Forum Index > Projects > Egg-Bot
 Custom electronics
 |  Printable Version
By: Anonymous: __monty__ () on Tuesday, March 22 2011 @ 10:27 AM PDT (Read 3099 times)  
Anonymous: __monty__

I have only recently found out about the eggbot and think it would be a great project.
However instead of buying a kit from EMSL I'd like to try and build it from scratch, mainly to see if I could pull of building a repstrap.

Since the plans are available the mechanical structure isn't really a challenge I assume.
The only thing I have mixed feelings about is the EBB. I would like to etch and solder my own pcb but it seems that the details needed for the board are too fine to do this.(And the board is two-sided?)

Which brings me to my question: Is it possible and/or easy to redesign the layout of the board?(I have no experience with eagle or designing pcb's.)
Additionally, I have two unipolar stepper motor's laying around which would be suited for the eggbot I believe. Would the electronics and/or software need a redesign to work with unipolar stepper's?

Thank you for your time, any comments are appreciated.





       
   
By: squall_line (offline) on Tuesday, March 22 2011 @ 10:52 AM PDT  
squall_line

Schematics, layout, Eagle files, firmware, etc are on the EiBotBoard website:

http://www.schmalzhaus.com/EBB/

Taking the design from dual-sided SMT to single-sided through-hole could be, um, interesting, to say the least. If nothing else, going from surface-mount to through-hole would increase the size fairly significantly. And if you want to take the time to learn to work with surface-mount tech, there are probably a number of MUCH simpler projects to start on.

Windell or one of the other members of the EggBot Design and Support team should be able to answer your questions about unipolar vs. bipolar steppers.


Forum Mad Scientist
Mad Scientist

Status: offline

Registered: 04/13/10
Posts: 96
Iowa, USA

Profile Email    
   
By: Windell (offline) on Tuesday, March 22 2011 @ 11:26 AM PDT  
Windell

if you want to take the time to learn to work with surface-mount tech, there are probably a number of MUCH simpler projects to start on.


Agreed. This is not a particularly simple circuit design, and some of the chips are QFN-- leadless little monsters that are very difficult to solder if you don't have the right equipment.

You can check the chip datasheets, but my impression is that you'll have significant work to do getting this to work with unipolar motors. The Eggbot system uses a bipolar motor with microstepping, where there are 16 steps per "motor step" -- 3200 steps per revolution.


Windell H. Oskay
drwho(at)evilmadscientist.com
http://www.evilmadscientist.com/

Forum Evil Scientist
Evil Scientist

Status: offline

Registered: 06/15/06
Posts: 1932
Sunnyvale, CA

Profile Email Website  
   
By: Anonymous: __monty__ () on Tuesday, March 22 2011 @ 12:15 PM PDT  
Anonymous: __monty__

What would be the easier thing to do, adapt the electronics and buy bipolar motors or begin from scratch, designing everything with through-hole components(or not).

The first option sounds very difficult, the second seems alot more interesting but at least as hard because I don't have any experience designing circuits. However what draws me towards trying to build an eggbot without a kit is the learning experience regarding circuit design.

I'm apparantly under the wrong impression, I thougth this would be a simple circuit as there's only 2 stepper's and a servo.

Is one of the above a feasible project or should look for something entirely different?





       
   
By: Windell (offline) on Tuesday, March 22 2011 @ 04:17 PM PDT  
Windell

What would be the easier thing to do, adapt the electronics and buy bipolar motors or begin from scratch, designing everything with through-hole components(or not).

Easier? Neither really... Just depends how you want to spend your many hours on this. Smile

Some unipolar motors can be driven as bipolar-- if there are 6 wires per motor, this is usually the case.

I'm apparantly under the wrong impression, I thougth this would be a simple circuit as there's only 2 stepper's and a servo.

"Only" two steppers: As in, four separate 16X microstepping bipolar current controllers, capable of driving 2A per winding. And, don't forget the whole USB interface thing.


Windell H. Oskay
drwho(at)evilmadscientist.com
http://www.evilmadscientist.com/

Forum Evil Scientist
Evil Scientist

Status: offline

Registered: 06/15/06
Posts: 1932
Sunnyvale, CA

Profile Email Website  
   
By: EmbeddedMan (offline) on Sunday, April 10 2011 @ 07:42 PM PDT  
EmbeddedMan

Also, I'm not aware of any nice 16x microstepping motor drivers (bi-polar or uni-polar) that are in a nice through hole package. Maybe there are some and I just haven't seen them - but anything that's actually available these days is going to be SMT.

The board is 2 sided. It is not extremely tight, as far as these things go, but it would be a substantial job to lay it out for a single sided board with jumpers. You could do it if you were pretty experienced in these things, I'm sure.

If you do want to try it, please feel free to contact me at my yahoo e-mail address and I can help you through it as best I can. If you're looking for a good project to learn SMT layout and Eagle PCB, then this is probably a pretty bad one as your first. :-)

*Brian


Forum Apprentice
Apprentice

Status: offline

Registered: 09/22/10
Posts: 7

Profile Email    
   
By: dnewman (offline) on Sunday, April 10 2011 @ 10:22 PM PDT  
dnewman

I'll take it that you don't recommend this as a wire-wrap project either Big Grin

(Do people still do much wire wrap these days? When I couldn't find
my tool a while back I was shocked to see them selling at mouser
and digikey for $43! And we're talking the little manual tool and not
a wire wrap gun. Needless to say, I looked harder for my tool and
eventually found it.)

Dan


Cow Canyon Saddle Clear Sky Chart


Forum Evil Scientist
Evil Scientist

Status: offline

Registered: 09/08/10
Posts: 149
Mt. Baldy,
California

Profile Email    
   



 All times are PDT. The time is now 06:09 AM.
Normal Topic Normal Topic
Locked Topic Locked Topic
Sticky Topic Sticky Topic
New Post New Post
Sticky Topic W/ New Post Sticky Topic W/ New Post
Locked Topic W/ New Post Locked Topic W/ New Post
View Anonymous Posts 
Able to Post 
Filtered HTML Allowed 
Censored Content 

Evil Mad Scientist Forum Archives — Read only!

Please visit our new forums for new discussions.


DIY Hardware for Electronic Art


The Original Egg-Bot Kit


Octolively
Interactive LED kits


Meggy Jr RGB
LED matrix game
development kit.


Business-card sized
AVR target boards


Peggy 2
LED Pegboard kits

My Account






Lost your password?