Thread: My baby 15" x 15" machine
ok strictly it hasn't started yet, but i need to gather everything together and start planning this machine now as the mrs has all but given the green light due to a lovely PPI claim coming through unexpected.
so i'm trying to understand where to start and i suppose you start with what are you going to cut as this kind of sets the boundaries for what spindle you can use.
so.. i want to do some engraving in mdf, other nice woods, some acrylic so it can be lit up from the sides ect.. obviously there is some need for speed to keep the finnish up.. so before i try and cut corners here and say i want to use a dremel or something similar do i need to go all out and go for a water cooled spindle or is there something else out there that will suit my needs?
now once i figure out what spindle i am using i can then find out how big it's mount needs to be and from there i can work outwards and figure out rail sizes, screw sizes and then i can work on the frame to hold everything.
so with all the above in mind am i missing anything?
as a small note.. if i decided at a later date i wanted to cut alu with the machine would a need to design it differently than with the mdf and acrylic in mind
Any reason you decided on 15x15 ?
and yes, cutting ally needs a very rigid build, and has to be designed in from the start.
Spindles ... it depends on your budget ? but a cheapish router will get you started. I've just bought a £25 one from Aldi.
ALDI - Sunday Special Buys 9th September 2012
I'll be fitting it to my build soon, as my Bosch router is about 20 yrs old and needs the bearings replacing.
You can change the router mount to a spindle mount at any time if you make it as a 'bolt on' to the main carriage.
Design the carriage so it has no interference from the router/spindle at the end of the gantry, else you'll loose some working area if you put anything bigger on later.
15 x 15 was decided to cover off a 12" subwoofer ring if ever i felt the need to make one as this is what i used to do alot.. and i just thought 15" was a good size. if someone said well for very little extra you could go to 20 x 20 then i'd possibly go that far.. the idea with this machine is to keep the cost down, show the missus what it can do and for it to prove itself then i'll move on to a 4ft x 4ft so i can atleast cut half a sheet of material.
as for a cheap £25 router i'm willing to pay more for the spindle and i think from what i've read a router doesnt lend itself to variable speeds very well and from what i've seen of my own router it doesnt finnish plastic very well. also the standalone spindles are less bulky meaning machine design can be kept smaller and the collet extends alot further down than a router
so far i've seen these CNC 300W Spindle Motor & Mount bracket For Engraving Carving MILLING GRINDING | eBay
but i have no idea how good they are and what the limits would be.. also i suppose i need to consider psu for one? and how is the speed controlled?
or these 0.8KW MORE PRECISE WATER-COOL SPINDLE MOTOR ENGRAVING MILL&GRIND WATER-COOLED k5 | eBay
or to go as far as a 2.2kw, but again i just dont know.
i am hoping that as my machine is going to be small it wont need such a big motor, but again i'm open to ides if needs be and i need to spend £150 on a motor then so be it.
the plan is to get a list of all the parts i need and then go to one of the chinese guys and ask for a price for the lot which will hopefully save myself some money overall, but i cant get to this stage until i design the router
when it comes to spindles, it doesn't matter that you have a small machine.
What matters is what you want to cut with it. Also, thinking of your woofer holes, you need to design in enough bed room for your sheet material, not just the cutting area.
I would say 300w is quite underpowered for anything except shallow engraving.
The larger spindles, and the water cooled ones are VERY heavy ! this will have to be considered into the design and motor/driver choice.
basicaly, lenght of screws/drive/r&P etc and length of rails/bearings determine the machine cost, (unles using extruded ally which is expensive). Most of the rest is the same cost regardles of machine size.
presuming i am going for the 2.2kw spindle, having a working area of 15" x 15" has anyone got any advice on the diameter of screw i should use?
15 x 15 .. a baby like mine 8 x 12 :) I want aiming to do the same as you , and some PCB's perhaps , mine off the shelf though, although someone did suggest now I havea small CNC I could build a bigger one with it well some of the parts at least, when I can get it to run that is , and its been sat there for a month now all I'm missing is a bloody cable! lol good look with the build..
Fiction is far more plausible when wrapped around a thread of truth
Nothing great was ever achieved without enthusiasm.
Ralph Waldo Emerson
As no one has answered yet .. I'll risk the wrath of posting a reply :)
For this size, I'd say 16 would be fine. 5 or 10 pitch depending on motors and drivers
are you going for ballscrews or acme (trapeziodal) ?
did you read the MicroCarve thread I linked you ?
i've been working 12 hour days for the past week and even working over the weekend.. what little time i've had i've spent with my family.. so no not read that thread yet... however i know how i want to make this machine i just need a few technical things ironing out.
16mm ballscrews is exactly what i had thought and it fits well with my budget so unless anyone has any good reason why i should go bigger then i'll likely go with them.
i'm on earlys this week with no call shift so i will be reading that thread at some point
I didn't mean you should read it to change your mind ! just that it's about the same size as you are making, so it might be interesting reading :) screw size for instance .
any updates wilfy?
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