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View Full Version : Hexapods: Lynxmotion Phoenix vs. Micromagic



THEkorean
04-16-2009, 04:32 AM
Hi everyone, I've been lurking these forums the past two days and finally decided to register to ask a few questions. First a little about me, Im a first year electrical engineering & computer science student at UC Berkeley and i recently fell in love with the hexapod while watching some youtube videos. I've been considering building one from the kit and was wondering which one you guys would recommend.

Some things that I want out of my hexapod:
- relatively quick (movement wise)
- expandability (secifically, what is the range of the logic boards, in terms of what they can and cannot do.)
- ease of use (i.e. quanity and quality of documentation/user base, how easy is it to program?)

Also, what kind of payload can i expect from these babies? Im not expecting too much, but i would like to make small additions here and there, maybe a small webcam or sensor turret sometime in the future.

I also understand that the MSR dosnt come with wireless controller, how hard/expensive would it be to program some kind of wireless controller for it?

Sorry for all the questions but im really anxious to start this project :P

darkback2
04-16-2009, 12:12 PM
Welcome to the forum.

Ok...so your looking to choose a hexapod...and your tossing up either the micro magic, or the lynxmotion...and by lynxmotion I believe you mean the phoenix? (sp).

Your looking for
- speed
- expandability
- ease of use.

So lets start with the first two. Speed will not be so much a function of the difference in design of either robot, as much as the class of servo motor that you use. Same can be said for payload. Stronger servos can carry more weight than weeker ones. That and given the desing of both of these bots, I think you may be hard pressed to cram much more into them...though you could probably fit some sensors and such on either.

Another option that accells in the payload / expandability department is the crust crawler HDATS (http://www.crustcrawler.com/products/hexcrawler_hdats.php?prod=4). This is a huge hexapod...that has plenty of payload capability due to a levered leg design.

As for ease of use...I would argue that that is more a matter of your own level of skill level, coupled with the way you do things. as for the micro magic hex...it hasn't been out as long, so the user base will be inherently smaller...

I would look at the control systems for each robot, and see which is more well documented.

Also...what is your experience level...

And finally...choosing a robotic platform is a largely gut based decision...so go with what you like the best.

DB

DresnerRobotics
04-16-2009, 01:01 PM
Hi everyone, I've been lurking these forums the past two days and finally decided to register to ask a few questions. First a little about me, Im a first year electrical engineering & computer science student at UC Berkeley and i recently fell in love with the hexapod while watching some youtube videos. I've been considering building one from the kit and was wondering which one you guys would recommend.

Some things that I want out of my hexapod:
- relatively quick (movement wise)
- expandability (secifically, what is the range of the logic boards, in terms of what they can and cannot do.)
- ease of use (i.e. quanity and quality of documentation/user base, how easy is it to program?)

Also, what kind of payload can i expect from these babies? Im not expecting too much, but i would like to make small additions here and there, maybe a small webcam or sensor turret sometime in the future.

I also understand that the MSR dosnt come with wireless controller, how hard/expensive would it be to program some kind of wireless controller for it?

Sorry for all the questions but im really anxious to start this project :P

I get this question a lot on the phones, so I'll try to relay what I tell most people about the difference between the two.

More than anything, its the electronics that make the difference.

The Phoenix is great for a starter kit if you're just getting into Hexapods and want something that is going to work out of the box. It has a Basic Atom Pro and SSC-32 servo controller combo for the 'brains'. There is some room for expansion on the Basic Atom Pro as the software doesn't take up all of your available resources, however you'll have to get quite familiar with how the program works to modify it. It's walking gait generation is integral in the main onboard controller.

The MicroMagic Systems hexapod uses the HexEngine, which is an onboard dedicated microcontroller dedicated towards generating IK walking gaits. You would need to add an additional microcontroller or wireless solution onboard to issue the HexEngine commands. The benefit here is that you can pick the controller (wireless or onboard) of your choice, program in whatever language you want, and not have to worry about learning the code onboard the HexEngine (like you would have to do with the Phoenix) as you can just issue it simple commands like "Walk forward" and it will take care of all of the servo movements for you. Adding either a wireless solution or an onboard micro is as complicated or simple as you want, a Bluesmirf is a nearly transparent wireless connection to your PC and pretty simple to interface with.

Payload is about the same on either, you can certainly add additional sensors, webcam, etc... but something like a Netbook would seriously be stretching it.

Noodle
04-16-2009, 04:27 PM
Adding either a wireless solution or an onboard micro is as complicated or simple as you want, a Bluesmirf is a nearly transparent wireless connection to your PC and pretty simple to interface with.
Infact, the p.Brain-SMB has the pins to plug an ESD200 Bluetooth Module straight in without any modification.

THEkorean
04-17-2009, 06:11 AM
Thanks for all the responses, didnt think id get that many in such a short time. Upon research I found a bunch of videos of Zenta(?) testing his original phoenix and the legs were amazingly articulate (e.g. it could lift its body into several different heights, raise appendages high while keeping other ones planted, using front legs to knock down boxes, etc. etc.) whereas the MSR seems unable to do any more than just walk, is this a problem with the design of the bot, a problem with the logic board, or software or what?

It seems to me that physical design and specs (body, servos, etc,) are more or less the same for both bots, its just a matter of the electronics. What can you tell me about the built in language for the phoenix, vs. the language used to program the MSR in terms of 'powerfullness' (i.e. range of possibilities).

THEkorean
04-17-2009, 06:14 PM
Wow ok, so I just stumbled on Matt Denton's pending muBug and I'm pretty impressed (especially with the price). However the fact that its nowhere near as articulate (limb wise) as the phoenix is sort of a turn off, any idea why it seems to be lacking in that category?

Noodle
04-18-2009, 09:23 AM
I'm certain that when using the control applications for MSR, you can adjust certain parameters of the locomotion engine. According to the datasheet/config guide that Matt supplies, the following can be altered:
Maximum forward leg stroke (Walk)
MSS Maximum sideways leg stroke (Crab)
MTA Maximum turn angle (Turn)
LZR Landing Zone Radius
LLH Leg lift height (normal mode)
LLO Leg lift height (Off road mode)
DLT Default leg transition speed
DGD Default gait delay
ORG Off road gait enable

These ultimately alter the 'natural' look of if it as well as efficiency amongst other variables.
Compare these two videos here & here and notice the difference in the fluidity, just by changing the leg transition speed.

Or you could be adventurous and develop your own engine :)

tom_chang79
05-27-2009, 09:46 AM
One question that should always pop up when getting into this hobby is are you a DIY (do-it-yourself) kinda of a person, or do you like canned moves to learn from?

I'm a DIY kinda guy, so I originally bought myself a Lynxmotion CH3-R (still probably the sexiest, most expandable platform, very roomy, and the symmetry itself is the pleasing part) then migrated to the LM's Phoenix because of aesthetics.

I never bothered to buy a controller for the CH3-R since I wanted my own inverse-kinematic engine that I have full control over (the one that is available on LM's site is very well-coded, but hard for me to understand since I didn't author it).

MicroMagic's came along later (in production, Matt from Micromagic had the hexapod before anyone else, it just wasn't available to the mass, it was more of his curiousity/hobby/prop). I have to say that I really like Matt's design.

The MCU seems to be much more powerful, the mechanical design is more aesthetically pleasing.

However, I'm not sure if I would've bought that kit, since $$$ was also a concern for me, the big reason I was able to jump to the Phoenix is because many of the stuff from my CH3-R transferred over...

It's a hard decision, I realized my $0.02 didn't accomplish anything. Both LM's and Micromagic's hexapod is RTW (ready to walk) out of the box (with the proper accessories/peripherals). It's a matter of adding up cost and ULTIMATELY going with your heart! If you argue with your heart, you will keep buying and buying until your heart finally shuts up and lets you sleep!

;)