January 27

DIY CNC Part 4: X Table and Gantry

Xtable2a

Being exiled to the garage for five days has given me the time to make some good progress on my DIY CNC. What started out as what I thought would be a simple build of the X table turned into somewhat of a project in itself.  Remember that “quality” plywood I had purchased for the table?   Well it turned out it had a bow in one of the corners and I was not able to use it.  I had to replace the “quality plywood” with some MDF from Home Depot.  A bill of materials is located at the bottom of the page.

xTable1
X table and rods

I had originally thought if the X table was smaller then I wouldn’t have to worry about the bow in the table or the little “wobble.”  There was a minor wobble in the X table when applying pressure to the Y axis.    I decided having a slight bow in the X table and a little wobble will cause problems later when cutting, so I replaced the plywood with the MDF.

Xtable
X Table and Gantry

Once again I had Home Depot cut me a piece of MDF and I was ready to install the X Table.    To give the X table a little support, I decided to install some supports as the MDF was quite a bit heavier than the plywood and I don’t want the rods to bend or the table to bind.  I installed four small coaster wheels I had purchased from Home Depot when I got the MDF.  After the installation I noticed the wheels were oblong and creating the X table to bind up along the axis.    This would make it hard for the stepper motors to move the table  so I removed the coaster wheels and just put a nice piece of pine underneath the X table.  I countersunk a few holes and screwed my newly created X table supports into position, tested for binding and proceeded to square up the X table and Y axis.

Xtablesupport
X Table support made from pine

Once the X table was complete and without any binding, the final assembly of the gantry was next.  I needed to make sure the Y axis was exactly square to the X table along the full length of the Y axis.  I used a speed square to check and make the adjustments.  Once I was satisfied with the Y axis being square to the X table all along it’s axis, I screwed the Gantry down on both sides of the frame and checked it again to make sure the Y carriage would transport across the Y axis without binding.

XY
Y axis square to the X table

At this point I thought I’m basically making a printer!  It’s looking like a printer anyway…  With the X and Y square to each other, the Z will also be square to the X table.  I had squared Z to Y when I constructed the Y/Z backplate.

GantryTopView
A look down the Z axis

Checking the X, Y, and Z axis I noticed the X table was slightly touching the clamps I had purchased to secure the 3/8 steel rods.  I trimmed the little rubber off the top so it was flush with the metal clamp and this provided enough clearance for the X table to move freely without touching anything other than the X table supports.  Was it time for a beer?

Xtable2a
X rod clamps from McMaster

With the machine pretty much constructed, I moved onto getting the stepper motors prepped for installation.  The stepper motors will be attached to the 1/4 20 threaded rod and transport each axis.

NEMAmountY
NEMA motor mounted on the Y axis

On the next post, I will go over the NEMA motors, the NEMA motor driver modules, and where I sourced those materials.  Yeah, it’s time for a beer or cough syrup.  Until next time,

Happy Building!

 

Bill of Materials to mount the steel rod on the X Table:

4 each – Vibration-Damping Clamp with SBR Rubber Insert, Zinc-Plated Steel, for 3/8″ OD, 3/8″ Tube Size  McMaster Part # 8981T62

 

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January 23

DIY CNC Part 1: Research

You ask yourself what is a CNC?  Well, CNC could stand for Chicken Noodle Coalition but I really am not interested in creating a chicken noodle coalition, however I am interested in building a machine to automate the process of cutting RC parts for my growing fleet of aerial platforms.  A CNC machine stands for Computer Numerical Control and is used for the automation of tools to cut, weld, drill, and/or to print objects in 3d.  Yes, star trek has arrived on scene and you can now print up any thing your heart desires like AR15 parts, but that is another DIY project for another day.

The system basically uses a computer which sends commands to a tool, like a Dremel, telling the tool what direction to cut, weld, draw, drill, or print.   There are desktop type machines for the hobbyist and industrial type machines but regardless of the size, they all function similar in that they generally operate on the x,y,and z axis to create the product.

To give you an idea of the difference between price gouging and what is available out there, I present this brief example.  I recently needed a part for one of my aerial platforms.  After several days of browsing on the internet I was not impressed and quite honestly I was extremely fired up about the cost of the part.  Who would think a little part cut out of carbon fiber would cost over $150.00 dollars?  Sure carbon fiber is nice, but after pricing the materials to make the part, it was clear to me what steps I should take.

Epoxy sheet $8 bucks, miscellaneous parts $20 bucks and so for approximately $30 dollars in parts,  I could make the part which would work and function as required, and save around $120 dollars in the process.  That kind of savings could purchase quite a few materials for my CNC machine.  A CNC machine used to make your own parts can have the effect of saving you a fist full of dollars in the long run.

Now keep in mind, I have never owned nor operated a CNC machine so building one is certainly going to be a challenging task but I hope to learn a few things along the way which I plan on sharing with you.  When I told a buddy I was building one his response was “good luck finding the parts.”  Sounded like the first challenge to me.

There are many sources of information and plans on the internet on how to build a DIY CNC machine and many choices on buying one.  I thought about just purchasing a kit but this would do nothing for me other than making it easy to get it up and running.  I wanted to understand the process so if I had any troubles with the machine I could easily troubleshoot the problems.

The first step was deciding what I wanted to build and I landed on a company page who sells an eBook with some good information at a reasonable price.  The $14 dollars for the eBook was reasonable and the startup company was located in the US who got the funding to develop their desktop CNC machines through Kickstarter.  I personally always try and support small US companies and often browse and support projects on Kickstarter.

The eBook was detailed enough to provide me with information on how to go about getting the parts and building the machine.  A link to the eBook can be found below.  Reading the book, it was clear I would be able to obtain most of the parts through Home Depot, Lowes, Ace Hardware and other sources and now the journey begins on the build.

eBook:  MYDIYCNC

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