Older blog entries for slap.fish (starting at number 2)

1 Mar 2006 (updated 1 Mar 2006 at 11:09 UTC) »

I promised a more up to date picture of 48k - so:

latest pic

It's in a somewhat 'stripped' state at the moment - the arm base joint, batteries, and electronics housings are missing - but it shows the mechanical layout clearer.

There is very little in the way of actual control elements in place yet - but I thought people might appreciate seeing a bit more of what's involved in the actual mechanics, as this is an area often overlooked. I for one like to see how something works under the skin.. a robots 'bones' if you like - the hardware solution is just as interesting to me as the software.

a couple more, showing some details:

drivetrain suspension

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I will be remounting the arm base joint and batteries soon - and then onto connecting up the pneumatics.. then it'll be on it's wheels and under power for the first time sometime soon [rubs hands and laughs like Vincent Price].

Some background on 48k - here are a few pics showing a somewhat disjointed progression of the build:

http://homepage.ntlworld.com/retro.spect1/robot.JPG http://homepage.ntlworld.com/retro.spect1/rob1.jpg http://homepage.ntlworld.com/retro.spect1/rob2.jpg http://homepage.ntlworld.com/retro.spect1/rob6.jpg http://homepage.ntlworld.com/retro.spect1/rob7.jpg http://homepage.ntlworld.com/retro.spect1/rob8.jpg http://homepage.ntlworld.com/retro.spect1/rob9.JPG

You can see that early on, I'd planned on driving the wheels via differentials and a single motor - that was changed in favour of a gearhead motor per wheel, arranged to drive the wheels directly (via couplings). Most recently, I have altered the drive arrangements again to a belt system, which means the drive train now has some allowance for slip built it, and any shock torques are unlikely to damage the gearheads - an extra 2:1 was used as it was looking increasingly likely that climbing a 15 degree incline was going to be close to exceeding the motors capabilities.

Last night I had the first wheel under power, using the new layout, and it works great - another added benefit of belt drive is I can quickly disengage the tensioner, effectively disconnecting drive, and allowing a freewheel mode - which I'm sure will come in useful when it's finally out and about, and I need to tow it home on a rope - picking it up will not be an option!

Well, 'Hello World'... I've been regularly checking up on Robots net for a couple of years now - but have finally motivated myself into joining.

I am currently working on this:

http://homepage.ntlworld.com/retro.spect1/rob9.JPG

This picture is a little old now, and I will endevour to get something more up to date on my site soon.

It is (will be) an autonomous Rover - as you can see it is no small undertaking, and the project is in it's 3rd year, I will add it to the list of robots when I feel it qualifies - for now, I am still tinkering with the mechanics, and getting them just right, before I set it down and get out the way (it will be in excess of 100kgs when fully built).. a Rover shaped hole in the wall is a distinct possibility in the future - not to mention me running down the road frantically warning people out the way.

Excuse my irreverence.. it IS a serious project - I, however, am constrained otherwise as, being only a hobby - it is the only way to remain sane. How else does one keep smiling, night after night in the shed - setting titanium turnings alight and picking aluminium swarf from surprising places ?

By the way - the large assembly torward the front is the base joint for a substantial arm, which I have provisionally pegged at a 5kg payload, fully extended (approx 1 meter)

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