CNC Build

[mswhin63]

I have started to build a CNC Machine, Although not astronomy related directly I intend to use it for astronomy related builds. Thought I share.

Based on the JGRO design (http://www.cnczone.com/forums/jgro_router_table_design/) I have made only some minor changes which after putting together worked well.

I can't afford some of the essential CNC component like linear rods at the moment so I am using threaded rod zinc plated as it is afford and smoother that galvanised rod. To resolve potential backlash I installed a spring system that pushes the bolt constantly to one side of the thread. The spring is a bit too heavy but is adjustable. I have done away with the end block for adjusting the steel tubing as the sag was prominent. Instead I used 25mm conduit clips which are so much more rigid. Basic measurement show less than 1mm variation in travel from one side to the next on all axis.

Once the money flows through I hope to make changes to the table improve speed.

The next stage is building the computer using LinuxCNC software and some imaging software which I am not sure as yet.

The rest of the build will have to wait for money to flow as the motors and controllers although economical are still pricey. The build itself has been relatively cheap, all the components have cost under $100.00 so far.

I have a number of other project taking hold, bicycles for the family and upgrading the battery system on my imaging set-up so this will take a bit of time. I am now looking at selling loads of stuff shortly to try and make some capital.

[ZeroID]

Sounds like an interesting project. What stepping (?) motors do you need? Not sure how much postage to you would cost but I have all sorts of electronic hardware lying around that might lend themselves to adaptation. Keep me posted and I'll have a look through my bits pile ...might be some swaps possible if you are moving astro stuff.
I have some motors with driver boards atached plus suitable cables\plugs. These all come from scrapped photocopiers and laser printers. Most are almost brand new condition, they don't get a hard life.

[snowyskiesau]

I started the build process of a similar CNC a few years ago but for various reasons, didn't proceed with it.
Since moving down to Tassie, I've bought a 6040 CNC (http://www.carving-cnc.com/) from eBay. Not brilliant but once the controller was replaced, more than adequate. A bit limited in the work envelope (600mm x 400mm x 90mm) but good enough for a learning process.

[alistairsam]

That's an impressive build Malcolm, but why not use steel rods and timing belts rather than the threaded rod?
best source is deskjet printers.
you could adapt the carriage head assembly quite easily just using a long stainless steel shaft. they'll be very smooth.
There are heaps of them for $10 or so on gumtree.
I like the bearing solution on your y axis.

old deskjets or laser printers are an invaluable source for stepper motors, encoder wheels, steel shafts, sensors and so on.
I have two 1.8deg steppers lying around, let me know if you're interested.
Also look at the DRV8824 controller chip for steppers, they support 1/32 microstepping.
are you buying or building the controller interface? I'm guessing there are heaps of solutions on the cncforum as well.
I think mach2 is the software used on most CNC's.
Cheers

[snowyskiesau]

Malcolm,

I know you're on a tight budget but there are a couple of good suppliers of CNC components in Oz.
Ausx (http://www.ausxmods.com.au/)
Homann Design (http://www.homanndesigns.com/store/)
I'm a happy customer of both.

A suitable stepper for your design will set you back about $45 - $50.

If you're into woodworking, there's a local woodworkers forum that has a great CNC section. http://woodworkforums.com

Look forward to seeing the rest of your build.

[mswhin63]

Hi All,

Thanks for all your input, and the links as well. The budget is so tight mostly because at this stage my wife has some needs and we came up with a solution to share the costs of projects. 3 main projects under-way, one for me, one for my wife and one for the family as a whole. I have reached the limit of spend now for this project and now have to concentrate on the other builds, all this before I start Uni.

I though of belts as an option but the size of the machine is not suitable for desktop printers. This unit has a working area of about 1m^2. This requires fairly heavy duty steppers. The Nema 23 or 24 look good although i haven't research much the amount of workload my machine will take. Either way It will require amendments to cutting depths when motor are finally purchased.

I have mostly machine parts and electronic parts along with general home stuff we are moving to make funds, although these funds have got to go across the other projects too. My wife had to quit work recently due to a wrist and shoulder injury (not work related) so finances are going to get tougher.

Anyway will be working hard to complete things and will update this post as it goes. Cheers all.

Other project on hands are.

Craft Table/storage solution.
Bike builds:
Kids are getting this - http://www.atomiczombie.com/Vigilante%20Stealth%20Bomber%20Styl e%20Chopper.aspx
Wife and I are getting this - http://www.atomiczombie.com/Aurora%20Delta%20Racing%20Trike.asp x

Just learning weld which will be another project - http://www.bigyella.com/ :lol:

[2stroke]

Looks pretty sweet there's so many people out there now making them its unreal :) Just keep the untreated mdf away from moister. Fleebay is full of cheap DIY cnc mill gear now which makes things alot more affordable, can't wait till you have some pics of it in action :) Lol I'am the same with projects, still working on TEC cooling my dslr and have yet to get my LCD panel light box on the go, just so little time :(

[mswhin63]

Thanks Jay, I don't intend to leave untreated. Nothing is glued yet as I want to take it apart again and complete the installation. Project seem to be never ending but they are enjoyable unless a piece of MDF flies off the table saw and into the gut. :P

[cventer]

Call me a kill joy, but those spikes between the handlebars are going to end up costing a whole lot more than any project here WHEN the kids crash that bike. Very cool looking though. Just not very safe.

[mswhin63]

I have already told them I will omit them. They didn't like them either. Fortunately the plans are very flexible.

[mswhin63]

Just received the next items, drive control and drivers for the steppers. Only a few micro-switches and the stepper motor left to get.

[mswhin63]

Hi,

Taken another step closer to completion, unfortunately started Uni again so things are going to slow mo for a while but I hope to allocate an hour or 2 a week just for my projects including the obs.

This time I have an embedded computer that I collared for $10.00 (actually 2 computers) along with a plotter that I have raided for bits. The bits for this build are:

240Vac to 24Vdc 8A power supply
Embedded 2Ghz embedded system PC.
Case to mount everything
some very high quality wire.

I also scored a load of other devices including motors installed with encoders and stainless steel linear sliders for building a 3D Printer in the future. This is a really good score for $10.00 mostly because people didn't want the plotter due to it's size. Link to plotter - http://www.oce.com.au/products/tcs300/Default.aspx :eyepop:

Still have to configure the PC but limited buy the manufacturer disabling the USB Legacy in BIOS, so I need a PS2 keyboard and mouse to reconfigure before going ahead.

The images show the case almost complete, the CNC motor driver are the 3 heatsinks on the case and 3 x 21kg Stepper motors. Best buy for most of this stuff is from http://www.hobbycncaustralia.com.au/ :thumbsup: although I got a 5 axis stepper controller on eBay.

[ZeroID]

You can get USB to PS2 adapters, I got a quite few at work, no longer needed.
Let us know if you need a couple.

[mswhin63]

Thanks for the offer, I have tried that method but did not work. I am not sure why but still unable to control the keyboard after booting up.

I could be something to do with the embedded design of the plotter to prevent potential hacking so I am going to have to go back to PS2 once I can get a hold of one.

There maybe some other reason but had to clear the bench to do some other work for the moment, I usually think better having a break. :P

[nebulosity.]

Hey Melcolm,

Just wondering how your cnc build is going, I am drawing up some plans for one at the moment and would be interested to know anything i should avoid.

Cheers
Jo

[mswhin63]

Hi Jo,

I am afraid the build has stalled for the moment, one thing I found is that it is best to build from Plywood, not MDF as it is prone quite a lot to moisture which my shop has very poor humidity control.

I have to completely redo the whole system, and have some new plans to make it. Fortunately all the electronics are fine, nothing to change there.

In real terms my University Degree is more important than just about anything I do. Even my Rental Observatory has stalled until I get everything under control.

Malcolm