Archive for the ‘fabrication’ Category

Pin headers

Thursday, January 13th, 2011

I’m a cheapskate.  Most of our kits use single-row headers, and it’s cheaper to buy 40-pin headers and break them down to size than buy headers pre-cut.  This of course takes time, which is in short supply.  And breaking headers apart with a pair of pliers is unreliable and inefficient.

Time to build a machine.

I’ve got a bunch of mediocre tools and a wild mechanical imagination.  So I invented a guillotine-like machine with an adjustable stop to get faster, more repeatable results.

You can also watch it in action on youtube. (sorry, couldn’t get the embedding to work on this blog)

Lots of time has passed…a little progress

Friday, April 16th, 2010

So our camera bit the dust shortly after the last post.  Since then, I have mounted the supports for the x-axis lead screws, put the gantry together, and done a few other things.  First, the assembled gantry:

And now, to slide the gantry on to the base.  I ran into a minor problem here–the gantry is about 1/8″ too narrow.  Fortunately, the 1/2″ MDF has just enough elasticity for me to force it onto the track.  It might actually be a good thing–I don’t have to worry about having enough tension to keep the gantry in place.  I will have to add some reinforcement to the vertical sides of the gantry at some point, to make sure I don’t end up breaking them.  Of course, from what I’ve heard, all it has to do is last long enough to cut the pieces for my next, better CNC machine!

Never enough clamps…

Tuesday, March 16th, 2010

Today:  put together the supports for the x-axis lead screws.  I will be using 1/4″-20 all thread (it’s cheap!).

I bought the cheapest 1/4″ ID bearings I could find.  They have a 12mm diameter shoulder and 22mm outside diameter.  That’s roughly 1/2″ and 7/8″, respectively.  Since I’m drilling the holes in MDF, there’s naturally some inaccuracy involved.  The small amount of slack will be quite welcome when the time comes to adjust the bearings’ position.

A while back, I also put together the slides for the y-axis linear bearing.  Nothing exciting here, just a couple pieces of MDF and some aluminum angle.

Big project…

Tuesday, March 2nd, 2010

I’ve been wanting to build my own CNC machine for years now, and I’m finally in a position to do so.  I’m cheap, which means I’ll be using inexpensive materials and lots of my own labor, rather than spending the money for a commercial project.

I’ve gone through a number of iterations on the design, and finally have one that I think meets the dual requirements of being A) within my skill-set, B) big enough to be useful, and C) within a modest budget.  Unlike previous iterations, I haven’t made a google sketchup model of the machine, and I’m making it up a bit as I go along, so I fully expect the design to evolve as I go.

Last weekend, I started on the base.  This is the simple stuff.  I added some bracing underneath for stiffness, and now have the two side rails for the linear bearings.

Top side of the base

It’s not much to look at, at this point.  Here’s the bottom:

Bottom side of the base