[uspl]

Hi all

Finally got moving on this project.

I have decided to start with the electro-mechanical part of the build first. This is partly due to not having the floor space for the actual machine just yet, but mainly because I want to do a full prototype of the mechanics. I am not finally decided on the gantry design, particularly in regard to the Y-axis mounting so I am going to do a few test of my motors and ball screws first to be sure of acceleration and speed results.


Rather than buy motors from one place, controllers from another, I have bought an entire kit from Ocean Controls in Melbourne. To be perfectly honest, the kit price is a fair bit over the component price if I did a lot of web buying; the simple answer is that these guys are only a few minutes from home, they provide excellent customer service and are very knowledgeable. I basically paid more than I needed to in order to get a local warranty and I am happy with that decision.


I bought a CNC-011 kit as shown here
430 oz-in 3-axis CNC Pack with Sinusoidal Drivers :: Large Stepper Kits :: CNC :: Welcome to Ocean Controls and it arrived a month ago.

2x nice big power supplies
1x little power supply for the breakout board
1x breakout board that has plenty of I/O for limit switches etc
1x cable to suit
3x micro-stepping drivers
3x 410oz motors

Anyway, I spent the last couple of weeks testing various motor configurations and tuning with Mach3. i have settled on 1/8 micro-steps for now, the motors still have good torque at that setting and I can run them at about 750RPM to give me 3500mm per minute on all axis. Not the fastest machine going round but plenty fast enough for what I intend to do.


My test rig consists of the X-axis ball screw bolted to my workbench and hooked up to one motor. I fitted a bracket to the nut and attached a wire rope that runs to a pulley in the roof of my workshop, then down to a 20 litre bucket filed with sand. That gives me a nice load to pull against and is easily adjustable if needs be.


Next the frame

Herewith the first dry assemble of the frame.
This is only rough to ensure the fabricator sent all the right parts.

Looks OK so far, one minor quibble with the alignment holes at one end but overall very happy with what they did. Cost with freight from Sydney was just over $1k. That may sound high but remember this extrusion goes for over $200 per length and I got them to do all the drilling and tapping plus supply fixings.

Anyhow, off to the hardware store this morning to gather bits for making a proper table, then move onto the full assembly.

To do:

• Go 20km across town to the only electrical place that sells the cable I need by the metre
• Tear down an old photocopier, fabulous source of limit switches and optical sensors for free
• Ditto an old 19" rack server, free rack mount case for my electronics and VFD
• Back to eBay for the linear bearings and rails
• Source a 600mm ground ball screw for the Z axis, that's my biggest stumbling block so far.

I have also added a couple of shots of my 2.2kW HuanYang water cooled VFD spindle.

More to come this week, if anyone is interested I am happy to post my plans for the frame.

Cheers

[uspl]

I made up the linear slide assemblies for the x-axis last night and this morning, pretty happy with them so far.
Everything is still a dry fit mock up for now, I intend to pretty much assemble the whole thing except for electronics to learn from my mistakes then tear it down and do an accurate final build.

After several hours work, my lady's comment was "so it slides, big deal"

More photos

Linear Slide
Three pillow block bearings mounted to a 1000mm length of profile. Made two of these. Socket head screws make a nice concealed fixing

X Rail
These are 25mm case hardened rods mounted on an aluminium carrier. Each is 1600mm long.

Table
Like it says, table on rails. The 1600mm rods and the offset bearings allow the 1000mm table to slide completely under the gantry meaning I will get my full cut area.

[uspl]

Hi All

32c degrees in the shed so better off in front of the PC under the fan for a while. I am working on some manufacturing drawings for my Z Axis, up until now it has mainly existed as an idea in my head.

Drawings herewith, comments and suggestions for improvement appreciated. I am aiming to keep it as compact as possible while allowing for 200mm plus of Z travel. The spindle alone weighs in at 6.4kg plus the motor and bearings so I am going to need some sort of compensation, gas struts or springs to balance the load.

[uspl]

Evening all,

The sparkie dropped by this morning and hooked up the spindle motor.

HuanYang HY02D223B VFD driving a 2.2kW

Interesting time working our way through the Chinglish manual but some Google and crossed fingers got us through.

Had a minor hitch with the water pump; memo to self, check hoses are tight before starting pump. Nothing like a fountain in the middle of the workshop with 3 phase wiring exposed everywhere. :withstupi

Anyway, all good in the end. The little spindle runs up to 24000 RPM in about 10 seconds and is pretty quiet too. I had it running for 30 minutes with the water cooler and the case temp stayed about 5 degrees above ambient so I am happy with that. Speed control is via a 10k pot on the analogue control port. When I go live I will probably swap that for digital control via RS-485.

Question:

I am using a 10k pot that meters at 8.9k when fully turned. That gives me speed control from 16000rpm to 24000rpm. Does that mean if I swap out for a 15k pot I can get a lower minimum speed ?


Cheers

[RTP_Burnsville]

I like your router build thus far....... I have been sketching a similar build with a fixed gantry for a couple months so enjoy reading the updates. Looking at a 2 x 3 foot working size for what I had in mind so similar to yours.

Is it correct that you mostly used 120x40 aluminum profiles?

I have several sketches with both linear rails and also the supported rod style, it will be interesting to see how your selection works out.

Thanks,
Robert

[uspl]

Hi Robert

Thanks for looking, I was beginning to think I was posting solo in this thread

Most of my frame is 80x40 with some 40x40 for trimming the table edges. Going to 120x40 would be overkill for this size project as far as I can see unless you have a cheap supply to use up.

If you would care to share your sketches i would be keen to see another perspective on the build; I am working through various ideas for the Z-axis right now.

Some of my latest ideas below.

[RTP_Burnsville]

Hi,

Will see if I can pdf a couple of my sketches.... At the moment they are just pencil and paper drawings.

Are you going to have any racking issues with your gantry? For some reason the photos make it appear not as solid as the main frame.

Thanks,
Robert

[uspl]

Hi

I don't expect to have issues with the gantry flexing or racking. It is not shown in the drawings but the gantry uprights are braced by 40x40 sections at a 45 degree angel both sides back to the base frame.

If I do get some movement, I have plenty of options to add stiffeners and further bracing including corner gusset plates at the back of the gantry cross member.

Look forward to seeing your sketches. My weather channel feed shows me it looks like a good day to be indoors in Burnsville and sketching. Down here it is just touching 100F in the shade, good day to clean up the workshop with a beer in hand.

Cheers

[aarggh]

Hi David, great looking build mate, for more rigidity if the sides of the gantry are flush with the outside of the frame, a 1/4" triangle plate of aluminium or steel screwed to the frame and gantry sides would make it rock solid.

cheers,
Ian

[uspl]

Hi all

Ian, comments noted, thanks for the kind words, and yes the outsides are flush so triangular brace plates can be added as needed. Once I get to the test cut stage I will review.

I got some stepper mount plates made up to suit, they came from a chat group contact who happens to be in Hawai; one week later they turned up USPS as nice as you like.

Fitted them last night, lovely job and they mate with the 8020 perfectly.

[uspl]

Saturday afternoon update time.

I was stripping some old gear at work for the dumpster and salvaged a 19" rack mount case. Perfect to house the electronics for this project.

See images below.

I am open to some suggestions for cables between the motors and the controller boards. I want to have them as plugable so i can easily pull out the electronics box for maintenance as needed. The motors are running at 42vDC at about 3A. I need a four conductor cable, preferably shielded. I have read a few posts on using DIN or MIDI cables but wonder if they will handle the current load.

Comments from someone with an electrical background ?

Thanks

Images:
From the back, the RJ-45 sockets will connect to the home and limit switch wiring.

Look inside, lots of space for lots of cool air to circulate.


With the lid on and slid back on it's rails. Note the kill switch mounted on the front.

[uspl]

Evening all

Attached herewith for you edification and enjoyment.
Sketchup files of some common parts I have done to create my build, thought they might be useful to someone.

[uspl]

Wow, nearly two months since I updated this.
Finally got some workshop time and now I have this:
[ame=http://www.youtube.com/watch?v=3qpyyCbEGyY&feature=g-upl]DIY CNC demo - YouTube[/ame]

I should get the cable carriers and limits/home done over the next few weeks and then maybe start actually producing something.

Cheers

[uspl]

Its alive I tell you, alive !!!
[ame=http://www.youtube.com/watch?v=nNXRJ_Ac9zk&feature=g-upl]FirstCut - YouTube[/ame]

Twelve months of test and re-test plus build, about $1000 over budget compared to what I told SWMBO but what the hell, it works.

Still needs a proper T-Slot clamping system (underway now) a cyclone dust extractor and lots more adjusting and tweaking but it does actually work. Some custom sign engraving will hopefully pay back some of the investment, some photograph etching will be fun and family and then we will see where it leads.

Whoo hoo, yes I am excited.