I don’t know if I am posting this thread in the right section, but I want to introduce myself to you all.
My name is Lars, and I’m from Holland. I am 24 years old and I am a newbie in this section of technology, but I am very interesting in hexapod robotics!
First I want to say that my English language is not so good, but I’ll do my best to make it readable for you all…
Normally I am busy with radio control models, like 1:6 cars and helicopters. It interests me a lot also, so I am working with servo’s for a long time and I think I can say that I am advanced in using servo’s.
I have seen a lot of movies on the internet about robots and I was getting interested in your hobby. I have searched a lot on google on names and products, so I found this forum but also Trossen and the hexapod forum, and now I am here.
I am very interested in the Hexapod Phoenix that is on the market. Maybe soon I want to buy an build it, but I have one problem. The problem is, that I’m not so specialized with computers…
So maybe I want to make a RC controlled Hexapod Phoenix.
Do you think this is possible??
Welcome to this community! It’s always good to see some more dutch guys coming to this forum.
As for your question, a RC car or helicopter got about 6 (?) servos that all do there own job. A single servo for steering, a single servo for the throttle, etc. A hexapod like the phoenix uses 18 servos. They all need to work together to make it walk and move the way you want it. This makes it impossible to drive all servos directly with a RC remote like with the car or heli. Instead of driving the servos directly they are controlled by a little brain and servo driver board. The brain will do all the calculations like inverse kinematics to make the hex walk if the joystick from the remote is pushed forward.
The phoenix will come with a good tutorial that explains how to build and program it. There’s a lot of information around here. This makes it suitable for both starters and experts. I have to admit that a hexapod isn’t the easiest platform to start with but… well… my first bot was a hex
You might want to start with a BRAT to learn the programming side of things. The brat uses 6 servos which makes learning to program in Mbasic a litte easier.
To make things even easier you may want to start with a 4WD Rover. The motor controller works the same as and RC car speed controller. Then you could add 2 more servos for pan or pan/tilt for other sensors. Controlling a rover with a single IR or Ultrasonic ranger on a panning head to do obstical avoidance is a very good first step. Then you can move to something like the X-Rover here: viewtopic.php?f=9&t=5580
Xan, first thnx for your answer. It helps me a lot because I want to learn a lot about robotics, and specially about hexabods, because I like them most.
Am I right that you mean, that the Phoenix is very good compatible to use a RC remote control? Because I don’t understand that so good. Maybe you can explain it a little more? Why is the Phoenix more compatible than others?
If I buy a robot, than it’s definitely a hex, and possible a Phoenix because this one is very nice in my opinion.
If I buy a kit, what is necessary to buy more, to complete the kit? I already have a 8-ch remote control.
I thought I read a topic of Zenta. He has done this Phoenix with Rc remote before, I thought. Am I right about this?
@ sn96 and fedasiuk, thnx for your reply, but right now only a hexabod has my interest. Sorry about that, but I can learn a lot, and I want this to! So many thnx for your advise.
First I want to say that I do agree with both Mike and Mark. Starting off with a Brat or Rover will be much easier. Starting with a Hexapod can be pretty rough since you start at pretty high level. Just want this to say so you can’t tell me I didn’t warn yah
I’m sorry to say that you didn’t got my point in the previous post. I tried to explain that there was a big difference between controlling a car by RC or a hexapod by RC. Check these flow diagrams
Car:
RC remote
|
\/
RC Receiver
|
\/
Single Servo (control steering OR throttle OR brake) so one channel on the remote = one servo in the car
another channel on the remote = a different servo in the car
Hexapod
RC remote
|
\/
RC Receiver
|
\/
Micro controller (This one needs to be programmed to receive data and put all servos in the correct angles for the movement)
|
\/
Servo driver (SSC, to update all 18 servos at once)
|
\/
18 Servos One channel on the remote = 18 servos in the hexapod.
Another channel on the remote = the same 18 servos doing something else
As you can see the Hexapod has got 2 additional steps in this flow chart. The servo driver (SSC) is an off the shelf product that doesn’t involve programming. The Microcontroller will contain a program to retrieve a command from the remote like walk forward. Do his logic like figure out what the next step in the gait may be. Then do inverse kinematics (IK) for all legs including the body. And send an update command to the servo driver (SSC). The update command will contain the angles for all 18 servos.
The code for the micro controller can be downloaded the tutorial site and will work directly in combination with a PS2 controller or the DIY RC. If you want to control in with another RC you will need to tweek the code to get it to work. This and most of the other changes will need a certain programming skill. Zenta did use his RC in combination with the Phoenix. Keep in mind that the send order can be different between different brands so it is possible that his code would not perform optimal with your remote.
Conclusion:
If you want to start simple and work your skill up along the way; try a brat or rover.
If you are ready for a big challenge; get yourself a hex. (and start with a PS2 remote first)
I started to answer this earlier but decided to let Xan answer first. I agree with him completely. I will reiterate if you want to build a Phoenix for PS2 control it’s really easy. Everything has been done for you, and all you need to do is follow the instructions. But converting to a stick radio control can be challenging.
Hi Xan,
I totally have your point now. Thnx for the good explanation! It helps me a lot for making my choise.
I think over a while I will buy myself a Phoenix, and than build it up slowly, so I can take my time for it, so I can learn everything.
Thnx also for the diagrams, it’s more clear now by me.
Maybe Zenta can help me with some explanation later to make fit a stick rc remote controller, like mine. But I think thats for later, because I think it’s a difficult challenge for me, like Robot dude says… I allready have download his “how to”, for fitting your rc remote control.
But, first learning and after that I will buy and build. But I am still in the learning mode, so I still want to learn more!
I am asking myself another question. If I will buy a complete Phoenix set, with servo’s in it. What do I more need to complete it? Do I need a motor, or does moves complete only on the servo’s?
Maybe some people have some more advise or some tips, please say them to me!! It helps me a lot!
The best thing to do is to get a full Phoenix kit. You can find it here. The kit includes all parts including servos and electronics needed to get it up and running.
There are two additional things you need to get:
A PC with an onboard RS232 communication port. If your pc doesn’t have a build in RS232 port you want to get yourself one of these. Most of the USB to RS232 converters don’t work pretty well for programming. The one in the link does. 8)
A good battery to power the servos. I think you’ve got some knowledge about batterypacks since you are used to RC toys. The servos for the phoenix run on 6V. This 6V 2800mAh Ni-MH battery pack will fit and will do the job. Personally I prefer to have some more power to get longer runtimes. Both Zenta and I are running on Li-Po batteries. They are a bit more expensive and dangerous but will give more run time. Just search on the forum for lipo (or ‘beefy’ ) to find the topics.
I hope this helps.
Xan
PS. Jim, the “includes†part from the given phoenix link doesn’t include the ps2 remote itself. The remote is noticed in the description. Can you check this?
Is the phoenix kit shipped with 475 or 485 since the 485 have a different housing?
I think you would have a lot of fun with the phoenix kit. I personally don’t have one as I already have a CHR-3 which is also a lot of fun. One day maybe… ( I could buy the body and all 485s and swap servos with CHR…,) But back on subject.
I think the kit does not include the PS2 remote, at least looking at the product page I see:
I need to look up to see who has the most beefy lipo these days . So far I have done fine with standard NIMH battery packs, as I spend more time tinkering and less time actually running the robot, but a big lipo would be great. But every time I think about trying one, I see a new video up on youtube or the like, such as: video.google.com/videoplay?docid=-7999636960714830130#docid=1184619833124419881
The new phoenix code from Xan also has a version that uses the DIY RC remote for control. You can find more information about this remote in the thread: lynxmotion.net/viewtopic.php?f=21&t=4399. The basics for using any of the RC controllers will be the same. You will need cables to connect all of the channels from the receiver to the Atom Pro. The code in the RC version of the phoenix reads in the pulses from your remote and basically fills in an array with the pulse widths (probably centering on 1500) for each of the channels that it receives. As your remote is probably different and does not have the same 7 channels of data, you will then need to modify the remote code to the specifics of your remote. There are a few of us who have done this so feel free to ask questions.
The Phoenix comes highly recommended! I’m sure you’ll have a lot of fun and opportunities to learn while building, programming and running it.
The setup is complex, but not hard. Pay close attention to get all of your servos accurately aligned to insure the best performance.
the PS2 is only $20, and the software is already set up for it, so I’d recommend starting with it. Adapting for your specific R/C might take a little work. Best to postpone until you are a little more familiar with the Phoenix.
I have a DIY chassis and tibias, but I’m considering buying the Phoenix body and converting!
Hi Xan, now I am thinking to buy a kit with no servo’s in it and than buy digital servo’s in Holland. I can buy these with discount in a shop near to my place. But what servo’s are the best for this model? Is it much better to use digital servo’s for mine, in thaught that I want to use RC remote later?
If I want to buy the kit in the following link trossenrobotics.com/store/p/5937-Phoenix-Hexapod-Comprehensive-Kit-No-Servo-Version.aspx, is this far so complete as a normal kit with servo’s?
Hi Alan, thnx for replying! I think I will buy ps2 controller with it and later upgrade is to RC controller. I think a Phoenix will give me a lot of fun! :mrgreen:
You have to be really careful about picking out your servos. There already have been a lot of discussions on this forum about where to get the best servos for your money. If you take some time searching trough the forum you will see that all cheap servos will end up burned pretty quick. So one big advice, get yourself some good servos and don’t waist any money on cheap ones because you will end up buying the expensive ones after all.
The phoenix is a very elegant design but it comes with a down side. The femur is only supported by the servos axis. This is why you want to have some good strong servos with metal gears in there. That’s why the 645’s are recommended.
I looked at different sites for servos in the Netherlands when I started robotics. But I couldn’t find a better price/quality servo then they are offering in the US. That’s why I ended up importing a set of Hitec servos from the US.
I am new to the Forum so thought I should say hello!This forums looks like its full of good info, I'll be visiting here often.Nice place to study and related topic discussion.Hope to find some new friends on here to chat on some important and informative topics.I hope that we will have healthy discussion and latest information sharing regarding to related topics.
I allready have download his “how to”, for fitting your rc remote control. 
) to find the topics.
as I already have a CHR-3 which is also a lot of fun. One day maybe… ( I could buy the body and all 485s and swap servos with CHR…,) But back on subject.