Monday, November 30, 2015

DIY Linear Guide

Linear guides are simple in concept, they turn the rotation of a small motor into linear movement.

They can multiply the power of a small motor making even a tiny motor lift a lot of weight.

Here is one of my designs.  This is the second of this model I have made.  It is still a little rough looking but it moves well.

I have since replaced the scratched plate that is missing some bolts with a new 12mm thick clear acrylic part and shiny new zinc chromate coated bolts.

The stepper motor is 2 amps and the black box under the motor is not a reduction gear, rather it houses a flex coupler.  That little box is 3D printed.  (using machines to make more machines)

This will hold the little trim router going into this particular machine and provides the up and down movement.

Since it is up and down movement I can get away using a threaded rod and nut without backlash

I have machined these as anti-backlash nuts, however the long nuts work just as well and I have yet to experience backlash with them even with months of use.  The thread rod is m8 stainless.  This moves the machine 1.25mm per turn.  The white part is 3D printed plastic.

I prefer stainless metric thread rod over English measure for my CNC machines mainly because the math comes out even.  I use mild steel nuts as stainless to stainless parts tend to stick together.

With English measurement rod, the fractions come out often times to for example steps  a stepper motor can not move in numbers that are not whole.  For example 10.5 steps.  

This is still a bit of a prototype design.  I am looking for a way to join the corners of the frame in a more reliable fashion.  Maybe by the use of corner brackets.

The Bootstrap Machine Shop

I am in the beginnings of a rather large project to create what I will call the Bootstrap Machine Shop Project.

I have found a open source 3D printer that is very low cost and it is the basis to build a much larger and sophisticated shop. 

Much as the Gingery book series had a series of machines that were all made using the beginning of a DIY lathe and DIY foundry, My project aims to tie together existing designs and plans to lay out a roadmap of sorts to start out with a sub $300USD 3D printer kit and take the budding maker to the point where they have a robust light manufacturing facility.  This facility could then be used to create up to a heavy industrial facility.

The 3D printer kit to start with is very small.  Working area is only 80x80x80mm.  However it is sufficient to build larger machines including those that can work alumium and engineering plastic.  Of which will be strong enough to build heavier machines that can machine steel.

It is like a machine shop seed.

Of course as in all seeds and growing things much study and hard work will be required.  However if one has a wealth of time and the endless library that is the internet, one will be able to create some pretty big stuff.

This tiny machine will be sufficient to build a CNC router that can be in turn used to machine aluminum and make everything from a lathe, higher quality mill, more printers, cnc lasers, auto parts, you name it.

This is not the only 'seed' that one can plant however.  Other machines like CNC routers can be built using hardware store materials like steel pipe, roller bearings and hardware store power tools.  However the tiny 3D printer will speed things up to make some of the more complicated parts.

I will have more photos coming soon.  Suffice to say that it will be ready before Christmas.  I have ordered parts to build 20 units and started fabrication of many of the parts myself.

The idea is to create 20 machines, and have enough profit to build an additional 40 machines along with the purchase of at least one or 2 CNC laser cutters to speed up production and not rely on outside vendors for some critical parts.

So what parts can one build with such a tiny machine?  Essential parts such as stepper motor spacers, bushings, brackets, mounts, cranks, are some examples.

One thing that I have observed is that when times go bad, those who produce real things with real value will survive and thrive. 

Start your own boot strapping project and learn a essential skill while you still have the luxury of a full time job, a full stomach, working internet, ample supply chain and working electricity.