DIY CNC Milling Machine

The Objective

I shall be fabricating a fixed gantry cnc milling machine over
coming weeks along with a blast furnace and thought it might
be of interest to some on OCAU

The plan is to construct a milling machine that will shape construction
foam, this foam will be used in 'lost foam metal casting' For those
unfamiliar with this metal casting technique and are curious as to
how it works my mate Frank has an excellent write up on his web site

TheWorkshopCA

Frank has kindly sent me 3 stepper motors (still in transit) and the
controller board to run the motors free of charge. I am also loosely
basing my mill design on one of Franks first mills

OK..so you know what is being made and why, now the how...

MDF and Delerin, 15mm solid steel rod, 1/2in threaded rod ~40
sealed bearings and few hundred screws and bolts 3 stepper
motors and PC PSU will be used to construct the mill.

I have also decided this mill will be used not only to shape the
foam for metal casting but to mill solid billet aluminium THUS
this mill will be reinforced ALOT more than mill used solely
for foam/wood/plastic....etc milling jobs.

The Start-->

I purchased a 1200x1100 sheet of 18mm MDF from Bunnings for
~$32 on the weekend, along with a few hundred screws and MDF
glue. The first part of the construction will be the base. The base
will support the gantry and house the slides for the 'X' axis table.
he Gantry will have the 'Y' and 'Z' axis.
I have decided on a 650 watt Ozito router for the 'engine' of this
machine.



(threaded rods in pic WILL NOT be the ones used in the mill)

I have started 'doubling up' the mdf to make a 36mm thick sides
for the base.Here's a few pics of the beginnings of this mill-->



The MDF was cut to length, MDF glue is spread on the pieces
before they are screwed together to form a solid side-->




Once all 4 sides have been constructed i cut MDF to size for a base-->





As this mill will be used for aluminum it will need to be
very sturdy, i have started adding supports to the base,
there will be 6 more to be added to the sides along with
the 8 already installed-->






The base measures 800mm x 730mm... The table will slide
enough for me to pop in a PC case side to cut windows
and also 'etch' a design on the plex, this was actually
my main reason for making it this large, initially i was
going to make it ~600x400mm.

Once the construction of the base and gantry are complete i
will seal the entire unit with shellac prior to coating it with
Silver Hammer tone paint. The table housing for 'z' axis will
be constructed entirely of Delerin complete with a 'tray' to
collect the cutting fluid that will be pumped to the bit when
ali is being milled. I also intend having a dust extraction unit
attached to the head of the mill to remove foam when foam
is being shaped.

progress on this project should be quite regular as i have the
majority of the parts to construct the mill. Things i still need
are bearings...the slides for the 'x' 'y' and 'z' axis require 12
sealed bearings each. DIYers on CNC Znone use and recommend
skateboard bearings, of which i have found a source online for
bulk lots of 50 for under 40 bucks...more on the construction
of the rails/slides later though....

Anyone interested in construction their own mills could do alot
worse than checking CNC Zone..Instructable website also have
3-4 decent DIY mills that can be constructed at home with
minimal tools.

Back with more soon...

KiM

 

looks interesting

 

Subscribed, Don't forget to keep up ya fluids mate.


Click to view full size!

 

a blast furnace or a furnace? and what fuel will you be using in it? i made a brake drum forge a while back and have successfully melted and unsuccessfully cast aluminium with it (coke fired)

mill looks cool so far, hope the MDF is strong enough!

 

haha can be sure of that mate, can't be working in a dehydrated state now can we

A blast furnace forced air and solid fuel fired, will be the second furnace i have built first was gas-->



Melted aluminum in around 4 minutes if i recall correctly...copper however was another story forced air will be required for that

Doesn't take much to melt aluminum a hot fart would soften it LoL...

MDF will be plenty strong enough theres a HEAP of them on CNC Zone it is what 99% of DIY homebuilt mills are constructed of

 

Nice work

There is a previous thread on DIY CNC'ing where a few of us have lots of discussions and pictures of our CNC adventures if anyone is interested in reading some more - http://forums.overclockers.com.au/showthread.php?t=629209

 

Cheers for the link buddy...i had a quick skim through seems alot of electronic discussion which is something i really don't wish to getting into, it over complicates things (not meaning to sound rude here, it is of no interest to me as i have little understanding of this level of electronics BUT admire those that have)somewhat as I have the electronic side sorted already (when it arrives LoL) My mate Frank made the board i will be using and its tried and tested in his mills so i am happy to go with what works and not modify this in any way, basically what i will receive is a 'plug-n-play setup. I have also decided on software to use (will go into that at later date) I shall however when time permits get back to the thread and have a full read through looks extremely informative. Hows the mill going now still using it I read it was a joint project between 3 people...top effort to mate, alot smaller scale than i am working on, would be very good for circuit board work no doubt, what sort of accuracy did you end up with? I shall have another update on my mill construction been working on it this morning hope to have the gantry semi finished by end of day...Have to say I MUCH prefer working with aluminium/steel though this MDF is dust business LoL..Screwing in screws V's welding...no match hand me a MIG any day LoL

KiM

 

Yea, the other thread is a lot more electronics focused, lots on the actual stepper motor controller portion of it all (Give me a soldering iron any day ) My mill has been sitting dormant for pretty much the whole year now, too many other things taking priority. I'm not happy about the accuracy, there is too much run-out in the lead screws and I'm planning to get some cheap ball screw thread for it.

So what sort of lead screw and bearings are you going to be using?

 

You need spring tension on the nuts on the threaded rod. You will be getting 'slop' within the threads no doubt, by putting tension on the nuts that run on the threaded rod you will eliminate the backlash.

I have opted for a 1/4in threaded rod for memory its around 11TPI, For the slides ill be using angle iron with skate bearings same as one of the mills pictured in the thread you linked to. Very simple very strong durable and accurate enough for the work i shall be doing.. I have 15mm solid steel round bar for the rods the slides will run on. Accuracy is important to me with that said i 'lil' play will be acceptable as all the work i will be doing will be larger scale, i gather yours would mainly be used for intricate circuit board typr work where accuracy is paramount....

I have just come in my faithful cordless drill is flat after drilling over 200 holes and screwing in over 200 screws haha...shall let it charge for 30 minutes or so have a game of COD4 and then do some more on the Mill...I have one side of the gantry complete the other side half complete....objective for the days is to have both done so im nearly there

Back with pics this evening

KiM

 

Subscribed AJ.

 

awesome, would love to have a small mill like this at home

then all the parts i want for my rc car and real car and m/bike would be easy to make

well if i could use autocad


anyone want to build me a mill?

 

HAHA i was into the whole RC thing when i was 15 (again when i was late 20s and then again few years ago mid 30's yest again with RC helis) ...thankfully my father "bankrolled" this and was also a talented machinist with a niiiiice home workshop, metal lathes and milling machines (non cnc) which gave me a wealth of experience at an early age, something i am very very grateful for. I take this for granted alot as a result am often quite 'short' with some of my posts on forums ( i apologize for that) my mindset at times is 'I know it you should to i did when i was your age' which i know is totally wrong way to think...I see now later in life how very privileged i was as a youngster.

Update

Few mates dropped around this evening for "re-hydration" purposes as BigDave would put it

(we had Bullet Burbon this evening though BigDave think you can organize a pic for that heheheh )

So the update is a lil late suffice to say the days objective of completing the gantry for the mill was achieved, here's a few pics of the days work-->

The Gantry side 'pillars'





I cut these to size prior to drilling/gluing and screwing









Side pillars complete (these will NOT be fastened to the lower base till all axis are complete so as i can move gantry to exact position to center tool bit)

Top panels were cut/drilled/glued/screwed





Sort of taking shape...to someone who knows whats being built...and has a vivid imagination ahaha

Front View



Overall i'm rapt with the way it has come together, it is so square/true i impressed myself. Next step will be applying some bog to the countersunk screw holes sand/shellac/and a coat of Hammertone paint. I shall order the bearings required tomorrow and proceed will milling housings for aforementioned bearings (thankfully i have dimensions) Shall also cut steel rods (for the rails) to size mill end housings/supports for these also...that should see me through the next 4-5 days then ill re-asses and tackle the next step LoL...

Back soon fellas...

KiM

 

I read the lost foam casting page... (http://www.theworkshop.ca/casting/foamcasting/foamcasting.htm) and one thing I thought might be interesting, I've seen it done with a very light plaster dip. You dip the foam in a fery fine thin layer of plaster, and it is ment to help keep the form, as well as give a very smooth finish.

I envey you, I'd love the chance to set up both of these progects.

 

I believe Frank uses a light coat of body filler and also i think he said he has also tried spray putty then sanding if he is after a super smooth cast. The plaster dip sounds like a good idea shall mention it to Frank tomorrow ;-)

It is a great method of casting very clever but so very simple, I plan to make all the pulleys for my electric trike using this method, same as Frank has done on the RM125 Suzuki electrification project. I also would like to run belts to lower the noise that comes from the chains used on my trike now. After the pulleys are cast i would like to pop them on the CNC and remove an -><- oomphf of a millimeter to leave them with a nice shiny bling bling finish. I shall ask Frank in the morning if he still has the g-coding for his pulley actually as it looks to be about the size i will be looking at for the trike, be a good first up test for the CNC too

dakiller I sent the schematics for the controller board you designed through to Frank he thought it was very impressive...means sweet f**k all to me when i look at it LOL ...but hes on your wave length and obvious higher intelligence level, and new exactly what it was for haha...

I wasn't to flash today leg was giving me grief (for those that haven't read many of my project posts in the past or seen my YouTube vids you won't be aware im a paraplegic and have alot of painful leg spasms that often keep me even more 'immobilized' than normal resulting in not alot getting done on a regular basis :-( ) I hope to get some more done tomorrow shall update the proceedings tomorrow afternoon (have a B'day party to attend Thursday evening)

KiM

 

That look about right?

Another exciting project from AJ, can't wait to see the final product of this one.

 

Is it VXB.com?

http://www.vxb.com/page/bearings/PROD/SkateboardBearings/Kit7339

They are a supplier in the US, I bought some from them, they have cheaper ones somewhere 100 for $25 or something like that with metal shields but the rubber seal ones would be better.

They are alright nothing like the $2.50 ones I bought from the local bearing mob but they do the job (I am very picky)

I would love to see how the allthread goes, I've only ever used Belt drive.

 

Finlay seen the merits of a cnc mill eh,

what kind of resolution are you hoping to get? and whats the rotation on the motors? half stepping at all?

Thats quite a hefty router so it would be good to have some degree of finesse to match.

 

ever thought about a oil fueled furnace?

I've been reading about it on the site

http://www.backyardmetalcasting.com/

have yet to build anything.

 

The bearings i originally saw aren't listed i did come across bulk lots of 100 im interested in though similar price...

http://cgi.ebay.com.au/Lot-of-100-R...3.l1177&_trkparms=240:1318|301:1|293:1|294:50

I will call Consolidated Bearings tomorrow and see what the cheapest 22mm ODish bearing they sell costs, if its within reason i will buy local to save few weeks waiting for dilivery via USA. I originally saw some bulk bearings for RC car use, they are little too small though at 16mm OD spewa too they are located in Australia :-S ...

I forget the specs on the stepper motors shall report back when i verify. The mill short term will be used for shaping foam i envisage later down the track the motors being updated to stronger units, the mill is being built with this in mind, the router will possibly also be upgraded...

http://www.backyardmetalcasting.com/ is an excellent site and yes i have seen and thought about oil...dismissed it though to much hassle/mess the charcoal works a treat and if i want to do a quick melt i still have the gas...



KiM

p.s

no i have always seen the merits in a cnc mill just havent got to building one till now. TBH i would probably get more use and enjoyment from a non-cnc mill for the work i will be doing but buying the one i would like is waaaaay beyond my finacial capabilities..seeing my mate Frank made me the offer of stepper motors and controller i thought i would have a crack at CNC Mill

 

You pay top dollar at a bearing mob its best to go to a sports shop for cheaper prices.

Well thats what CBC Bearings told me. I was there at the time so I just bought mine from them, great quality ~$2.50 each.

The Skate bearing would be the cheapest as it is mass produced.

22 high
7 wide
8mm diameter

Anyway I will keep a eye on the thread I would love to see how it turns out.