Newbie CNC Build

[JunkieHobbo]

@JAZZCNC: No worries, I am really appreciative of your Help and anything that can help me make a better machine I will gladly accept, keep on picking!

OK, I have made some changes as you suggested, I have gone with 80mmx40mmx3mm, every penny helps! Regarding the Flat plates, I get what you mean but how would you do it, would you mount a plate on the upright and also on the base of the 80x40 that will hold the rail, picture is worth a 1000 words.....:whistling:

I have noted down your points regarding the Z-Axis, once I get to the Z-Axis I will incorporate the suggestions.

Belts, I am convinced it is the way to go now, only 1 Stepper, I am assuming a larger stepper than Y&Z? Do you have some pics of your setup using the Belts, I have looked around and was not really able to find any good pics for reference to build on.

Here is an updated drawing, I added in some triangles as Jonathan suggested, I was just going to add some tabs to mount the panels to but Triangles will work and also add extra support.



If the base is good I can then work on the X-Axis rails and Belt drive.

That is some seriously nice work there, hopefully once I get my machine up and running I will be able to produce something half as good!

@Jonathan: Thanks for the advise, I added some triangles they will have uses, one for support as you mentioned and secondly to hold my "Dirt Splash Panels" up, see the pic above. I might have some more questions as I progress but for now the pics will do great!

@m.marino: I will be going with 2 Ballscews on both sides of the X-Axis, and will be driven by one stepper and a belt. Added a Center brace as suggested by yourself and JAZZCNC's example. I have about 1200mm x 1000mm x 1000m Space to work with, so I want to build the Biggest/best possible machine to fit into that area.

@C.AlveSilva: I am by no means a Guru on this but from what I have researched and have learned from the guys on the Forum, Ballscrews are the way to go and Profile rails.

[JAZZCNC]

Hi JunkieHobbo,

Couple of things regards the frame.! It's weight and the ease of build and adjustment.?
I know on my Cad model it looks like the frame is all welded but it's not and actually bolts together quite a bit. Really my models are not fully accurate models regards detail and more for me to visulise so don't pay massive attention to the detail. Thou they are to scale and dimensionally accurate regards materials and compnents which is also why I use them so I can judge component fit etc.

When you build this machine you need to incorparate as much adjustabilty as possible. Thats why the plates on the uprights for the top rail section to sit on.
On the machines I'm building now the main frame(excluding adjustable bed) is actually made up of 5 pieces bolted together (7 if you include top rail sections)
This gives adjustabilty in lots of ways and also helps with moving around.!!!!. . . . . It will be very very heavy so makes life much easier when in pieces.

Regards the plates there's several ways but this is how I do it.!. . . Basicly I machine flat plates with both holes and M12 nuts welded to them which are then weld onto the uprights, taking care to get them square as possible to the boxsection.
!!!!!!! (This next bit will be hard to explain so bear with me.!!!)
The plates are longer than the upright section for the middle uprights so can be bolted either side of uprights into the top rail section which has nuts welded into it. The end upright plates are only longer on one side so bolted on inside from below into top rail then another bolt accessed thru the open ends into plates which have M12 nuts welded to them.
These plates could be drilled and tapped but that would require thick plate so thats why I use welded M12 nuts. The same M12 nuts are welded into the top rail as the 3mm box section doesn't allow enough thread.
It may sound faffy and complicated but in reality it's not and doesn't take long if you have a decent drill press and can weld half decent.

The frame pics below will give a better idea. I'm still building the frames but when get a chance then I'll post a few pics of the actuall steel work, when I'm further along I'll probably start a thread showing it(them) coming along.

Regards the belt drive then there's better ways than I've done it. Mine was rushed and thou it works very well it's not pritty so wouldn't do it that way again or recommend you follow it.
I've done a quick alteration of my frame and mock up to give a rough idea of one way, needs belt tensioner etc but should give you an idea.!! There's other ways if you look around and easily done with motor at same end in line with belt acting as the tensioner incorporation with an idler.

Hope this helps.

[JunkieHobbo]

@JAZZCNC: Thanks again for the reply and your time.

When you build this machine you need to incorporate as much adjustabilty as possible.

I really like your way of thinking, that the machine should incorporate adjustability. I like the modular approach aswell, I do feel this would be a far easier build for me by doing it this way with minimal welding.

BUT

Just a quick question, I know another question! :whistling: Will the bolted sections hold up and keep structural stability as good as the welding would? I am asking because it is a CNC machine that works on precision and bolts are " not a fixed" part of the structure, so there is a chance for them to loosen, how would you solve this problem? Then again, I could be obviously missing something here as usual.

Regarding the Plates, the pics answered my Question 1000%, Thanks again!

[JAZZCNC]

BUT

Just a quick question, I know another question! :whistling: Will the bolted sections hold up and keep structural stability as good as the welding would? I am asking because it is a CNC machine that works on precision and bolts are " not a fixed" part of the structure, so there is a chance for them to loosen, how would you solve this problem? Then again, I could be obviously missing something here as usual.

Well think about it Just about every CNC machine even those costing 10's thousands of pounds are bolted together in some form or another. . . . They are not welded in one piece.!!
The bolted sections will hold up fine so long as you use correct size and good quality bolts and tighten them correctly. If you want to ensure they don't move then use locking/locateing pins.!!. . but they don't move if good quality bolts with locking washers with a bit of thread lock for good measure.!