Hexapod Information Request

I am looking to develop an open source repraped Hexapod robot and would ask if anyone has spotted one on the net.

I don't feel like reinventing the wheel, so If there is any firmware available for the Arduino Mega or CAD models floating around could you post links here please.

Is there anyone here that would be willing to collaborate on the design or could share their knowledge please?



A couple of models I have found so far, but no links to hardware or firmware.

Hexapod CAD 1

Hexapod CAD

... maybe something here: [micromagicsystems.com]

Or here in the forum: [forums.reprap.org]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Having looked around a bit last night, it appears that probably the best and simplest solution for control board is the following item. Not too bad at £35. I think I should be able to add a bluetooth plug in module at a later date to go wireless.

Dagu Robot Controller

It includes simple connectors for upto 48 servos (I need about 18) and also has an arduino mega based chipset so I should be familiar with programming / modifying any sketches I find.

Just need to locate some firmware that controls the servos directly, rather than outputs through a serial connector to a servo board and the project should be on its legs (pun intended!)

Heres an image of the design progress so far.



More info on the Helium Frog website

You're likely to run into some serious problems hanging so much weight on the servo shafts. They aren't designed for a lot of torsional stress.

Typically robot designers will add a dummy shaft on the back of the servo so that the weight is evenly distributed and the servo only has to deal with rotation movement.

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Lem Fugitt
3D Printing Dreams
Robots Dreams
"The map is not the territory."

Yes I might double up on the Tibia and Femur joints. The Coxa joint has a 3mm bearing underneath, but there are many hexapods running about with this setup, in fact the majority of purchased kits of this size use a single sided servo design.

I have read that it depends on the servo type. As I am using low cost servos, this might be an issue. At first I will be running without onboard batteries, so the loading should be quite low.

AFAIK you need then (expensive) servos with all metal gears and axes ... best with ball bearings for the axes - the standard types won't last very long this way ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

The servos I have chosen are Hextronik HX5010, which do have double bearings. The recommended ones for hexapods seem to be Hitec HS-645MG but these retail at £21.99. They are metal gear type

The Hextronic are £7.49. I have only purchased 4 at the moment for some single leg trials. The HX5010 are high torque units so should be up to the job, but I want to confirm this first. As you can see the cost savings are enormous if you can use these (A Hexapod uses 18 servos). Even if I have problems I think a dual support design would be better than going for the Hitec units.

I found a nice site that gives a good specification comparison of many servos and the Hextronic seemed to be the best low cost option. I found a few hexapod designs on the net that do use these servos.

Servo Database