Project Second Amendment – Quad Mech

[Upgrayd]

Second Amendment – Quad Mech

Hey everyone Upgrayd here. I have been a lurker for a while now and just recently got the urge to jump in and start my own project. I figured I would share my progress with you all as I go along.

Progress so far:

6/25/09

My leg part order arrives from UPS.

After much contemplation with the construction of my robot’s legs I decided the Lynxmotion SES parts were the best starting point. I have the ability to manufacture similar parts but the time/cost of doing so was not appealing.

I also went ahead and ordered the Lynxmotion SSC-32 servo controller. Serial commands are easy enough to program in visual studio so it will be a great way to get the legs moving in short order.



6/26/09

I spend the afternoon designing and machining matching linkages to the SES kit.



A few hours with the screwdriver and the 4 legs are together.

1 complete leg assembly:



4 assembled legs:



6/27/09

Not much going on this weekend so I get to spend the majority of the day working down in the shop!

For today the plan is to design and machine a few parts of the body support for the legs.

Here is a shot of the CAD design and one of the finished pieces:



Pair of legs:



All 4 legs:



Its still early so I get to work on the outside leg supports...

Machined and installed:



Both sides and messing around with the servo controller:

[Adrenalynn]

Hi There, UpGrayd - welcome to the forum!

Sorry you fell into the moderation queue [I was out all day]. Your post is visible now!

Looks like a good start!

[darkback2]

Hey Upgrayd,

I really like your leg design. Especially how you are coupling the shoulder lift servos using the SES hinges and the flat pieces you made for the ends.

I can't wait to see how you tie it all together, and the brackets you come up with for mounting the electronics and such.

What are your plans for feet? It is a quad, so that doesn't matter too much, but it almost looks like with another DOF or two per leg that thing could stand on its hind feet.

Seriously cool.

DB

[jes1510]

Awesome work! I'm impressed with your machine work, it's really clean. Definitely keep this thread updated. I want to see how this one turns out.

[Upgrayd]

Adrenalynn: No need to apologize... I'm patient Thank you for the welcome and kind words.

Darkback2: The SES parts sure are great. I had my doubts when I placed the order but once i got them in hand I knew it was the right choice. Great quality, lightweight and spot on dimensions.

For feet I am on the lookout for some kind of rubber ball about 1inch in diameter. The plan is to cut them in half, drill out the center and insert a section of threaded rod for mounting.


Updates...

6/30/09

Decided to play around with some servo control today.

I cut two pieces of scrap wood and used some clamps to temp hold the two sides of the mech together.



To command the servos I am building a C# windows application in visual studio.

I was able to get each servo moving into position individually but started to run into trouble when trying to command multiple servos at the same time. Not sure where the issue is but ill keep at it.

I have also realized my initial post was a little bit sparse on information. Ill edit it sometime soon to include things like project goals, materials list and design ideas.

[mannyr7]

I see you're using the SSC32 jumpered to VS==VL. Moving that many servos at once, will most likely reset the board. Try unjumpering and running a separate 9v supply for the logic and/or upping the current supply to the servos. Upon closer inspection, I noticed your SSC-32 with the 9V clip going into the VS1 terminals. This should be going to the center terminals.

[Upgrayd]

I went ahead and update the first post with some project goals...
I hope to also keep a running list on all materials and parts purchased and plan to release CAD drawings of all parts I manufacture.

jes1510: Thanks! Ill try to update this thread as I work. It will help keep me motivated.

mannyr7: Yup, I am positive its a power issue. The SSC-32 must have been resetting itself. Ill grab some 9 volt batteries on the way home this afternoon to separate the logic and servo power and give it another shot.

[Adrenalynn]

You shouldn't be running the servo power for that many servos through the regulator at all. Nor a 9v battery (which will just heat up and supply too much voltage to your servos).

You need a decent 6v battery or a good high current 6v supply to run the servos.

[Adrenalynn]

And before you try and blow fuses - that BK Precision that you have in the background there shouldn't be running more than ~5 or so of those 645's. You really need something that'll give you ~10A or more.

[Upgrayd]

The 9 volts are for the logic. And I said ill get a few because knowing me ill be staying up late playing around, get myself tired and end up going to bed without disconnecting. So ill need a few!

That BK power supply is just my little guy. Not sure why I had it out. Ill be powering it all with my 20A supply.