[dex918]

Hi,

I design this after learning from reading CNCZONE.

The specs is

X travel = 18 inches
Y travel = 16 inches
Z travel = 4.7 inches

The distance of the table top to the highest point of the gantry is about 12 inches.
Machine footprint is 35 inches (including motor at the back) x 26 inches and height is 13.5 inches.

I have not finalised this design as I need feedback or comments from you guys. This is my first attemp to build this machine. Any negative or positive comments is welcomed.

[widgitmaster]

According to the picture, the Z-axis leadscrew will be lifting both the spindle motor and the z-axis leadscrew motor! That's a lot of unnecessary work to move all that weight! Your screw and nut will wear out fast!

My 2 cents.

Widgit

[dex918]

widgitmaster,

Thanks for the comments. I agree with you. However, redesigning the Z axis will definitely eliminate or reduce the unnecessary load. This will however reduce the X travel. Furthermore, the it will also reduce the clearance from the table top upward.

But, I will definitely consider your approach.

[rustamd]

if you flip around the Z assy you will not loose any travel and motor will not have to lift itself

[dex918]

after considering your suggestions, I finally decided to re-design the setup and this is what I have for now. Most likely it is final and will start to fabricates the needed parts.

[widgitmaster]

Good design, but don't forget the four adjusters in the corners of the base, so you can level your machine for accuracy!

Widgit

[dex918]

just for updates.. The parts I receive for the machine... It's the parts for Y and Z assembly and the leadscrew mount bearing block.

[IMG][/IMG]

[stevehez]

Real nice keep us posted.

[svenakela]

My machines are running the same config as your first (as many others), if the motor has a problem lifting itself you have too small motors.

Both designs work though, it's just a matter of taste.

Regards,
Sven

[dex918]

Sven,

Thanks. I already re-design the Z assy as shown in the second attachment.

I am now waiting for other parts to arrive. I am using acme screw instead of ball screw due to the cost factor. As for the lead nut, I am still deciding between brass or delrin... which one should I use??

[JMcDonald]

My concerns about using brass, a plastic, or even a soft aluminum (6063) is how accurate they will stay if you preload them or use another method of anti-backlash. It seems that while they would indeed run smoother because of their self-lubricating properties, they would constantly need adjustment due to the threads wearing. Is this true?

[dex918]

This is my Leadnut. I plan to use delrin for it. The width is 50mm and the slit is 3mm wide. I am using 12mm acme, 2mm pitch. I use double row A/C bearing for the Acme mounting block (driven side), with 2 hex nut to lock it to the bearing and normal radial bearing for the floating side to prevent the Acme from whipping.

Now I have a problem where to put my machine since I am staying in a 850sqft flat.

Although I have dedicated room for my hobby works, it's only 5ft x 8ft.

[dex918]

Latest progress of my cnc router. All plates are 15mm thickness. So far, the structure is rigid. You may notice one profile is missing. This is because the profile length I bought is only 5m and it's only enough for now.

At the moment, I have huge hole is my pocket.. so, table top, Z axis, lead screw & stepper motor will come later.

[dex918]

[dex918]

Latest update.. The Z axis assembly without the lead screw and lead nut.
Still sourcing for stepper motor and lead screws..

[vcooney]

Dex918

Are you sending your drawings out to a shop or are you making them yourself?
Your router looks good, anyway good luck with the build.

Vince

[dex918]

Dex918

Are you sending your drawings out to a shop or are you making them yourself?
Your router looks good, anyway good luck with the build.

Vince

vcooney,

Unfortunately, I have no tools or machines. So I have to send my drawings to a friend of mine who runs his own machining shop. I design and draw all the parts that I need then send it to him.

Next weekend will make a trip to a junk yard too look for ball screw and motor.

[vcooney]

Junk yard....never thought of that. what type of machine are you looking to pull your ball screws from? Junk yards around me only have cars.
Just curious

Vince

[dex918]

Junk yard....never thought of that. what type of machine are you looking to pull your ball screws from? Junk yards around me only have cars.
Just curious

Vince

LOL... sorry for the misunderstanding... I am referring to a automation machine junkyard.... hahaha...

p/s.. not only cars end in the junkyard...

[dex918]

Got the ball screw over the weekend. Also found a new cable tractor (or whatever it is called)

Will send the ball screw to the machine shop to turn down the journal to fit the bearing block.