Instructions for the PSCC v1.3

So I wrote up some instructions on how to put together the Pololu controller carrier board.  The board is fairly simple, but I put together some step by step instructions with pictures.  You'll have to solder on the through hole components, so be ready with your iron, solder, diagonal cutter and other tools you'll need to solder.

http://www.johnyang.com/www/pscc

stepper boards work great

Finished rewiring my arduino mega shield and plugged in the stepper controller and it worked great.  Had to make one adjustment to one of the resistors.  Had to change R2, the pullup resistor used with the jumpers to select the microstepping from 100K Ohms to 10K Ohms.  There are 100K Ohm pulldown resistors built into the pololu controller, and I pull down MS1 with a 100K Ohm resistor for when that pin isn't jumpered.  When I had everything plugged up, it only did full steps, no matter what combination of jumpers I set.  So I replaced the resistor on the pullup side to 10K Ohms and now all the microstepping options work great.  Now to solder up 3 more boards and hook things up to my repstrap.

I've got 15 boards to sell, if you want one, let me know.

stepper driver soldered up

Just finished up soldering up one of the pololu carrier boards I had made up.
Here's the board with all the components



And here it is all soldered up



And here's a picture of the board layout



It's late so I'll have to test it tomorrow.  I have to solder up some headers on my arduino mega protoboard shield.  I had the pololu drivers on the protoboard shield, but I want to remake the shield so it'll be pin compatible with the makerbot gen4 electronics.  I rewired my shield, but it is a big mess of jumper wires, and I figured it'd be cleaner to make a carrier for the pololu board and remake the shield.

stepper boards arrived

The stepper controller carriers I designed were made and arrived a few weeks ago.  I finalized the BOM and ordered the parts and those are in too.  I'll be building a few stepper carrier boards tonight and documenting the process.  I hope I didn't leave anything out when I made up the PCB design.  We'll find out tonight.

belting up

So while waiting for the components for my stepper boards to arrive, I was digging around amazon and found some pulleys and belts that I could use to switch my wolstrap based repstrap from 1/4-20 leadscrews to belts.

Here are the pulleys I bought: Timing Belt Pulley Nylon Glass Filled, Double Flange, 1/5

and here are the belts:Timing Belt Fiberglass Reinforced Neoprene, One-Sided, 1/4

The belts were on sale for $0.57 so it was hard to pass the deal up.  Regular price was $7 something.  The belts are 30" loop.  so it is enough to provide the 12" motion for my X axis as the continuous loop.  For the Y axis I'm going to mount the stepper to the platform and use a S routing of the belt to provide motion since I have around 20" of motion in that direction.

I also bought some skate bearings from amazon to use for the idlers for the belt.  These Skate Bearings are the ones I bought.  Although I'm sure any 608 bearing would work fine.  Or any size really, but the skate bearings seemed the cheapest.  Looks like Makerbot has them for $5 which is less than half what I paid.  I have a prime shipping account with amazon for our other household ordering, so no shipping fees, but any bearings work fine.  I'm using 5/8" bolts and fender washers to do up the idler bearings for the X axis.

I'll post up some pictures this evening of my belt setup.  I'll also try to add some details to the wolfstrap page on the reprap wiki.

Electronics progress

Yet another pololu carrier board

pololu carrier board

So I've got most of the mechanics done, but I'm looking to rebuild it with belts instead of the leadscrews.  While I'm trying to design a workable belt system with some scraps I have from a few steppers, I've been working on the electronics side.  I've got the stepper drivers finished and will be sending it out to a boardhouse in the next few days and hopefully will have some boards built in a little while.  I've uploaded pics of my design on the reprap wiki and thingiverse.
http://reprap.org/wiki/Pololu_Electronics#ljyang
http://www.thingiverse.com/thing:3634

I'm still putting the final touches on the silkscreen before I send it out for prototype and will post up the final design files for the board soon.

New build, new blog

So I've been reading about the reprap project for a while, and I thought it was time to actually start my build.  I'll be building a combined cncrouter/repstrap.  I've been going over things and I think that I have a good base of knowledge now and a design sketched out to build.  I am building a variant of the Wolfstrap machine.  The Y base and X standards are being built from a re-purposed Ikea Rast nightstand I had in my shop.  I will be using an arduino mega with Pololu stepper drivers for movement.  I will be building the Cartesian robot first then integrating the electronics so that I can hopefully use both reprap software with the arduino, and EMC2 from linuxcnc.org for a cnc router.  I am hoping to accomplish this by decoupling the stepper drivers from the arduino in some manner and connecting the cabling to a parallel port for the Linux cnc control.

I am keeping records of my purchases so that I can calculate my total build cost and also provide a complete BOM after it is completed.  I am working on this in the evenings and hope to finish and have my first print by the end of 2010.  I am being realistic with my goal given my two children take most of my time and I have only 1-2 hours in the evening 2-3 days a week to work on this project.  Progress will likely be slow, but hopefully will be completed by the end of the year, or hopefully sooner.

Items already in hand:
Ikea rast
4x steppers (nema 17 from sparkfun)
5x pololu stepper drivers (from pololu.com)
1/4-20 threaded rod (from home depot, had it in my shop from a previous project, some of it is a bit bent so hopefully can get it to work)
1/4-20 nuts (also from home depot from the previous projects)
10-24 x1.5inch screws, nuts and washers.
Arduino Duemilanove (using it to test out stepper drivers, need to order a mega)
drawer slides for linear motion - 2x 22", 1x 14". 22" for x/y motion, 14" for z motion (home depot)
breadboard for prototyping
miscellaneous passive electronic components (resistors, capacitors, etc)
PC power supply
atx breakout connector (from sparkfun)

Items to buy/make
breakout board/shield for mega to house stepper drivers
Arduino Mega
extruder

I'll post pictures as progress is made.
LJ