budget diy cnc controller question

[george uk]

Hi Dave

MAKE = Materials to be constructed from.
WEIGHT = Mass to move IE gantry etc
FUEL = Voltage running motors at.
WHEELS = Pinion Size
GEARS = Ratios

Just to give you a heads up

WEIGHT = Mass to move IE gantry ==== Frame steal 80mm by 4mm or 100mm by 4mm or 5mm. == Gantry, either steal or ally. Its quite easy to calculate the weights, it will be the gantry weight thats important, not the frame

FUEL = Voltage ==== The gantry weight will tell you what motors and drivers are required ( most of the time nema 23/4 sometimes geared. ). ==== also, your power pack ratings are important,

WHEELS = Pinion Size ( or ballscrews, ) Again, your gantry weight/style will help you decide this, 16mm or 20mm if ballscrews i suggest ( i dont know enouigh about R&P ), same with rails

GEARS = Ratios ===== This is about the speed and accuracy that you want from the motors, its a curve, higher speed, less accuracy.

Most supplyers of metals give the the weight per meter, and you might even fine something suitable for the frame ( with adjustments ) at the scrap yard if your trying to save a few £.

My opinion if your going the cheep route.

There is no cheap route with motors and drivers, you will just need what you need, and its machine specific

Spindle - ebay 2.2kw, water cooled with VDF around £ 250, Aldi ( or other cheep place ) cheap £ 30 dremile type. You get what you pay for. The cheap one will not last long on even modrate use, but it will cut/mill thin stuff ( slowly ) ( just add a cooling fan ), If you got the mounting plate right on the Z, you could even use a cheep router. You might try with the cheap one, to convince yourself you need to pay for the more expencive one, and £ 30 is not a big loss,

Software -- for what you want to do, Mach3/4 would be good ( £ 120 ), there are cheaper alternatives, some free, but unless you have reasonable programming skills, and a good understanding math, you wont beat mach for the support for newbies. In all honestly, with mach, the £ 120 is worth it just for the support,

I hope with what i have put above you have an idea at what parts you can go cheeper on and what parts you can not. If i was you, i would give myself a scrapheap challange, and go looking for something you can use for the frame, your luck might be in. and what you save on that, put into the electronics.

[JAZZCNC]

FUEL = Voltage ==== The gantry weight will tell you what motors and drivers are required ( most of the time nema 23/4 sometimes geared. ). ==== also, your power pack ratings are important,

[COLOR=#333333]WHEELS = Pinion Size ( or ballscrews, ) Again, your gantry weight/style will help you decide this, 16mm or 20mm if ballscrews i suggest ( i dont know enouigh about R&P ), same with rails

No disrespect meant George but what your doing is dangerous and quite missleading to new users.? . . . . I'm tempted to say Blind leading the blind but I know you have done lots of reading upto now but still you need to be careful what you post to new users because you can send them in wrong direction quite easily, all done with good intentions I know but still misleading and wrong.

For instance you Say Mostly Nema23 and sometimes geared.!! . . . . Actually Often for a 8x4 machine using Rack n pinion then Nema 34's are prefered for there higher torque and 99.9% of the time you'll always have a gear ration of at least 2:1

Also suggesting 16mm ballscrews for a machine this length is totally wrong unless very specific things are done, like using a Rotating ballnut. I won't use 16mm screws much over 1500mm and wouldn't dream of using a 16mm or 20mm rotating screw at nearly 3000mm.

Not picking on you here and know your only trying to help but much better advise rather than trying be specific, unless you have first hand experience is to suggest Nothing and tell them to go look around and learn. Then ask questions that are more informed and specific to there needs.