This is my new CNC

[DigiSoft]

Hi. I am researching this field for months and I decided to make one. I ordered almost all parts except the linear rails. I am going to make them.
I have all the parts but I'll post pictures tomorrow because it is late now to take pictures . Anyway this is the parts info:


4 x Axis Driver 2M542 4.2A & Breakout interface board for Router system for CNC
2 x ballscrew RM1605-1300mm (for dual X axis)
1 x ballscrew RM1605-900mm (for Y axis)
1 x ballscrew RM1605-250mm (for Z axis)
4 x flexible couplers
3 x NEMA23 425 oz-in CNC stepper motor /3.0A (two for X, one for Y)
1 x NEMA23 287 oz-in CNC stepper motor (for Z)
4 set BK12/BF12 ballscrew end support
12 x SBR20UU BLOCKS
3 x Cable drag chain wire carrier 10*20mm 1000mm (40")



I have all of this parts and I hope I am on the right track, I'll be so frustrated if I made some mistake because my budget IS VERY VERYYYYYY TIGHT.

Here are some picture to get this project started

[DigiSoft]

This is my design for the gantry and Y
Please tell me your suggestions, what do you think about it?

1. What type of bolts should I use for connecting the parts?

The aluminum thickness of the plate is 20mm

[awerby]

It looks pretty good so far, except that your Z axis won't work. It's at the bottom of its stroke, but it can't raise up because the moving front plate that the spindle's attached to is stuck under the top plate. Trim that back and it will work better.

Usually I use Allen-head cap-screws for assembling machines. You might want to use some thread-locker as well, since these machines tend to vibrate a lot and the screws can work themselves out. Where you can, use through-bolts and lockwashers, since tapped holes in aluminum aren't as strong.

Andrew Werby
www.computersculpture.com

[PaulRowntree]

It looks pretty good so far, except that your Z axis won't work. It's at the bottom of its stroke, but it can't raise up because the moving front plate that the spindle's attached to is stuck under the top plate. Trim that back and it will work better.

Unless my old eyes are failing me (again) the Z slide blocks are mounted to the gantry side, and the router is on the rail side. This makes the drawing show the router in the top most position, not the bottom of the stroke.

That being said, the router itself is rather low for the top most position; the gantry is forced to fly high above the work. I would have the bottom of the collet nearer to the lowest point of the gantry system, then size the gantry supports to provide the Z range that is really needed.

Plus, although it is nice to have the Z screw in the middle of the Y rails as shown, the gantry itself is weakened in this geometry. My guess would be that if you put the screw on the back of he gantry frame and put another skin on the front covering the gap where the screw is now, the gantry would be much, much stiffer in both the X and Z directions using much, much less than 20mm Al thickness of metal total. Or just secure the two tubes together. Boxes are better than sheets.

[DigiSoft]

It looks pretty good so far, except that your Z axis won't work. It's at the bottom of its stroke, but it can't raise up because the moving front plate that the spindle's attached to is stuck under the top plate. Trim that back and it will work better.

Usually I use Allen-head cap-screws for assembling machines. You might want to use some thread-locker as well, since these machines tend to vibrate a lot and the screws can work themselves out. Where you can, use through-bolts and lockwashers, since tapped holes in aluminum aren't as strong.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

Like PaulRowntree said it is most-top position and it won't go any higher than that.

@PaulRowntree you think like this?

[DigiSoft]

This is my latest design.

I changed the front plate to 10mm and the back is now 20mm to be more weight balanced. What do you think about the front plate. Is it enough 10mm?

[CarveOne]

You have the rails mounted to the back side of the same plate that the router is attached to. This is good for stiffening the plate, but it is limiting the travel somewhat.

The Z axis could be made a little taller so that the lower bearing blocks can ride the full rail length. The plate can't be made shorter because the rails would still hit the plate the motor is mounted to.

The rails and blocks can be reversed. With the blocks on the moving plate and the moving plate made shorter at the top end, you can go up farther, and down farther depending on where the blocks are located (and the block vertical spacing). It isn't quite as stiff that way but the moving assembly is also lighter. Use a thicker moving plate.

[DigiSoft]

You have the rails mounted to the back side of the same plate that the router is attached to. This is good for stiffening the plate, but it is limiting the travel somewhat.

The Z axis could be made a little taller so that the lower bearing blocks can ride the full rail length. The plate can't be made shorter because the rails would still hit the plate the motor is mounted to.

The rails and blocks can be reversed. With the blocks on the moving plate and the moving plate made shorter at the top end, you can go up farther, and down farther depending on where the blocks are located (and the block vertical spacing). It isn't quite as stiff that way but the moving assembly is also lighter. Use a thicker moving plate.

If you think again, it is the same where you place the bearing blocks.
I was thinking that alot and i came to that conclude.

For the Y gantry I am thinking to use steel square beams but I am not sure what wall thickness is good. The beams should be 60mm x 60mm but I don't know 4mm or 5 mm thickness. I was also thinking about bigger Z so I can put bigger Y beams like 80mm x 60mm. Would that be good idea?
Right now the Z part is 285mm height. I was thinking to go to 350mm. Is that too much?

[louieatienza]

If you think again, it is the same where you place the bearing blocks.
I was thinking that alot and i came to that conclude.

For the Y gantry I am thinking to use steel square beams but I am not sure what wall thickness is good. The beams should be 60mm x 60mm but I don't know 4mm or 5 mm thickness. I was also thinking about bigger Z so I can put bigger Y beams like 80mm x 60mm. Would that be good idea?
Right now the Z part is 285mm height. I was thinking to go to 350mm. Is that too much?

I think the design is fine, but I definitely would use the thicker plate for your carriage plate. I'd also move your router mount higher as Paul mentioned so you can use the full travel of your Z. What I did on my machine was make a couple mounting points so I can move my router to where it is most advantageous.

If you need more Z travel you can also use timing belt and pulleys to move the motor away; you can mount the stepper on the carriage plate itself (though you'll need a stronger motor to move the Z); or you can notch your carriage plate to allow clearance for your stepper...

Mounting the rails to the plate actually allows the most travel of the two methods; and most all commercial 5-axis machines are made exactly that way.

[PaulRowntree]

Like PaulRowntree said it is most-top position and it won't go any higher than that.

@PaulRowntree you think like this?

Not exactly ... I was thinking of having a front and back skin, making a tube of the gantry.

Sooner or later you are going to have to make your material and dimension selections, and in the end they are all controlled by the deflections that are caused by the motion and cutting. You should check out the calculators available on-line at EngineersEdge,
Structural Beam Deflection and Stress Formula and Calculation - Engineers Edge

or better yet download BeamBoy and start really trying to understand the forces involved and how to best make it work.

[hacker7]

Just wondering where you got your control box from ? And what size is it?

[DigiSoft]

Just wondering where you got your control box from ? And what size is it?

I bought it from local store for electrical supplies.
It is standard box for mounting VFDs, fuses, and other electrician stuff.
The size is 400mm x 4mm x 210mm

Today the aluminum plates arrived.
1 piece / 1070mm x 182mm x 20mm
1 piece / 555mm x 190mm x 10mm

It is some kind of hardened aluminum made for aircraft parts.
It weights around 14Kg and it cost me 120$.

Tomorrow I'll be making the foundry for melting aluminum for the homemade linear rail supports.

[DigiSoft]

Ok long time no update but I am working. I am almost finished with my CNC.
I hope you like the pictures.

[DigiSoft]

xsgfsdfdsfdsf

[Zekyx]

Somehow missed your build (I'm a very long time lurker), but this is absolutely beautiful! Čestitke, apsolutno savršeno izgleda!

[bill south]

Very Professional Job!
If it works half as good as it looks, you'll be very happy!
Bill

[gasmandave]

Outstanding CNC build, and very heavy duty. Congrats! I have a question since I'm about the same place in my build and I have similar parts as you. What grease will you be using for the ballscrews?

[justindewoody]

Where did you get that t-slot table? Who made it? I really want one!

Justin

[Devastator]

Where did you get that t-slot table? Who made it? I really want one!

Justin

If you look at the photos, it is made from what appears to be aluminum flat bar standoffs with larger steel flat bar top, then surfaced flat on the machine.

[aarggh]

Wow! Excellent build, by far one of the best I've seen!

cheers, Ian