First CNC projects

Christmas Presents

After a successful CNC build, and subsequent set-up, calibration, and test run, it's now time to make something ?  I've got a couple of ideas straight away, firstly a Christmas decoration, and then a couple of Christmas presents for 2 family members. This year it has been suggested that all Christmas presents should be handmade, running a little late with mine as it's the 20th December already !!  However Alison has been busy in the pottery shed making a few presents for the past 2 months and are nearly all complete, just waiting for the last kiln firing to finish.

Snow Flake

The Christmas decoration is going to be a large snow flake, 250mm diameter, made from 6mm MDF, an off cut from previous projects. Going to be using fairly cheap bits of timber and other materials for the first few projects just in case of any mistakes, this could be a steep learning curve ?

I am using a web based design and G code app called "Easel", a very simple app that basically does everything from the first steps of the design right through to starting the CNC up and carving the design. I shall be using this for the first few projects until I am used to how it all works, then possibly move onto a more advanced program as ideas progress.

Found a suitable design of a snow flake and enlarged it to fit my piece of MDF, slightly manipulated it for the cutter I was using. Not got the process in photo or video form to show you, but in the video below you can see the laptop running the program, and the CNC cutting it out. All too exciting for my first project !

Finally after several passes, (0.9mm depth each time) It's finished.

Rather pleased with the outcome, a very light sanding, then a primer coat, followed by a suitable finish... still thinking on that one ?

 Beer Bottle Opener

Going to make 2 Beer Bottle Openers, these are going to be approx 300mm x 120mm x 20mm in a shape of a beer bottle, with a little bit of text, a fixed bottle opener, and a hole for fixing to a wall or cabinet. Made from some off cuts of Pine and finished with a clear satin hard wax oil which should make it resistant to and splashes from opening bottles.

Using "Easel" again it was easy to find a shape of a bottle, then manipulate it to fit the size of my timber, add some text, then space it all for that final look. Again you can see the video with the design on the laptop and the CNC running and cutting the design out...

As you can see from the video, the cutter was dragging up the grain of the timber, causing wood "swarf" especially along the direction of the wood grain. I was using a single flute spiral up-cut bit, after a bit of research it would have better to use either a straight flute bit or a down-cut bit to minimise the grain tear out.

Now both are finished with the CNC.

So that the carved text will stand out, I shall spray them with black acrylic paint, then sand back to highlight the text carving...

 The text really "pops" out now...

I feel that all this hard work should have a "makers" signature on it somewhere ? So back on the CNC and carved the workshop name on the reverse...

Sanded the bottle opener plaques with 120, 180, 240 grit papers ready for the wax oil...

And lastly the bottle openers...

Summary


Pleased with these gifts, however thoughts of making a proper makers sign or signature ? possibly via a branding iron ? might see about getting a small billet of brass and making my own with the CNC ?

No costings going down for these projects, just the times...

Snow Flake... Computer work and setting up ready to carve... 1 hr
                       Carve time... 40 Min's

Bottle openers... Computer work and setting up ready to carve... 1 hr
                           Carve time... 20 Min's each
                           Finishing time...  2 hrs over 2 days for both.

CNC The Build part 4

Think the 80/20 rule has come into play with this build ? for those unfamiliar with this rule, it is said that the first 80% of the build takes 20% of the time, then the last 20% of the build takes 80% of the time ? Feels like it dragging a bit, but determined to finish it today.

Wiring Continued

Yesterday I left the wiring after getting it through the first drag chain, now this morning I have got to build up an extension side board to hold the second drag chain and also the power supply with the control box.

The extension board came with the main components, something I had not expected, and was prepared to make my own, however as it's in I'll use it.

Construction of the extension was very straightforward, very similar to the bed rails on the main bed.

The side extension is connected to the main waste board rails with a couple of angle brackets. With this in place we can now attach the 2nd drag chain and feed the wires through...

 Tie wraps to the rescue again !

Next is to locate a suitable point to attach the lower part of the drag chain so that the wires can reach the controller...

The X Controller

The X Controller and power supply is in kit form, and again is fairly straightforward to assemble. The series of photos show the process...

All the bits ready for assembly...

Power supply and main printed circuit board

USB, emergency stop button and control buttons

Cooling fan and rear panel fitting... and finally in position.

With the X Controller now fixed to the extension board the final part of the wiring can be done. A simple process of following the wiring diagram to connect up all the motors and switches.

 Again cable ties to the rescue !


Calibration, Set-up, and test carve

The last steps of the build are nearly all via the Internet, on the web based program called Easel.

It takes you through a series of questions and tests on the laptop, which in turn is connected the the X Controller via a USB lead.
It tests the movement of the 3 axis and homing switches.
The program also sets up the type of X Carve you have so certain parameters are set.

After all this it says ... "Ready to Carve" !

Easel has a "Test Carve" program, and after a few minutes going through it's "Wizard" I'm ready for a test carve...

A short video of the router CNC in action, Timber not the best, an off-cut of OSB but I needed to test the CNC on something ! ...

Summary

Build time today... 6 hrs

Total build time... 23 hrs

CNC The Build Part 3

CNC The Build Part 3

Belting up...

Next on the build list is to fit the drive belts, these are cut to length for each of the axis, 1 for the "X", 2 for the "Y" and a small loop belt for the "Z" axis.

The following photos show the routes of the belts and the tensioning brackets...

The "X" axis was a bit fiddly as access to the idler pulleys was restricted, having to feed the belt through from the top, and putting a bit of a "curl" in the belt helped...

The far back side of the belt was just fastened to the end plate, no adjuster on this side, just at the front.

The "Z" axis loop belt before and after tensioning...

Dust extraction system

Quite possibly the most important accessory to a router CNC machine is a good extraction system, the cutters on the router are quite small, and the "Chip Load" of the cutters is also small, therefore the router will produce more dust and small chippings than shavings. So this will plumb into the extraction system I installed a couple of weeks ago.

Chip Load...

Without going into to much great detail, Chip Load is the amount of material removed by each flute of the cutter, other things to take into account with Chip Load is the speed of the cutter, the speed of travel, and the depth of the cut.

Dust extractor mounts

These brackets needed to be bolted onto the "Z" axis, but also needed to be twisted and slotted in a particular way to fit. Then bolted, but nothing is quite that easy ? finally got them in position and the then found out that my hex key was too long ? ... bit of modification needed with the bench grinder to make the hex key fit.

The front brackets simply slide in and are held in position with a couple of screw clamps...

The dust collection boot is held in position with magnets, and too keep the suction high a small clear plastic insert in placed inside the boot assembly...

Photo of boot in situ to follow... 




Spindle fitting

Inserting the router spindle is straightforward, however the housing assembly is a very tight fit, so a little help from a wedge to open up the spindle clamp was needed...

Wiring

Time to get the wiring routed through and attach one of the drag chains.

All the wires are labelled, so a simple case of connecting them to the right place, and making the wiring nice and neat...

Opening up the drag chain helps with putting the cables in, also removing the end connector helps fixing it to the support arm.

Drag chain assembly and wiring up the motors and limit switches.

Cable ties overkill !

"X" axis wiring and drag chain complete.

Summary

Time taken today... 5 hrs

Total build time... 17 hrs

CNC The build... part 2

Part 2

Following on from my previous blog a few people have asked what is the "Y" axis ? Hopefully I can explain ?

Overview

The CNC (Computer Numerical Control) converts a design produced by a CAD (Computer Aided Design) into numbers. These numbers are basically coordinates of a graph, and these numbers can then control the movement of the motors connected to 3 different axis of a graph, X, Y, and Z.
The router and cutter are connected to the Z axis.

X is the side to side movement
Y is the front to back movement
Z is the up and down movement

So in the last blog I said that the Bed Rails are used to hold the "Y" axis rails; which will be in the "front to back" orientation of the CNC. This will become clearer later on in this blog post with the aid of photos.

Side Plates x 2

Construction of a side plate for the "Y" axis are made up of a mounting plate, 4 "V" pulleys, 2 static and 2 adjustable, a stepper motor with GT2 belt pulley, 2 smooth idle wheels, and a few ancillaries. Series of photos shows the progress of the build.

V pulleys and idler wheels fitted

Stepper motor fitted

X Carriage Assembly

Similar build to the Side plates but in a rectangle extrusion with "V" pulleys, idler wheels, motor etc. But this will also support the "Z" axis assembly.

This part is a little fiddly, having stubby fingers doesn't help, and having to angle spanners to get a good grip on the nuts as these are recessed inside the "V" pulleys.

The adjusters for the "V" pulleys are small eccentric nuts as shown in the photo above, and these have to fit into the holes on the "X" carriage, unfortunately they don't fit? but with the aid of a small circular file to remove the coating from the main body of the carriage they now fit perfectly.

Motor and limit switch fitted...

"Z" Axis assembly

This holds the router and with a "lead" screw raises and lowers the router.

Attaching the top plate to the maker slide to the "X" carriage, and inserting the bearing and lead screw with a "GT2" pulley.

Mounting the "V" pulleys and adjusters to the router holder.

"Z" assembly now connected to the "X" carriage.

Gantry Rail Assembly

The side plate assembly now needs to be attached to the main "X" Gantry Rail.

A couple of drag chain brackets were also added to the side plates.

Before putting on the other side plate the "X" carriage and "Z" assembly is rolled onto the gantry rail.

With both side plates firmly connected to the gantry, we can now more onto the "Y" rails and attach the end plates, which in turn will connect to the bed rails as explained earlier...

Lots of small fiddly nuts, bolts, screws, etc this morning, but good progress made. Getting cold now, and a snowstorm is forecast for later on, so stopping for today.


Summary

Time on build today 4 hrs

Total build time 12 hrs