Custom Lynx6 Questions + Stater Info on Bits and Bobs

Lynxmotion Robot Arms
1

Hi!

I’ve just joined and have quite a few questions. So please go easy on me!! Some of my questions may not fit in this section, but they all relate to my arm project. I plan make it over the summer.

  1. I wish to design + build a Robot Lynx6 Arm, but made from Aluminium sheet etc. I know I can order the kits etc., but I want it to be more of a challenge to desgin and build the same one from photos etc. I have my own CNC milling machine at home to cut the parts, so that is not a problem. If this is OK, I intend to copy the design, just to start me off, is that OK? I aim to make most of the “non electronics” harware myself. Pretty much all of it apart from the screws and the bearings and acorn nuts etc. I’ve ordered 1m of alluminium hex rod (1/4") to make my own swish looking posts and spacers!!! I have got a M3 taper and bottoming tap to cut the threads into it.

But as i live in the UK most of the stuff i want to buy, i can’t e.g. the SSC-32 etc.

  1. I am planning to use Hitec 475-HB servos, i’ve found a supplier in the UK, so there sorted. (I’m also using the 85 for the gripper)

But, in terms of controlling them, i want to use the SSC-32, I’m using a PC, so i was tempted to go for the Atom Bot Board, but that can wait for now. Can i use the PS2 controller plugged into my PC to control the arm i make? or does it have to go though the Bot Board? Does anyone have a guide for using it with the PC? I know i need a USB -> PS2 controller adpater.

So, do you think that my aim is realistic, i.e. start off basic and then possilby expand to the bot board later etc.? Also as delivery is a problem to the UK, are there any suppliers of the SSC-32 in the UK?

I don’t suppose any one has a parts list or diagrams etc. Please?

On the software side, how is the RIOS better than the sequencer, is it really worth getting both, or just one? To me, the RIOS sounds better from what i’m doing at the mo, but the sequencer sounds better for future projects with the ssc-32???advice plz!!!

Can I buy a downloadable copy (of RIOS)?

I’ve found this: active-robots.com/products/m … ervo.shtml
they sell the controller and the sequencer. As a starter package, if i ordered those two, my alluminium materials and the servos from servoshop.co.uk/ is there anything that is missing or am i being unealistic for a first go?

BTW: if anyone in the UK wants small things cnc cutting / 3d moddeling etc. I’ll be happy to cut them.

If you guys give my project the go-ahead, and you want me to, i’ll do a mini blog type thing from designing, through to machining and then to servos and electonics etc. i dunno, it could be useful to someone out there wanting to do the same?!?

So basically, what i’m after, are some pointers and tips as well as answers to my questions above on making a robot arm.

Many Thanks in Advance!

Dan :slight_smile:

2

Well, I can answer a few of your questions.

First off, the RIOS is definitely the way to go if you have an arm.

With RIOS, all you have to worry about is where the end effector (gripper) needs to be, and the software will take care of all of the rest.

With the sequencer, you have to painfully adjust each servo one at a time.

If you do plan to take appart your arm, later and build something else, I suppose that you might want to get the sequencer.

However, I’d buy the RIOS now, and the sequencer later, if you do change projects.

You’re missing batteries and a charger.
You could use a wall supply (or even regulate your computer’s supply) instead.

For those servos, you’ll need a 6V supply that can handle about 3 Amps.
Be sure to throw a fuse in, if you’re using a power supply, and not a battery.

I live in the US, so I can’t help you with the availability problems, and I don’t know enough about the PS2 controllers to help there, either.

3

While I don’t know much about arms or RIOS, I do know about getting bits in the UK. I’ve bought servos from servoshop before and would do so again - they arrive in a few days and postage was cheap.
Ordering from Lynxmotion was a bit more difficult because I didn’t want to use an electronic wire transfer. Instead I contacted all the of UK distributors to see who I could buy through. In the end I placed an order through Total Robots; they don’t have much Lynxmotion stuff in stock normally but they seem to order from them regularly and put my order in with theirs. It didn’t take long to arrive and everything was perfectly packaged.

As far as the PS2 controller goes, it depends what you want to do: if you want to connect the controller direct to your PC through USB, you will probably need to make a GUI, a program on the computer that interprets the signals, then sends serial commands to the SSC32. (Other people on this list have more experience with this, but I can’t remember names right now, sorry)
Alternatively ( + easier in my opinion), you can buy a cable from Lynxmotion that lets you plug the PS2 controller into the botboard. This can be used as an input in the program.
Both methods acheive the same thing in a similar way, but by connecting the controller directly to the botboard you eliminate the need for a computer to control the arm.
What are you trying to achieve with the arm? If you just want to experiment and play around with an arm, you are probably best off going with the botboard, as the price will be about the same. IIRC, there was a tutorial for a hexapod and arm with PS2 control - you might be able to take bits of the code from that to control the arm.
Dave

4

I found the tutorial I mentioned:
lynxmotion.com/images/html/build074.htm
but whilst looking I found this, which is definately more useful:
lynxmotion.com/images/html/build091.htm
Hope this helps
Dave

5

Thanks Nick, I didn’t realise about you only had to move the gripper, that could be really useful. I can’t find a supplier for the RIOS, does anyone know one in the UK, if not i might try Daves advice and ask Total Robots.

I know i’m venturing into another topic, but it relates to the arm (just)!

So, would you all recomend going for a stamp and bot board with the ssc-32? I’m a bit confused when it comes to the BASIC chips. i.e. what is the difference (practically) in all 4 different models. Is it a different language between the stamp and the stamp 2 etc.? If i wanted to make a program, say, design the paths and sequence etc. in RIOS, could i then export them to the STAMP or would i have to write the code in a different language for the STAMP?

About the PSU, so would a 3A 6V get about 8 servos running smooth and dandy? Roughly, how much current does a 475HB use (max), as on the SSC-32 there is something for 2 sep. PSU’s for 1-16 and then 17-32 or something??? Or is 3 amps suitable for 32 servos (if i had the money :wink: ) - i’m probably only going to use 7-8 at the mo, but i was just thinking for expansion.

So, apart from using the PS2 controller, what are the advantages from using a Bot Board and a STAMP? I know that you could use it without a PC on :slight_smile: but just for my use, is there going to be any other point?

Thanks Dave for your comments too! - I’ll give those guides a good read over later.

The main reason for me building the arm is basically a challenge. Most of it will be in the actual building, using it will be a side effect, if you know what i mean. i.e. i’m not building it to use for any particular task, when i would use it would be to mess about (show off!) with etc.

Just a last thought, about controlling the arm without a PS2 controller, but without a mouse and keyboard. I have a TV card for my Media Centre PC, but the remote with the card, can not control Media Centre itself, so i downloaded a program that interecepts the infrafred signals from the reciever and depending on what key is pressed on the remote, it will send set keys to the active window. Could i use the same program to control my arm, by sending the keys to RIOS software?? I think the program was called: HIP or something. But its compatable with loads of remote controls. It might be useful to someone?

Many, many thanks on your comments so far - my mind is whirling with info and plans!!!

Dan :slight_smile:

6

Unless Jim has some non-USA distributors RIOS is available solely through Lynxmotion.

I am fairly certain that Jim does ship his products worldwide so getting something to the UK shouldn’t be a hassle.

Somebody please correct me if any of that is wrong or misleading.

7

Hi!

Thanks very much, does anyone have answers to my other questions above?

Dan :slight_smile:

8

I’d definitely recommend the BotBoard and the SSC-32.

As to which microcontroller you pick, that’s largely up to you.

I believe that the Basic Atom is the way to go if you’re going to be controlling it with a PS2 controller.

The left vertical joystick signal can’t be interpretted properly by a Basic Stamp microcontroller, so you’d be at a loss of one joystick’s direction, if you went with a Stamp.

Yes, the languages between chip brands are different.
Although, there’s really only two main types:
C and Basic.
PIC’s use C and Stamps, Atoms, BasicXs, use Basic.

The “Basic clone” languages are very similar to each other.
Yes, actually, the language differs slightly between the Stamp and the Stamp2.
They’re different versions of “PBasic”.

I can’t remember what RIOS can export to.
:frowning:

Yep, that’d do, unless you stall out every single servo.
That’s where the fuse would come into play.

3A is probably not suitable for 32 servos.
I’d say that you could do about 16, without overdrawing it frequently.

Advantages of Botboard + microcontroller =
Autonomous behaviors (you won’t need to plug your bot into the computer to make it do things).
Large amount of I/O pins to read sensors.
Large amount of I/O pins to drive servos/motors.

Hm…
I don’t think that RIOS accepts custom key inputs.
What you really need is a GUI (Graphical User Interface).

I’d suggest buying yourself a copy of a high-functioning programming language (C++, C#, Java, Visual Basic 6, Visual Basic Express, etc.).
Personally, I’m fond of Visual Basic Express.NET, but I’m quite biased.
:stuck_out_tongue:

Anyhow, with those languages, you can create yourself just about any type of windows program.
The key and mouse interpretations that your talking about from another program are very simple to impliment in those higher languages.

9

Ahh… I forgot to mention servo draw values.

The amount of current (in Amperes) that a servo will draw at stall (tries to move, but isn’t strong enough to move it) can be multiple times greater the amount of current that it normally will draw.

Each servo type will differ between other types in the actual amount of stall current (a.k.a. peak current) and normal current (a.k.a. continuous current).

You’ll have to contact the maker (probably HiTec) of your servos to find out exactly what these values are.

If you’ve got reasonably efficient servos, you’re looking at about quarter of an amp each, at stall.
If you’ve got inexpensive (read: inefficient) or large servos, you might get around a half of an amp each, at stall.

I sort of lied about the 3A being able to do 16 servos well.
It could, most of the time, but I wouldn’t trust it.
With decent servos, you should only try using 3A on about 12 servos.

10

Oh Right!

Thanks very much. I think i know what i’m going to do now!
I’ve decided to go for:

1x SSC-32
1x RIOS
1x PS2 Controller with PS2->USB comverter
6x HiTec HS-475 HB Servo
1x HiTec 85 Micro Servo
Loads of aluminium fixings, fittings and plate etc.

I don’t really need automonous control (for now! :wink: ) i think sensors and stuff like that can come later etc.

My project is starting to come together now! I’ve got my 1/4" aluminium hex rod, my taps (M3), (for making the joints and spacers) i’ve already cut my aluminium plate for the base on my CNC, and the screws and dome nuts etc. are on order in the post. All i’ve got to do now, is finish designing the rest of it (i’ve done the base - on CAD with dimension etc.) then order the rest of the aluminium plate, then save up for the servos and ssc-32. then BUILD IT!!!

Should be a laugh!!

I think a nice brushed effect will look quite nice, maybe stick some blue leds in?? :slight_smile:

I’ll keep you updated.

Thanks for your help,

Dan :slight_smile:

11

Hi All!

I’ve been doing a slight bit of CAD for my aluminium Lynx 6, this is only the base. I know it should go in a new thread, but hey, others can read above etc.

There are various views, if you want to download the standard res pack you can do so here:

uk.geocities.com/danielbriggs@bt … ection.zip

The Hi-Res bitmaps can be obtained if you email or PM me. (If any of you feel the urge to see more :confused: ) :slight_smile:

So here they all are, let me know what you think!

http://uk.geocities.com/[email protected]/Images/isometric.jpg

http://uk.geocities.com/[email protected]/Images/plan.jpg

http://uk.geocities.com/[email protected]/Images/trimetric.jpg

http://uk.geocities.com/[email protected]/Images/view1.jpg

http://uk.geocities.com/[email protected]/Images/view2.jpg

http://uk.geocities.com/[email protected]/Images/view3.jpg

http://uk.geocities.com/[email protected]/Images/view4.jpg

http://uk.geocities.com/[email protected]/Images/wireframe1.jpg

http://uk.geocities.com/[email protected]/Images/wireframe2.jpg

That’s all for now!

Dan :slight_smile:

12

One question…
What is it?

It sort of looks like a rotating base for the arm.

Is that so?

13

Hi!

Yes i forgot to mention, it is the rotating base! I’m gonna build the whole lynx 6 in cad first. Then make it out of aluminium!

What do you all think?

Dan :slight_smile:

14

The parts look to be 0.125" thick in your renderings. If you continue to use this thick material for the arm you will be dissapointed as the servos will not be able to control the added weight…

15

Hi!

Thanks!

The base is going to be made from the following:

the bottom of the base - 6mm aluminium plate
the top of the base - 4mm plate
the rotating base plate - 3mm aluminium plate

and all the other bits for the shoulder and elbow and gripper either 1.5mm or 2mm.

Should i go for 1.5 to make it lighter, or 2.0mm for strength?

I’ve alread made all of the hex spacers from aluminium 1/4" hex rod, and tapped them with an M3 thread! I’ve also bought the socket M3 button head screws and dome nuts (acorn). I intend to buy the SSc-32 and the servos. But intend to make EVERYTHING else from raw materials i.e. sheet metal and bar etc.

Let me know what you think!

Dan :slight_smile:

16

I’d say to go with the 1.5 mm.
That’s closer to the SES bracket thickness.

The bends that you’ll be putting in the upper-arm brackets should negate any small flimsibility (I just made that one up) issues.

Plus, on your “ASB-04” brackets (the ones that directly surround the servo), they’ll have the support of the servo’s casing to bolster it.

With servo robotics, it’s almost always better to err on the side of lightness, when you feesably can.

17

Thanks for your advice!

I think i will go for the 1.5mm then, i think that your right (2mm is a bit too thick!)
I’ll keep you posted on my progress

Dan :slight_smile:

18

I say go 1.5mm also, I would also recomend cutouts to remove material. It makes it look better and it reduces weight. Here is an example of what I am talking about:

http://img89.imageshack.us/img89/3765/armplate6bl.gif

This is just an example. You can add cutouts how ever you want, just make sure you don’t make any weak areas where there might be heavy loads or stress areas. You have to pay attention to the material, and not the holes. Another benefit of holes is it allows you more options for cable routing also.