Let's Make Robots!

My CNC Senior Project


This is a secondary documentation page for my Senior Project for highschool, I'm building a cnc router with a budget of $700 bucks.

Basically, the plan is to build my router (codename Soundwave, like the decepticon transformer :P) and upon completion, use it to produce all of the circuitry, brackets and axis for a seconed router to donate to the technology department of my school. This project will take place over the course of this school year, and will be completed in Febuary (I hope).

I have more info here, on the projects actual webpage (that one will be graded)

 

PART ONE: MY MACHINE

So far I have the control box built. I have 3 ProboStep Unipolar stepper motor drivers, a parallel port breakout board and a Wier HS100 24 volt PSU I had lying around.

   

   Here you can see the finished heatsinking done with a 1/16" aluminum angle with fins cut into it.

 

 

More updates soon as mechanical components come in

 


 

UPDATE! 4/4/11

https://sites.google.com/a/webstercsd.org/lgary/

Its easier for me just to keep the updates here, All the mechanics should be finished up in a week or two, Ill keep this page updated!

 


 

This project has consumed my workshop!

I am also renaming it "Prowler", then I'm going to put a peacekeeper symbol on it, everything is better with sci-fi references!

 

 


 

PART TWO: THE SCHOOL MACHINE

 

For the motor drivers to be used on the seconed machine, I am between programming a PIC to interperate step and dir signals then driving the motor coild with MOSFETS or a L298 H-Bridge, or using a L297 and a L298 as a pair, the problem is that L297 chips are eight USD a piece. What do you guys think I should go with?

 


 

So I have finally settled on a design "train of thought" for the control for Machine part deux, behold the Xilinx XC9536 CLPD!!!! I was able to get ahold of a couple from my mentor for the project, (he literally had a case of these things)

Since I am much more comfortable designing at the gate level rather than verilog, or C/assembler with a MCU, CPLD's are a natural choice for me. I'm going to design and build an in circuit programmable CNC dedicated cpld dev board to create the step sequences for each motor, then break out those signals with some darlington transistors to drive the motors. I figure this will be a pretty simple and easily updatable design, should be pretty fun too!

A far as the mechanics, It will be similar to the "Mantis" if anyone has ever seen it.

 

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smartpartzzkidd's picture

Thanks so much for that link! I will definatley take a look.

But this machine is far from finished, I still need to do some re-alignment on the tool mount, I am going to have to do a complete redesign on it, there is just wat too much play and it just doesnt want to sit perpendicular to the x-axis slide, but for simple demo purposes its okay.

Hopefully it will be done this week so I can get this thing really dialed in to do pcb's, my goal for the next two weeks is to get it to cut QFP traces (I have a bunch of cpld's and fpga's lying around that need a home!)

More updates sure to come!

Chris the Carpenter's picture

I am so impressed with this one. Fantastic.

Now that you are cutting wood, my carpenter senses are perking up. I got a couple links that I think might help...

Rockler Woodworking

First off, they have the clamps you need to hold the work to the table of the cnc.

They also have a ton of T-track stuff and different kinds of fences and holders and toggles etc. All good stuff.

Not to mention that they have the dust collection parts and hoods you need. Especially the hood.

 

smartpartzzkidd's picture

correction for the video, I have limited the current to the stepper at 1.5 amps (half the handling of the driver), If I put the current up, I would be able to push it faster, but calibrating this thig this a pain in the neck, literally

all of that vibration is just from the table, the z stage slides smoothly :)

smartpartzzkidd's picture

I have renamed him "Prowler" ...for all you aussies out there, just kidding, really for my farscape fan-ness

TinHead's picture

If the PIC you decide does have analogic inputs you can use the L298 directly and use the analog inputs to sense the current and adjust the current accordingly.

Also have a look at the TEA3718, 1.7 USD a piece at Digikey, I'm using them to drive my machine currently, see my implementation with them here: http://letsmakerobots.com/node/23343 It is somwhere in the alpha-beta stage currently but it works pretty well.

 

smartpartzzkidd's picture

3-Axis test video uploaded :)

I have the x and y motors mounted now, will update again when it moves on it own

birdmun's picture

http://pminmo.com/

is a website that could offer you many choices for stepper drivers and at least one option uses PICs to assist in driving the steppers.

smartpartzzkidd's picture

updated on my website, take a look :p

https://sites.google.com/a/webstercsd.org/lgary/

smartpartzzkidd's picture

Yea, I think I will put in the extra work and just make the controllers with a PIC, plus the PCB design should be easier with those, Thanks for the input!

don't bother with samples, just put a lot of thought into what component you need and get it.