which servos will you be using? I use 2 cell 7,4V Lipo batteries to power servos,  fully charged they are 8,4V. That voltage is to high for the servos I use (MG995/MG996R), so I use an UBEC to drop the voltage to 5-6V. You find Lipos is all sorts of forms/sizes.  UBEC can be found cheaply on Ebay.

Been looking at batterys today.. I agree a decent one will defo be needed. 

I'm not so hot on electronics so unsure if the power regulator in the nano would take care of the drop down voltage or if I would need a seperated regulator. 

The battery I've been looking at are the ones they use in the AR Drones. It's an 11.1v it's slightly bigger than my body so it might have to be a back pack. They weigh about 110g so not that heavy really.

I'm hoping they will have enough power for 20 mins + activity

again any advice on this would be great :-)

Make sure you have room for a decent battery to power 12 servos.

Before I go much further I need to work out how I'm going to control it all and design enough room into the case !!.. 

So.. here is my idea so far........

1 x nano (slave) with a servo sheild for control of 12 servos.

1 x nano (master) with wifi shield (maybe yellowjacket) that also controls the nano servo

The master nano arduino will then have enough pins left for all the sensors

For now only a single nano will be used to testing :-)

 

Well that's the idea... comments ? advice ? lol I'm making it up as I go along.

 

Steve

Hi fella.. 

Errr.. not really thought about what I want him to do.. Walk around, thats about it for now lol. Once I have a working bot then I can start adding stuff I hope, but it will be just basic to start with. He will stand about 250mm with a head but I dont think there is anything stopping it being scaled up to support full size servos. 

Just getting him to walk / get up when knocked over and turning will be a battle I'm looking forward too. I'm printing the lower legs 100% plastic.. then the upper 50%.. decreasing the mass as I go up. This is to try and keep the COG as lower as possible and to try and give a bit of weight to the feet. I have thought about putting the batterys in the legs but will have to see how it goes first.

Just ordered some nice silver pla for my printer.. shame I didnt order the blue servo's, I ended up with black lol

anyway, should fnish the basic design this weekend so it's a waiting game then for the servo's.. I already have a arduino but will by a cheapo servo shield for ease.

more to come.. I hope !

Steve

Well its a very exciting project so keep us all posted. Also, this is pretty ambitious for a first bot, so dont be discouraged if tings dont turn out 100% as intended, but always feel free to come to LMR for support!

Is there any specific task this is supposed to complete? Either way, its a fun looking little guy!